Search

Investigations at Pepper Arden Bottoms, a lake basin site on the interfluve between the rivers Tees and Swale in northeast England, have recovered lithostratigraphical, pollen and plant macrofossil sequences which have allowed the reconstruction of sedimentary and vegetation history from the Lateglacial Interstadial to the post- Ulmus Decline mid-Holocene. Although the calcareous nature of the sediment and lack of terrestrial plant macrofossils precluded radiocarbon dating of sediments pre-dating the Ulmus Decline, pollen analyses showed sediment accumulation from the middle of the Lateglacial Interstadial, with the lake catchment remaining poorly vegetated until the Holocene, with low values for woody taxa, and grasses and sedges dominant. The late Interstadial cold phase GI-1b is present in the pollen stratigraphy, with a major reduction in Betula frequencies, replaced by Juniperus , and an increase in cold-tolerant herbs, mainly grasses and sedges. Microcharcoal frequencies are consistently substantial throughout the Lateglacial levels, probably indicating a natural fire regime, but are absent from the Holocene, suggesting little Mesolithic or Neolithic activity nearby, which is confirmed by a lack of pollen indicators of disturbance. The Lateglacial (Loch Lomond) Stadial is entirely dominated by Cyperaceae and Poaceae pollen, with very few trees and shrubs. The successive migration of postglacial thermophilous trees is recorded in the Holocene and possible effects of the Preboreal Oscillation and the 8.2 ka BP cold events are recognised. An Ulmus Decline occurs near the top of the profile, after which the assemblage is dominated by Alnus as the lake became terrestrialised and was occupied by fen and then alder carr. The very open Lateglacial vegetation adds this site to a northern group in northeast England with poor Lateglacial woodland development, in contrast to sites to the south, in North Yorkshire, where Lateglacial Betula woodland was much better established. [ABSTRACT FROM AUTHOR]

Lithological cycles with a repetitive pattern of sandstone overlain by limestone or shale comprise the middle Minnelusa Formation in the Black Hills region, USA. At least eight lithological cycles were observed at Boulder Canyon Road (BCR), eight at Vanocker Canyon Road (VCR) and four at Hot Brook Canyon (HBC). These rocks were deposited in a nearshore to offshore marine environment, and the shale and limestone intervals at the top of these cycles yielded conodonts. Five biostratigraphically distinct Middle to Upper Pennsylvanian conodont faunas were recovered from these marine units. An upper Desmoinesian assemblage was recovered from VCR cycle 1. Two Missourian assemblages were recovered, one indicative of the Idiognathodus cancellosus Zone from VCR cycle 3 and the other indicative of the Streptognathodus gracilis Zone from VCR cycle 6. Two Virgilian assemblages were recovered, one indicative of the Heckelina simulator Zone from VCR cycle 7, VCR cycle 8 and HBC cycle 2 and the other indicative of the lower part of the "Streptognathodus" group 4 virgilicus Zone from HBC cycle 3. Two conodont biofacies were recognized within the middle Minnelusa, the low energy, offshore, Idiognathodontidae-Idioprioniodus biofacies and the higher energy, nearshore Idiognathodontidae-Hindeodus biofacies. [ABSTRACT FROM AUTHOR]

Cuttings and logs from four boreholes in the Mediterranean Sea, offshore the northwestern side of the Nile Delta, Egypt (30°00'–30°24' N, 31°18'–31°30' E), were examined lithostratigraphically, biostratigraphically and paleoenvironmentally. Five planktonic foraminiferal zones were determined assigning the studied boreholes to be late Miocene-Early Pliocene in age. These zones are Globorotalia mediteraneaneana Zone Sphaeroidinellopsis seminulina Zone, Globorotalia margaritae margaritae Zone, Globorotalia puncticulata Zone and Globorotalia inflate. Studying benthonic foraminifera indicated a general shallowing upward trend in all boreholes and tracking the distribution of the foraminiferal assemblages by counting the total number of foraminifera and planktic/benthic ratios provide a history of the progression of deltaic facies with secondary cycles of sea-level change. [ABSTRACT FROM AUTHOR]

Chandarpur–Raipur sequence in Chattisgarh basin is represented as siliciclastic-dominated Chandarpur Group and carbonate-dominated Raipur Group. Here, we introduce 'Devsagar Sandstone Member', the only sandstone-dominated member in the carbonate-dominated Charmuria Formation of Raipur Group, that marks a period of rapid siliciclastic deposition identifying a phase of forced regression between two carbonate platforms of Charmuria–Chandi formations, thereby indicating a drastic change in palaeogeography of Raipur Group. In addition, this study revised the litho-stratigraphy of Mesoproterozoic Chattisgarh basin to clarify the confusion raised due to the existence of different stratigraphy in different basinal parts and different nomenclature for the same lithologic units. Detailed geological mapping with facies analysis in the eastern part of the basin manifests the entire basin-fill succession as part of the Chattisgarh basin itself, rather than sub-dividing some parts as Baradwar sub-basin and Singhora proto-basin. Singhora Group deposited in Singhora proto-basin has already been presented as equivalent of Chandarpur Group. Here we propose, Bamandihi–Saradih–Raigarh formations of Raipur Group in Baradwar sub-basin, as lateral equivalent of Gunderdehi–Chandi–Tarenga formations of Raipur Group and Sarnadih–Nandeli formations of Kharsiya Group in Chattisgarh basin. Inferred depositional environment and tectonic setting of Chattisgarh basin support the lithostratigraphic revision, which will help in basin analysis as well as intrabasinal–interbasinal correlation in regional and global contexts. Research highlights: Devsagar Sandstone Member introduced as the only sandstone-dominated member in carbonate-dominated Charmuria Formation of Raipur Group. Devsagar Sandstone Member represents a tidal shelf in between two carbonate ramp platforms (Charmuria and Chandi), marking a period of rapid siliciclastic deposition and the only phase of forced regression in overall sea-level rising scenario of the carbonate-dominated Raipur Group. Stratigraphy of Chattisgarh basin revised. The entire Chattisgarh succession is represented as deposits of Chattisgarh basin only, without further subdivision into sub-basin and/or proto-basin, thus resolving the stratigraphic and basinal correlation problem. [ABSTRACT FROM AUTHOR]

The contribution of sediment transport and accumulation to soil formation was investigated in an area characterized by continental sedimentary activity since the Late Pleistocene. The area was the north-eastern portion of the large Quaternary graben represented by the Campania Plain, which is rimmed to the north–east–south by the Mesozoic carbonate Apennine nappes. The plain was filled mainly by products generated by eruptions from the Phlegrean Fields, which were also distributed on the slopes bordering the plain and remobilized toward the adjacent surfaces. Five sites were selected in the area in question. They were studied using morphological features and pertinent characteristics of the mineral soil fraction >2.0 mm, such as their volume and lithological description. Soils were compared to selected lithostratigraphic sequences characterizing the studied area, which were collected from literature and reinterpreted in pedological keys. The results showed that soils derived from the emplacement of Phlegrean primary volcanic materials, such as Campania Ignimbrite (~39–40 ky B.P.) and Neapolitan Yellow Tuff (~15 ky B.P.), with the related weathering products, and from volcanic materials reworked and transported by alluvial/colluvial episodes. The latter formed contrasting soil horizons which, differing in both rock fragment content and lithological composition, testified to the presence of lithological discontinuities. The formation of the horizons in question interrupted the genetic sequence derived from the in situ alteration of the volcanic substrata, suggesting that processes of transport and redistribution of sediments from the adjacent mountain slopes contributed to soil formation. The comparison of the pedostratigraphies with the lithostratigraphic sequences indicated a strong relation between geomorphic and pedogenetic events. [ABSTRACT FROM AUTHOR]

The shallow marine carbonate strata of the Lower Jurassic Sarki Formation are exposed at the northeastern limb of the Handreen and Spibalies anticlines in Rawanduz area, Kurdistan region, northeastern Iraq. The Sarki Formation is made up of light grey dolomitic limestone, dark grey dolomite, brecciated dolomite, grey brecciated dolomitic limestone, and thinbedded dark grey marlstone. Based on the crystal size and geometry, five dolomite textures are identified, Dolomite-1: fine crystalline, planar-s (subhedral); Dolomite-2: fine to medium crystalline planar-e (euhedral); Dolomite-3: medium to coarse, planar-e (euhedral) to planar-s (subhedral) dolomites; Dolomite-4: coarse crystalline, planar-s (subhedral) to nonplanar-a (anhedral) dolomites; Dolomite-5: planar (subhedral) pore-filling dolomite cement. The Sarki dolomites have depleted values of d 18O from Dolomite-1 to Dolomite-5. The notable decrease in d 18O is due to an increase in the temperature of the dolomitization fluid relative to the increase of burial depth. Fine to medium crystalline dolomite is associated with the early stages of dolomitization, whereas coarse crystalline dolomite is associated with the late diagenetic stage. The petrographic study, that is, stable carbon and oxygen isotope analysis, suggests a sabkha and mixing zone models of the Sarki dolomites. [ABSTRACT FROM AUTHOR]

Lithostratigraphy of the Yongtan Group is newly established based on detailed sedimentologic and stratigraphic studies on recently exposed, less deformed, relatively continuous outcrops and comprehensive review of previous studies, mainly focusing on the Jeongseon Formation which occupies most of the group spatially and stratigraphically. The Yongtan Group is divided into the Jeongseon, Haengmae, and Hoedongri formations in ascending order, and all the units are assigned to the Ordovician. The Jeongseon Formation is divided into three members based on lithology. Eleven sedimentary facies are recognized in the Jeongseon Formation and organized into five facies associations (FAs), FA1 (tidal flat), FA2 (inner-ramp), FA3 (shoal), FA4 (mid-ramp), and FA5 (ramp-slope to outer-ramp). The formation is interpreted to have been deposited on a homoclinal ramp. The Yongtan Group is divided into two supersequences separated by type 1 sequence boundary and the lower and middle members of the Jeongseon Formation belong to Supersequence I and the Upper Member to Supersequence II which includes the Haengmae and Hoedongri formations. The relative sea-level curve inferred from sequence stratigraphic analysis suggests that the formation evolved through two depositional stages in accordance with second-order sea-level changes separated by the boundary between the Sauk and Tippecanoe sequence, and the curve is greatly similar to that of the Taebaek and Yeongwol groups. The southeastward thickening of FA3 and northwestward prevalence of shale-rich facies suggest that topographic highs and lows were present in the Taebaeksan Basin and a slope might have developed along the carbonate platform during the early stage of deposition. The correlation and lateral thickness variation of the facies associations additionally suggest that the basin was deeper toward the northwestern part of the Jeongseon area. The deepening is likely attributed to the weakening of the productivity of the carbonate factory during the early Ordovician. [ABSTRACT FROM AUTHOR]

The atypical Tien Shan and Carpathians flysch is compared and correlated to recognize the local (regional) and general (inter-regional) peculiarities of its structure and place in the evolution of mobile belts. The objects of study include the Upper Carboniferous flysch of the Khanaka Syncline (Tien Shan) and Upper Eocene flysch of the Podhale Syncline (Carpathians). Flysch of the Khanaka and Podhale synclines is compared for the first time using the historical–geological analysis based on the study of lithostratigraphy, tectonic structure, and geodynamic setting of objects. The objects of study belong to different mobile belts and tectonic cycles, but they are similar in internal structure and tectonic setting atypical of flysch and exhibit some features atypical of flysch: the formation on a quasiplatform basement, a significant volume of conglomerates, a simple configuration of geological bodies, an absence of internal deformations, and a narrow temporal period of formation. It follows from the comparative analysis that the studied objects belong to a specific flysch type that we suggest naming the final flysch of rear blocks of the mobile belts, whose formation reflects the specific geodynamic evolution of the Hercynian and Alpine mobile belts. [ABSTRACT FROM AUTHOR]

Provenance and stratigraphic correlations across the exposed Eocene-Miocene sedimentary sequences of southern Nigeria that exhibit similar lithologies and are biostratigraphically-barren have been carried out. Heavy mineral assemblages in the 63–250 μm sand fractions of 43 sediment samples across the sedimentary sequences were assessed via wet-sieving, centrifugation, and polarizing petrologic microscopic analyses. Opaque, apatite, garnet, kyanite, zircon, rutile, staurolite, tourmaline, and epidote heavy mineral species were identified and point-counted. Electron microprobe analysis was carried out on the garnet-heavy mineral species using a CAMEBAX Cameca electron microprobe with a link four-wavelength energy-dispersive mode spectrometer analyser. This study revealed the existence of three heavy mineral associations and three lithostratigraphic formations. Heavy mineral association A is characterized by assemblages of kyanite, zircon, and rutile grains. The occurrence of kyanite in this association indicates derivation from schist and gneissic rocks. Zircon grains indicate sialic to intermediate igneous rocks derivatives that has sustained several periods of recycling, and redeposition. The occurrence of rutile indicates metamafic and metapelitic rocks with other sources being minor. Heavy mineral association B is characterized by assemblages of staurolite, opaque materials, garnet, and epidote. The presence of opaque grains indicates a shorter distance of transport possibly from proximity. The occurrence of staurolite grains indicates metamorphic and magmatic rock derivatives from schists, slates, and gneisses. Garnets are predominantly derived from high-grade metamorphic rock (granulite-facies) metasediments and charnockites and lower grade (amphibolite-facies) metasedimentary rocks and granitoids. An epidote is a metamorphosed igneous rock derived from the adjoining radix. Heavy mineral association C is characterized by assemblages of tourmaline and apatite. Tourmaline grains indicate pneumatolytic rocks, pegmatite, schist, gneisses, and marble source rocks. Apatite indicates derivation from local outcrops exposed during the Benue Trough uplift. The occurrence of apatite and its assemblages with tourmaline indicate felsic igneous rocks with ultramafic compositions, metamorphic rocks with low to high grades and derivatives of diverse protolith compositions. The exposed Eocene-Miocene sedimentary deposits that exhibit similar lithologies and biodata are relatively lacking. They were differentiated into three different lithostratigraphic formations and correlated. These analyses were performed using heavy mineral characterization, optical property, garnet geochemical composition, and inference supported by multivariate statistical analyses. Variations in the numerical values of unstable heavy minerals reveal dissolution and overgrowth through acidic groundwater, changes in climatic conditions, and relative eustatic sea-level changes. This study was able to derive information and demonstrate, differentiate, and validated the significance of resolving provenance and stratigraphic uncertainties using a heavy mineral and garnet geochemical-based approach. These findings were supported by multivariate statistical analyses. This methodology will help to facilitate the prediction and correlation of hydrocarbon reservoirs and source rocks in sedimentary basins globally.

This paper presents a 1:50,000 scale map and lithostratigraphic synthesis of the Huajuapan region, which has one of Mexico's most complete geological records. The region represents a critical area for understanding the marine flooding process after the breakup of Pangea. This process formed small extensional basins, such as the Ayuquila basin, and dismantled a primary fluvial system that drained the ancient central Pacific slope of Pangea. In the Huajuapan region, the Ayuquila basin developed in a tectonic SSE–NNW extension framework that prevailed from the Middle Jurassic to the Turonian. In its beginnings, this basin developed a thick siliciclastic fluvial deposit during the Middle Jurassic. Later, during the Late Jurassic, although with local unconformities, the deposition of marine successions began. Marine deposits continued throughout the Cretaceous. During the Cenozoic, continental conditions were re-established with clastic-evaporite successions and volcanic activity.

Fifty groundwater samples were collected from the Oligocene sand and Middle Eocene limestone aquifers and analyzed for major ions and stable isotopes. Aquifer sediment samples were examined to determine hydraulic properties, and sixty-six well logs were investigated to understand the subsurface geology. The study reveals that lithofacies, mineral composition, and geologic structures significantly influence groundwater quality and behavior. Karst features in the Middle Eocene limestone aquifer create subsurface caves, leading to challenges such as abrupt salinization and well failure. In the Oligocene aquifer, groundwater is predominantly of the sodium chloride type. In the Middle Eocene aquifer, 80 % of samples are sodium chloride, with variations of sodium bicarbonate (10 %) and sodium sulfate (10 %) types. Remote sensing from 2013 to 2021 shows significant agricultural expansion, with vegetation increasing by over 227 km². This growth, driven by large agricultural projects, has led to substantial groundwater consumption, resulting in a 5-meter decline in water levels within just one year (from 2020 to 2021). The over-extraction poses a risk to the aquifers, threatening long-term sustainability. Understanding the region's geology is crucial for mitigating these issues and ensuring sustainable groundwater management.

The Silurian palaeontology and stratigraphy of the Qinghai-Tibetan Plateau have been studied for more than 100 years. With the launch of the Second Tibetan Plateau Scientific Expedition and Research, it is necessary to update the summaries of the Silurian stratigraphy and fossil assemblages of the Qinghai-Tibetan Plateau and their correlation with its surrounding areas. In this study, we have selected 33 sections from the Qinghai-Tibetan Plateau and its surroundings areas, summarised the available data in terms of stratigraphic regionalisation, lithostratigraphy, chronostratigraphy, and biostratigraphy, and divided the study area into four stratigraphic provinces: the Xizang-Western Yunnan-Western Sichuan Province, the Kunlun-Qilian Province, the South China Province, and the Tarim Province. In general, the Silurian strata in the Qinghai-Tibetan Plateau is more complete than those in other areas of China. Palaeobiogeographical studies of the vertebrate faunas, sporomorph assemblages, and brachiopod faunas of the study area indicate a closer geographical relationship between the South China, Tarim, and Indochina palaeoplates, than previously considered. Compared with the surrounding areas where Silurian strata have been extensively studied, the study of Silurian strata in the main part of the Qinghai-Tibetan Plateau is still in the preliminary stage. In the future, it is necessary to conduct research on the age, distribution, and resource potential of basal Silurian black shales to provide new directions for shale gas exploration and development in China. The shallow marine strata of the middle to upper Silurian require further subdivision. Considering that the Silurian System in the Qinghai-Tibetan Plateau is more complete, it has the potential to supplement and improve the study of the carbon isotope stratigraphy of the Silurian in China. [ABSTRACT FROM AUTHOR]

The Ordovician rocks on the Qinghai-Tibetan Plateau represent the oldest non-metamorphic strata, and are critical to understanding the history of regional geology and biotic evolution of the entire plateau. Strata of Floian, Darriwilian, Sandbian, Katian and Hirnantian are represented in the plateau with a hiatus of variable duration occurring underneath the basal Ordovician across the area. Five stratigraphical regions, including the Himalaya, Gangdise-Zayu, Qiangtang-Qamdo, Songpan-Garze, and Karakoram-Kunlun-Altun, are differentiated for the Ordovician strata, which are correlated with their equivalents in the Sibumasu, Indochina, Qaidam-Qilian, Tarim-Tianshan, and the Yangtze (western margin) stratigraphical regions. On the Qinghai-Tibetan Plateau, graptolites, conodonts, and cephalopods are the most common and useful fossils for the Ordovician biostratigraphy. The Ordovician biotas of the Qinghai-Tibetan Plateau bear some distinguishable palaeobiogeographical signatures, among which the cephalopods are characterized by the flourishing actinocerids of North China affinity in the Early-Middle Ordovician, and by the thriving lituitids and orthocerids of South China affinity in the Middle-Late Ordovician. Fossil occurrences and their palaeobiogeographical evolution provide critical evidence bearing on the reconstruction of the geological history of the Qinghai-Tibetan Plateau and surrounding terranes in northeastern peri-Gondwana. The stratigraphical successions of the Cambrian-Ordovician transition in the Himalaya and Lhasa and nearby Sibumasu terranes were significantly affected by the Kurgiakh Orogeny, which resulted in the extensive unconformity between the Ordovician and the underlying rocks in most areas of the Qinghai-Tibetan Plateau. In southern Xizang, a warm-water biota of Middle Ordovician age was recovered from oolitic limestones, suggesting a likely palaeogeographical location in low-latitudes near the equator. In the Himalaya and Sibumasu regions, the Upper Ordovician was typified by the occurrence of red carbonates with distinctive reticulate structures, which are correlative to their equivalents in the Yangtze region of South China, and might be deposited under similar geological conditions. The global end-Ordovician glaciation and sea-level drop likely caused the wide absence of late Katian strata in western Yunnan of China and the Shan State of Myanma, and may have also affected deposition in the Xainza and Nyalam areas of the Qinghai-Tibetan Plateau during this time interval. [ABSTRACT FROM AUTHOR]

Rocks of the Qinghai-Tibetan Plateau (QTP) host abundant Triassic fossils. So far, the well established marine fossil sequences based on ammonoids, conodonts, bivalves, brachiopods, radiolarians, and terrestrial spora-pollen sequence have become standard for biostratigraphic correlation of the QTP. For much of Triassic time, the QTP occupied a marine setting as suggested by the dominance of marine deposits. The main sedimentary types represented in the Triassic successions include littoral to shallow marine clastic rocks, shallow marine carbonate platform carbonates, bathyal to abyssal slope carbonates intercalated with clastic and siliceous deposits, coal-bearing clastic strata contained within paralic facies deposits, and littoral and terrestrial volcaniclastic rocks. These deposits are organized into four stages in ascending order: (1) Early Triassic deposits that record marine transgression, including extensive shallow marine carbonate platform strata. (2) Middle Triassic Ladinian to Late Triassic Carnian deposits, including thin-bedded limestone, fine clastics, and siliceous rocks, that accumulated at greater depths than underlying Early Triassic strata and reflect the peak of the transgression. Magmatic activity appears to have occurred in some areas during this stage. (3) Late Triassic Norian deposits that record the onset of marine regression as suggested by the widespread occurrence of platform carbonates. It is noteworthy that stage 3 deposits of the Qin-Qi-Kun area in the northernmost region of the QPT is dominated by terrestrial strata and displays evidence of local erosion. (4) Late Triassic Rhaetian littoral and shallow marine clastic and coal-bearing deposits that preserve the record of continued marine regression continued. The Indus-Yarlungzangbo Suture Zone (IYSZ) appears to have been the rifting axis during Triassic time as suggested by sedimentary facies trends that reflect deepening to south and north. Thus, the Himalaya Block to the south of the IYSZ was part of the passive margin of Gondwana whereas the north side of the IYSZ, including the Gangdis (or Lhasa) and South Qiangtang blocks, belonged to the passive margin of Eurasia. The similarity of rocks of the Bangongco-Nujiang Suture Zone (BNSZ) to the north of the IYSZ with those of the Gangdis Block to the south and the South Qiangtang Block to the north does not support the contention that the BNSZ was a rift axis during Triassic time. Results of palaeobiological research also suggest that the IYSZ rather than BNSZ was a biogeographic boundary during the Triassic. Early and Middle Triassic break-up of Pangea was accompanied on the QTP by rifting along the IYSZ. The expression of crustal shortening induced by the Indosinian Orogeny on the QTP is largely a change of sedimentary facies induced by Late Triassic uplift. Deposits of the Gangdis to South Qiangtang regions of the QTP record a transition from shallow marine carbonate platform deposits to littoral and paralic coal-bearing strata. Moreover, the stratigraphic succession of the Qin-Qi-Kun area preserves a transition from littoral clastic deposits to terrestrial facies and local erosion. [ABSTRACT FROM AUTHOR]

During the Carboniferous Period, the Qinghai-Tibetan Plateau and its surrounding areas were located in quite different paleogeographic positions with various sedimentary and biological types. It is important to systematically compile and summarize the Carboniferous strata and biotas of the Qinghai-Tibetan Plateau and its surrounding areas, to establish an integrated stratigraphic framework for correlation, and to reconstruct the paleogeography for correctly understanding the breakup of the Gondwana Continent and the evolution of the Paleo-Tethys Ocean in the Late Paleozoic. The Carboniferous of the Qinghai-Tibetan Plateau and its surrounding areas can be subdivided into the Gondwanan, Cimmerian, and Tethyan types. The Gondwanan-type Carboniferous are distributed in the North Himalayan, Kangmar-Lhunze, and Zanda-Zumba regions of the South Tibet Subprovince and northern India-Pakistan Area, where only the Mississippian is developed and the biota is of Gondwanan affinity. The Cimmerian-type Carboniferous, which are found in the Baoshan, Tengchong, Coqen-Xainza, Lhasa-Zayu, Nagqu-Biru, and South Qiangtang regions, as well as Shan-Thai and South Afghanistan-Pamir areas, also represent only the Mississippian strata, but their biota is characterized by mixed characters of European, South China, Australian, and North American types. The Tethyan-type Carboniferous are distributed in the Tanggula Mountains, Hoh Xil-Bayanhar, Chamdo-Hengduanshan, Tiekelike, West Kunlun, Karakorum, East Kunlun-Central Qinling, and Qilian regions, where the Carboniferous succession is well developed, and the biota is of warm-water Tethyan affinity. The biostratigraphical correlation of the Gond-wanan-type and Cimmerian-type Carboniferous is based mainly on conodonts and additionally on brachiopods and rugose corals. The Mississippian of the Tethyan-type Carboniferous is correlated mainly by using rugose corals and brachiopods, whereas in the Pennsylvanian foraminifera (fusuline) and conodonts are regarded as primary fossil groups, subordinated by rugose corals and brachiopods. Adhering to the International standard chronostratigraphy of the Carboniferous, we have reconstructed a framework of the litho- and biostratigraphic subdivision and correlation of the Qinghai-Tibetan Plateau and its surrounding areas. Further studies should focus on isotope geochronology, geochemistry, paleoclimates, and paleoenvironments of the Carboniferous in the Qinghai-Tibetan Plateau and its surrounding areas. [ABSTRACT FROM AUTHOR]

Rakhi Nala (Gorge) section of Eastern Sulaiman Range, Pakistan hosts world-class geological sections from the Cretaceous to the Recent. Here, Late Eocene Kirthar Formation is having a conformable lower contact with the greenish grey massive shale of the Baska Member of the Ghazij Formation. The rusty beds of the Oligocene Chitarwatta Formation are overlying the Kirthar Formation. To understand the detailed microfacies and depositional setting, detailed fieldwork was carried out in the Kirthar Formation in the outer Sulaiman Foldbelt. The late Eocene Kirthar Formation includes Habib Rahi Limestone, Domanda Shale, Pirkoh Limestone, and Drazinda Shale. Domanda Shale Member was deposited in transgression before Habib Rahi Limestone Member was deposited. It was followed up by the deposition of the second member Pirkoh Limestone and Marl Member. Habib Rahi Limestone, Pirkoh Limestone, and Marl Member have catch-up-to-keep-up deposition with rise and fall of sea level. Some facies of Drazinda and Domanda Shales represent a restricted setting supported by the presence of gypsum, while deep sea facies were also identified. This study will provide a guide for evaluating sedimentological concepts and understanding complex facies in highly oil and gas-prone stratigraphic sequences especially in the Eastern Tethys Region. [ABSTRACT FROM AUTHOR]

A new biostratigraphic biozonation for the Paleocene to Late Oligocene succession of the onshore Niger Delta has been developed based on the identification of significant stratigraphic dinoflagellate cyst events. This study is aimed at applying rarely used dinoflagellate cysts events in dating, correlating and inferring the paleoenvironment of penetrated sedimentary successions in the studied area. Palynological processing and analysis were carried out on two hundred and twenty ditch cutting samples recovered from two exploration wells (BN-1 and FJ-1) located in the Greater Ughelli and Northern Depobelts of the onshore Niger Delta respectively. Abundant and diverse dinoflagellate cysts recovered included marker Peridinales species Apectodinium sp., Palaeocystodinium australinum, and Gonyaulacales such as Areosphaeridium arcuatum, Cordosphaeridium gracile, Tuberculodinium vancampoae, Polysphaeridium zoharyi and Hystrichokolpoma rigaudiae. Three dinoflagellate cysts Palynological Zones - DPZ 100 (Early to Late Paleocene), DPZ 200 (Early to Late Eocene) and DPZ 300 (Late Eocene to Late Oligocene) are proposed herein. The biozones were subdivided into ten subzones based on the Top occurrence, Quantitative Tops and Quantitative base as well as ACME events of dinoflagellate cysts marker taxa which are used to date the rock sequence to be Paleocene to Late Oligocene. Abundant and diverse shallow outer neritic to inner neritic dinoflagellate cysts are identified from thick grey soft shales at the lower section of the studied wells. The upper section show significant reduction in dinocysts assemblage dominated by inner (coastal) neritic taxa. This dinocysts occurrence and distribution suggests inner (coastal) neritic paleoenvironment at the upper sections which deepened into shallow outer neritic conditions at the lower intervals of the studied wells. The thick brown to grey shales at the lower section and the medium to fine grained, moderately well sorted sandstone interbeds at the middle section of the studied wells are interpreted to be potential source and reservoir rocks respectively. These datasets are useful for correlating possible hydrocarbon source rocks and potential reservoir carrier beds in the Gulf of Guinea.

The contribution of sediment transport and accumulation to soil formation was investigated in an area characterized by continental sedimentary activity since the Late Pleistocene. The area was the north-eastern portion of the large Quaternary graben represented by the Campania Plain, which is rimmed to the north–east–south by the Mesozoic carbonate Apennine nappes. The plain was filled mainly by products generated by eruptions from the Phlegrean Fields, which were also distributed on the slopes bordering the plain and remobilized toward the adjacent surfaces. Five sites were selected in the area in question. They were studied using morphological features and pertinent characteristics of the mineral soil fraction >2.0 mm, such as their volume and lithological description. Soils were compared to selected lithostratigraphic sequences characterizing the studied area, which were collected from literature and reinterpreted in pedological keys. The results showed that soils derived from the emplacement of Phlegrean primary volcanic materials, such as Campania Ignimbrite (~39–40 ky B.P.) and Neapolitan Yellow Tuff (~15 ky B.P.), with the related weathering products, and from volcanic materials reworked and transported by alluvial/colluvial episodes. The latter formed contrasting soil horizons which, differing in both rock fragment content and lithological composition, testified to the presence of lithological discontinuities. The formation of the horizons in question interrupted the genetic sequence derived from the in situ alteration of the volcanic substrata, suggesting that processes of transport and redistribution of sediments from the adjacent mountain slopes contributed to soil formation. The comparison of the pedostratigraphies with the lithostratigraphic sequences indicated a strong relation between geomorphic and pedogenetic events.

Copyright of Stratum Plus Journal is the property of P.P. Stratum plus and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In a pilot study, hyperspectral image analysis was applied to four boreholes from the North Midlands Block in Ireland. The selected holes are extremely well characterised lithologically and have a detailed micropalaeontology accurately constraining stratigraphic positions. Hyperspectral facies were defined using features extracted from the hyperspectral data and compared with existing litho- and biostratigraphic logs and samples. These were able to distinguish changes in the lithologies of the cores and were useful for defining unbiased lithological contacts and for regional correlations. [ABSTRACT FROM AUTHOR]

The comprehensive overview of Neogene lithostratigraphy in the eastern Netherlands dates back to the mid-1970s. In the present study, continuous gamma-ray logs and in situ sediment core samples from six boreholes in the area allowed palynological and mollusc analyses and wireline log-based correlation. These investigations were aimed at updating and revising the existing Neogene lithostratigraphy within the Stratigraphic Nomenclature of the Netherlands by integrating litho-, bio-, and sequence-stratigraphic approaches. The analytical results yielded the establishment of new holo- and lectostratotype sections, together with cross-border interregional correlation. The lithostratigraphic revision resulted in the modified definition of the Aalten, Eibergen and Delden members and the definition of two new proposed members: the Dale and Doetinchem members. The Ticheloven bed, removed in earlier studies, is proposed to be reinstated, and the Stemerdink Bed is upgraded in its hierarchical status to the Stemerdink member. All lithostratigraphic units are included in the present Miocene subdivision of the Groote Heide and Diessen formations, which include three recognisable unconformities: the Early-Miocene Unconformity (EMU), Mid-Miocene Unconformity (MMU) and Late-Miocene Unconformity (LMU). The new, revised, reintroduced and existing local lithostratigraphic units and sequences are discussed with their counterparts in the south and southeast of the Netherlands, in Germany and Belgium, and from this a regionally consistent framework has emerged of the regional Neogene lithostratigraphy.

ABSTRACTThis study produced a drift thickness model for the southwestern Great Slave Lake area of northern Canada, using 12,692 lithostratigraphic records (seismic shothole drillers’ logs, diamond drill holes, petroleum wells), and field observations. Numerous algorithms and modelling parameters were tested using 6122 records of absolute drift thickness, and based on a cross-validation analysis, an empirical Bayesian kriging K-Bessel detrended algorithm was found to produce the best fit. The final model, incorporating selected maximum and minimum thickness estimate data, produced a root mean square error of 4.98 m, with 94.8% of the data points within ±2 m of the modelled drift thicknesses. The model identifies widespread areas of drift >10 m thick, and prominent southeast-northwest aligned bedrock ramps. Karst structures buried by ≤73 m of drift were identified southwest of Great Slave Lake and appear to be aligned with regional fault systems like ore-associated karst at Pine Point. These may be the source of anomalous glacial sediment-derived base metal indicators collected proximally to the west. The most striking drift anomaly is in Cameron Hills where the eastern and northern margins are comprised of shale and siltstone bedrock overlain by 20–40 m of glacial sediments, but the central and western uplands have petroleum well logs identifying glacial sediments up to 400 m thick. In addition to mineral exploration, results of this study provide baseline data that can be used predictively by the petroleum industry in designing future seismic and drilling (casing depth) operations, and by those modelling groundwater sources and flow.

Based on field lithostratigraphic studies, microfaunistic and palynological analyses, and optically stimulated luminescence (OSL) dating of sediments exposed in the lower part of Quaternary sections along the Zimnii coast of the White Sea, it is established for the first time that they accumulated during the Boreal transgression in the beginning of the Last Interglacial under marine and coastal marine conditions and form the Upper Pleistocene Mikulinian Horizon. This is supported by the lithology; the species composition of foraminifers, ostracods, and aquatic palynomorphs; and the OSL ages in the range of 118–104 ka. The composition of benthic microfossils indicates that the beginning of the Boreal transgression along the entire Zimnii coast was characterized by a coastal marine basin with sea-ice cover and water depths of >50 m, as well as by high sedimentation rates and stratification due to inflow of melt/river waters. The coastal marine sedimentation conditions were dominant during the regression stage along the Zimnii coast. [ABSTRACT FROM AUTHOR]

The Mamfe Basin has been the subject of many studies, but some debates persist, especially concerning the stratigraphic nomenclature, corundum origin, and marine transgression. The aims of this work are (1) to propose a new lithostratigraphic nomenclature of the Mamfe Basin formation based on new field observations, (2) to determine the source rock distribution and the origin of gem deposits and (3) to correlate the Cameroon section of the Mamfe Basin with the Nigerian deposits. The main results show that the name Manyu River Group is more appropriate as the Manyu River crosses all the facies in the Mamfe sedimentary Basin belonging to the Manyu Division. According to the facies analysis, the age of deposition, the mineralogic and geochemical data such as the V vs. Al2O3 and ∑REE vs. Al2O3, TiO2 MgO, Na2O, P2O5, and CaO diagrams, this Group is composed of at least five Formations, including four Cretaceous Formations, from bottom to top: the Etoko Formation (alluvial and fluvial channel to fluvio-lacustrine deposits), the Nfaitok Formation (lagoonal deposits), the Bachuo Ntai Formation (fluvial braided channels or fluvio-deltaic environment) and the Eyumojock/Nsanaragati Formation (fluvio-lacustrine deposits) and the new Cenozoic Formation named Bakebe Formation (fluvio-lacustrine deposits). The gem minerals such as corundum, rutile, or tourmaline in the Cretaceous deposits of the Mamfe Basin are mainly detrital as indicated by the presence of worn shapes and fragments of these minerals. The presence of sapphire in the Albo-Cenomanian deposits indicates a Precambrian age of the felsic source rock, likely the plutonic rocks such as granite or pegmatite as indicated by the abundance of tourmaline and high LREE/HREE ratios (14.81–34.29) and slightly negative and positive Eu anomalies (0.85–1.15). This marine incursion in the Mamfe Basin was probably from West Nigeria, according to the geographic location of the Mamfe Basin and the general palaeogeographic evolution of the Benue Trough. [ABSTRACT FROM AUTHOR]

In order to study the lithostratigraphy and biostratigraphy of the Ruteh Formation in central Alborz basin, a stratigraphic section was selected around 30 km south of Amol city. This formation with a thickness of 642 m, mainly consisting of limestone, dolomitic limestone, limy dolstone, dolomite, shale and sandstone disconformably lied on the Ruteh Formation and underlied disconformably by the Nesen Formation. Based on the biostratigraphy studies 31 genera and 57 species of benthonic foraminifera were identified. The age of the Ruteh Formation in the studied section was determined based on the distribution of the index of benthic Foraminifera. The Ruteh Formation has 3 biozones Neoendothyra bronnimanni-Neoendothyra reicheli assemblage zone, Chusenella sinensis-Codonofusiella erki-Pachyphloia sp. assemblage zone and Pciraglobivcilwl c - Dagmcita cba clciiej-isis assemblage zone. The age of the Ruteh Formation in the studied section is Late Murgabian to Early Julfian. It's age was determined based on the above-mentioned biozones and fossil assemblages. [ABSTRACT FROM AUTHOR]

In the Middle Anisian the opening of the Neo‐Tethys started and this is characterized by a significant change in deposition in the whole Western Tethys Realm. In the Dinarides the Middle to Late Anisian tectonostratigraphic and basin evolution is mirrored by their sedimentary successions. In the Middle Anisian, the evolution of the shallow‐water Ravni Carbonate Ramp ended relatively abrupt in the late Pelsonian: a rapid decrease of carbonate production is accompanied by formation of a horst‐and‐graben topography. This change is expressed by the change in deposition from shallow‐water carbonates to deepwater sedimentary rocks, i.e. the Ravni Carbonate Ramp experienced a drowning. Contemporaneously neptunian dikes were formed in the underlying Ravni Formation, filled with deep‐water limestones. In the grabens, near to the newly formed escarpments mass transport deposits accumulated. During the time span late Pelsonian to middle Illyrian a general deepening trend is mirrored in the sedimentological trend and the microfacies characteristics. Fossilla ‐ gerstätten (mainly cephalopods) and hardgrounds occur widespread in the deeper‐water red nodular limestones formed widespread above the Ravni Carbonate Ramp. Around the middle/late Illyrian boundary a second intense pulse of tectonic motions, related to the onset of volcanic activity, resulted in a crosscut of the older horst‐and‐graben topo graphy. A second generation of neptunian dikes was formed, the blocks tilted, and again mass transport deposits accumulated near to escarpments. The late Illyrian is characterized by an overall deepening trend expressed also in a change in the microfacies characteristics to radiolarian‐rich wacke‐ to packstones. In cases even radio larites or silicified limestones are characteristic sedimentary rocks in late Illyrian to Ladinian times beside silicified volcano‐sedimentary rocks. This paper will define the late Middle‐Late Anisian red nodular limestones and related sedimentary rocks with mass transport deposits overlying the Ravni Carbonate Ramp on base of new sedimen tological, stratigraphic and micro facies data following the international rules and standards. The palaeo geographic position together with characteristic litho‐ and microfacies features cause the lithostratigraphic definition of the different units. Included in the newly introduced Bulog Group are: 1) the emended and formalized Bulog Formation and 2) the newly introduced and defined Komarani Formation. The type‐section of the Bulog Formation east of Sarajevo (Han Vidović, central Bosnia and Herzegovina) is revisited. The Komarani Formation is introduced with the type‐section in Komarani village (Zlatar Mt. in SW Serbia). The reference sections for the Bulog Formation in SW Serbia (Klisura quarry on Zlatibor Mt.), Bosnia and Herzegovina (Pridvorica locality at Romanija Mt.) and in Montenegro (Boljevići near Virpazar), are defined. In the reference sections some characteristic lithological and microfacies features are better preserved as in the type‐section and included in the emendation and formalization of the Bulog Formation. The Bulog Formation at the type‐section and all reference sections are in the Late Triassic overlain by the shallow‐water carbonates of the Wetterstein and Dachstein Carbonate Platforms. Age and facies equivalent red nodular limestones deposited in the outer shelf region are part of the Middle to Late Triassic Hallstatt Limestone succession. In the type‐region of the Hallstatt Limestones these late Middle to Late Anisian red nodular limestones are named Schreyeralm Limestones. The name Schreyeralm Limestone was introduced earlier as the name Bulog Limestone. It is discussed if also in the Dinarides the name Schreyeralm Limestone should be used for such Anisian red nodular limestones deposited in the outer shelf region, for priority reasons, or if they should be included into the Bulog Formation to avoid confusion, for historical reasons.

Abstract Continent-derived tectonic units in the Tauern Window of the Alps exhibit stratigraphic and structural traces of extension of continental margins eventually leading to the opening of the Alpine Tethys. In this study, we reassess lithostratigraphic data from the central part of the Tauern Window to reconstruct the post-Variscan evolution of this area, particularly the rift-related geometry of the European continental margin. The lithostratigraphy of the Alpine nappes reflects systematic variations of the structure of the European margin. The lowest tectonic units (Venediger nappe system, Eclogite Zone and Trögereck Nappe) are characterized by a thick succession of arkose-rich Bündnerschiefer-type sediments of probably Early Cretaceous age that we interpret as syn-rift sequence and which stratigraphically overlies thinned continental basement and thin pre-rift sediments. In contrast, the highest tectonic unit derived from Europe (Rote Wand Nappe) preserves a thick pre-rift sedimentary sequence overlying thinned continental basement, as well as a thick syn- to post-rift succession characterized by turbiditic Bündnerschiefer-type sediments of probable Cretaceous age. These observations point towards a highly segmented structure of the European rifted margin. We propose that this involved the formation of an outer margin high, partly preserved in the Rote Wand Nappe, that was separated from the main part of the European margin by a rift basin overlying strongly-thinned continental crust. The along-strike discontinuity of the Rote Wand Nappe is proposed to reflect the lateral variation in thickness of the outer margin high that resulted from margin-parallel segmentation of the European continental crust during highly oblique rifting antecedent to the opening of Alpine Tethys.

Copyright of Aeronautical Science Bulletins / Repüléstudományi Közlemények is the property of National University of Public Service and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Six new formations (Gaba, Roumi, Poula, Mbissiri, Lende andKali) are proposed forCretaceous to Paleogene sediments of the Koum Basin, northern Cameroon. The Koum Basin is one of numerous sedimentary basins lining theWest and Central African Rift System and presents a complex evolutionary history involving extensional shearing and compressional events spanning the Cretaceous to Paleogene. Recent discoveries of hydrocarbons in associated basin such asDoba in Chad, motivated exploration of the Koum Basin. However, existing studies of the Koum Basin lack a viable lithostratigraphic framework, which is crucial for ongoing exploration efforts in this basin. The present study integrates lithologic, petrographic and palaeontologic data to map, stack and correlate several outcrop sections across the basin. Facies analysis suggests that deposition occurred in a fluvio-lacustrine palaeodeposional environment. The new units were described following the guidelines of the International Stratigraphic Guide. An updated geologicmap depicts the spatial distribution of the lithostratigraphic units that make up the Koum Basin. Palynomorphs, bivalves and dinosaur footprints are used to date the studied sections. [ABSTRACT FROM AUTHOR]

The present article is an outcome of three years of exploration in the Dulung river valley of Eastern India. It is comprised of detailed reporting of 28 newly discovered prehistoric sites in this region. In the course of exploration, discovered archaeological and geological sites were mapped and their relative locations were recorded and analysed by using various GIS tools. In each site, the context of the exposed archaeological materials was recorded along with natural and artificially exposed Quaternary sedimentary sections in and around them. In this article, discovered prehistoric sites have been described along with their cultural materials, relative locations, geomorphological contexts and litho-stratigraphic features. Preliminary analyses of the recovered artifacts were done in the laboratory and some of their results have been presented in this article also. Field observation of the present study reveals that Lower Palaeolithic artifacts were mainly found from the ferricrete deposits and Microlithic artifacts were found from calcrete bearing silt deposits of the study area. This study establishes the Dulung river valley as one of the several important geographical and environmental places of eastern India where prehistoric man's activity took place at least since the early-middle Pleistocene. [ABSTRACT FROM AUTHOR]

Pliocene (Zanclean to mid Piacenzian) marine deposits from Cape Vigli on southwestern Rhodes (Mediterranean Sea, Dodecanes, Greece) are described, and assigned to the newly defined Cape Vigli Formation. Highly fossiliferous sandy to silty mudstones contain a diverse parautochthonous mollusc assemblage dominated by articulated specimens of the bivalves Pinna nobilis and Megaxinus ellipticus, and by abundant Persististrombus coronatus gastropods. These taxa formed part of a seagrass community. Combined with sedimentological evidence and microfossil assemblages (foraminifera, calcareous nannofossils), they indicate a very shallow (<5 m deep) depositional environment in a sheltered marine embayment close to the coast. The fossil community is characterised by the occurrence of several Late Miocene to Pliocene warm-water mollusc taxa, which had their acme in the Zanclean and have become extinct in the Mediterranean in the early Piacenzian. Consequently, these molluscs testify to a Zanclean to mid Piacenzian age. This assignment is corroborated by the calcareous nannofossil assemblages of the deposits, which support a potential latest Miocene (latest Messinian) to Early Pleistocene (early Gelasian) age (calcareous nannofossil zones NN12 to NN17). The occurrence of marine Pliocene deposits on Rhodes indicates that the depositional history of the island is more intricate than previously assumed. The shallow marine nature of the studied strata provides new evidence to reconstruct the position of the palaeo-coastline during Pliocene times, when Rhodes was still connected to Anatolia. So far, fossiliferous shallow marine strata of Zanclean to mid Piacenzian age in the eastern Mediterranean had been documented from Hatay Province (southern Turkey) and Agia Triada (southwestern Peloponnese, Greece). The newly discovered locality of Cape Vigli thus provides a significant, novel dataset, which helps to evaluate the palaeobiogeography of Pliocene biota. [ABSTRACT FROM AUTHOR]

The stratigraphy of the European late Permian-Triassic commonly lacks chronostratigraphic constraint due to the scarcity of diagnostic fossils for biostratigraphy. This is particularly true for the United Kingdom, and as a result, stratigraphic correlation within and between sedimentary basins is primarily reliant on lithostratigraphy. Evaporitic sulphate can be used to develop time series of δ34Sevap data that can be utilised for stratigraphic correlation. However, the availability of continuous drillcore is limited, whilst drill cuttings are commonly acquired but are widely overlooked for stable isotope stratigraphy. We derive a δ34Sevap record from drill cuttings from the southern North Sea Basin, and successfully correlate it with an equivalent published δ34Sevap record from a continuous drillcore in the Cleveland Basin, Yorkshire, United Kingdom. We have chosen seven points in the δ34Sevap records for stratigraphic correlation, defining eight packages of isotopically distinct coeval strata. This is significant, as the ubiquity of drill cuttings presents the opportunity to derive δ34Sevap curves with high geospatial resolution. Equivalent gamma ray logs were used for correlation and compared with the δ34Sevap curves. The correlations agree relatively well, however, the δ34Sevap correlation permits the development of more robust chronostratigraphic constraints. Specifically, the δ34Sevap records constrain the age of the Bunter Shale and Bunter Sandstone in the western Southern North Sea to the latest Permian. This has significant implications for understanding the stratigraphy and palaeogeographic evolution of United Kingdom Permian-Triassic sedimentary basins, and may have economic implications, since the Bunter Sandstone is being considered as a potential reservoir for CO2 storage in the United Kingdom sector.

In a pilot study, hyperspectral image analysis was applied to four boreholes from the North Midlands Block in Ireland. The selected holes are extremely well characterised lithologically and have a detailed micropalaeontology accurately constraining stratigraphic positions. Hyperspectral facies were defined using features extracted from the hyperspectral data and compared with existing litho- and biostratigraphic logs and samples. These were able to distinguish changes in the lithologies of the cores and were useful for defining unbiased lithological contacts and for regional correlations.

This study produced a drift thickness model for the southwestern Great Slave Lake area of northern Canada, using 12,692 lithostratigraphic records (seismic shothole drillers’ logs, diamond drill holes, petroleum wells), and field observations. Numerous algorithms and modelling parameters were tested using 6122 records of absolute drift thickness, and based on a cross-validation analysis, an empirical Bayesian kriging K-Bessel detrended algorithm was found to produce the best fit. The final model, incorporating selected maximum and minimum thickness estimate data, produced a root mean square error of 4.98 m, with 94.8% of the data points within ±2 m of the modelled drift thicknesses. The model identifies widespread areas of drift >10 m thick, and prominent southeast-northwest aligned bedrock ramps. Karst structures buried by ≤73 m of drift were identified southwest of Great Slave Lake and appear to be aligned with regional fault systems like ore-associated karst at Pine Point. These may be the source of anomalous glacial sediment-derived base metal indicators collected proximally to the west. The most striking drift anomaly is in Cameron Hills where the eastern and northern margins are comprised of shale and siltstone bedrock overlain by 20–40 m of glacial sediments, but the central and western uplands have petroleum well logs identifying glacial sediments up to 400 m thick. In addition to mineral exploration, results of this study provide baseline data that can be used predictively by the petroleum industry in designing future seismic and drilling (casing depth) operations, and by those modelling groundwater sources and flow. [ABSTRACT FROM AUTHOR]

The Quetta and surrounding areas are part of the collision zone between the Indian and Eurasian plates, named as Kirthar and Sulaiman Fold-Thrust belts. The collision is accommodated by folding, thrusting and the Nushki-Chaman Transform Fault System. Detailed high-resolution (scale 1:50,000) mapping and structural analyses were carried out using modern remote-sensing techniques of the ArcGIS to understand mutual relationships of the structural patterns and geometries, and the regional and local stress patterns in the study area. Fieldwork was carried out to acquire the stratigraphic, structural and geomorphological data, using topographic maps and satellite images as base maps in order to plot additional information and further incorporate them in the GIS-based map. Balanced structural cross-sections were also prepared along the selected lines using ArcGIS techniques. Based on new mapping, the understudy area has been subdivided into five distinct structural domains. These domains are classified as; Domain I: broad syncline intervened by a narrow anticline; Domain II: upright folds and thrusts; Domain III: tight, over-turned thrust zone; Domain IV: flysch and molasse successions of Paleocene-Holocene age; and Domain V: suture belt (ophiolites) and associated mélanges and sediments. [ABSTRACT FROM AUTHOR]

Recognition, identification, and correlation of formal lithostratigraphic units should always follow the rules of the definition of lithostratigraphic units established in the Stratigraphic Code of Nomenclature, set by the International Stratigraphic Commission. This case study is attempting at elaborating on this argument by discussing the identification and differentiation between the Sinjar and Khurmala formations in outcrop and well sections. Stratigraphic data for this study were compiled basin-wide, with nearly fifty localities of both formations from the Zagros foreland basin of Kurdistan in NE Iraq. Examinations include a review of microfacies documentation, Facies reinterpretation as well as sequence analysis. The Sinjar and Khurmala formations are carbonate units developed during the final filling stage of the Zagros foreland basin of northeast Iraq. The Sinjar Formation is characterized by shallow marine coralgal-foraminiferal limestone of reefal, lagoonal, shoal, and overall ramp setting. Other lithologies such as dolomitic limestone or marly limestone are minor and secondary. The Khurmala Formation, on the other hand, is dominated by thick beds of dolostone with secondary lithologies including recrystallized limestone and dolomitic limestone and marly limestone. Microfacies analysis of the Khurmala Formation reveals that it represents a lagoonal lithofacies equivalent to the lagoonal facies of the Sinjar Formation but intensively dolomitized at specific areas of the basin. This close relationship between the two formations, leading in some cases to mixing between both lithologies or rather confusion and misidentification. The best way of differentiating between the two units is by adhering to the lithostratigraphic rules and principles of the formal stratigraphic description, which emphasize the formal lithostratigraphic description of each formation. [ABSTRACT FROM AUTHOR]

Continent-derived tectonic units in the Tauern Window of the Alps exhibit stratigraphic and structural traces of extension of continental margins eventually leading to the opening of the Alpine Tethys. In this study, we reassess lithostratigraphic data from the central part of the Tauern Window to reconstruct the post-Variscan evolution of this area, particularly the rift-related geometry of the European continental margin. The lithostratigraphy of the Alpine nappes reflects systematic variations of the structure of the European margin. The lowest tectonic units (Venediger nappe system, Eclogite Zone and Trögereck Nappe) are characterized by a thick succession of arkose-rich Bündnerschiefer-type sediments of probably Early Cretaceous age that we interpret as syn-rift sequence and which stratigraphically overlies thinned continental basement and thin pre-rift sediments. In contrast, the highest tectonic unit derived from Europe (Rote Wand Nappe) preserves a thick pre-rift sedimentary sequence overlying thinned continental basement, as well as a thick syn- to post-rift succession characterized by turbiditic Bündnerschiefer-type sediments of probable Cretaceous age. These observations point towards a highly segmented structure of the European rifted margin. We propose that this involved the formation of an outer margin high, partly preserved in the Rote Wand Nappe, that was separated from the main part of the European margin by a rift basin overlying strongly-thinned continental crust. The along-strike discontinuity of the Rote Wand Nappe is proposed to reflect the lateral variation in thickness of the outer margin high that resulted from margin-parallel segmentation of the European continental crust during highly oblique rifting antecedent to the opening of Alpine Tethys. [ABSTRACT FROM AUTHOR]

The Western Ghats sections of the Deccan Volcanic Province (DVP) are considered the 'type area' for most of the established models of its eruptive history and age. The prevailing chemostratigraphy and lithostratigraphy of the Western DVP based on the study of these sections are largely comparable but have subtle conceptual and practical differences. Although based on higher resolution data, the latter failed to get widespread acceptance. Horizons of giant phenocryst basalts (GPBs) have been used in both stratigraphic classifications as marker horizons. They can be traced across many tens of kilometres and serve as efficient and easy-to-map horizons during field mapping. We demonstrate the lateral continuity of the GPB horizons across the Western DVP to reiterate their relevance in stratigraphic classification of the otherwise uniform pile of basaltic flows. We propose a unified stratigraphy for this subprovince, which reconciles existing chemostratigraphic and lithostratigraphic classifications. [ABSTRACT FROM AUTHOR]

This paper presents the first integrated regional outcrop-based sedimentological study of the northern Aaiun-Tarfaya Basin located in Morocco (NW Africa). The Lower Cretaceous Tan-Tan Formation has been subdivided into six new members and placed within a sequence stratigraphic framework that includes two incomplete depositional sequences. Strong thickness variations of individual lithostratigraphic units from north to south suggest differential subsidence during sedimentation and/or the existence of major topography on the basal unconformity that the succession onlaps. The results provide valuable insights into the timing of local tectonics in the Western Anti-Atlas and the control on the evolution of the sedimentary system. Deposition of each of these six units is interpreted to be the result of a complex interplay between an overall eustatic sea-level rise during the early Cretaceous, sediment delivery controlled by tectonic movements in the Western Anti-Atlas and Reguibat Shield and periods of differential subsidence in the basin. The results document the style of evolution of a back-stepping wave-dominated system feeding into the Central Atlantic during the passive margin phase. The improved facies and depositional models together with improved understanding of the evolution of the delta have significant implication for exploring the deep-water equivalents offshore. • Integrated stratigraphy of the Lower Cretaceous of the northern Aaiun-Tarfaya Basin • The Tan-Tan formation represent a pro- and retrograding linear shoreline system • Deposited during long-level rise modulated by sediment supply change and teconics [ABSTRACT FROM AUTHOR]

The Transversal Zone Domain (TZD) is the central segment of the Borborema Province, with its limits given by the Patos and Pernambuco shear zones, to the north and south respectively. This part of the province presents Archean nuclei surrounded by Paleoproterozoic units that together correspond to the basement of belts of Neoproterozoic metasupracrustal rocks. All this set was intruded by syn to post-tectonic granitoids related to the Brasiliano Orogeny (c. 640 – 500 Ma). The TZD records important shear zones of regional scale, dextral (Patos and Pernambuco), and sinistral (Serra do Caboclo, Afogados da Ingazeira and Congo), being the dextral used to delimit the TZD of adjacent domains and the sinistral ones for internal compartmentalization in four subdomains: Piancó-Alto Brígida, Alto Pajeú, Alto Moxotó and Rio Capibaribe. The lithostratigraphic units of this domain were described and organized in a way that would be regionally presentable. An unprecedented dating is presented for a metagranitoid of the Serra de Jabitaca Complex, with maximum crystallization age at 1790 ± 40 Ma and metamorphism at 615 ± 3 Ma. The tectonic evolution of the domain begins with an orogenic event and development of magmatic arches at the beginning of the Paleoproterozoic (involving Archean portions), in addition to an extensional event at the end of this period, already in the transition with the Mesoproterozoic. The Neoproterozoic begins with two extensional events (Cariris Velhos and pre-Brasiliano) until the formation of the magmatic arches related to Brasiliano Orogeny.

The map ‘Geology of the Monte Banchetta – Punta Rognosa area (Troncea valley, Western Alps)’ details the lithostratigraphy and structural setting of a key sector in the Alpine chain, characterized by close associations of continental and oceanic basements, and meta-sediments. The mapped Monte Banchetta – Punta Rognosa unit (BRU), tectonically juxtaposed to different metaophiolitic units, comprises the Punta Rognosa succession, made of serpentinized mantle overlain by Middle-Upper? Jurassic polymictic meta-breccia, with oceanic and continental clasts, and metasandstone, and the Monte Banchetta succession, consisting of continental crust and Lower–Upper? Jurassic carbonate-bearing quartzite, micaschist and polymictic meta-breccia. These two successions share the uppermost stratigraphic levels consisting of post-rift Upper Jurassic-Cretaceous carbonate-micaschists. The deciphered stratigraphic architecture indicates that the lower succession of the BRU represents portions of continental crust and exhumed mantle reworked and emplaced before deposition of post-rift sediments.

Detailed geological mapping of the Urtier Valley in the Western Alps allowed to realize a new geological map 1:10.000 in scale. In the mapped area, a complete nappe stack of the axial part of the Alpine belt crops out. The study focused on the two units derived from the Piemonte-Ligurian oceanic domain, Broillot and Bardonney units, for which, in addition to the classic petrographic and structural considerations, a lithostratigraphic approach was applied. The lithostratigraphic approach, combined with structural analysis, led to reconstruct a nappe stacking significantly different from that generally proposed for the Western Alps. In the Urtier Valley in fact, the eclogite facies units are at the top of the nappe pile, overlapped on the blueschist facies units. This anomalous stacking order could be explained by interpreting the study area as an inverted limb of a regional fold with the eclogite facies units at the core.

The northern portion of the Borborema Province, located north of the Patos Shear Zone (northeast of Brazil) is formed by litho-stratigraphic units dating from the Archean to the Neoproterozoic, with complex evolution resulting from several orogenic and extensional events occurring in this interval. In this work, the litho-stratigraphic units of the Northern Borborema Province were reviewed and ordered here, regarding the rock associations and their chronological positioning. Zircon U-Pb dating of three samples of migmatitic orthogneisses from the Rio Piranhas-Seridó Domain, defined crystallization ages of 561 ± 2 Ma, 574 ± 6 Ma and 547 ± 5 Ma for their protoliths. Thus, the origin of the orthogneisses is related to the syn- to late-tectonic magmatism in relation to the Brasiliano Orogeny. From the Jaguaretama Complex, U-Pb dating of detrital zircons of a migmatitic schist indicates Paleoproterozoic sources, with a maximum deposition age of 2144 Ma. The protolith of a migmatitic orthogneiss has crystallization age of 2186 ± 10 Ma, therefore, contemporary compared to other litho-stratigraphic units of the Borborema Province, which are interpreted as having been developed in the Rhyacian Orogeny.