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The paper by Schito et al. (2017) contains many misquotations of the regional literature on the Holy Cross Mountains, that may confuse the reader. Present comment suggests more appropriate references related to the stratigraphic, tectonic and palaeothermal aspects of the commented paper. The burial-thermal history as interpreted by Schito et al. is based on doubtful, poorly documented or even unsubstantiated thermal maturity and stratigraphical data, ignoring important regional evidence, such as Caledonian (sub-Devonian) unconformity and Permian thermal anomaly. The 1-D modeling study performed by Schito et al. (2017) did not consider published alternative concepts of the temporal and spatial heat flow patterns. The resulting models, assuming uniformly low heat flow between the Ordovician and the earliest Cretaceous, are inconsistent with independent regional data pointing to a hotter Variscan (Carboniferous-Permian) thermal regime.

A global sea-level fall during the Latest Danian Event (LDE) is observed in a regional and worldwide context in widely-separated locations with different tectonic and depositional settings (Clemmensen and Thomsen, 2005). A similar trend in the central and south-western Desert of Egypt is synchronous with a weak tectonic event, which results in the absence of the upper portion of the regressive phase during the LDE, of the P3b Subzone which is seen in “tectonically stable” areas. This weak tectonic event is linked to more intense deformation of the Syrian Arc (Swell) of the Bahariya Oasis, which is synchronous with the global Laramide orogeny. Over the entire Dakhla Basin, the similar vertical sequence tracks can be traced across the area and indicate relative sea-level changes rather than shoreline shifts, and consequently reflect a eustatic origin. Correlation with the Arabian Plate charts (Sharland et al., 2001, 2004; Haq and Al-Qahtani; 2005; Simmons et al., 2007) do not match with the regional reconstruction of Farouk and El-Sorogy (2015) because these Arabian Plate charts are based on mega-sequences controlled by a dramatic tectonic event with erosion along the northeast Arabian plate (Haq and Al-Qahtani, 2005). Recently, after recalibration of many eustatic charts the conclusions made by Farouk and El-Sorogy (2015) concerning the late Danian sea-level fall (e.g., Haq et al., 1987; Hardenbol et al., 1998; Luning et al., 1998; Guasti et al., 2005; Clemmensen and Thomsen, 2005; Schmitz et al., 2011; Gradstein et al., 2012) have been confirmed.

The overall palynology of the upper Horseshoe Canyon Formation to lower Scollard Formation within the Edmonton Group is reviewed providing new insights into biostratigraphic relationships for the interval, including the recognition of unconformities in the stratigraphic package. The palynomorph recovery from the Horseshoe Canyon Formation and overlying units documents a number of significant events that allow the subdivision of the section. The Albertosaurus bonebed occurs within the lower Maastrichtian portion of the Edmonton Group. The bonebed is situated just below the base of the Scollardia trapaformis Palynomorph Zone, an important marker assemblage that has been documented from areas of the Yukon, Northwest Territories, Alberta, and Saskatchewan. This indicates that the bonebed lies at the top of the Mancicorpus vancampoi Zone. The transition between the zones is marked by a colour change in the sediments, the appearance of coals and organic-rich sediments above the transition, a decrease in numbers of vertebrate fossils, and the appearance of new pollen species. It is inferred that the observed changes reflect a climatic switch from dry to wetter conditions. At a large scale, palynomorph assemblages across this transition do not clearly indicate marked differences that can be attributed to the climatic change, with the exception of the appearance of Scollardia trapaformis and Mancicorpus gibbus in the assemblages. On a microscale of a few metres, there are changes in relative abundance of plant groups.

Seismic-reflection techniques have been applied in several studies over the last 20 years as a uranium-exploration tool within the Athabasca Basin and have been utilized to provide the larger structural context for known uranium deposits within the basin. At the crustal scale, deposits within the eastern Athabasca Basin are shown to be associated with deep-seated shear zones that originated during Trans-Hudson orogeny and have subsequently been reactivated during and subsequent to deposition of the basin-fill sandstones. Seismic properties of the Athabasca sandstones and underlying basement have been determined through in situ borehole measurements. Reflectivity within the sandstones is generally weak. Seismically recognizable signatures are primarily associated with variations in fracture density, porosity, and degree of silicification. The basement unconformity and regolith, a prime target of exploration, is widely imaged as it is characterized by variable but generally distinct reflectivity. Results from the McArthur River mine site suggest that the spatial coincidence of seismically imaged high-velocity zones and deep-seated faults that offset the unconformity may be a more broadly applicable exploration targeting tool. Three-dimensional (3-D) seismic imaging near existing ore zones can define the local structural controls on the mineralization and point the way to new targets, thus leading to more efficient exploration drilling programs. Furthermore, seismically generated structural maps of the unconformity and rock competence properties may play a significant role at the outset of mine planning.

Most Ordovician volcanic rocks of southern Britain were produced in volcanic island settings and the Borrowdale Volcanic Group (BVG) of the Lake District has traditionally been interpreted in this way. However, a review of lithofacies associations in the BVG indicates a subaerial environment. Pyroclastic surge deposits, thin welded tuff beds, lava flow morphologies, abundant erosional unconformities, and fluviatile and laharic facies indicate widespread subaerial emplacement. Volcano-tectonic subsidence aided preservation of subaerial facies, although a preservation bias favoured lacustrine deposits. Erosional unconformities above subaerial aggradational volcanic sequences are to be expected, so the sub-Windermere Group unconformity does not necessarily imply tectonic uplift.

A major seismic reflection transect, acquired by the British Geological Survey between 1984 and 1986, has elucidated the deep geology and structure of some well-known surface features of central England. The Worcester Basin, a Mesozoic extensional graben system, is bounded to west and east by major, sub-planar normal faults which formed by the extensional reactivation of much older structures; respectively the Malvern Axis and a similar though concealed structure forming its mirror image to the east. Within the Worcester Basin a thick Permo-Triassic sequence rests directly upon Precambrian basement rocks. To the west and east, Permo-Triassic rocks are thin or absent, but relatively thick Palaeozoic sequences are preserved above the Precambrian. These strikingly different successions, together with the fault geometry, suggest that the Worcester Basin lies within a major, inverted oblique-slip fault system or flower structure. In Palaeozoic times transpressivt stresses led to reverse faulting along the Malvern Axis and its complementary structure to the east with consequent regional uplift of the intervening tract and the formation of a positive flower structure. In Permian and early Mesozoic times, transtensional stresses caused collapse and negative inversion of the flower structure and consequent subsidence of the Worcester Basin.

For more than 60 yr, the term “Barrow arch” has been used to describe a regional structural high beneath northern Alaska and the Beaufort and Chukchi Seas that is of chief importance to the area’s petroleum systems. However, there are multiple interpretations of what, precisely, constitutes the Barrow arch. For example, most, but not all, interpretations invoke the arch as a basement feature. Other interpretations refer to a Barrow arch that existed in different forms at widely variant times, from the early Paleozoic to the present, and although many authors refer to the feature as “composite” or “complex,” the arch is normally drawn on maps as a single lineation. Numerous meanings of the term Barrow arch have been conflated in the literature resulting in some contradictory usages; this paper is an attempt to clarify the nomenclature. Six primary usages of the term Barrow arch are identified in this paper. These are the (1) basement high, (2) ancestral highlands, (3) rift margin, (4) Lower Cretaceous unconformity antiform, (5) Brookian sill, and (6) dip reversal usages. These usages are deconstructed herein, and other names of more exacting definitions are introduced. These newly defined terms are the “basement arch,” “Ellesmerian highlands,” “rift shoulders,” “northern Alaska anticlinorium,” and “Colville rim.” “Basement subcrop areas” are introduced as regions where basement rocks were eroded to a peneplain beneath unconformities; these help to isolate the various northern Alaskan rift shoulders. It is recommended that the term Barrow arch be discarded. The northern Alaska anticlinorium is the most significant newly defined feature for northern Alaska’s petroleum systems.

Yanwu area is located in the southwest of Ordos basin, with the structure located in Tianhuan depression, covering an area of about 1500 km2. In this paper, the basic geological characteristics, such as strata top structure, sand body plane distribution, paleogeomorphology and so on, were studied, and the controlling effect of various factors on oil accumulation were analyzed, so as to point out the direction for exploration and reserves increase. On the basis of previous work, the Jurassic strata in this area were subdivided into sub sections, and quantitative analyses were made on the main control factors of hydrocarbon accumulation, such as nose uplift structure, sand body thickness, distribution of branch river valley. According to the examples of the discovered oil reservoirs, the accumulation modes and plane distribution rule of Jurassic oil reservoirs in this area were summarized, and the favorable oil reservoir forming areas were defined. Through this study, the current top structure pattern of the strata in this area was inversely displayed, the sand body plane distribution law was depicted and four paleogeomorphic units, including valley, branch valley, highland and slope, were identified. It is considered that the unconformity surface formed after the Triassic strata eroded by valley and branch valley is the main migration channel of oil, and the slope on the flank of the valley and the highland near the river valley are favorable oil reservoir forming areas of Jurassic formation in this area, which can be used as a key target area for exploration and reserves increase. In favorable exploration and reserves increase areas, the oil reservoirs plane distribution is controled by sand body distribution morphology and stratigraphic structural characteristics. That is, the nose-uplift structure matches with the main sand belt can form a good reservoir trap, and the oil reservoirs in different layers are distributed in the “beaded-like” form. In this paper, two main reservoir forming models of Jurassic in Yanwu area were summarized and clarified the plane distribution law of Jurassic oil reservoirs in this area for the first time. Through subsequent exploration and development, a concentrated distribution of Jurassic oil reservoirs group was found in this area, which ensure the orderly succession of stable production resources.

This paper aims to contribute to the stratigraphic and geochronological knowledge of the Neogene–Quaternary of the geologic province of Tandilia by doing lithostratigraphic, paleomagnetic and paleontological analyses. Four lithostratigraphic units have been recognized. The oldest (Late Miocene) constitutes a unit composed of colluvium deposits; it lays in erosional unconformity over the Neoproterozoic rocks. This unconformity is related to important events in the Andes during the Middle-Late Miocene. Over the oldest colluvial sediments, and placed in erosional unconformity, there are sediments assigned to the Barker Formation which are essentially fluvial deposits with a development of several paleosols. Owing to the fossil remains, this unit is assigned to the Montehermosan- Chapadmalalan Stage/Age, whereas the paleomagnetic record would correspond to C3A, Gilbert and Gauss chrons. So, the age is narrowed to the timespan 7.1–3.1 Ma (Late Miocene–Early Pliocene). The Vela Formation lays in erosional unconformity over the Barker Formation. It also has fluvial origin, while the youngest unit (Las Ánimas Formation) corresponds to loess. Both units provide normal polarity and were assigned to Brunhes chron (\0.78 Ma). The Vela Formation presents fossil remains from Bonaerian- Lujanian Stage/Age and belongs to the Middle Pleistocene. The hiatus between the Barker and Vela Formations seems to be considerable: it represents at least 2.6 million years. The reason for the lack of sedimentary records is still a matter of discussion. The deposition of Las Animas Formation seems to span the last 40,000 years. However, this could be linked to a major entrance of windcarried sediments during dry periods, including the Last Glacial Maximum. The hiatus between the Vela and Las A ´ nimas Formations may have been over 100,000 years.This paper aims to contribute to the stratigraphic and geochronological knowledge of the Neogene–Quaternary of the geologic province of Tandilia by doing lithostratigraphic, paleomagnetic and paleontological analyses. Four lithostratigraphic units have been recognized. The oldest (Late Miocene) constitutes a unit composed of colluvium deposits; it lays in erosional unconformity over the Neoproterozoic rocks. This unconformity is related to important events in the Andes during the Middle-Late Miocene. Over the oldest colluvial sediments, and placed in erosional unconformity, there are sediments assigned to the Barker Formation which are essentially fluvial deposits with a development of several paleosols. Owing to the fossil remains, this unit is assigned to the Montehermosan- Chapadmalalan Stage/Age, whereas the paleomagnetic record would correspond to C3A, Gilbert and Gauss chrons. So, the age is narrowed to the timespan 7.1–3.1 Ma (Late Miocene–Early Pliocene). The Vela Formation lays in erosional unconformity over the Barker Formation. It also has fluvial origin, while the youngest unit (Las Ánimas Formation) corresponds to loess. Both units provide normal polarity and were assigned to Brunhes chron (\0.78 Ma). The Vela Formation presents fossil remains from Bonaerian- Lujanian Stage/Age and belongs to the Middle Pleistocene. The hiatus between the Barker and Vela Formations seems to be considerable: it represents at least 2.6 million years. The reason for the lack of sedimentary records is still a matter of discussion. The deposition of Las Animas Formation seems to span the last 40,000 years. However, this could be linked to a major entrance of windcarried sediments during dry periods, including the Last Glacial Maximum. The hiatus between the Vela and Las Ánimas Formations may have been over 100,000 years., El objetivo del presente trabajo es contribuir al conocimiento estratigráfico y geocronológico del Neógeno-Cuaternario de la provincia geológica de Tandilia por medio de análisis litoestratigráficos, paleomagnéticos y paleontológicos. Se han reconocido cuatro unidades litoestratigráficas. La más antigua (Mioceno tardío) está compuesta por depósitos coluviales y se encuentra en discordancia erosiva sobre las rocas neoproterozoicas. El origen de esta discordancia se relaciona con importantes eventos en los Andes durante el Mioceno medio-tardío. Sobre los mencionados sedimentos coluviales, mediante una discordancia erosiva, yacen los sedimentos asignados a la Formación Barker. Son esencialmente fluviales, con desarrollo de varios paleosuelos. Debido a los restos fósiles, esta unidad es asignada a la Edad/Piso Montehermosense-Chapadmalalense, mientras que el registro paleomagnético correspondería a los crones C3A, Gilbert y Gauss. Por lo tanto, la edad de la unidad se encuentra en el lapso 7.1–3.1 Ma (Mioceno tardío–Plioceno temprano). La Formación Vela se apoya mediante discordancia erosiva sobre la Formación Barker. También tiene origen fluvial, mientras que la unidad más joven (Formación Las Ánimas) corresponde a loess. Ambas unidades proporcionan polaridad normal y se asignan al Cron Brunhes (, Facultad de Ciencias Naturales y Museo, Comisión de Investigaciones Científicas de la provincia de Buenos Aires

Northeast Alberta is the location of one of the world’s largest petroleum deposits, the Athabasca Oil Sands, hosted in Lower Cretaceous McMurray Formation sandstones. The McMurray Formation was deposited on a deeply eroded Upper Devonian unconformity surface that was strongly influenced by underlying carbonate and evaporite units. Development of the oil sands has resulted in a significant increase in new data related to the underlying Devonian of northeast Alberta. In particular, the requirement for deep disposal of water has resulted in a number of wells being drilled into and through the porous dolomites of the Middle Devonian Keg River Formation that is a few hundred metres below the McMurray bitumen deposits. In addition, the acquisition of large areas of high-resolution 3D seismic data to assist the delineation and development of the oil sands reserves has provided powerful insights into the depositional patterns and later dissolutive geometries of the underlying carbonate and evaporite deposits. The Keg River and overlying Prairie Evaporite formations that are the focus of this paper were deposited in the intracratonic Elk Point Basin that covered most of the area now delineated by the Western Canada Sedimentary Basin. These units and their lateral equivalents have been extensively studied in Saskatchewan, northwest Alberta, southern Northwest Territories and northeast British Columbia. In contrast, the two formations have been lightly studied and rarely published upon in northeast Alberta. The current detailed study of several areas with abundant new data, combined with a review of the regional dataset in northeast Alberta has provided new insights into the geology of these units. A revised stratigraphy for the two formations is presented which includes the formal definition of the proposed Aurora Member, a significant anhydrite unit within the Prairie Evaporite Formation that was previously included as a sub-unit of the Whitkow Member. The Keg River Formation is divided into the Lower and Upper Keg River members. The Lower Keg River Member is a thin, regionally consistent unit composed of an upward deepening transgressive systems tract. In most places, the Lower Keg River is overlain by the Upper Keg River Member which has two distinct facies. At the base is a widespread shallowing upwards microbial oncolitic facies, here referred to as the Keg River Ramp, which provided the foundation for more aerially restricted overlying deposits of shallow water carbonate. On the edge of the basin, a Basin Margin Platform formed and prograded out over the Keg River Ramp. In the centre of the basin, biogenic build-ups developed. Integrated interpretation of the seismic with the wells shows that the build-ups often have well established but aerially restricted reef margins of frame-building organisms. However, the bulk of these build-ups consist of loosely consolidated peloidal grainstones and packstones. A drop in sea level in conjunction with the development of a continuous barrier reef trend, the Presqu’ile Barrier, across the mouth of the Elk Point Basin caused restriction of the basin resulting in widespread laminites forming at the transitional contact between the Keg River and overlying Prairie Evaporite formations. As sea-level continued to drop, evaporitic drawdown converted the Elk Point Basin into a vast inland saline sea with an exposed marginal platform and emergent carbonate build-ups. The Prairie Evaporite Formation deposits of dolomite, anhydrite, gypsum, halite and potash were deposited in and around this sea. During this evaporitic phase almost all of the underlying Keg River limestone was converted to dolomite. The dolomitization resulted in the development of excellent porosity in most of the Keg River strata. The Prairie Evaporite is divided into two major brining upward cycles of deposition. The lower Prairie Evaporite cycle began with anhydrite and gypsum deposits forming adjacent to the exposed Keg River build-ups. These anhydrite units have been recognized and described in other parts of the Elk Point Basin but have never been formally defined stratigraphically. The paper provides detailed description and stratigraphic definition for this unit as the proposed Aurora Member. In the deeper parts of the basins between the reefs, evaporitic laminites accumulated. Eventually, the brines became supersaline and the remaining topography between the reefs was filled up with the Whitkow Member which consists mainly of halite. The upper Prairie Evaporite brining upward cycle began when a renewed rise in sea-level breached the Presqu’ile Barrier and allowed mesohaline brine to flood back across the basin. Continuing sea-level rise allowed reef growth to re-establish on top of the barrier which again led to restricted marine water flow into the basin. The vertical aggradation of the Presqu’ile Barrier as sea-level rose provided the accommodation space for the upper Prairie Evaporite cycle. The anhydrite portion of the cycle is represented by the widespread Shell Lake Member which transitions upward into the Leofnard Member which is composed predominantly of halite. In northeast Alberta, the Prairie Evaporite is capped by a thin clastic unit and the cycle of deposition is terminated by a significant unconformity at the base of the Watt Mountain Formation.

As an important tool in natural resource exploration, palaeogeography provides a portrayal of deep time Earth. The South China Block located in the eastern Palaeotethys includes multiple natural resources (e.g., coal, shale gas, bauxite, etc.) in the Permian, which are well known for their important economic significance. In this paper, data gathered from literature amount to 431 stratigraphic sections of Wuchiapingian age from South China. These data were quantitatively analyzed and dynamically reconstructed in the global context under the revised plate motion model by GPlates software for the first time. A schematic 3-D model was constructed based on the high-resolution reconstructions in this paper, showing two relatively large highlands developed in the South China Block during the Wuchiapingian, including the Kangdian Highland in the west and the Cathaysia Highland in the east and a small Yunkai Highland in the south. A broad platform-dominated depositional system with small uplifts and depressions was developed between these two highlands. These reconstructions show great potential to explore enriched coal seams and shale gas in the peripheral areas of the two ancient highlands in the west and east of the South China Block. Based on the dynamic evolution of this depositional system, South China experienced an overall sea-level rise with frequent secondary transgressions and regressions during the Wuchiapingian. This is in contrast to the widespread continental and evaporite deposits on much of Pangea and its surrounding margins after the end-Guadalupian global regression. Compilation of conodont biostratigraphic data suggest that the temporal and spatial constraints on the unconformity across the Guadalupian-Lopingian boundary (GLB) resulted from Dongwu Uplift movement. The regression began during the Jinogondolella shannoni Zone and ended in the Clarkina leveni Zone, but the response time varies in different localities of South China. These results provide detailed information about sea-level eustacy, tectonic uplift, sedimentary hiatus, resource accumulation and palaeoclimate change from the South China Block during the Wuchiapingian.

Eocene to Pliocene paleochannels of the Sierra Nevada (California, USA) were first exploited for gold placer deposits during the California gold rush (1848), and then mapped in surveys more than century ago. The surveys showed that the paleochannels flowed westward, like the modern rivers of the range; it then was assumed that the heads of the paleochannels were at the modern range crest. A first paradigm shift occurred ∼50 yr ago, when it was recognized that at least some of the paleochannel fill was sourced from the region of the current state of Nevada, and it was proposed that the Sierra Nevada range was younger than the paleochannels (younger than 6 Ma). More recent work has demonstrated that Sierran paleochannels are ancient features that formed on the shoulder of a broad high uplift (the Nevadaplano) formed during Cretaceous crustal shortening; the headwaters were in central Nevada prior to disruption of the plateau by Basin and Range extension. A second paradigm shift occurred in the past decade: the Sierra Nevada range front is formed of north-northwest transtensional structures of the younger than 12 Ma Walker Lane belt, not north-south to north-northeast–south-southwest extensional structures of the Basin and Range. In this paper we use detailed geologic mapping to reconstruct the paleogeographic evolution of three Oligocene to Pliocene east-west paleochannels in the central Sierra Nevada, and their progressive south to north derangement by Walker Lane structures: the Stanislaus in the south, the Cataract in the middle, and the Mokelumne in the north. Previous work has shown that east-west Nevadaplano paleochannels in the central Sierra have four stratigraphic sequences floored by erosional unconformities; we describe distinguishing characteristics between the ancient Nevadaplano paleochannels and the north-northwest–deranged paleochannels of the Walker Lane grabens. In the east-west paleochannels unconformity 1 is the deepest, eroded into mesozonal Cretaceous plutons; it is overlain by the Oligocene to early Miocene Valley Springs Formation (sequence 1), consisting of ignimbrites erupted ∼250 km to the east in Nevada. Sequence 1 is the most useful for tracing the courses of the paleochannels because it was deposited before faulting began; however, it is incompletely preserved, due to erosion along unconformity 2 (with as much as 500 m of relief) as well as later erosional events. Sequence 2 consists of ca. 16–12 Ma andesitic volcaniclastic rocks referred to as the Relief Peak Formation; it occurs in all three paleochannels (Stanislaus, Cataract, and Mokelumne) as stratified fluvial and debris flow deposits, with abundant cut and fill structures. However, we show for the first time that Relief Peak Formation also forms the basal fill of a Walker Lane transtensional basin system that began to form by ca. 12 Ma, in a full graben along what is now the Sierra Crest, and in transfer zone basins and half-grabens on what is now the eastern range front. The Relief Peak Formation in the Walker Lane transtensional basins consists of massive (nonstratified) andesitic debris flow deposits and debris avalanche deposits, with slabs as much as 2 km long, including slabs of the Valley Springs Formation. Sequence 3 in the Nevadaplano paleochannels consists of distinctive, voluminous high-K lavas and ignimbrites of the Stanislaus Group. The lavas were erupted from fissures in the transtensional Sierra Crest graben-vent system, which beheaded the Stanislaus paleochannel prior to development of unconformity 3 and eruption of the voluminous basal lavas, referred to as the Table Mountain Latite (TML). In the Cataract paleochannel, TML lavas are inset as much as 100 m into the Relief Peak Formation along unconformity 3, indicating fluvial reincision within the paleochannel; TML lavas were ponded in the graben-vent system to thicknesses 6 times greater than the paleochannel fill, with no reincision surfaces. Sequence 3 ignimbrites of the Stanislaus Group (Eureka Valley Tuff) were erupted from the Little Walker caldera, and mark the course of all three paleochannels, with channel reincision surfaces between them (but not in the grabens). Sequence 3 lavas in the paleochannels differ from those in the grabens by having interstratified fluvial deposits, stretched vesicles parallel to the paleochannels, tree molds, peperitic bases, and kuppaberg (cobble jointed) tops, which form when water penetrates into a cooling lava along vertical joints, allowing secondary joints to form perpendicular to them. The Cataract paleochannel was deranged from its ancient (Mesozoic) east-west Nevadaplano trend into the north-northwest Walker Lane tectonic trend prior to development of unconformity 4 and deposition of sequence 4 (Disaster Peak Formation). The north-northwest–deranged Cataract paleochannel is along the Sierra Crest between the Stanislaus and Mokelumne paleochannels, with fluvial deposits indicating northward flow; this paleochannel is perpendicular to the ancient east-west Nevadaplano paleochannels, and parallel to modern Walker Lane drainages, indicating tectonic reorganization of the landscape ca. 9–5 Ma. This derangement was followed by progressive beheading of the Mokelumne paleochannel, development of the Ebbetts Pass pull-apart basin (ca. 6 Ma) and the Ebbetts Pass stratovolcano within it (ca. 5–4 Ma), which fed lava into the relict Mokelumne paleochannel. The derangement of central Sierran paleochannels proceeded as follows, from south to north: (1) the Stanislaus paleochannel was beheaded by ca. 11 Ma; (2) the Cataract paleochannel became deranged from an east-west Nevadaplano trend into a north-northwest Walker Lane trend by ca. 9 Ma, now exposed along the Sierran crest; and (3) the Mokelumne paleochannel was beheaded by ca. 6–5 Ma, and the Carson Pass–Kirkwood paleochannel several kilometers to the north was deranged from east-west into the north-northwest Hope Valley graben ca. 6 Ma. The next paleochannel to the north is in the southern part of the northern Sierra at Lake Tahoe, and based on published descriptions was beheaded ca. 3 Ma. The timing of paleochannel beheading corresponds to the northward migration of the Mendocino Triple Junction and northward propagation of the Walker Lane transtensional strain regime. This paper illustrates in detail the interplay between tectonics and drainage development, exportable to a very broad variety of settings.

In their recent paper, Loseth et al . (2013) propose a new model for the late Cenozoic evolution of the northern North Sea. They propose that during the early Pleistocene ( sensu ICS 2013), large volumes of sand were ejected from the Paleocene through the Eocene–Oligocene Hordaland Group, and deposited both as extrusive sand on the Pleistocene seafloor and as intrusive sand within the Oligocene section, c . 180 m below the seafloor. The paper builds on two earlier studies: (1) that by Loseth et al . (2012) in which the Pleistocene extrusive sand is presented in more detail; (2) that by Rodrigues et al . (2009) in which an experimental model related to such sand deposition is presented. The model of Loseth et al . (2013) is illustrated by a seismic section in their figure 12, showing intrusive sands within the Oligocene and extrusive sands within the Pleistocene. Details of this model, such as feeder dykes and blowout fissures that create ditches, are shown in their figure 8 (Visund Field) and figure 11 (Snorre Field). The geological events are summarized in their figure 16. As illustrated on a stratigraphic scheme (their figs 2 and 15), Loseth et al . interpret the Oligocene sands as being injected from a Paleocene parent sand. They propose that the mounds at the top of the Hordaland Group resulted from forced folding over the sand injectites, as exemplified in their figure 11. Furthermore, Loseth et al . interpret escarpments on the Top Hordaland Group Unconformity as cliff sections similar to those of southeastern England today and claim that the northern North Sea was subaerially exposed during a 10 myr Miocene time span. Loseth et al . (2012, 2013) not only challenge our previous turbiditic interpretation of the Pleistocene sand (Eidvin & …

Longmen Shan is located at the boundary between the Sichuan Basin and Tibetan Plateau, representing the steepest gradient of any edges of the plateau. Three endmember models of uplift process and mechanism have been proposed, including crustal thickening, crustal flow, and crustal isostatic rebound. Here, we use tectonostratigraphic units in the Late Triassic foreland basin to restraint uplift process and mechanism in the Longmen Shan during Indosinian orogeny. The Late Triassic foreland basin developed as a flexural foredeep on the Yangtze passive continental margin during the Indosinian orogeny. The basin fill includes the Maantang Formation, the Xiaotangzi Formation and the Xujiahe Formation, and it is divided into four tectonostratigraphic units with wedge-shaped or tabular cross-sectional geometry by unconformities and flooding surfaces in this paper. The first and third ones are wedge-shaped tectonostratigraphic units and correspond to underfilled condition with basal unconformities or major flooding surfaces, the high rate of subsidence and sediment accumulation, coarsening-upward succession and a dual sediment supply, and them may link to strong active thrust loading events or the rapidly advance rate of the orogenic wedge; the second and fourth ones are tabular tectonostratigraphic units and correspond to overfilled condition with the unconformity, the low rate of subsidence and sediment accumulation, fining-upward succession, a single sediment supply, the mass emergence of conglomerate layers, and they may be related to isostatic rebound and erosion unloading. Two endmember models of uplift process and mechanism in the Longmen Shan during Indosinian cycle have been proposed by coeval Late Triassic sedimentary sequences in the foreland basin here: (1) crustal thickening during the wedge-shaped tectonostratigraphic units, (2) crustal isostatic rebound during the tabular tectonostratigraphic units. This two endmember models proposed in this paper may be helpful to understand the mechanism of the Wenchuan Earthquake.

Main production layers of Tahe oilfield are Ordovician carbonate karst reservoirs, but the control factors of this series of karst reservoirs remains unclear. Combining with drilling, seismic data etc., this paper analysis the control factors of karst from 3 aspects that fractures, paleogeomorphy and unconformity surface in this paper. Research shows that the main control factors of karst are fractures and their associated cracks, unconformity surface and karst landforms. Unconformity surface, karst landforms are the main control factors of karst in early Hercynian period. Fractures and their associated cracks are the important control factors of karst in middle Caledonian and early Hercynian period. On the basis, summarizes genetic model graph of karst.

Tracing hydrocarbons migration pathway is of great significance in studying hydrocarbon accumulation process and predicting hydrocarbon bearing potential of exploration targets, but it is very difficult to trace the hydrocarbons migration pathway in ancient carbonate formations due to strong heterogeneity. In this paper, a combination of geological and geochemical methods is used to discuss the hydrocarbons migration pathway in Ordovician carbonate rock of the Lunnan-Tahe Oilfield in the Tarim Basin. Deep faults and karst unconformity constitute the hydrocarbons passage framework in this area. High angle fractures caused by tectonic stress, pores and cavities formed by karstification played an important role in the connectivity and continuity of this network system. Core observation and thin-section identification revealed that the karsted holes communicating with fractures in the geologic history were the effective pathway for hydrocarbons migration in carbonate formation. The marks of hydrocarbon migration were left in these kinds of fractures and cavities, which were the direct evidence of hydrocarbon migration. The regularities of geochemical parameters of crude oil and hydrocarbon inclusion could effectively indicate the direction of hydrocarbon migration. It could be seen from the section analysis results in this paper that the features of vertical migration in a single well are apparent due to fracture communication; while in the lateral direction, the network system in which fractures and cavities are interconnected constitutes the main lateral pathway for hydrocarbons migration. Analysis results of such wells as Lunnan 63, Jiefang 127, Lunnan 39 and Lunnan 44 indicate that hydrocarbons migration direction was from bottom to top in the vertical direction and from south to north and from east to west in the lateral direction.

IODP Expedition 307, targeting the 160 m high Challenger Mound and its surroundings in the Porcupine Seabight, NE Atlantic, was the first occasion of scientific drilling of a cold-water coral carbonate mound. Such mound structures are found at several locations along the continental margin but are especially numerous off Ireland. All rooted on a common unconformity (RD1) and embedded in drift sediments, the mounds in the Porcupine Seabight remain enigmatic structures, and their initial trigger and formation mechanisms are still not entirely clear. This paper discusses the sedimentary environment during the initial stages of Challenger Mound, and at the start-up of the embedding sediment drift. The results are interpreted within the regional palaeo-environmental context. Based on detailed grain-size analyses and planktonic foraminifera assemblage counts, a 14-m interval overlying the regional base-of-mound unconformity RD1 is characterised at IODP Sites U1317 (on mound), U1316 (off mound), and U1318 (background site). Several sedimentary facies are identified and interpreted in relation to regional current dynamics. Using the foraminifera counts, existing age models for the initial stages of on-mound and off-mound sedimentation are refined. Sedimentation within the initial mound was characterised by a two-mode system, with the observed cyclicities related to glacial/interglacial stages. However, the contrast in environmental conditions between the stages was less extreme than observed in the most recent glacial/interglacial cycles, allowing continuous cold-water coral growth. This sustained presence of coral framework was the key factor for fast mound build-up, baffling sediments at periods of slack currents, and protecting them from renewed erosion during high-current events. The off-mound and background sedimentation consisted mainly of a succession of contourite beds, ranging from sandy contourites in the initial stages to muddy contourites higher up in the sequence, representing the true onset of drift sedimentation. The latter illustrate the increasing importance of glacial conditions after the Mid-Pleistocene Revolution. The overall findings are summarised in a descriptive conceptual model.

This paper is focused on a compilation of known data from the low-grade metamorphosed rocks of the Ediacaran period in the German part of the Saxo-Thuringian Zone at the northeastern margin of the Bohemian Massif. The geotectonic setting during the formation of Ediacaran rock units is characterized by Cadomian orogenic processes from c. 650–540 Ma at the periphery of the West African Craton. The basin development during that time is characterized by the formation of a Cadomian backarc basin with a passive margin, and the outboard sitting Cadomian magmatic arc originated at c. 570–560 Ma. This arc-marginal basin system was formed on stretched continental crust in a strike-slip regime and reflects an active-margin setting in a style similar to the recent West Pacific. The backarc basin was closed between c. 560–540 Ma by the collision of the Cadomian magmatic arc with the cratonic hinterland: this resulted in the closure of the backarc basin and the formation of a Cadomian retroarc basin. Collision of an oceanic ridge with the Cadomian Orogenic Belt led to a slab break-off of the subducted oceanic plate resulting in an extreme heat flow, and a magmatic and anatectic event culminating at c. 540 Ma that was responsible for the intrusion of voluminous granitoid plutons. Ediacaran rock complexes in Germany are restricted to the Saxo-Thuringian Zone in the Bohemian Massif, which represents the largest and most important basement inlier of the Central European Variscides (Fig. 1). Low-grade Ediacaran metamorphic rocks occur mainly in the Saxo-Thuringian Zone (Germany) and the Tepla-Barrandian Unit (Czech Republic) (Fig. 2). This paper presents a review on the weakly metamorphosed Ediacaran to Early Cambrian rocks of the Saxo-Thuringian Zone. These rocks units are affected by the tectonometamorphic overprint of the Late Neoproterozoic–Early Cambrian Cadomian and the Late Devonian–Early Carboniferous orogenies. In some areas of the Saxo-Thuringian Zone, such as the Erzgebirge Mountains, some of the rocks display a high-grade metamorphic overprint. These rocks are not discussed in this paper. Cadomian orogenic processes comprise a series of complex sedimentary, magmatic, and tectonometamorphic events that spanned the period from the mid-Neoproterozoic (c. 650 Ma) to the earliest Cambrian (c. 540 Ma) (e.g. Linnemann et al. 2000; Nance et al. 2002). Rock units formed by the Cadomian orogeny are generally referred to as ‘Cadomian basement’. Due to very similar contemporaneous orogenic processes in the Avalonian microplate, the collective term ‘Avalonian-Cadomian’ orogeny has often been used in the modern literature (e.g. Dorr et al. 2004). Peri-Gondwanan terranes, microcontinents and crustal units in Europe and in North Africa are affected by the Cadomian orogeny (e.g. Murphy et al. 2004). Related orogenic events, such as the Avalonian orogeny, are known in the Appalachians (eastern US and Atlantic Canada), and from the non-Laurentian part of Ireland and the British Isles (e.g. Nance & Murphy 1996). Baltica escaped the Avalonian-Cadomian orogenic activity, although the ‘Cadomian affinity’ of the late Precambrian orogenic events in the Urals and in the Timanides on the periphery of Baltica was recognized (Roberts & Siedlecka 2002; Glasmacher et al. 2004). The Cadomian orogeny was first defined in the North Armorican Massif in France on the basis of the unconformity that separates deformed Precambrian rock units from their Early Palaeozoic (Cambro-Ordovician) overstep sequence (Bunel 1835; Dufrenoy 1838; Barrois 1899; Kerforne 1901). ‘Cadomus’ is an old Latin term for the modern city of Caen and is the source of the name of the orogeny. The term ‘discordance cadomienne’ was first used by Bertrand (1921). The best illustration of the unconformity in Rocreux (Normandy) was published by Graindor (1957). In Central and Western Europe the unconformity is commonly referred to as the ‘Cadomian unconformity’. It is possible that the youngest metasedimentary rocks From: VICKERS-RICH, P. & KOMAROWER, P. (eds) The Rise and Fall of the Ediacaran Biota. Geological Society, London, Special Publications, 286, 35–51. DOI: 10.1144/SP286.4 0305-8719/07/$15.00 # The Geological Society of London 2007. affected by the Cadomian deformation are earliest Cambrian in age. Many geologists assume that the final stages of Cadomian orogenesis were spatially diachronous, lasting from the latest Neoproterozoic to the earliest Cambrian. From this viewpoint the term ‘Cadomian basement’ includes Neoproterozoic (Ediacaran) to Early Cambrian sedimentary, igneous and metamorphic complexes. The stratigraphic range of the involved rock complexes changes from region to region. In some publications, the term ‘Pan-African orogeny’ is used in the same sense as Cadomian orogeny, because both events were related to the Gondwana supercontinent in the late Precambrian and occurred more or less in the same time interval. The main difference between the Cadomian and Pan-African orogenic events is their position within the configuration of the Gondwana supercontinent in Neoproterozoic time. The crustal units affected by the Pan-African orogeny are located between the cratons assembling Gondwana and reflect continent–continent collision, at least in most cases (e.g. compilation of Windley 1996). In contrast, the Cadomian orogen or, alternatively, the Avalonian-Cadomian orogenic belt is a peripheral orogen at the edge of the Gondwanan supercontinent and was characterized by orogenic processes similar to those presently observable in the Andes and the Cordilleran chains of the American continents and in the West Pacific Region (Murphy & Nance 1991; Nance & Murphy 1994; Buschmann 1995; Linnemann et al. 2000; Nance et al. 2002; Linnemann et al. 2004). Provenance studies including: (1) U/Pb-ages of detrital zircon grains from sedimentary rocks and inherited zircons from igneous rocks; (2) Nd–Sr– Pb isotope; and (3) palaeomagnetic and palaeobiogeographic data, suggest that the origin of the Cadomian basement of Central and Western Europe was at the periphery of the West African craton of Gondwana (e.g. Linnemann et al. 2004; Murphy et al. 2004). Remnants of the old cratonic basement derived from the cratonic source areas are represented by the Icartian basement (2.01–2.06 Ga) in the Armorican massif, and the Svetlik gneiss (2.05–2.1 Ga) and the Dobra gneiss (1.38 Ga) in the Bohemian Massif. In view of the occurrence of these rock complexes, and many Archaean and Palaeoproterozoic detrital zircons in Neoproterozoic sedimentary rocks, it seems that most of the Cadomian basement had developed on a stretched and thinned old cratonic crust, from which cratonic material was available for erosion and deposition into basins and also for the incorporation of large blocks from the basement into the Cadomian orogen. Nance et al. (2002) proposed a Cordilleran model for the evolution of the Neoproterozoic to Cambro-Ordovician rock complexes in Avalonia that was a part of the ‘Avalonian-Cadomian orogenic belt’ on the periphery of the Gondwana supercontinent during the Neoproterozoic and the Early Palaeozoic. This model uses the North American plate at Baja California as a modern analogue to explain the plate-tectonic setting, including terrane accretion, subduction-related processes, ridgetrench collision and rifting. The impact of the Variscan orogeny during the closure of the Rheic Ocean in Devonian and Carboniferous times resulted in a penetrative overprinting and recrystallization of the Cadomian basement rocks and of their structures in many areas during Pangea amalgamation. Therefore, this compilation is focused on the Saxo-Thuringian Zone at the periphery of the Bohemian Massif, which is less affected by younger orogenies. This zone contains a number of the best-preserved and most representative Ediacaran rock complexes in the Cadomian basement of Central Europe. The Precambrian of the Bohemian Massif The Bohemian Massif is bounded to the north and the NE by the Mid-German Crystalline zone, which most likely represents the suture formed during the closure of the Rheic Ocean in the Late Devonian to Early Carboniferous period. To the south and SE the Bohemian Massif is covered by the Meso-Cenozoic orocline of the Alps and the Carpathians. Steeply dipping faults in the SW, such as the Franconian Line and the Danube Fault, divide the basement rocks from Mesozoic platform sediments and the Alpine molasses (Fig. 1). The Bohemian Massif represents the most prominent inlier of basement rocks in Central Europe that underwent a long geological history from Cadomian orogenic processes to the core of the Variscan Orogen in the Central European Variscides. Some of the marginal units and inliers contain very weak metamorphosed and deformed Ediacaran to Palaeozoic rock complexes. Good examples are the western and northern parts of the Saxo-Thuringian Zone and the Tepla-Barrandian Unit (Fig. 1). The Bohemian Massif is generally interpreted as a part of Armorica (Van der Voo 1979). Tait et al. (1997, 2000) suggested that Armorica drifted across the Rheic Ocean during Ordovician to Devonian times. In contrast, the interpretation of palaeobiogeographical, geochronological, geochemical and sedimentological data led to the conclusion that Armorica never left Gondwana mainland in pre-Pangean time (Robardet 2002; Linnemann et al. 2004). The Cadomian basement of the Armorican Massif, the French Central U. LINNEMANN 36

This paper provides an overview about a geophysical survey with Ground Penetrating Radar (GPR) imaging over a striated glacial pavement close to the SW border of the Parnaiba Paleozoic Basin in the NE of Brazil Platform. The striated pavement is situated in the upper part of the Cabecas Formation where there is an erosional unconformity separating the Cabecas sandstones and overlying tillites. The Cabecas Formation consists of cross-bedded conglomeratic sandstones and sandstones, massive tillites, and laminated rhythmites with dropstones. Clasts in tillites range in size from small pebbles to boulders, with some of them striated, faceted and polished. The Cabecas Formation is as old as Famennian (late Devonian). The Famennian time lasted from 374.5 to 359 million years ago and it was preceded by the Frasnian stage and followed by the Tournaisian (Mississipian) stage. This formation was deposited on a plataform setting, tidal-dominated deltaic system and was accumulated under periglacial and glacial conditions. The principal objective of the GPR application over this glacial pavement was to know if the EM GPR system is able to show some important internal sedimentary structures below to the surface. The good resolution of the 200 Mhz antenna results shows indeed several internal structures, radar facies and differences in the signal amplitude that could be correlated with changes in sedimentary layers/deposition/facies and correlations with the ice flow direction records in depth. Almost 3 selected radar packages interpreted as equivalent to lithofacies assemblages were observed. Introduction The Calembre Striated Pavement Area is located in southern portion of Parnaiba Paleozoic Sedimentary Basin, 360 km South of Teresina City and near the Calembre village, in the Brejo do Piaui Municipality. This site was close to the area released by Malzahn (1957), who was the first to describe striated pavements, when he was mapping the region for Petrobras (Brazilian State Oil Company). On the other hand several papers from Caputo described glacial rocks in northern Brazil (Caputo, 1984,1985, Caputo et al. 2005, 2008, Caputo and Ponciano, 2013). The most interesting paper was the record of the Calembre Striated Pavement as a Geologic and Paleontologic Site in Brazil (Caputo & Ponciano, 2013). Figure 1 shows the geographical localization of the Calembre Site in the Parnaiba Basin, in the NE portion of Brazil, in the Piaui State. The site is located about 360 km in the south direction of Teresina City. The nearest town is Canto do Buriti, where through the BR 324 road we can reach the village of Calembre in Sao Raimundo Nonato city direction (Figure 1).

The paper by Bordy et al. (2004) represents a useful contribution to one of the most neglected parts of the Karoo succession, despite its importance in terms of biological and climate change, and evolving basin tectonics. However, the paper also raises a number of issues that warrant further discussion. The paper highlights one of the major problems with the Karoo Basin: the lack of reliable radiometric dates for the age of the basin fill. Bordy et al. (2004) divide the Upper Karoo succession on perceived unconformities which they link to more than twenty year old Ar/Ar dates for synchronous orogenic events in the Cape Fold Belt (Halbich, et al. , 1983). Unfortunately, most geochronologists do not consider such dates reliable because the Ar-Ar system, being based on the K-Ar system, is rather prone to the effects of alteration/diagenesis, which may induce a non systematic loss or gain of radiogenic Ar. In addition, with improvements in mass spectrometry techniques, there is now significant argument about fundamental issues relating to the methodology, more specifically: uncertainty in the half life of 40K; lack of agreement on the precise age of neutron flux monitors used to calibrate ages for unknown samples; the inherent variability of the neutron flux in a given reactor used to irradiate samples, leading sometimes to significant uncertainty in the “J”-factor; and differences in approach to criteria used for accepting data for use in age calculation. These uncertainties combine to mean that the absolute error on a given 40Ar-39Ar is significantly greater than the “in-run” uncertainties quoted in most publications. This can lead to errors of several percent in the absolute age of a Mesozoic rock. The age of the upper Karoo succession is poorly constrained (see discussion in Turner, 1999), and apart from the base of …

The Late Miocene ''Solitary Channel," Tabernas-Sorbas basin, SE Spain, has been interpreted as a submarine channel fed by sediment gravity flows from the east. In this paper, the channel is reinterpreted as a lower-slope erosional channel fed by sediment gravity flows from the west. The channel shows cobble/pebble lag deposits, including breccias, associated with erosional phases with substantial sediment bypass, and a later infill by episodes of inclined backstepping macroforms (the primary focus in this paper), mainly comprising sands, interpreted here for the first time as channel backfill deposits. These inclined sandy macroforms, typically 2-5 in in height and 3040 in in length, are described in detail for the first time in this paper, and are interpreted as a new large-scale sedimentary structure. We observe that the seeding process for the inclined sandy macroforms appears to have been in the upstream depression immediately behind ridges on the surface directly overlying cohesive debris-How deposits.The internal channel architecture is interpreted in terms of fluctuating relative base levels. A purely local tectonic explanation for the inclined sandy macroforms is discounted because within the bed bundles, dips are essentially constant across the intrachannel disconformities. We speculate that the most likely overall change in base level throughout the history of the channel was driven by regional tectonic change. The higher-frequency variations were probably a consequence of fluctuations in sediment supply/caliber from the source area and/or of cycles of eustatic or regional sea-level changes. The channel was abruptly overlain by about 200 in of marls and then a heterolithic sheet-like turbidite system typical of a confined basin-floor setting. This change in depositional style represents a response to a significant overall decrease in basin-floor gradient, in which there was a differential change in base level, shown by the coeval development of a major angular unconformity farther east (Sorbas area). The channel history is important for sequence-stratigraphic modeling because it demonstrates that a backstepping fill can be caused by an overall tectonic control on the accommodation space (initiation and abandonment). Higher-frequency source-area changes in sediment flux/caliber and/or eustatic sea level probably exert a strong influence on the detailed depositional architecture in the channel (multiple bypass-backfill events).

In western Canada, a major paleoenvironmental change at the Albian-Cenomanian boundary is related to a eustatic sea-level rise overprinted by a relative sea-level fall in conjunction with preexisting topography within the basin. This paper shows the lateral variability of sedimentology, paleoecology, and biostratigraphy of the latest Albian to Cenomanian interval along the Canadian western margin of the Cretaceous interior seaway. This paper (1) provides an integrated depositional and paleoecological examination of the Albian and Cenomanian lithologic units in the northern Western Interior Seaway; (2) demonstrates the effect of antecedent paleotopography within the basin at the time of the transgression; (3) documents the variability in sedimentary facies and paleoecology controlled by paleorelief; and (4) demonstrates the diachroneity, lateral extent, and extremity of the multiple unconformities controlled by this paleorelief. An enigmatic aspect of the lowermost Cenomanian Fish Scales Formation has been the regional occurrence of chert, quartz, and bioclastic pebbles associated with black anoxic shale. A regional north-south traverse across Alberta provides insight into this problem. In southwestern Alberta, chert- and quartzite-pebble conglomerate and sandstone that are equivalent to the Fish Scales Formation—known as Barons Sandstone (subsurface) and Blairmore Grits (outcrop)—represent proximal shelf sedimentation. This coarse-grained sediment was flushed out during sea-level lowstand and then reworked by a subsequent transgression associated with the Belle Fourche Formation. A large paleohigh existed in southwesternmost Alberta at this time. Northward, the Fish Scales Formation is bounded top and bottom by unconformities and conglomerate, indicating multiple sea-level fluctuations and deposition in a wave-influenced shelf environment. In west-central Alberta, preserved deposits of the Fish Scales Formation indicate deposition in a nearshore setting. Farther to the north and, most distally, in northwestern Alberta and elsewhere to the east, the coarse component of the Fish Scales Formation is predominantly gravel-sized fish and other vertebrate debris with significantly less siliciclastic detritus. Regionally, the unconformity at the base of Fish Scales–Barons becomes more pronounced southward and westward where the underlying shale of the Westgate Formation (or Westgate Member) has been eroded or was never deposited. The regional paleogeographic setting for the Barons Sandstone and Fish Scales Formation indicates greater amounts of erosion and coarser-grained deposition in the southwest associated with the paleohigh. Northward and eastward, there was greater accommodation space, less erosion associated with the unconformity, and finer-grained sediment.

The outer sector of the Neoproterozoic Katangan Orogen of Central Africa is characterised by nappes thrust northwards, toward the foreland region, the major part of which occurs in the Democratic Republic of Congo (DRC). The rocks called R.A.T. (‘Roches Argilo-Talqueuses’) are terrigenous clastics traditionally considered as the oldest stratigraphical interval of these allochthonous units. They are correlated with the terrigenous clastic sediments at the base of the autochthonous Katangan succession in Zambia to the south, which were deposited at the opening stage of the Katangan Rift Basin. The lower interval of the R.A.T. represents red beds, whereas the upper one was deposited in anoxic conditions. Therefore, they are called red and grey R.A.T., respectively. This paper presents stratigraphic, structural and geochemical arguments against the traditional stratigraphical view and demonstrates that the R.A.T. rocks are younger than previously considered. They are interpreted here as synorogenic sediments of the Katangan foreland basin. Olistostromes with R.A.T. olistoliths, which occur either interbedded within ‘normal’ R.A.T. sediments or overlie angular unconformities, testify to pronounced tectonic movements and palaeotopography of the basin in which the R.A.T. sediments were deposited. The provenance of other olistoliths implies that, contrary to the previous views, the R.A.T. olistostromes are younger than the overlying rock complexes and the contact between the two is tectonic. Clastic dykes of the incompetent R.A.T. lithologies injected into the overlying competent units suggest that the former were partly unconsolidated sediments over-ridden by the Katangan nappes. Plots of the geochemical compositions point to two distinct tectonosedimentary cycles and two types of sources, each related to a different stage of orogen evolution. The terrigenous materials of the Katangan autochthonous strata (Roan and Kundelungu Groups) and correlative allochthonous units are derived from basement granitic and metamorphic rocks eroded during the opening of the Katagan rift basin. By contrast, the R.A.T. rocks are related to the closure of the basin. Their provenance is from the orogenic source-the Katangan nappes advancing towards the foreland region in the north. The autochthonous Roan Group rocks in Zambia and their allochthonous correlatives in DRC contain one of the richest Cu-Co deposits known. In accord with the previous correlation, the CuCo mineralisation in the grey R.A.T. rocks was considered of the same age as the Zambian deposits. However, the results presented in this paper imply that the grey R.A.T. deposits represent a second generation of mineralisation in the Katangan belt, younger than the Roan Group orebodies. The R.A.T. Cu-Co mineralisation is related to the anoxic stage of the foreland basin, and the advancing nappes containing Roan-correlative orebodies acted as the sources of the metals. In conclusion, points pertaining to the revision of stratigraphical classification of the Katangan Supergroup are proposed.

In this paper, we present the general tectonic framework that conditioned the evolution of the Lusitanian Basin during the Jurassic, when most of the filling of the basin was accumulated. The rifting episodes and the evolution of the basin’s geometry are presented and their close relationship with the main basin-wide unconformities is discussed. The unconformity-bounded sequences are briefly presented as a basis for understanding the evolution of the sedimentary environments. This constitutes the basic geological information to construct the palaeogeographical maps presented in Part II of this paper (this volume).

This paper shows the results obtained from an integrated study (geology, biostratigraphy and geochemistry) carried out on the Miocene edimentary deposits in Central Italy in order to define the timing of the sedimentary basin evolution. This paper deals also with the causes of the unconformities recorded in these basins. In the Miocene deposits of the Latina Valley and the Ernici-Simbruini Mts. several unconformities which distinguish different stratigraphic sequences have been recognized (D 0 , D 1 , D 2 D 3 and D 4 ). For each unconformity a general description together with a geodynamical significance is provided. In particular, D 0 unconformity appears to be related to a regional tectonic event (Adria-Europe collision). As a consequence, the Adria lithosphere folded and the area underwent a regional erosive event. D 1 , D 2 and D 3 unconformities have had a more local tectonic control since they represent the stratigraphic record of the migration of the Apennines thrust belt/foredeep system. D 1 and D 2 unconformities are related to the late Tortonian foredeep stage, whereas D 3 is linked to the early Messinian piggy-back stage. Moreover, the D 4 unconformity, which took place during the Messinian piggy-back stage, is strictly linked to the sea-level drop of the Messinian salinity crisis. In this paper the genesis and evolution of a late Tortonian foreland basin is also stressed (Latina Valley foredeep basin). Finally, taking into account sequence boundaries, nannofossil biostratigraphy and geochemistry isotopic data, a comparison with the curve of the 3rd order of the relative coastal onlap (Haq et al., 1988) has been attempted in order to distinguish the unconformities controlled either by tectonic or eustatic processes.

Diagenetic modification of the Albian-Turonian in the Middle East is complex and multiphase, and has provided a critical control on reservoir quality. This paper presents a summary of this diagenetic overprint, gathered from published case studies from across the region. The most important diagenetic events comprise marine cementation, along discontinuities and overprinting bioturbation, incipient karst formation at intraformational sequence boundaries and deep cutting karst at the late Cenomanian/early Turonian unconformity. Finally, leaching of micrite and early diagenetic cements has often created large volumes of secondary micro- and macroporosity. This leaching could have taken place from meteoric pore waters or deep burial brines. This paper will assess the relative importance of these key in order to provide the basis of a predictive regional diagenetic model for the Albian-Turonian of the Middle East.

This paper reevaluates the geometry and processes of extension in the boundary zone between the western Colorado Plateau and the Basin and Range Province. Based on new mapping of extensional detachment faults, restored cross sections, and 40Ar/39Ar K-feldspar thermochronology, we present an alternative to the previously published model that the Gold Butte block is a tilted 15-18-km-thick intact basement crustal section. Mapping of windows of crystalline basement at 1:12,000 scale delineates a bedding-parallel detachment fault system that parallels the Great Unconformity in the Tramp Ridge block, just north of the Gold Butte block. Above this detachment fault, extensional allochthons containing Upper Paleozoic through Tertiary (>18 Ma) rocks exhibit tilting due to westward translation and tilting. We project this geometry above the Gold Butte block itself based on restoration of slip across the Gold Butte fault. This reconstruction suggests that the detachment system extended over lateral distances of >1000 km 2 , helping define a region of relatively modest extension (∼25% for cover; 10% for basement) within the Nevada transition zone between the Colorado Plateau and Basin and Range. In agreement with previously published mapping and structural cross sections, our restored cross sections suggest that extensional deformation initiated with formation of hanging-wall anticlines above a listric Grand Wash fault system and evolved via a combination of both listric faulting and domino-block translation and tilting. New data presented in this paper document that extension was also facilitated by slip on bedding-subparallel detachment zones in the Bright Angel Shale, along the basement unconformity, and along other zones of weakness, such that the extended Paleozoic cover was partly decoupled from less-extended basement. This detachment system ramps down into basement to merge with the South Virgin-White Hills detachment at the west end of Gold Butte, the principal extensional detachment of the region. Our mapping and structural model suggest that movement on these detachment faults initiated at low angle. Further, using the geometry from restored cross sections, we infer that the deepest rocks now exposed in the western Gold Butte block resided at depths of∼4 km below the Great Unconformity (∼8 km below the surface) rather than the previously published 15 km below the unconformity (∼19 km below the surface). New 40Ar/39Ar K-feldspar thermochronology from the Gold Butte block, added to a compilation of published thermochronologic data, is used to help evaluate alternative models. K-feldspar multiple diffusion domain (MDD) modeling suggests that rocks throughout all but the westernmost part the block had cooled through 150-200 °C before the Phanerozoic and resided at temperatures

A widespread unconformity between Ordovician metasedimentary rocks and nonmetamorphosed Mesozoic sedimentary rocks across the Eastern Cordillera of Bolivia provides evidence for significant pre-Late Cretaceous deformation and erosion. In this paper, we refine the middle to late Paleozoic tectonic history of the central Andean segment of Gondwana's western margin. We combine Raman spectroscopy of carbonaceous material (RSCM) thermometry with semi-quantitative deformation temperature estimates from quartz recrystallization microstructures and published illite crystallinity values from Cambrian-Devonian sedimentary rocks that span the Eastern Cordillera of southern Bolivia at ~21°S. Estimates of peak temperature and deformation temperature range primarily between ~220 and ~ 400 °C and show a general increase with depth that defines a metamorphic field gradient between ~37 and ~ 47 °C/km. Temperatures obtained from Ordovician rocks directly below the unconformity require erosion of a > ~5 km overburden prior to the Late Cretaceous, which was likely accomplished by a combination of distributed cleavage development and Paleozoic folding and thrust faulting revealed from cross-section reconstructions. The peak temperature data are incorporated into thermal models along with published illite K Ar, zircon (U Th)/He, and zircon fission-track cooling ages that refine the timing of Paleozoic orogenesis in the central Andes. We interpret shortening-related flexural subsidence driven by cratonward growth of a pre-Andean orogenic wedge along the western margin of Gondwana, with peak temperature conditions attained during eastward advance of a foreland basin between ~420 and ~ 318 Ma during the Devonian-Carboniferous Gondwanide Orogeny. Erosional exhumation between ~352 and ~ 294 Ma was the result of continued growth and eastward expansion of the associated Transpampean tectonic highland across the Eastern Cordillera. The growth of this pre-Andean contractional orogen coincided with global plate reorganization and the reestablishment of subduction and arc magmatism along the western margin of Gondwana, as indicated by a significant influx of Carboniferous arc-related detritus into the foreland basin system.

The depositional sequence concept was established in newly developed sequence stratigraphy, as an unconformity-bounded stratigraphic unit formed during one complete sea-level cycle. This paper reviews general meanings of “sequence”, the definition of depositional sequences, their hierarchial patterns and recognition, and sequence boundaries problems, from a viewpoint of sedimentary geology based on outcrops and bore-hole samples.Though the word, “sequence” has many meanings generally applied to successive geologic events and processes in chronologic order, a depositional sequence is defined in a special sense, as “a relatively conformable succession of genetically related strata bounded at its top and base by unconformities and their correlative conformities”. The depositional sequence as one of hierarchial transgressive and regressive units (T-R units), has the first- to forth-order operational units, that is, the megasequence, supersequence, sequence and parasequence in descending order. A sequence boundary with a significant hiatus (=unconformity) is formed by subaerial exposure, concurrent subaerial erosion and partly submarine erosion during eustatic falls or low-stand sea level.The latter half of this paper emphasizes the difference between sequence boundaries and ravinement surfaces. The ravinement surface formed as one of diastems or “transgressive surfaces”, is an erosional surface by shoreface retreat during the following transgression after a sea-level fall. In general, it is lithologically more distinct than the underlying sequence boundary. The right recognition of the difference leads correct reconstructions of sedimentary history.

A study on Danian to Selandian foraminifera (planktic/benthic ratios, benthic assemblages) in 23 sections on a N-S transect in eastern Egypt documents a transient biotic excursion associated with sea-level fluctuation at ∼60.5 Ma (Subbiochron P3a). In southern areas, the inner to middle neritic (30–70 m) Neoeponides duwi assemblage expanded into deeper parts of the shelf (∼70–250 m), temporarily replacing the Anomalinoides umboniferus and Angulogavelinella avnimelechi assemblages. In the deeper parts of the basin (∼400–600 m) in the northern part of the transect, the Gavelinella beccariiformis assemblage appears to have been persistent throughout the studied time interval. Biofacial and sedimentologic data suggest a relative sea-level fluctuation, possibly with an amplitude of 50–100 m, which may correlate with a eustatic sea-level cycle during the Danian-Selandian transition. During early sea-level rise, total organic carbon–enriched, partially laminated sediments, containing abundant fish-remains and planktic foraminifera (>99.5% planktics), were deposited, reflecting oxygen deficiency at the seafloor. The patterns of biotic and sea-level change at the Danian-Selandian transition strongly resemble those across the Paleocene-Eocene Thermal Maximum in the same basin, suggesting similar operative processes. Considering the close coincidence with a recently postulated brief period of oceanic warming at 60.5 Ma, the question arises whether the observed patterns in Egypt could in part be related to a global warming event, similar to the Paleocene-Eocene Thermal Maximum. 275 Speijer, R.P., 2003, Danian-Selandian sea-level change and biotic excursion on the southern Tethyan margin (Egypt), in Wing, S.L., Gingerich, P.D., Schmitz, B., and Thomas, E., eds., Causes and Consequences of Globally Warm Climates in the Early Paleogene: Boulder, Colorado, Geological Society of America Special Paper 369, p. 275–290. © 2003 Geological Society of America. blages within the Danian-Selandian transition, and tentatively correlated it with Danian-Selandian sequence boundary Se-1 of Hardenbol (1994). The foraminiferal succession in Aweina included the transient occurrence of the shallow water Discorbis (=Neoeponides) duwi assemblage between deeper shelf benthic assemblages (Speijer and Schmitz, 1998). New observations on DanianSelandian benthic foraminiferal assemblages from 23 sections on a N-S transect in eastern Egypt reveal the incursion of the Neoeponides duwi assemblage in other sections in the southern part of the transect. In this paper, I present a summary of these observations, provide a new view on the relationship between biotic and sea-level patterns during the Danian-Selandian transition, compare these with those related to the PaleoceneEocene Thermal Maximum in the same basin, and speculate on possible implications from this comparison. Danian-Selandian transition in the type region, Denmark In its type region, Denmark, Danian chalks and limestones are unconformably overlain by Selandian greensands and marls (e.g., Thomsen and Heilmann-Clausen, 1985). This transition to more terrestrially influenced deposition terminated a >35 m.y. period of hemipelagic carbonate deposition in the Danish basin 276 R.P. Speijer Figure 1. Lithostratigraphy, biostratigraphy, and sequence stratigraphy of the Danian-Selandian transition in the type region, Denmark. Biostratigraphic terminology as adopted in Berggren et al. (2000). Sequences TA1.3/1.4 after Haq et al. (1988) and sequence boundary Sel 1 after Hardenbol et al. (1998). PF—planktic foraminifera; CN— calcareous nannofossils. (Hakansson et al., 1974; Schmitz et al., 1998). This change in depositional regime between 60 and 61 Ma is related to the opening of the northeastern Atlantic and the uplift of west European landmasses (Berggren, 1994). Determining the exact biostratigraphic positions of the bounding surfaces of the unconformity marking the Danian-Selandian boundary in the type region, Denmark (Fig. 1), has proven difficult. Age and duration of the unconformity vary geographically, but there is general consensus that the top of the Danian correlates with a level within calcareous nannofossil Zone NP4 and planktic foraminiferal Subzone P1c or Zone P2 (e.g., Bignot et al., 1997). The base of the Selandian correlates with a level in the upper Figure 2. Location map with sections studied (triangles). Numbers refer to the following localities: (1) a transect composed of four sections across the Areif en Naqa anticline; (2) eight sections west of Taba; (3) a transect composed of five sections south of the Galala platform. See Table 1 for biostratigraphic information and references.

Within the scope of this paper, seismic reflection and bathymetry studies were carried out in the shallow marine area forming the westernmost part of the Tekirdag Basin using the R/V Selen Research Vessel within the MTA Marine Research Department. In the study area, ~ 500 km length bathymetry data and ~191 km shallow seismic profiles ( 41 lines) were collected. By means of the data, tectonic structures and deformation textures of the North Anatolian Fault System (NAFS) in the marine area of Gazikoy were examined. As a result of the processing and interpretation of the seismic sections, compression structures occurring due to the SW rotation of the NAFS in the study area, the morphology of the Ganos depression that formed as a result of faulting and also three different stratigraphic units were distinguished. These units are separated from each other by distinct unconformity surfaces and each unit presents different deformation structures. One of the most significant results obtained from the seismic data is that the unconformity surface that separates the current sediments of the seafloor from the older units is represented by the overlapping structures indicate sea level changes. It has been assessed that this situation occurred as a result of the erosional process developed during sea level fall.

This work presents the facies analysis and depositional environment for the Eocene rocks in the southern Llanos Basin (SLLB) and southern Llanos Foothills. Cores and outcrop samples were analyzed by palynology and detrital zircon U-Pb geochronology. In this paper, we present ages for the facies and two important paleosol markers. The lower member of the Mirador Formation consists of amalgamated sandstones and conglomerates accumulated in a braidad channel belt. The lower Mirador is 33 m thick and early Eocene in the Foothills, whereas in the SLLB, it ist is 22 m thick and middle Eocene in age; it pinches out approximately 33 km to the east. The fluvial facies rests over an unconformity marked by a mature and intensively-weathered paleosol developed over Paleocene, Cretaceous and older rocks to the east. This mature paleosol was dated by U-Pb detrital zircon geochronology as middle to late Paleocene. At the top of the lower Mirador, we describe an interval of sandstones with root casts capped by a thin layer of coal or coaly mudstone. This facies succession evolved as A compound paleosol is a polygenetic soil that marks a change from well-drained conditions under a subaerial vegetation cover to poor-drained conditions of marsh and swamps, which halt vegetation growth, which is incorporated as coal or coaly mudstone, see the section of Facies Successions. At the top of the lower Mirador facies and recorded the cessation of the fluvial system and its stabilization by vegetation. The coal layer marked the posterior rise on the water table and flooding. Detrital zircon U-Pb geochronology dated this compound paleosol as middle Eocene. Above the fluvial facies of the lower Mirador, shallow marine facies deposited during the middle and late Eocene in the Foothills and western SLLB. The marine facies consist in shelf mudstone and shoreface sandstone in a coarsening upward trend. These facies correspond to the C8 member of the Carbonera Formation. The correlative middle Eocene facies to the east of the SLLB are carbonaceous mudstones and coals that were deposited in swamp-marsh and lagoon environments in backshore to coastal-plain environments during the middle Eocene. The fluvial and coastal plain, as well as the marine facies, fossilized an erosional relief less than 50 m high, corresponding to a paleo-landscape. The paleo-landscape was carved at the end of the Paleocene and is capped by the intensely-weathered paleosol indicating subaerial exposition. The paleo-landscape was modeled over Paleocene, Cretaceous, Paleozoic, and basement rocks toward the east and south of the basin. This paleo-landscape lasted until the end of the middle Eocene in the studied area. The Fluvial reservoirs are not continuous but distributed along channel belts composed of channels and braided bars in an NW direction. The marine shoreface reservoirs are distributed as swaths of sandstones in a perpendicular direction to the fluvial belts. These reservoirs have excellent seal rocks above. The plays include fluvial valley sandstones and buried hills of Cretaceous sandstones. RESUMEN Este trabajo presenta el análisis facies y ambiente de depositación de las rocas del Eoceno en la Cuenca Llanos Sur y Piedemonte. Se utilizaron muestras de roca de núcleos y afloramientos para dataciones mediante palinología y U-Pb en zircones detríticos. Esto nos ayudó a conocer la edad de las facies y unos importantes niveles de paleosuelos. El miembro inferior de la Formación Mirador está compuesto de conglomerados y areniscas amalgamadas, con una tendencia grano-decreciente, depositadas en sistema fluvial trenzado. El miembro inferior del Mirador en el Piedemonte tiene 33 m de espesor y es de edad Eoceno temprano, mientras que en la Cuenca Llanos Sur tiene 22 metros como máximo y es de edad Eoceno medio; este miembro se pincha 33 km al oriente. Estas facies fluviales yacen sobre una inconformidad marcada por un paleosuelo maduro y bastante meteorizado, desarrollado en estratos rocosos del Paleoceno, Cretácico y en substratos más antiguos hacia el oriente. Este paleosuelo maduro fue datado por geocronología detrítica U-Pb como Paleoceno medio a tardío. Hacia el tope del Mirador inferior, se describe un intervalo de areniscas con marcas de raíces y sobre este, una capa de carbón o lodolita carbonosa. Esta sucesión de facies evolucionó como un suelo compuesto sobre la litología fluvial del Mirador inferior y marca el final del sistema fluvial y su estabilización por vegetación. La capa de carbón marca una subida del nivel freático e inundación del sistema. Este suelo compuesto fue datado como Eoceno medio. En el piedemonte llanero y la Cuenca Llanos Sur, sobre las facies fluviales y el suelo compuesto, se depositaron facies marinas someras durante el Eoceno medio a tardío. Esas facies están compuestas de lodolitas de plataforma y areniscas de shoreface en un arreglo grano creciente. Estas facies corresponden al miembro C8 de la Formación Carbonera. Las facies correlativas del Eoceno medio hacia el este de la Cuenca Llanos Sur, corresponden a lodolitas carbonosas y carbones que fueron depositados en sistemas transicionales de marismas, pantanos y lagunas costeras atrás de la playa. Las facies fluviales y de planicie costera, igual que las facies marinas, fosilizan un relieve erosional de menos de 50 m que constituye un paleo-paisaje. Este Paleo-paisaje fue tallado al final del Paleoceno y fue cubierto por el paleosuelo maduro y bastante meteorizado indicando la exposición subaérea. El paleo-paisaje fue modelado sobre rocas del Paleoceno, Cretácico, Paleozoico y rocas del basamento hacia el oriente y sur de la cuenca. Este paleo-paisaje existió hasta el final del Eoceno medio, pero estudios regionales han mostrado que esta geoforma perduró hasta el final del Oligoceno temprano. Los reservorios en esta parte de la cuenca Llanos nos son continuos sino distribuidos a lo largo de valles ocupados por canales braided en dirección NW. Los reservorios de origen marino somero están distribuidos como fajas de areniscas perpendiculares a la dirección de los valles fluviales. Estos reservorios tienen excelente roca sello encima del C8. Se configuran dos tipos de play el de areniscas en valles fluviales y el de colinas enterradas compuestas de areniscas del Cretácico.

Here I provide critical notes on a multiauthored paper purported to show the absence of a major gap in the Upper Pennsylvanian stratigraphic succession in North America (and, by inference, in northern Western Europe). It is observed that intellectually satisfying explanations for the discontinuities in the North American successions, having recourse to climate-driven alterations, do not take into account that the more continuous succession in northwestern Spain only shows gradual changes in floral composition. Inaccuracies in the use of scientific literature are pointed out. Perhaps, there are few experiences so satisfying as to see complacency disturbed, and to bring a large continental area, like North America, in contact with a wider world. The closing of the ranks, as exemplified by Falcon-Lang et al. (2011), is a very human response to new information from outside brought to bear on a large continental area where the general assumption has been that size guaranteed completeness of record. Of course, not everyone subscribed to this notion. David White’s papers on the Carboniferous of eastern North America show an awareness of certain comparisons with North and Central European successions that imply changes in stratigraphic development attributed to climatic changes, the suddenness of which inspire doubts about the continuity of the stratigraphic record. Darrah (1969, p. 26) mentioned ‘‘a marked floral break’’ in mid-Conemaugh of the Appalachian succession, and Kosanke and Cecil (1996) also observed a floral break. It may be helpful from a historical perspective that the present writer, after a couple of decades involvement with the International Union of Geological Sciences (IUGS) Subcommission on Carboniferous Stratigraphy (as Secretary and Chairman) was engaged for a report (unpublished) analyzing the Carboniferous (Pennsylvanian) stratigraphy of the British, northern French, Belgian, Dutch and West German areas surrounding the southern North Sea. This involved a revision of borehole material in the Netherlands and the examination of borehole samples in West Germany, in close cooperation with H.W.J. van Amerom. A major conclusion was the recognition of a sizeable lowangle unconformity, with physical evidence including secondary reddening, between lower Rotliegend and various different levels of upper Westphalian strata. The size of the unconformity could only be grasped by the recognition that most of Stephanian time was missing. The date of the unpublished report was 1985. This knowledge was available (privately) when P.C. Lyons (U.S. Geological Survey, Reston) organized a joint fieldtrip in the Appalachians in 1995, primarily with the aim to establish the level at which the Westphalian-Stephanian boundary could be recognized in the Appalachian succession. This had been assumed to lie close to the Middle

The structural and depositional history of the Cooper basin in eastern central Australia has revealed that the basin is a mildly compressional structural depression controlled by northwest-trending and northeast-trending pre-Permian basement features. Pronounced pre-Permian compressions are indicated by northeast-trending major structures, the Gidgealpa-Merrimelia-Innamincka and Murteree-Nappacoongee trends. Detailed chronostratigraphic facies analysis, with closely spaced palynological control, of the Patchawarra Formation revealed that two pronounced phases of uplift occurred during the Sakmarian. The major intrabasin highs were rejuvenated during these tectonic events, as documented by crestal unconformities (middle and upper Patchawarra unconformities). Evidence of each event is dominantly tectonic in character, with similar depositional patterns over these highs related to each event. These events are also recognizable in midflank areas and basin margins with contemporaneous deposition in deeper parts of the basin. Results from this research show potential for future hydrocarbon discoveries within structural, stratigraphic, and structural/stratigraphic traps in the Cooper basin. Various trap styles are closely associated with faults, unconformities, and lateral facies changes. Lowside fault closures, onlap plays, and unconformity traps are expected to be well ©Copyright 1997. The American Association of Petroleum Geologists. All rights reserved.1Manuscript received February 22, 1995; revised manuscript received August 6, 1996; final acceptance November 12, 1996. 2Geological Survey of Western Australia, 100 Plain Street, East Perth, WA, Australia 6004 (E-mail: n.apak@dme.wa.gov.au). 3National Centre for Petroleum Geology and Geophysics (NCPGG), University of Adelaide, Thebarton Campus, University of Adelaide, SA 5005, Australia. 4Santos Ltd., 101 Grenfell Street, Adelaide, SA 7000, Australia. The authors wish to thank the Cooper Basin Consortium Group of Companies for permission to publish this paper. The drafting staffs at Santos Ltd. and Geological Survey of Western Australia (GSWA) are sincerely thanked for their efforts in preparing figures.This paper is dedicated to the memory of Bill Stuart.

Pre-Khuff (Silurian-Lower Permian) Sedimentation in the 'A' Structure, Offshore Abu Dhabi. T.H. Hassan, M.A. Al Dabal & M.E. El-Said, Abu Dhabi Marine Operating Co. (ADMA, OPCO), Abu Dhabi, U.A.E. Abstract The objective of this paper is to describe the stratigraphy and sedimentation of the Pre-Khuff Formations in offshore Abu Dhabi. The thickest penetrated section ranges in age from early Permian to late Silurian. To date, only one paper has been published on the Pre-Khuff in this area. The recent deep well drilled in "A" structure in offshore Abu Dhabi has proved the occurrence of one major unconformity in the Pre-Khuff: the Hercynian unconformity underlain by the early Carboniferous?/Devonian clastic sequence. Another unconformity may occur at the top of the Silurian. The Lower Permian sequence is characterised by an interbedding of grey to brown, medium to coarse-grained, well rounded, argillaceous, cross bedded sandstone, silty sandstone, brown to grey pyritic argillaceous sandstone and brown shale, brown to grey, occasionally silty with plant debris. The interpreted Lower Permian is of fluvial origin. The Upper Carboniferous is made up of thick bedded sandstone, fine to medium-grained with subordinate siltstone and shale. The upper Carboniferous is also interpreted to be of fluvial origin with the sandstones, representing sandfilled channels and the siltstones and shales are the overbank deposits. The lower Carboniferous and upper Devonian consists dominantly of fine to very fine-grained sandstone with very minor siltstone and claystone/shale and is interpreted to be largely of deltaic origin. The Devonian (upper to middle) is made up of an interbedding of sandstone, siltstone, shale and claystone. The Devonian was probably deposited in a marine sub-littoral environment. The Silurian is not fully penetrated in the deep well and consists mainly of shales, claystones, silstones with minor thin bedded sandstones. The Silurian is of open marine origin. Introduction The Paleozoic clastic sequences have long been known to be hydrocarbon-bearing in Oman, where a number of fields currently produce from this sedimentary section. More recently, several hydrocarbon discoveries were made in the Paleozoic clastics of Saudi Arabia (McGillivrey and Husseini, 1992). In the Offshore Abu Dhabi (OAD) area, deep drilling started in the late seventies with the objective of investigating the hydrocarbon potential of the late Permian/early Triassic Khuff Formation as the primary target and the Pre-Khuff clastics as a secondary target. The first deep well was drilled on the Umm Shaif structure and only penetrated 177 ft of the Pre-Khuff (Early Permian); a DST across a sandstone unit in this section yielded formation water with salinity of 319,950 ppm (Ali and Silwadi, 1989). A well in the Hair Dalmah structure in western Offshore Abu Dhabi penetrated 803 ft of the Pre-Khuff (Lower Permian & Carboniferous) and produced H2S-free gas from two sandstone intervals. The gas consists primarily of methane but with substantial amounts of CO2 and N2. A number of other wells penetrated varying thicknesses of the Pre-Khuff. In some of these wells, the Pre-Khuff had good gas shows. However, tests failed to produce hydrocarbons due to formation damage and/or mechanical problems. The objective of this paper is to assess & describe the Pre-Khuff penetrated in a deepest well in U.A.E. - here named Well 6 - recently drilled on the "A" structure. Other wells will also be considered in order to allow regional assessment of the Pre-Khuff. Well 6 penetrated 2600 ft of the Pre-Khuff and terminated at a depth of 17926 ft. SS. in the Silurian. The objective of this well was to investigate the hydrocarbon prospects of as greater part of the Pre-Khuff as practically possible. In fact, Well 6 was the first well in the U.A.E. to drill into the Silurian. P. 293

The chronostratigraphy of the Cuu Long Basin, offshore Vietnam to the south of the Mekong Delta, is poorly understood, especially for the Palaeogene succession. This paper utilises a comprehensive biostratigraphic database from 46 exploration wells to establish a high-resolution sequence biostratigraphic framework for the Oligocene and upper Eocene based on the identification of 36 transgressive-regressive depositional cycles. They are shown to be climate-driven and correlate to 406 kyr ‘heartbeat of the Oligocene’ eccentricity cycles. Their occurrence has been rigorously cross checked against seismic across the basin. This re-evaluation requires the repositioning of the Oligo-Miocene boundary in the Cuu Long Basin from the C seismic pick to the BI.1 seismic pick. By integrating sequence biostratigraphic and seismic datasets, the Oligocene can be seen as characterised by two types of depositional sequence. Firstly, thin and repetitive depositional packages, here termed ‘Sequences’ but perhaps better visualised as parasequences, the deposition of which was controlled by cyclically changing climate. Secondly, much thicker packages, each comprising a succession of parasequences separated by unconformities, and which tie to the main seismic divisions within the Oligocene/upper Eocene and were driven by tectonics. The latter are visualised as 3rd order sequences, with the parasequences forming 4th order sequences. Correlating the succession of parasequences to the 406 kyr ‘heartbeat of the Oligocene’ isotope cycles allows accurate ages to be proposed for each parasequence boundary, and in doing so an accurate time framework is established for the basin. The first sediments may have been deposited during the latest middle Eocene (Seismic group F/G) at the same time as or just prior to the initial stage of faulting prior to the opening of the South China (East Vietnam) Sea, with deposition of seismic group E commencing at about 36.6 Ma during the late Eocene. Unconformities reflecting 3rd order sequence boundaries are dated at 33.4 Ma, 29.8 Ma and 27.4 Ma.

The stratigraphic architecture of aeolian sandstones is thought to record signals originating from both autogenic dune behavior and allogenic environmental boundary conditions within which the dune field evolves. Mapping of outcrop-scale surfaces and sets of cross-strata between these surfaces for the Jurassic Page Sandstone near Page, Arizona, USA, demonstrates that the stratigraphic signature of autogenic behavior is captured by variable scour depths and subsequent fillings, whereas the dominant signatures of allogenic boundary conditions are associated with antecedent surface topography and variable water-table elevations. At the study area, the Page Sandstone ranges from 55 to 65 m thick and is separated from the underlying Navajo Sandstone by the J-2 regional unconformity with meters of relief. Thin, climbing sets of cross-strata of the basal Page representing early dune-field accumulations fill J-2 depressions. In contrast, the overlying lower and middle Page consist of cross-strata ranging from less than 1 to 15 meters thick (average 2.44 m), and packaged between outcrop-scale bounding surfaces, though parts of the lower Page are bounded from beneath by the J-2. These bounding surfaces have been previously correlated to highstand deposits of the adjacent Carmel sea and at this site possess up to 13 meters of erosional relief produced by dune scour. Notably absent in packages of cross-strata bounded by these outcrop-scale surfaces are strata of early dune-field accumulations, any interdune deposits, and climbing-dune strata. Instead, these packages preserve a scour-and-fill architecture created by large dunes migrating in a dry, mature, dune field undergoing negligible bed aggradation. Any record of early phases of dune-field construction for the lower and middle Page are interpreted to have been cannibalized by the deepest scours of later, large dunes. Interpretations are independently supported by the relatively large coefficients of variation (cv) in middle Page set thicknesses (cv = 0.90), which are consistent with set production by successive deepest trough scours, the relatively low coefficient of variation for the depression-filling basal Page and lower Page sets consistent with a significant component of bed aggradation in J-2 depressions (cv = 0.64 and 0.49), and the fit of set thickness distributions to established theory. Numerical modeling presented here and more completely in the companion paper demonstrates how this cannibalization of early-phase stratigraphy is an expected outcome of autogenic dune-growth processes, and that early-phase strata can be preserved within antecedent depressions. Relative rise of the inland water table from basin subsidence and changing Carmel sea level forced preservation of 5–6 stacked packages composed of scour-and-fill architecture. Without these allogenic forcings, the Page would be little more than an erosional surface.

The Tarim Craton of NW China hosts abundant hydrocarbon resources within clastic reservoirs characterized by a complex entrapment and fill history. In this paper, we review the processes of hydrocarbon accumulation in typical clastic reservoirs from the literature, and combine this with new research from six hydrocarbon-bearing regions (the Yakela Faulted-Uplift, the southern slope of the Tabei Uplift, the Tazhong Uplift, the northern slope of the Tazhong Uplift, the southern margin of the Bachu Uplift, and volcanic reservoirs) to identify the key controls on hydrocarbon accumulation and distribution in reservoirs of the Tarim Craton. Favorable reservoir–trap configurations exist on structural highs created during the evolution of paleo-uplifts and paleo-slopes in the region, with hydrocarbons accumulating in both structural (fault, salt dome, and thrust-fault anticline) and combined structural-primary stratigraphic traps. Vertical hydrocarbon migration occurred via deep–shallow superposed faults, and (rarely interpreted) fault textures in volcanic conduits. Unconformity surfaces and sand bodies provided pathways for both limited lateral redistribution and significant long-distance (>100 km) migration of hydrocarbons. The prospectivity of upper Paleozoic sandstone facies and paleogeography was controlled by denudation of the paleo-uplifts, and these reservoirs are most likely to host giant oil and gas fields in the region.

The Axmouth to Lyme Regis Undercliff National Nature Reserve contains three highly unusual landslides; the Plateau, Dowlands and Bindon. The failure surface of the Plateau landslide is clearly within the Triassic strata rather than on the Jurassic-Cretaceous unconformity, which is the primary failure surface elsewhere along this coast. The nature of the famous Bindon Landslide of 1839, which formed Goat Island and the Chasm, has been the subject of much debate since it was first described by Buckland and Conybeare in 1840. While it is broadly agreed to be a translational failure, the stratigraphic location of the failure surface is still not agreed. This paper examines the Plateau slip in detail and attempts to apply what can be seen there to Dowlands and Bindon. While Pitts undertook a highly detailed mapping exercise of the landslides throughout the undercliff itself, he did not map the foreshore in any detail. Therefore an Unmanned Aerial Vehicle or drone was used to generate a high resolution photomontage of the foreshore in front of all three landslides to enable detailed mapping of the features contained within it. The results are available on the web. The mapping does not resolve the question of the location of the failure surface of both Dowlands and Bindon but it provides further detail for interpretation.

This paper is the first systematic documentation of Eocene organic-walled dinoflagellate cyst (dinocyst) assemblages from the northwestern shelf of the Tethys. A taxonomic list of the rich and well-preserved dinocyst assemblages found within 28 samples collected at the Adelholzen section in southeastern Germany is presented herein. The sediments accumulated during the Lutetian and Priabonian stages at a ramp-type margin. One-hundred organic-walled dinocyst species were found at the section, which is riddled with unconformities. The composition of the successive dinocyst assemblages reflects the sea-level changes within the depositional area. Areoligera coronata and Cordosphaeridium gracile dominate the assemblage within the glauconite-rich siliciclastic sandstone (lower Adelholzen beds) of the lower transgressive system tract, which spans the calcareous nannoplankton sub-Zones NP15a and NP15b. A hiatus comprising at least c. 1.5 million years truncates these deposits and indicates an erosional episode. Rapid sea-level rise in Biochron NP16 caused a new transgression and the deposition of calcareous marlstone and limestone rich in nummulitids. In this part of the section (middle Adelholzen beds), Homotryblium tenuispinosum is by far the most abundant dinocyst species, and rare but consistent occurrences of Impagidinium spp. suggest a more open marine environment. A lithological shift from limestone to marlstone, a change from nummulitids to discocyclinids, and finally the complete disappearance of larger benthic foraminifera indicates continuous deepening of the environment. An increase in Spiniferites spp., Operculodinium spp., and occurrences of Homotryblium floripes characterize the dinocyst assemblage of this marlstone (upper Adelholzen beds). A 0.5 m thick condensed layer, which consists essentially of iron-coated glauconite grains and scattered phosphate nodules, represents the maximum flooding surface of the transgressive sequence, for which a paleodepth of c. 300 m is assumed. The overlying marlstone (“Stockletten”) of the highstand system tract is punctuated by a hiatus of c. 4.3 million years spanning the entire Bartonian. The stratigraphically important species Rhombodinium longimanum, Rhombodinium perforatum, Distatodinium ellipticum, Nematosphaeropsis labyrinthus and Selenopemphix nephroides have their lowest occurrences in the Priabonian (Zones NP18 and NP19) of the section.

This paper organizes the member lithic unit nomenclature for the San Joaquin basin of California according to “Sequence Stratigraphy” terminology and philosophy of Vail et al (1977)(See Figure 1). Member units are organized by sequences (See Figure 2) that contain a low-stand system and often, a transgressive/high-stand system. The systems respond to relative eustatic sea level changes. Vail et al (1977) deal with unconformities in the sense that they reflect only erosional events and emphasize the unconformity created during relative sea level drops. This paper pays equal attention to both a transgressive sea level change and a relative sea level drop. An updated stratigraphic chart shows sand and shale units which are organized by genetic categories relative to sequences and systems tied into a chronological framework based on California benthic foram stages. Twelve complete sequences are defined. Systems are filled with their specific depositional units. The text provides references for most of the lithic units described. Rock names are identified chronologically and then spatially by working from the Stockton arch fault in the north (See Figure 3), to the south end of the San Joaquin basin. Six diagrammatic cross sections are included to aid in illustrating the geologic relationships.

The Ganos Fault, a part of the Northern strand of the North Anatolian Fault system, is an active- strike slip fault and divides the narrow NW shelf of the Sea of Marmara into two parts near the town of Gaziköy. This paper presents recently collected shallow high-resolution seismic data to discriminate the sedimentary successions, each characterized by distinctive stratigraphic patterns on both sides of the Ganos Fault. Two main units, namely U1 and U2, and three para-sequences (U1a, U1b and U1c) were identified, depending on their internal reflection patterns, accommodation depths as well as the presence of conformity and the unconformity surfaces. The thickness of Unit U1 reaches its maximum at the northern side of the Ganos Fault; it is much thinner to the south. The para-sequences of U1b and U1c have “progradation” and “aggradation to progradation” depositional characters, respectively. This probably implies fluvial deposition controlled by sea- level fluctuations. Unit U1b can only be observed at the northern side of the Ganos Fault, while Unit U1c at the southern side. Units U1a and U1b were deposited during the transgressive system tract, while Unit U1c was deposited during a sea-level fall and/or a lowstand phase marked by an erosional surface. The marine terraces in the study area are shallower than those along the northern shelf of the Sea of Marmara, possibly due to successive tectonic displacements along the Ganos Fault, which also controls the distribution and thickness of the parasequences identified in this study.

Geomechanical assessment of rocks requires knowledge of phenomena that occur under the influence of internal and external factors at a macroscopic or microscopic scale, when rocks are submitted to different actions. To elucidate the quantitative and qualitative geomechanical behavior of rocks, knowing their geological and physical–mechanical characteristics becomes an imperative. Mineralogical, petrographical and chemical analyses provided an opportunity to identify 15 types of igneous rocks (gabbro, diabases, granites, diorites, rhyolites, andesites, and basalts), divided into plutonic and volcanic rocks. In turn, these have been grouped into acidic, neutral (intermediate) and basic magmatites. A new ranking method is proposed, based on considering the rock characteristics as indicators of quantitative assessment, and the grading system, by given points, allowing the rocks framing in admissibility classes. This paper represents a comprehensive geo-mechanical study of the magmatic rocks represented by a wide range of varieties; it is structured into two parts, experimental and interpretation of experimental data, showing the methodology to assess the quality of igneous rocks analyzed, and the results of theoretical and experimental research carried out on the analyzed rock types. Applying this evaluation system allows determining the specific parameters of the rock quality requirements, namely the conformity and unconformity degrees, and more specifically the safety level that these rocks can provide if they are used in the construction field, either as aggregates or as construction materials. The proposed method represents an appropriate tool for assessment and verification of the requirements regarding the quality of rocks used in construction. The last part includes a general classification of analyzed magmatic rocks based on the geomechanical assessment model.

Segmentation of the Guyanas continental margin of South America is inherited from the dual-phase Mesozoic rifting history controlling the first-order post-rift sedimentary architecture. The margin is divided into two segments by a transform marginal plateau (TMP), the Demerara Rise, into the Central and Equatorial Atlantic domains. This paper investigates the heterogeneities in the post-rift sedimentary systems at a mega-regional scale (>1000 km). Re-sampling seven key exploration wells and scientific boreholes provides new data (189 analysed samples) that have been used to build a high-resolution stratigraphic framework using multiple biostratigraphic techniques integrated with organic geochemistry to refine the timing of 10 key stratigraphic surfaces and three megasequences. The results have been used to calibrate the interpretation of a margin-scale two-dimensional seismic reflection dataset, and to build megasequence isochore maps, structural restorations and gross depositional environment maps at key time intervals of the margin evolution. Our findings revise the dating of the basal succession drilled by the A2-1 well, indicating that the oldest post-rift sequence penetrated along the margin is late Tithonian age (previously Callovian). Early Central Atlantic carbonate platform sediments passively infilled subcircular-shaped basement topography controlled by the underlying basement structure of thinned continental crust. Barremian–Aptian rifting in the Equatorial Atlantic, caused folding and thrusting of the Demerara Rise, resulting in major uplift, gravitational margin collapse, transpressional structures and peneplanation of up to 1 km of sediment capped by the regional angular Base Albian Unconformity. Equatorial Atlantic rifting led to margin segmentation and the formation of the TMP, where two major unconformities developed during the intra Late Albian and base Cenomanian. These two unconformities are time synchronous with oceanic crust accretion offshore French Guiana and in the Demerara–Guinea transform, respectively. A marine connection between the Central and Equatorial Atlantic is demonstrated by middle Late Albian times, coinciding with deposition of the organic-rich source rock of the Canje Formation (average total organic carbon 4.21%). The succession is variably truncated by the Middle Campanian Unconformity. Refining the stratigraphic framework within the context of the structural evolution and segmentation of the Guyanas margin impacts the understanding of key petroleum system elements. Supplementary material: Photographs of sandstone petrography thin sections (Fig. S1); calcareous nannofossil plates (Fig. S2); palynology reports for A2-1 and FG2-1 (Fig. S3); taxonomy description of new species; sample table and organic geochemistry results (Table S1); and nannofossil distribution charts (Table S2) are available at https://doi.org/10.6084/m9.figshare.c.5280490

The High-Tatric succession of the Tatra Mountains represents the Tatricum domain of the Central Western Carpathians, which in the Jurassic was located on the southern margin of the incipient and expanding Vahic Ocean – a branch of Western Tethys. This paper describes the various depositional consequences of extensional tectonic activity as it impacted on sedimentation in the High-Tatric succession of the Tatra Mountains during the Early and Middle Jurassic. Evidence of such impacts on depositional style and facies development are present within the Dudziniec, Smolegowa and Krupianka formations, in all the High-Tatric tectonic units. These impacts also include erosional surfaces and sedimentary gaps separating particular formations, commonly associated with minor angular unconformities. The Lower Jurassic, pre-Bajocian, Dudziniec Formation of the Kominy Tylkowe (autochthonous) Unit is developed in mixed carbonate-clastic facies. The occurrence and proportion of sand-dominated and carbonate-dominated facies, as well as their thickness differences, were controlled by syndepositional tilt-block tectonics, taking place both in depositional and in neighbouring source areas. The Smolegowa and Krupianka formations (Bajocian–Bathonian) occur in all High-Tatric tectonic units, but in the Czerwone Wierchy and Giewont units they are represented mainly by laterally discontinuous bodies of crinoidal limestone of very limited thickness. The preservation of these deposits only in some areas, as well as their thickness reductions, are effects of differentiated subsidence and uplift of isolated blocks taking place in an extensional regime. Moreover, the Krupianka Formation abounds in condensed facies with ferruginous crusts and stromatolites – a feature characteristic of rapidly drowning ocean margins. Deposits of the Dudziniec, Smolegowa and Krupianka formations are also preserved as infills of extensive systems of neptunian dykes penetrating mainly the Triassic substrate, which is yet another classic symptom of synsedimentary extension. The dominant influence of tectonics on sedimentary development ceased with the onset of deposition of the Raptawicka Turnia Formation in the Callovian.

The aim of this paper is to elucidate the impact of unconformity surfaces on diagenetic alterations and their influence on reservoir quality evolution of the siliciclastic sequence. Samples were collected from the sandstones above and below two major unconformity surfaces in the Paleozoic successions of Saudi Arabia, including the Permo-Carboniferous Pre-Unayzah unconformity and the Ordovician Pre-Sarah unconformity. The main diagenetic alterations include the formation of kaolinite, calcite, and Fe-Ti oxide cements. The Pre-Unayzah unconformity shows an overall trend of increasing kaolinite towards the sequence boundary with severe dissolution of feldspar and mica which suggests a humid-wet climate that prevailed during the Permo-Carboniferous time. The general trend of increasing authigenic kaolinite abundance approaching the unconformity is observed for non-marine and marine successions. The reservoir quality of the overlying Unayzah Formation is negatively impacted by the occurrence of authigenic kaolinite owing to reduced porosity and permeability as well as causing potential “fines-migration” issues. The Ordovician Pre-Sarah unconformity, in contrast, shows no distinct trend in mineral leaching or kaolinite abundance which is consistent with the presumed cold-dry glacial environment during deposition of the Sarah sandstones. However, calcite- and ferruginous-cemented zones found along the Ordovician Pre-Sarah unconformity surface may act as localized seals for fluid flow within the sandstone. Such seals can adversely impact aquifer and reservoir compartmentalization. This study provides a better understanding of the vertical distribution, origin and timing of kaolinitization, and its impact to the prediction of reservoir quality along and below unconformities.

MNK Skull is one of the most significant archaeological sites in Olduvai Gorge, particularly due to the previous discovery of human fossils referred to in the paper where the Homo habilis taxon was originally defined. An important archaeological assemblage is contained in the same horizon as the hominin fossils, constituting the last evidence of both Homo habilis remains and handaxe-free tool kits in the Olduvai Gorge sequence. Our excavations at the site are the first to be conducted since the original work in the 1960s, and sought to refine the archaeological context wherein the Homo habilis remains were discovered. Chronostratigraphic results place the MNK Skull sequence in Middle Bed II prior to deposition of Tuff IIB. The assemblage was deposited near the shoreline, as Palaeolake Olduvai withdrew into the basinal depocentre, and fossils and stone tools were subjected to significant post-depositional processes. The assemblage was affected by mudflow deposits that buried and preserved the assemblage but also entrained surficial bone and lithic elements into the flow. Rather than an occupation site as originally interpreted, the assemblage is better understood as a background deposit, possibly accumulated on an unconformity surface over a long period of time. The stone tool assemblage is typical of the Oldowan, with no technological elements announcing the appearance of the Acheulean, which is well attested to across the Olduvai sequence in post-Tuff IIB times. Our results highlight that, with an approximate age of circa 1.67 Ma, MNK Skull stands as a key site to understand the late Oldowan and the disappearance of Homo habilis in East Africa.

Correlation of the Permian-Triassic boundary (P-T) is impeded, in part, by the lack of biostratigraphic correlations between tethyan and boreal settings and the presumed unconformity at many P-T sections in the world. Sequence stratigraphie and biostratigraphic data were collected from six sections of the basal part of the Blind Fiord Formation (Confederation Point Member) on northwestern Ellesmere and Axel Heiberg islands; sequence biostratigraphic data are presented in this paper for only the Griesbach Creek and South Otto Fiord sections. These data address some of these impediments, and allow comparisons to be made with the possible Global Stratotype Section and Point (GSSP) at Meishan, China.

In the present paper, sequence stratigraphy and microfacies of the Dariyan Formation in the two sections of the Gadvan and Zana Mountains located were studied in NE and NW of Shiraz (Fars province, SW Iran). An area of 429.5 m of the Dariyan Formation sediments was studied through 187 thin sections. Also, the index microfacies were closely identified. Generally, index microfacies of the studied thin section were mudstone, wackestone, packstone, and grainstone microfacies. Received paleontological data confirm Aptian–lower Albian age of the Dariyan Formation. According to the lithostratigraphic aspect, the lower contact of Dariyan Formation with the Gadvan Formation in the Gadvan Mountain was described as a gradual type and in Zana Mountain; disconformity was found due to the sign of water withdrawal. Given the upper contact of the Dariyan Formation concerning the formation percentage, contact disconformity was observed due to the changes in the Allochem element and the situation of the entity from water and also according to the high percentage of iron nodules and Gluconate. According to the sequence, stratigraphic studies in the section of Gadvan Mountain, the lower border of the Dariyan Formation with Gadvan Formation was in the gradual form [type 2 Sequence Boundary (SB2)] and there was a disconformity in the upper border of this formation with Kazhdumi Formation [type 1 Sequence Boundary (SB1)]. Dariyan Formation included the system tracts (transgressive system tract, early highstand system tract, and late highstand system tract). There was a disconformity in its lower of the Gadvan Formation and disconformity in its upper boundary with the lower of the part Kazhdumi Formation (SB1) and it included the system tracts (highstand system tract, transgressive system tract, and lowstand system tract). Overall, lap sequence grade3 was seen in the two sections.

New sensors aboard recently launched satellites have induced the development of several measures aimed to indicate the presence of many materials over the Earth. Karsts are places rich in carbonate rocks and present large economic and environmental importance. This paper aimed at assessing the performance and consistency of different carbonate estimators derived from orbital images acquired over a controlled karst area. Experiments were assisted by a multi-scaled reference data built through a high spatial resolution Unmanned Aerial Vehicle (UAV) image acquired over the selected area. Results show a considerable unconformity among selected measures and better performance presented by indices exploiting measures along visible and infrared spectral regions.