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Recently, exploration breakthroughs have been made in the Lower Cretaceous sandstone reservoirs in the Doseo Basin, but the identification of reservoir fluid property is difficult due to variable reservoir lithology, complex oil-water contact within and faint responses of the oil zone, which causes the lower accuracy of reservoir fluid property identification with conventional mudlogging and wirelogging techniques. Applying the geochemical logging, fluorescent logging, mud logging and cutting logging technology, in combination with formation test data, this paper distinguishes the crude oil types, analyzes the logging response characteristics of oil zone after water washing, and establishes the interpretation charts and parameter standards for reservoir fluid properties. The crude oil can be divided into two types, namely viscous-heavy and thin-light, based on total hydrocarbon content and component concentration tested by mud logging, features of pyrolysis gas chromatogram and fluorescence spectroscopy. The general characteristics of oil layers experienced water washing include the decrease of total hydrocarbon content and component concentration from mud logging, the decrease of S1 and PS values from geochemical logging, the decrease of hydrocarbon abundance and absence of some light components in pyrolysis gas chromatogram, and the decrease of fluorescence area and intensity from fluorescence logging. According to crude oil types, the cross plots of S1 versus peak-baseline ratio, and the cross plots of rock wettability versus fluorescence area ratio are drawn and used to interpret reservoir fluid property. Meanwhile, the standards of reservoir fluid parameter are established combining with the parameters of PS and the parameters in above charts, and comprehensive multiparameter correlation in both vertical and horizontal ways is also performed to interpret reservoir fluid property. The application in the Doseo Basin achieved great success, improving interpretation ability of fluid property in the reservoir with complex oil-water contact, and also provided technical reference for the efficient exploration and development of similar reservoirs. [ABSTRACT FROM AUTHOR]

The utilization of sequence stratigraphic concepts in identifying sands and their spatial continuity in distinct gross depositional settings is key, especially in frontier settings where data paucity is a common challenge. In the Baka field, onshore Niger Delta, detailed reservoir correlation guided by sequence stratigraphic framework analysis showed the distribution of sand and shale units constituting reservoirseal pairs (RSP) correlatable across the field. Within the 3rd-order packages, it is observed that the lowstand systems tract (LST) and highstand systems tract (HST) contain more RSPs and thicker 4th- and 5th-order sands than the transgressive systems tract (TST). In terms of bathymetry, it is noted that irrespective of systems tracts, the RSP Index (RI) decreases from the proximal shallow/inner shelf settings to the more distal outer shelf areas. Amongst all three systems tracts, intervals interpreted as lowstand prograding complexes contain the best developed sands and highest RSP. Sand development within the LSTs has been controlled by a pronounced growth fault regime accompanied by high subsidence and sedimentation rates. This is linked to the basinward migration of the sands during prolonged sea-level fall, creating significant accommodation space for sand deposition. On the other hand, the TSTs known to mark periods of progressive sea-level rise and landward migration of sandy facies, show thinner sands enclosed in much thicker, laterally extensive, and better-preserved deeper marine shales. Interpreted seismic sections indicate intense growth faulting and channelization that influenced the syn- and postdepositional development of the sand packages across the field. The initial timing of deformation of subregional faults in this area coincides with periods of abrupt falls in sea level. This approach could be useful for predicting sand-prone areas in frontier fields as well as possible reservoir-seal parameters required for some aspects of petroleum system analysis and quick-look volume estimation. [ABSTRACT FROM AUTHOR]

A silicified, thick-shelled, smooth-surfaced nuculanoid bivalve has been recovered using acid maceration of the Late Triassic (Carnian–Norian) strata of the Luning Formation, Nevada. Comparable modern nuculanoid clams inhabit water depths from 525 to 2562 m, and the living clam (an undescribed species of Pseudoneilonella from Caleta Sierra, Coquimbo, Chile) most similar to the fossil lives at 878–933 m. The Triassic nuculanoid clam (possibly a neilonellid) is inferred here to have inhabited marine waters at approximately 1000 m deep during the deposition of the Shaly Limestone Member of the Luning Formation. The acid maceration sample also produced a silicified specimen of an abyssochrysoid gastropod. The most similar living species to the fossil snail is Abyssochrysos brasilianus, an abyssochrysoid known to occur in water depths from 1540 to 620 m. This depth range also suggests an approximate 1000 m depositional depth for the silicified fossil-producing acid maceration sample from the Luning Formation. These new fossil discoveries falsify hypotheses that the ichthyosaurs (Shonisaurus popularis) of Berlin-Ichthyosaur State Park, Nevada, USA, were deposited, respectively, in either shoreline deposits or in strata that accumulated above the storm wave base. Evidence is also presented here for the existence of a giant Triassic cephalopod that, by comparison with the modern Mesonychoteuthis, preferred water depths of approximately 1000 m. [ABSTRACT FROM AUTHOR]

The Atlantic is the only ocean basin almost entirely surrounded by passive margins, and a major global long‐term sink of carbonate carbon that has evaded subduction. Quantifying the history of carbonate accumulation in the Atlantic has been limited by the absence of well‐defined regional carbonate compensation depth (CCD) models. We determine the CCD for the northern North Atlantic, central North Atlantic, and South Atlantic, and use these reconstructions to compute the carbonate carbon mass and carbonate carbon flux in a tectonic framework at 0.5 m.y. intervals since 66 Ma. We find that the total carbonate carbon mass of the Atlantic has grown 2.5‐fold from ∼1,500 Mt at 66 Ma to ∼3,800 Mt at present day. The overall Cenozoic increase in carbonate carbon flux toward the present day is punctuated by "carbonate crash" phases in the mid‐Eocene at ∼44–38 Ma and in the mid‐late Miocene at ∼19–8 Ma. During these times the flux decreases from ∼45 to ∼25 Mt C/yr, likely caused by carbonate dissolution and reductions in productivity. Reduced carbonate carbon flux in the mid‐Eocene also coincides with reduced calcification rates of small coccolithophores previously observed offshore Africa. After ∼8 Ma the carbonate carbon flux rises to a Cenozoic maximum of ∼75 Mt C/yr at ∼3 Ma, possibly driven by enhanced flux of nutrients into the ocean. Our CCD curves and the resulting carbonate accumulation history are useful for calibrating ocean chemistry models, and constraining global terrestrial weathering rates, climate perturbations, and carbon cycle models. Key Points: Carbonate carbon flux and storage has been computed for the Atlantic Ocean spanning the entire Cenozoic at 0.5 m.y. intervalsThe total carbonate carbon mass of the Atlantic has grown 2.5‐fold from ∼1,500 Mt at 66 Ma to ∼3,800 Mt at present dayCarbonate carbon flux fluctuations are linked to carbonate crash and bloom phases, and changes in deep‐water circulation [ABSTRACT FROM AUTHOR]

Abstract The Atlantic is the only ocean basin almost entirely surrounded by passive margins, and a major global long‐term sink of carbonate carbon that has evaded subduction. Quantifying the history of carbonate accumulation in the Atlantic has been limited by the absence of well‐defined regional carbonate compensation depth (CCD) models. We determine the CCD for the northern North Atlantic, central North Atlantic, and South Atlantic, and use these reconstructions to compute the carbonate carbon mass and carbonate carbon flux in a tectonic framework at 0.5 m.y. intervals since 66 Ma. We find that the total carbonate carbon mass of the Atlantic has grown 2.5‐fold from ∼1,500 Mt at 66 Ma to ∼3,800 Mt at present day. The overall Cenozoic increase in carbonate carbon flux toward the present day is punctuated by “carbonate crash” phases in the mid‐Eocene at ∼44–38 Ma and in the mid‐late Miocene at ∼19–8 Ma. During these times the flux decreases from ∼45 to ∼25 Mt C/yr, likely caused by carbonate dissolution and reductions in productivity. Reduced carbonate carbon flux in the mid‐Eocene also coincides with reduced calcification rates of small coccolithophores previously observed offshore Africa. After ∼8 Ma the carbonate carbon flux rises to a Cenozoic maximum of ∼75 Mt C/yr at ∼3 Ma, possibly driven by enhanced flux of nutrients into the ocean. Our CCD curves and the resulting carbonate accumulation history are useful for calibrating ocean chemistry models, and constraining global terrestrial weathering rates, climate perturbations, and carbon cycle models.

Extended shallow carbonate platform, pelagic, and drift deposits were drilled during International Ocean Discovery Program (IODP) Expedition 359 in the Inner Sea of the Maldives. These sediments yield rich and well-diversified benthic, planktonic foraminiferal and nannofossil assemblages spanning from the early Oligocene to the Recent. We present here the shore-based revised integrated biostratigraphy of these microfossil groups at IODP Hole 359-U1468A together with the paleobathymetric reconstruction. Our data suggests the presence of a late Oligocene carbonate platform, marked by the shallowest water depths of the entire sequence of around 80 m. This carbonate platform sequence occurred from around 29 Ma, the extrapolated minimum age estimate, at least up to 27.5 Ma and possibly up to 25.4 Ma. Up the sequence, similar carbonate production conditions occurred until 22.5 Ma across the Oligocene–Miocene transition, equated at 23.04 Ma, with increased water depths >120 m. Notably, in the time interval approximately from 24 to 21.5 Ma, orbitally induced sapropel layers indicate a change of open to restricted circulation. However, at around 22.5 Ma, pelagic deposition at a distal slope occurred with sedimentation rates of 3 cm/years. This initially occurred in water depths of >350 m but gradually reached deposition in water depths of >500 m, which persisted from 21.12 Ma until approximately the extrapolated age of 12.8 Ma. Sedimentation rates gradually increased to 10.5 cm/1000 years at around 450 m below sea floor, marking the initiation of the drift sequence as identified in seismic lines with an age estimate of 12.8 Ma. The initiation of the drift sequence is also marked by a drastic decrease in the preservation of benthic and planktonic foraminifera from good to very poor at around 12.8 Ma. The drift sequence essentially continued to the present day but was interrupted by two events: the deposition of distinct shallow water benthic shoals and a large hiatus. From 12.8 Ma, a shallowing upward bathymetry is suggested by the occurrence of shallow benthic foraminiferal assemblages that close to around 11.93 Ma reached a maximum water depth of 80 m. This shoal then prograded into the basin and persisted at least until 9.89 Ma. Basin conditions with water depths exceeding 500 m were re-established in the upper part of the sedimentary succession after a hiatus spanning approximately from 9.83 Ma to 2.39 Ma, implying that renewed open ocean conditions occurred in the Pliocene–Pleistocene part of the sedimentary record. [ABSTRACT FROM AUTHOR]

Marine Piacenzian deposits are extremely rare in the eastern Mediterranean region, resulting in a stratigraphic gap in our knowledge of the late Pliocene evolution of the marine ecosystem and its fauna. Fish assemblages moreover are scant throughout the Pliocene. We present here the teleost fish fauna of the Piacenzian Polis basin (SW Cyprus) based on otolith assemblages, and we use them to reconstruct the paleoenvironment. Twenty-six teleost fish taxa are identified, placed under sixteen genera and five families. Planktonic foraminifera biostratigraphy places the studied outcrop within the subzones MPL4a and MPL5a (early–middle Piacenzian). Four species and two genera of fish are reported for the first time in the Piacenzian of the Mediterranean. The studied otolith assemblage from Androlykou section consists of very shallow-water fish mixed with mesopelagic taxa indicating topographical steepness with easy access to the open ocean. In addition, the fish assemblages mainly include representatives of subtropical taxa suggesting a climate warmer than today. These data provide new information on the composition of the ichthyofauna of the eastern Mediterranean during the Piacenzian, paving the way for new studies in the Cyprus area. [ABSTRACT FROM AUTHOR]

An integrated interpretation of processed 3D seismic data, a suite of well logs, biostratigraphic data and core photographs of AMO Field, deep offshore Niger Delta, is carried out for the sequence stratigraphic analysis of strata penetrated by wells. Lithologic and key stratigraphic surfaces, that is, the maximum flooding surfaces (MFSs) and sequence boundaries (SBs), are identified based on bioevents and log motifs. Biostratigraphic data help the delineation of MFSs and SBs, as well as dating, determination of depositional environment and paleobathymetry. The sequence stratigraphic study reveals seven MFSs (of 13.0 Ma, 11.0 Ma, 9.5 Ma, 7.4 Ma, 5.8 Ma, 5.0 Ma and 2.7 Ma) and six SBs (of 12.1 Ma, 10.3 Ma, 8.5 Ma, 6.3 Ma, 5.5 Ma and 4.2 Ma). The key stratigraphic surfaces identified involve three depositional sequences characterized by lowstand, transgressive and highstand system tracts respectively. The studied section is deposited in a deepwater environment ranging from Lower to Upper Bathyal and can be dated back to the Middle Miocene - Middle Pliocene in age. Seven faults and two horizons (corresponding to reservoir units) are identified and mapped across the seismic data volume to establish a continuity of the reservoir to areas lacking well control. The established sequence stratigraphic framework displays successions of sediments (system tracts) where the reservoir sand units of the lowstand and highstand system tracts are of hydrocarbon prospective units in the field. [ABSTRACT FROM AUTHOR]

Hydrostatic pressure exerted by the ocean water column fundamentally influences magmatic and hydrothermal processes in submarine volcanic settings and is therefore an important parameter to know when investigating such processes. Currently, there are few reliable methods for reconstructing past ocean depths for ancient volcanic terranes. Here, we develop and test an empirically calibrated statistical approach for determining paleodepths of eruption from the concentrations of H2O and CO2 dissolved in volcanic glasses, utilizing the well‐defined pressure‐dependent solubility of these volatiles in silicate melts. By comparing newly determined and published glass compositions from the Samail and Troodos ophiolites with sedimentary and fluid inclusion evidence, we propose that the Samail lavas erupted at ocean depths of ∼3.4 km, and the Troodos lavas at ∼4.1 km. These depths are 1–2 km deeper than those assumed in most previous studies of hydrothermal activity in the two ophiolites. These high depths imply high hydrostatic pressures within the underlying oceanic crust. Such pressures may have allowed convecting hydrothermal fluids to attain significantly higher temperatures (e.g., >450°C) than in typical modern ocean ridge hydrothermal systems during metal leaching in the crust and metal precipitation in seafloor sulfide deposits. Plain Language Summary: The pressure of seawater exerts a fundamental influence on volcanism and related processes in Earth's oceanic crust. This article presents an improved method for estimating the depth of seawater above ancient oceanic volcanic rocks as they were forming. Determining these depths allows us to better define the pressure under which this ancient crust formed and hence more accurately model it and compare it to modern examples. Key Points: The H2O–CO2 contents of volcanic glasses in the ophiolites are used to estimate ocean depths during lava extrusion on the seafloorOcean depth during volcanism is constrained to between 3.2 and 4.0 km for the Samail ophiolite and 3.6 and 4.9 km for the Troodos ophioliteHigh subseafloor fluid pressures may have allowed convecting hydrothermal fluids to reach temperatures above 450° [ABSTRACT FROM AUTHOR]

Abstract The Southern Ocean is a key player in the climate, ocean, and atmospheric system. As the only direct connection between all three major oceans since the opening of the Southern Ocean gateways, the development of the Southern Ocean and its relationship with the Antarctic cryosphere has influenced the climate of the entire planet. Although the depths of the ocean floor have been recognized as an important factor in climate and paleoclimate models, appropriate paleobathymetric models including a detailed analysis of the sediment cover are not available. Here we utilize more than 40 years of seismic reflection data acquisition along the margins of Antarctica and its conjugate margins, along with multiple drilling campaigns by the International Ocean Discovery Program (IODP) and its predecessor programs. We combine and update the seismic stratigraphy across the regions of the Southern Ocean and calculate ocean‐wide paleobathymetry grids via a backstripping method. We present a suite of high‐resolution paleobathymetric grids from the Eocene‐Oligocene Boundary to modern times. The grids reveal the development of the Southern Ocean from isolated basins to an interconnected ocean affected by the onset and vigor of an Antarctic Circumpolar Current, as well as the glacial sedimentation and erosion of the Antarctic continent. The ocean‐wide comparison through time exposes patterns of ice sheet development such as switching of glacial outlets and the change from wet‐based to dry‐based ice sheets. Ocean currents and bottom‐water production interact with the sedimentation along the continental shelf and slope and profit from the opening of the ocean gateways.

The evolution of the Northern Hemisphere oceanic gateways has facilitated ocean circulation changes and may have influenced climatic variations in the Cenozoic time (66 Ma–0 Ma). However, the timing of these oceanic gateway events is poorly constrained and is often neglected in global paleobathymetric reconstructions. We have therefore re-evaluated the evolution of the Northern hemisphere oceanic gateways (i.e. the Fram Strait, Greenland–Scotland Ridge, the Central American Seaway, and the Tethys Seaway) and embedded their tectonic histories in a new global paleobathymetry and topography model for the Cenozoic time. Our new paleobathymetry model incorporates Northeast Atlantic paleobathymetric variations due to Iceland mantle plume activity, updated regional plate kinematics, and models for the oceanic lithospheric age, sediment thickness, and reconstructed oceanic plateaus and microcontinents. We also provide a global paleotopography model based on new and previously published regional models. In particular, the new model documents important bathymetric changes in the Northeast Atlantic and in the Tethys Seaway near the Eocene–Oligocene transition (~34 Ma), the time of the first glaciations of Antarctica, believed to be triggered by the opening of the Southern Ocean gateways (i.e. the Drake Passage and the Tasman Gateway) and subsequent Antarctic Circumpolar Current initiation. Our new model can be used to test whether the Northern Hemisphere gateways could have also played an important role modulating ocean circulation and climate at that time. In addition, we provide a set of realistic global bathymetric and topographic reconstructions for the Cenozoic time at one million-year interval for further use in paleo-ocean circulation and climate models. Unlabelled Image • New global Cenozoic paleobathymetry/topography model • Detailed reconstructions of the Northern Hemisphere oceanic gateways • The influence of the Iceland mantle plume pulsations is included in the NE Atlantic paleobathymetry • Global reconstructions are made available for the entire Cenozoic time (66 Ma–0 Ma). [ABSTRACT FROM AUTHOR]

The Southern Ocean is a key player in the climate, ocean, and atmospheric system. As the only direct connection between all three major oceans since the opening of the Southern Ocean gateways, the development of the Southern Ocean and its relationship with the Antarctic cryosphere has influenced the climate of the entire planet. Although the depths of the ocean floor have been recognized as an important factor in climate and paleoclimate models, appropriate paleobathymetric models including a detailed analysis of the sediment cover are not available. Here we utilize more than 40 years of seismic reflection data acquisition along the margins of Antarctica and its conjugate margins, along with multiple drilling campaigns by the International Ocean Discovery Program (IODP) and its predecessor programs. We combine and update the seismic stratigraphy across the regions of the Southern Ocean and calculate ocean‐wide paleobathymetry grids via a backstripping method. We present a suite of high‐resolution paleobathymetric grids from the Eocene‐Oligocene Boundary to modern times. The grids reveal the development of the Southern Ocean from isolated basins to an interconnected ocean affected by the onset and vigor of an Antarctic Circumpolar Current, as well as the glacial sedimentation and erosion of the Antarctic continent. The ocean‐wide comparison through time exposes patterns of ice sheet development such as switching of glacial outlets and the change from wet‐based to dry‐based ice sheets. Ocean currents and bottom‐water production interact with the sedimentation along the continental shelf and slope and profit from the opening of the ocean gateways. Plain Language Summary: The Southern Ocean is the only ocean which connects all three major world's oceans and therefore plays a vital role in our planet's oceanographic and atmospheric systems. We reconstruct the changing depth and geometry of the Southern Ocean seafloor since the establishment of a major ice sheet in Antarctica (34 Ma). We also provide an inventory of ice‐sheet eroded sediments deposited in the Southern Ocean, which has previously been highly underestimated. This ocean‐wide study shows the development of the Southern Ocean from individual, separated basins into the home of the strong Circumpolar current system, by the deepening of the land bridges between Antarctica and Australia and Antarctica and South America. The sediments deposited in the Southern Ocean, especially along the Antarctic margin, illustrate the growth and retreat of the Antarctic ice sheets showing two distinct pulses of enhanced sedimentation at the first continental‐scale glaciation of Antarctica (34 Ma) and after the warm phase of the Miocene Climatic Optimum. On a local and regional scale, we trace the amount of erosion provided by glacier systems along the Antarctic coast. The presented suite of seafloor grids will be made available to the geoscientific community and is an important additional input parameter for paleo‐models. Key Points: Suite of paleobathymetric grids encompassing key time intervals in Southern Ocean development since the Eocene/Oligocene BoundaryDetailed sediment isopachs reveal two distinct sedimentation surges in relation to the advancement of the Antarctic Ice SheetsReconstruction of the Southern Ocean gateways point to the potential of deep‐water exchange in the middle Oligocene [ABSTRACT FROM AUTHOR]

The evolution of the Lycian Foreland and Aksu basins are associated with the Africa-Eurasia convergence and collision of intervening continental blocks. Both basins developed around the Beydağları, a Mesozoic carbonate platform, which constitutes the main component and western limb of the Isparta Angle. The Gömbe Basin is an integral part of the Lycian Foreland Basin that comprises mainly Eocene to Late Miocene turbidites, onto which the allochthonous Lycian and Antalya nappes thrust over. The Aksu Basin, however, developed in the inner part of the Isparta Angle and is bounded by the Aksu Thrust in the east. During their evolution, these basins experienced significant bathymetric changes, possibly due to vertical motions and variations in the sediment supply. This study provides a detailed analysis of the paleobathymetric evolution of these basins. This conducted paleobathymetric study was based on the determination of the depositional depth by the abundance ratio of planktonic versus benthic foraminifera, which is the function of the water depth. The percentage of planktonic foraminifera relative to the total foraminifer population (%P) increases from shallow to deep water. However, some benthic foraminifera species are directly affected by the oxygen level of the bottom water, rather than by paleobathymetry, i.e. stress markers, and were discarded in the calculation. Additionally, the dissolution of the foraminifera has the potential for miscalculations, since planktonic foraminifera are more prone to dissolution than benthic ones. Nevertheless, the obtained quantitative results were verified and validated qualitatively by specific benthic depth markers that lived at specific depth ranges. Aksu Basin had a shallowing trend, and the sedimentation rate exceeded the subsidence in the middle of the section. Calculated depths for the Gömbe Basin indicated depths around 1000 m, which was contrary to the high sedimentation rates indicated by the turbiditic facies of the basin infills. [ABSTRACT FROM AUTHOR]

The early Eocene is a period with very high atmospheric CO2 levels, which receives many interests from climate modelling aspects. To simulate the early Eocene paleoclimate, a realistic reconstruction for land-sea distribution, paleotopography and paleobathymetry is the fundamental step. Here, we present global paleogeographic reconstructions for the early Eocene (∼55 Ma), based on integrated paleogeographic data set, the plate-tectonic reconstruction software (GPlates) and geographic information system software (ArcGIS). Comparing with previous paleogeographic reconstructions, we improve the reconstructions by incorporating many recent geologic data and data set, including: (1) Better representations of the Tethys Sea, some marginal or inland seas in the East and Southeast Asia, Atlantic and Arctic region, and the Drake Passage and Tasmanian Gateway; (2) integrated paleoelevation data of global high plateaus and mountains, especially the paleotopography of East Asia, and adopting the latest paleotopographic reconstruction data of the Antarctica; and (3) using the latest data set of oceanic crust paleo-age and oceanic sediment thickness to reconstruct the paleobathymetry. [ABSTRACT FROM AUTHOR]

Coastal fish assemblages are especially vulnerable to environmental changes, but little is known about their evolution through time, mainly due to the scarcity of fossil material from such settings. The aim of this study is to characterize the early Pleistocene coastal fish assemblages of the eastern Mediterranean and to reconstruct the related paleobathymetric and paleoecologic conditions. Based on otolith findings, we identified thirty-seven teleost fish species from three sedimentary outcrops on the northeastern part of Rhodes Island (southeastern Aegean, Greece, Eastern Mediterranean), which have been placed within the Gelasian (early Pleistocene). The stratigraphic distribution of fifteen taxa is expanded for this interval, while five species are reported for the first time as fossils. The otolith assemblages provided paleodepth estimates indicative of shallow coastal environments. The ecosystem consisted mostly of substrates of sand and mud, with significant rocky micro-habitats and underwater vegetation; the climate was subtropical. These data complement existing knowledge on the study area, while providing new information on the composition of the ichthyofauna of the eastern Mediterranean during the Gelasian. [ABSTRACT FROM AUTHOR]

Trace fossils have been used worldwide to access paleoecologic data in sedimentary sections. In Paraná Basin (southern Brazil), trace fossils are stratigraphically well distributed; however, they are understudied if compared to body macrofossils or microfossils. Only few studies applied ichnology to the Silurian-Devonian strata, and mostly focused in an ichnotaxon. This comprehensive study aims to analyze the ecospace colonization represented by trace fossils in a Silurian-Devonian section from Paraná Basin, and to associate the paleoenvironmental data provided by trace fossils with the decline of the Malvinokaffric Realm. In this sense, trace fossils were analyzed in six sedimentary sections to encompass the whole outcropping supersequence. The vertical distribution of trace fossils (Glossifungites, Skolithos and Cruziana ichnofacies) was compared with the distribution of the Malvinokaffric macrofossils. Paleoecologic and ichnodisparity analyzes allowed to infer dominance of stable conditions throughout the Silurian-Devonian section; however, some levels express dysoxic to anoxic conditions, and in others the high energetic conditions biased the ichnologic record. The stratigraphic distribution of Zoophycos suggests a change in the basin configuration during Eifelian, which might be related to the decline in the diversity of the Malvinokaffric fauna. • Trace fossils analysis allowed paleoecologic interpretations regarding oxygenation and paleobathymetric curves. • Paleobathymetryc trends suggest high subsidence rates during Pragian-Emsian in Paraná Basin. • The decline both of Malvinokaffric fauna and Zoophycos seems to be related to a basin restriction. • Global events influenced the marine biota in the southern Gondwana. [ABSTRACT FROM AUTHOR]

This study deals with the foraminiferal assemblages of Plio-Pleistocene sediments of the northern side of the Peloritani Mountains (North-Eastern Sicily). Six sections were closely sampled in the surroundings of Rometta (Sottocastello Sud, Sottocastello, Torrione, Sperone, Sottorometta, Rometta}, three in nearby valleys (Torretta, S. Sehastiano, Serro), and three others come from a quarry in the northern plain toward the Tyrrhenian Sea (Villafranca Tirrena).

Veacute;rard et al. (2015, Journal of Palaeogeography, 4(1): 64-84) claim that their global geodynamic model allows one to reconstruct the surface features of topography on land and in adjacent oceans (i.e., paleobathymetry) anywhere on the globe and at any geological time during the past 600 million years (Ma). Such a grand model requires a rigorous scrutiny. The purpose of this discussion is to illustrate that the model suffers from (1) the selective omission of real-world datasets that do not fit the model, (2) the inclusion of datasets without revealing their original sources or without citing relevant peer-reviewed publications, (3) the emphasis on ‘unpublished’ internal company datasets that disallow open access to the international scientific community, and (4) the use of poorly understood concepts without providing the basic conceptual clarity. These deficiencies undermine the credibility of the heuristic model.

Abstract To understand the Late Pleistocene human dispersals to the Japanese Archipelago, we examine the paleobathymetric changes in and around the archipelago based on the results of recent paleoclimatological study of the Japan Sea that has provided millennium-scale sea level changes, the Pleistocene mammalian faunal record (e.g., extinct proboscideans), and the Paleolithic archaeological record. Proboscideans likely migrated from continental East Asia to Paleo-Honshu (consisting of the present day Honshu, Shikoku, and Kyushu islands) and the Ryukyu islands via land bridges across the Tsushima Strait and Yonaguni Strait during the coldest periods of the Middle Pleistocene (MIS 6, 12, 16, and probably 35). However, no clear evidence of hominin arrival in the archipelago has been dated to the Middle Pleistocene. Further, land bridges connecting continental East Asia and Paleo-Honshu were not present during the period of initial major human dispersals to the Japanese Archipelago, i.e., Marine Isotope Stage (MIS) 3 and 2. Thus, initial dispersals to Paleo-Honshu and the Ryukyus were achieved by watercraft and would have involved advanced seafaring skills. The paucity of archaeological sites before the onset of late MIS 3 (prior to 40 ka) and the significant increase of archaeological sites since late MIS 3 suggests that increasing population density on the East Asian mainland may have been a factor for humans to disperse into the Japanese Archipelago. Highlights • Paleobathymetric data were examined to discuss the presence/absence of land bridges around the Japanese Archipelago. • Mammals migrated to the Japanese Archipelago via land bridges during the Middle Pleistocene. • No clear evidence of hominin dispersals to the Japanese Archipelago during the Middle Pleistocene • Initial hominin dispersals to the Japanese Archipelago were MIS 3 and 2. • Dispersals were achieved by water craft and seafaring skills. [ABSTRACT FROM AUTHOR]

Abstract: Various methods of ostracod analysis with reference to paleobathymetric and paleotemperature reconstruction are considered in detail, using Callovian-Lower Oxfordian ostracod assemblages from the Mikhailovtsement reference section (Ryazan Region) as an example. Based on generalization of the data obtained by different methods, seven transgressive-regressive events are reconstructed, five of which had a pan-European scale and were accompanied by the intensified boreal effect. For the Upper Callovian of the East European Platform, ostracod index species of paleotemperatures, paleoeutrophication, and paleodepths on the upper subtidal depths are recognized for the first time. [ABSTRACT FROM AUTHOR]

Abstract Remote mapping of bathymetry can play a key role in gaining spatial and temporal insight into fluvial processes, ranging from hydraulics and morphodynamics to habitat conditions. This research introduces Multiple Optimal Depth Predictors Analysis (MODPA), which combines previously developed depth predictors along with additional predictors derived from the intensity component of the HSI color space transformation. MODPA empirically selects a set of optimal predictors among all candidates utilizing partial least squares (PLS), stepwise, or principal component (PC) regression models. The primary focus of this study was on shallow (<1 m deep) and clearly flowing streams where substrate variability could have a pronounced effect on depth retrieval. Spectroscopic experiments were performed under controlled conditions in a hydraulic laboratory to examine the robustness of bathymetry models with respect to changes in bottom type. Further, simulations from radiative transfer modeling were used to extend the analysis by isolating the effect of inherent optical properties (IOPs) and by investigating the performance of bathymetry models in optically complex and deeper streams. The bathymetry of the Sarca River, a shallow river in the Italian Alps, was mapped using a WorldView-2 (WV-2) image, for which we evaluated the atmospheric compensation (AComp) product. Results indicated the greater robustness of multiple-predictor models particularly MODPA rather than single-predictor models, such as Optimal Band Ratio Analysis (OBRA), with respect to heterogeneity of bottom types, IOPs, and atmospheric effects. The HSI intensity component enhanced the accuracy of depth retrieval, particularly in optically-complex waters and also for low spectral resolution imagery (e.g., GeoEye). Further, the enhanced spectral resolution of WV-2 imagery improved bathymetry retrieval compared to 4-band GeoEye data. Highlights • A robust bathymetry method: Multiple Optimal Depth Predictors Analysis (MODPA) • Intensity components of HSI color space are incorporated in MODPA. • Intensity predictors enhanced the accuracy of depth retrievals. • Enhanced spectral resolution of WorldView-2 improved bathymetry retrievals. • Evaluation of atmospheric compensation (AComp) product of DigitalGlobe [ABSTRACT FROM AUTHOR]

Abstract The Ordovician-Silurian transition was a significant period when an obvious variation occurred worldwide in terms of tectonics, climate, oceans, paleontology, and sedimentology. Here we use stratigraphic forward modeling constrained by paleobiota, paleobathymetry, sedimentology, and geochemistry to study the tectonic subsidence history of the Early Silurian in the western Yangtze Block, South China. Numerical modeling suggests that the tectonic subsidence was not uniform during the deposition of the Early Silurian black shale of the Longmaxi Formation, with acceleration of tectonic subsidence during the later regression period. Furthermore, the subsidence rate at this time was at least three times that during the early transgression period. This acceleration resulted from the collision between the Yangtze Block and the southeastern Cathaysia Block, which affected the tectonic subsidence and the heterogeneity of the black shale. The results may provide quantitative implications for the reconstruction of the paleoenvironment, the evolution of paleobiota, the temporal-spatial distribution of the black shale, and the mechanism of block assemblage in South China. Highlights • Non-uniform subsidence with late acceleration is found by stratigraphic modeling. • Stratigraphic forward modeling is well constrained by multi-disciplinary data. • The late acceleration of tectonic subsidence results from plate collision. • The non-uniform subsidence controlled the evolution of paleobiotics and deposition. • The western Yangtze Block during Early Silurian is not a classic foreland basin. [ABSTRACT FROM AUTHOR]

Abstract As a sill constricting the exchange of deep water masses between the Nordic Seas and the North Atlantic, which forms an essential part of the Atlantic Meridional Overturning Circulation, the dynamic height of the Greenland Scotland Ridge and thus its overflow have an important influence on global climate. Several DSDP, ODP, and IODP sites have been drilled in the North Atlantic to shed light on the overflow and climate development. Reconstructions of bathymetry and sediment thickness have been put forward as well as calculations of the potential temperature of the conduit feeding the Iceland plume. The available studies have been screened to construct a conceptual model for the evolution of the palaeo-circulation in the North Atlantic and identify possible weaknesses in our knowledge. Details, e.g., timing and location, about the onset of the overflow are unknown, and especially the Paleogene development remains enigmatic. The database for this period is inadequate, and covers only small areas. The discussion centres on the earliest traces of the overflow leading to formation of sediment drifts in the eastern North Atlantic. More data provide a better base to reconstruct variations for the Neogene overflow, but also appears insufficient for in-depth analyses in time and space. Sediment drifts in the Iceland Basin indicate a first Iceland Faroe Ridge overflow for the early Miocene. Denmark Strait overflow appears to have started in mid-Miocene times, but evidence for this still is sparse. Grids of high-resolution seismic reflection data across all sediment drifts and all limbs of the Greenland Scotland Ridge combined with deeper drill sites targeting the complete sedimentary column down to basement are needed to fully understand the chronology of the Greenland Scotland Ridge overflow and its detailed impact on climate. Highlights • conceptual model for the GSR overflow chronology is constructed based on published hypotheses • late Oligocene/early Miocene deep water circulation appears to have been present only in the eastern North Atlantic • deepening and widening of the GSR allowed overflow of the IFR and later the DS since the early, resp. middle Miocene • large gaps in the distribution of the available datasets lead to conflicting suggestions for the timing of the overflow [ABSTRACT FROM AUTHOR]

Petroleum exploration activity in the deep basins of the Eastern Mediterranean has been rejuvenated over the last decade with the discoveries of the giant Tamar and Leviathan gas fields made by Noble Energy and its partners, and more recently with the discovery of the Zohr field by Eni. With exploration efforts pursuing deeper and older leads, a first-principles quantitative study of the region seems timely. While it is generally agreed that the Levant Basin formed along the northern passive margin of Gondwanaland during the Early Mesozoic, its complex post-rift evolution has not been documented in detail. Located in a unique junction of three active tectonic plates and at the distal end of the Nile, one of the largest rivers on Earth, the Levant Basin is characterized by a thick sedimentary section, more than half of which has accumulated since the Oligocene, in the last ∼15% of its existence. This study implements a quantitative basin-modelling workflow that assesses the three-dimensional crustal geometry of the Levant Basin and its post-rift evolution, by integrating 3D-gravity-inversion and 3D-flexural-backstripping techniques. The focus of the gravity inversion, which includes corrections for the lithosphere thermal gravity anomaly resulting from lithosphere thinning and for the magmatic addition from decompression melting, has been to predict both the 3D crustal-structure and the magnitude of total lithospheric stretching for the Levant Basin. The 3D-flexural-backstripping workflow, using the outputs of the gravity inversion, invokes three major processes in its calculations, accompanying the layer-by-layer removal of the stratigraphy: (i) 3D flexural-isostatic unloading, (ii) decompaction in response to the removal of overburden and (iii) reverse thermal-subsidence modelling, controlled by the stretching factor derived from the gravity inversion. Backstripping has produced a series of maps and cross sections depicting the evolution of post-rift palaeobathymetry in the Levant Basin. The integration of these techniques allows us to assess the evolution of the basin and the various sedimentary and tectonic events that have occurred since basin initiation. Although the calculated stretching factors indicate that while the lithosphere underlying the Levant Basin has been very highly stretched and thinned, the stretching did not progress to the formation of new oceanic crust. Predicted palaeobathymetry portrays a thermally-subsiding basin reaching maximum water-depths at the onset of the Cenozoic. This deep basin provided ample amount of accommodation space for the large volumes of terrigenous clastics, sourced from the contemporaneous uplift and exhumation of the basin margins and delivered in large part, at least since the Oligocene, by the continental drainage of the Nile. These sediments have been filling and shallowing the basin ever since. The basin evolution described here is consistent with available geophysical and geological data and has important implications for petroleum-systems modelling within the basin. [ABSTRACT FROM AUTHOR]

The trace fossil Paleodictyon is characterized by a regular hexagonal network and has been widely considered to be a characteristic of the Nereites ichnofacies, indicative of a deep-marine environment. Recently, however, some researchers have reported Paleodictyon occurrences in relatively shallow settings, leading to suggestions that the habitat of these burrowers was not restricted to deep-marine environments. A new occurrence of this trace fossil is presented in this study from a shallow-marine succession of Upper Cretaceous deposits in northern Japan. Paleobathymetric and temporal variations in the habitat range of shallow-marine examples of this ichnotaxon are also discussed based on a compilation of previous works. The new Paleodictyon specimens discussed here are from the lowermost part of the Mikasa Formation within the Yezo Group, interpreted as a deposit representing the lower shoreface through to the inner shelf transitional zone. This paper presents the first record of a shallow-marine Paleodictyon from the Pacific region; combined with data from previous studies, records suggest that shallow-marine Paleodictyon are observable from Paleozoic-to-Mesozoic shelf deposits, although no reliable records of their occurrences have so far been reported from the Cenozoic. Increasing bioturbation intensity and predation pressure during the Mesozoic and Cenozoic may have been significant factors preventing the preservation of this ichnogenus in post-Mesozoic shallow-marine settings. The Paleodictyon -bearing interval of the Mikasa Formation also preserves evidence for low-intensity bioturbation, which may account for preservation of the traces in this case. [ABSTRACT FROM AUTHOR]

Abstract: The pyBacktrack software package allows the backtracking of the paleo‐water depth of ocean drill sites, providing a framework for reconstructing the accumulation history of sediment components through time. The software incorporates the effects of decompaction of common marine lithologies and allows backtracking of sites on both oceanic and continental crust. Backtracking on ocean crust is based on a user‐selected lithospheric age‐depth model and the present‐day unloaded basement depth. Backtracking on continental crust is based on syn‐rift and post‐rift subsidence that is modeled using the total sediment thickness at the site and the timing of the transition from rifting to thermal subsidence. On sites that did not penetrate basement, the age‐coded stratigraphy is supplemented with a synthetic stratigraphic section that represents the undrilled section, whose thickness is estimated using a global sediment thickness map. This is essential for estimating the decompacted thickness of the total sedimentary section, and thus bathymetry, through time. PyBacktrack further allows the consideration of the effects of mantle‐convection driven dynamic topography on paleo‐water depth. The user can select one of the dynamic topography models bundled with pyBacktrack or add other models. PyBacktrack runs on all platforms with a Python 2.7 and a pyGPlates installation and is available via Github. [ABSTRACT FROM AUTHOR]

Abstract: Motivation: Past sea level fluctuations have shaped island area and archipelago configuration. The availability of global high‐resolution data on bathymetry and past sea levels allows reconstruction of island palaeo‐geography. Studies on the role of palaeo‐area often consider only the Last Glacial Maximum, which neglects the dynamics of island fusion and fission resulting from cyclic sea level fluctuations throughout the Quaternary. Currently, no global database is available to test the role of changing island geographies driven by Quaternary sea level change on evolutionary, ecological and archaeological patterns. However, data on island palaeo‐environments is crucial for understanding insular biodiversity distributions and human settlement patterns. Here, we present the Palaeo‐Islands and Archipelago Configuration (PIAC) database, containing sea level‐driven palaeo‐geography changes over the late Quaternary of 178 islands in 27 archipelagos, and discuss its relevance, limitations and uncertainties. The R functions developed to create the PIAC database are provided to allow calculations for other islands, time steps, sea‐level curves and higher spatio‐temporal resolutions. Main types of variables contained: Polygon shapefiles with archipelago configuration and tables with palaeo‐area per island. Spatial location and grain: The database has a global representation, with 27 archipelagos being covered: Aldabra, Azores, Balearic Islands, California Channel Islands, Canary Islands, Cape Verde, Comoros, Cook Islands, Crozet Islands, Dutch Caribbean, Galápagos, Gulf of Guinea, Hawaii, Inner Seychelles, Juan Fernández, Kuril Islands, Madeira, Marianas, Marquesas, Mascarenes, Phoenix Islands, Pitcairn Islands, Prince Edward Islands, Revillagigedo, Samoan Islands, Society Islands and Tristan da Cunha. All data are at 1 km2 spatial resolution. Time period and grain: The focus of this paper is on the last 35 kyr; data for the last 140 kyr are also provided. The grain is 1 kyr temporal resolution. Level of measurement: Data are per island, grouped per archipelago. Software format: The data were produced in the R programming language. [ABSTRACT FROM AUTHOR]

Borehole Bh-3, located at the eastern part of the Corinth Isthmus (Greece) in a highly active extensional tectonic environment, is studied in detail. The lithology of the 70-m-long borehole is described, and 55 samples extracted from the core are analyzed for their micropaleontological content. Quantitative analysis of foraminiferal fauna assemblages, along with magnetic susceptibility measurements, indicates alternations between different paleoenvironments ranging from upper shoreface and fluvial-terrestrial to lagoon and shallow marine. The borehole site regional paleodepth was estimated, ranging from a few meters to ~40 m on the basis of foraminiferal assemblages within the borehole, and the vertical stacking of the facies was interpreted as transgressive and regressive system tracts. Calcareous nannofossils found within the core, based on the presence of Emiliania huxleyi specimens, correlated with the glacioeustatic sea-level changes, and the uplift rate of the area indicated a post-240-ka age, corresponding to sea-level highstand marine isotope stages 7 to 5. [ABSTRACT FROM AUTHOR]

The Eocene-Oligocene Transition (EOT) marks a major step within the Cenozoic climate in going from a greenhouse into an icehouse state, with the formation of a continental-scale Antarctic ice sheet. The roles of steadily decreasing CO 2 concentrations versus changes in ocean circulation at the EOT are still debated and the threshold for Antarctic glaciation is obscured by uncertainties in global geometry. Here, a detailed study of the late Eocene ocean circulation is carried out using an ocean general circulation model under two slightly different geography reconstructions of the middle-to-late Eocene (38 Ma). Using the same atmospheric forcing, both geographies give a profoundly different equilibrium ocean circulation state. The underlying reason for this sensitivity is the presence of multiple equilibria characterised by either North or South Pacific deep water formation. A possible shift from a southern towards a northern overturning circulation would result in significant changes in the global heat distribution and consequently make the Southern Hemisphere climate more susceptible for significant cooling and ice sheet formation on Antarctica. [ABSTRACT FROM AUTHOR]

Otoliths from the Middle Miocene of the Moravian Carpathian Foredeep revealed the presence of 84 nominal species of bony fishes, as well as 22 taxa identified in open nomenclature only. Two species, Ijimaia rara n. sp. and Coryphaenoides scrupus n. sp., are described as new. The otolith assemblage is quantitatively dominated by myctophids, but stomiiforms and macrourids are significantly represented as well. Bregmacerotids, gadids and trachichthyids are common, but only represented by a single species each. The genera Trachyscorpia, Serrivomer and Ijimaia document the first fossil records of these taxa and the genera Nansenia and Zenion are recorded for the first time in sediments of the Paratethys. A paleobathymetric analysis of the otolith assemblages indicates water depths greater than 400 m in the depressions of the Carpathian Foredeep in Moravia. The high frequency of otoliths of Gadiculus argenteus supports the onset of the cold phase of the Middle Miocene Climatic Transition during the Middle Badenian. The high proportion of Recent species (~ 32%) in the otolith association of the entire Badenian of the Central Paratethys also documents the rise of modern fishes in the wider Mediterranean area since the early Middle Miocene. [ABSTRACT FROM AUTHOR]

Limestone and shale facies of the Upper Ordovician Grant Lake Formation (Katian: Cincinnatian, Maysvillian) are well exposed in the Cincinnati Arch region of southern Ohio and north-central Kentucky, USA. These rocks record a gradual change in lithofacies and biofacies along a gently northward-sloping ramp. This gradient spans very shallow, olive-gray, platy, laminated dolostones with sparse ostracodes in the south to offshore, nodular, phosphatic, brachiopod-rich limestones and marls in the north. This study uses facies analysis in outcrop to determine paleoenvironmental parameters, particularly those related to water depth (e.g., position of the photic zone and shoreline, relative degree of environmental energy). Within a tightly correlated stratigraphic interval (the Mount Auburn and Straight Creek members of the Grant Lake Formation and the Terrill Member of the Ashlock Formation), we document the occurrence of paleoenvironmental indicators, including desiccation cracks and light-depth indicators, such as red and green algal fossils and oncolites. This permitted recognition of a ramp with an average gradient of 10–20 cm water depth per horizontal kilometer. Thus, shallow subtidal (“lagoonal”) deposits in the upramp portion fall within the 1.5–6 m depth range, cross-bedded grainstones representing shoal-type environments fall within the 6–18 m depth range and subtidal, shell-rich deposits in the downramp portion fall within the 20–30 m depth range. These estimates match interpretations of depth independently derived from faunal and sedimentologic evidence that previously suggested a gentle ramp gradient and contribute to ongoing and future high-resolution paleontologic and stratigraphic studies of the Cincinnati Arch region.

Abnormal zones of the Bazhenov Formation originated in the Neocomian as a result of protobazhenite reworking by submarine slide and slump waste wedgings, which eroded and deformed slope toe protobazhenite. But gas hydrate (GH) cementation might restrict the rock ability for plastic deformation. The conditions for GH thermodynamic stability in protobazhenites are inferred from reconstructions of paleogeographic and paleo-oceanic evironments. Joint analysis of Neocomian marine paleodepths and deep water paleotemperatures provides an explanation of the Bazhenov abnormal-zone extension. [ABSTRACT FROM AUTHOR]

At present, global paleoclimate simulations are prepared with bathtub-like, flat, featureless and steep walled ocean bathymetry, which is neither realistic nor suitable. In this article, we present the first enhanced version of a reconstructed paleobathymetry for Cenomanian-Turonian (94 Ma) time in a 0.1° x 0.1° resolution, that is both realistic and suitable for use in paleo-climate studies. This reconstruction is an extrapolation of a parameterized modern ocean bathymetry that combines simple geophysical models (standard plate cooling model for the oceanic lithosphere) based on ocean crustal age, global modern oceanic sediment thicknesses, and generalized shelf-slope-rise structures calibrated from a published global relief model of the modern world (ETOPO1) at active and passive continental margins. The base version of this Cenomanian-Turonian paleobathymetry reconstruction is then updated with known submarine large igneous provinces, plateaus, and seamounts to minimize the difference between the reconstructed paleobathymetry and the real bathymetry that once existed. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous-Lower Paleogene succession at Gabal Qreiya area that covers six rock units, Quseir, Duwi, Dakhla, Tarawan, Esna, and Thebes formations, is reviewed through a high-resolution sequence stratigraphic analysis. Six third-order depositional sequences and their associated surfaces and systems tracts are recognized based on stratigraphic, sedimentological, and high-resolution foraminiferal studies. The pre-Campanian sequence, comprising the Quseir Formation, was accumulated in inner neritic paleodepths, on marginal to shallow subtidal shelf. The Lower Campanian sequence that covers the Duwi Formation was accumulated in oscillating settings between inner to middle neritic paleodepths, on a shallow subtidal shelf. The Upper Campanian-Maastrichtian sequence that covers the lower part of the Dakhla Formation was accumulated in outer neritic-upper bathyal to middle neritic paleodepths, on a deep subtidal shelf to a shallow subtidal shelf. The Danian sequence that covers the middle part of the Dakhla Formation was accumulated in oscillating conditions between upper bathyal and middle neritic paleodepths, on a deep subtidal and a shallow subtidal shelf. The Selandian-Thanetian sequence that comprises the upper part of the Dakhla, Tarawan, and the lower part of the Esna formations was accumulated in fluctuating conditions from upper bathyal to middle neritic paleodepths, on a deep subtidal to a shallow subtidal shelf. The Ypresian sequence that includes the main parts of Esna and Thebes formations was accumulated in fluctuating settings among middle bathyal and middle neritic paleodepths, on a deep subtidal to a shallow subtidal shelf. Most of the sequence boundaries coincide with the global sea-level curve whereas some of them suggest a local tectonic event. [ABSTRACT FROM AUTHOR]

In the reservoir exploration phase, different types of information are gathered and used for a reliable geological description. Combining seismic data, well log analysis, statistical rock physics or even paleobathymetry ranges, several methods have been proposed to estimate a probability field for each facies type in the reservoir model. However, these probability fields are typically not conditioned to the reservoir production history. Once the reservoir starts production new information becomes available, and an update of the probability fields is needed. The work presented here introduces a new framework for simulation of facies fields in the context of plurigaussian simulation where the facies fields are conditioned to the prior probability fields provided. The methodology is based on the probability integral transform and the topological characteristics of the facies types (number of the facies type and relative position among facies types). The developed method generates an ensemble of facies fields that honor the facies distribution as described by a probability field. The proposed method can easily condition the facies field to hard data and preserve the facies field during history matching in an ensemble based framework. A demonstration with the adaptive Gaussian mixture filter is presented here. [ABSTRACT FROM AUTHOR]

The sequence stratigraphic architecture of the Neogene section from the subsurface Nile Delta is resolved based on exceptionally well-preserved microfossils from the offshore NDOB-1 borehole. The architecture is configured on bathymetry variations and statistical parameters as deduced from the relative abundance of foraminiferal associations. The statistical parameters include ratios of planktic versus benthic foraminifera, and cluster and correspondence analysis of the twelve most commonly used benthic foraminiferal genera as proxies of water depths. The combination of cluster and correspondence analysis was employed to decipher the evolution and dynamics of the basin and the mechanisms that controlled the deposition of Neogene sequences in the Nile Delta region. Four basic environmental settings were recognized: 1.) a middle to outer neritic eutrophic setting, 2.) a middle to outer neritic mesotrophic setting, 3.) an outer neritic to upper bathyal mesotrophic setting and 4.) an upper bathyal mesotrophic setting. Eight stratigraphic sequences were identified in the Neogene Nile Delta section. Three sequence in the Miocene (MSeq1, MSeq2 and MSeq3), three in the Pliocene (PSeq1, PSeq2 and PSeq3) and two in the Pleistocene (PtSeq1 and PtSeq2). These sequences are systematically measured and described in terms of time, space and water bathymetry. The sequence boundaries and flooding surfaces were dated using high-resolution microfossil biochronology and stratigraphic index markers. Individual sequences and boundaries were correlated with international and local sequence stratigraphic models. The new sequence stratigraphic model established here provides age calibrated surfaces for inter-basinal correlations and opens new avenues for hydrocarbon reservoir exploration. [ABSTRACT FROM AUTHOR]

In the field of paleoceanographic modeling, the different positioning of Earth’s continental configurations is often a major challenge for obtaining equilibrium ocean flow solutions. In this paper, we introduce numerical parameter continuation techniques to compute equilibrium solutions of ocean flows in the geological past, where we change the continental geometry and allow the flow to deform using a homotopy parameter. The methods are illustrated by computing equilibrium three-dimensional global ocean circulation patterns over the last 65 Ma under a highly idealized atmospheric forcing. These results already show interesting major transitions in ocean circulation patterns due to changes in ocean gateways, that may have been relevant for Cenozoic climate transitions. In addition, the techniques are shown to be computationally efficient compared to the established continuation spin-up approach. [ABSTRACT FROM AUTHOR]

The reconstruction of glacial paleolake formation and evolution allows the understanding of glacier advance and retreat behavior for longer periods of time. New datings obtained from paleolacustrine deposits in the Argentinian Patagonian Andes (Northwestern region of Santa Cruz Province) reveal that glacial lakes formed before the Last Glacial Maximum, they being as old as 31,278 cal yr BP, and evolved until 6900 cal yr BP. The interpretation of stratigraphic profiles described in different sectors of the Perito Moreno National Park (PMNP) allows reconstructing lacustrine, glaciolacustrine, glacial till and delta paleoenvironments. In each sector, organic-rich sediments were also sampled to obtain four absolute ages through AMS methodology. Thus, the paleogeographic reconstructions proposed are based on paleobathymetries performed from digital elevation models, datings and facies distribution of lacustrine deposits (mainly composed of laminated silts with subordinated sands and muds). Based on these new data, the paleogeography of this area is characterized by two lakes at 880 m.a.s.l at 31,200 ca yr BP, one directly related to modern Belgrano lake, while the other is probably related to the Burmeister lake but more than 10 km toward the East as respect to its current position. The paleogeography reconstruction shows, between 11,731 cal yr BP and 10,819 cal yr BP, the existence of a major paleolake at 900-920 m.a.s.l. which was connected to several modern lakes. Finally, a decrease of the paleolake level between 900 and 890 m.a.s.l. was recorded at 6900 cal yr BP which produced two major lacustrine systems separated by moraine deposits. [ABSTRACT FROM AUTHOR]