Preprints
Filtering by Subject: Stratigraphy
The Anthropozoic era revisited
Published: 2020-07-22
Subjects: Earth Sciences, Physical Sciences and Mathematics, Stratigraphy
This paper explains in some detail the poorly known proposal of Stoppani (1873) regarding the Anthropozoic era, whose beginning was defined by the first traces of human presence on Earth. This author set the stratigraphic bases for the definition of the “human era”, but the proposal had two main weaknesses: the dismissal of biological evolution and the lack of an absolute chronology. Further [...]
“Enriching Lives within Sedimentary Geology”: Actionable Recommendations for Making SEPM a Diverse, Equitable and Inclusive Society for All Sedimentary Geologists
Published: 2020-07-15
Subjects: Earth Sciences, Education, Geology, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Innovative science benefits from diversity of thought and influence at all waypoints along the scientific journey, from early education to career-length contributions in research and mentorship. Scientific societies, like the Society for Sedimentary Geology (SEPM), steward their innovators and the direction of the science, thereby defining the societal impact and evolution of a discipline. They [...]
Geological Facies Modeling Based on Progressive Growing of Generative Adversarial Networks (GANs)
Published: 2020-06-21
Subjects: Artificial Intelligence and Robotics, Computer Sciences, Earth Sciences, Geology, Geophysics and Seismology, Hydrology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Geological facies modeling has long been studied to predict subsurface resources. In recent years, generative adversarial networks (GANs) have been used as a new method for geological facies modeling with surprisingly good results. However, in conventional GANs, all layers are trained concurrently, and the scales of the geological features are not considered. In this study, we propose to train [...]
Tectonic-Sedimentary Interplay of a Multi-Sourced, Structurally-Confined Turbidite System in a Foreland Basin Setting: The Pennsylvanian Lower Atoka Formation, Ouachita Mountains, USA
Published: 2020-06-19
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Submarine fans deposited in structurally complex settings record important information on basin evolution and tectonic-sedimentary relationships but are often poorly preserved in outcrops due to post-depositional deformation. This study integrates both new field data as well as data compiled from literature to demonstrate the spatial facies variability of the deep-water lower Atoka formation [...]
Architecture and controls of thick, intensely bioturbated, storm-influenced shallow-marine successions: an example from the Jurassic Neuquén Basin (Argentina)
Published: 2020-06-05
Subjects: Earth Sciences, Geology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Thick (>100 m-thick), highly bioturbated storm-influenced shallow-marine deposits are not frequent in the stratigraphic record, but they tend to be unusually common in aggradational to retrogradational successions. Individual storm-event beds have typically low preservation in these successions, yet depositional settings are characterized on the basis of storms processes. We present a [...]
Holocene tephrochronology of Kerguelen Archipelago, Subantarctic Indian Ocean
Published: 2020-05-20
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Volcanology
Up to now, no geochemical or geochronological data has been published about Holocene volcanic activity on the Kerguelen Archipelago. Here we present the first continuous Holocene chronology of volcanic eruptions on the archipelago. We compared sedimentological, geochronological and geochemical data from two lake sediment cores taken in two different depocenters of Lake Armor, located ca. 70 km [...]
The enigma of the Albian Gap: spatial variability and the competition between salt expulsion and extension
Published: 2020-04-14
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
The Albian Gap is a uniquely large (up to 65 km wide and >450 km long), enigmatic salt-related structure in the Santos Basin, offshore Brazil. It is located near the basin margin and trends NE (i.e. sub-parallel to the Brazilian coastline). The gap is characterized by a near-complete absence of Albian strata above depleted Aptian salt. Its most remarkable feature is an equivalently large, [...]
International disparities in open access practices of the Earth Sciences community
Published: 2020-03-31
Subjects: Biogeochemistry, Cosmochemistry, Earth Sciences, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Hydrology, Library and Information Science, Mineral Physics, Other Earth Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Social and Behavioral Sciences, Soil Science, Speleology, Stratigraphy, Tectonics and Structure, Volcanology
Short communication on international disparities in open access practices of the Earth Sciences community
Shallow-water mudstone architecture and depositional process variability: evidence for heterogeneity at kilometre-scale
Published: 2020-03-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Mudstone studies that use a large spacing (>5km) between datapoints provide little insight into the architecture and depositional process variability at kilometre scale. This often leads to the assumption that mudstones are laterally homogenous at kilometre and sub-kilometre scales. To better understand the lateral variability of mudstones at kilometre scale, the Mancos Shale in the eastern [...]
New composite bio- and isotope stratigraphies spanning the Middle Eocene Climatic Optimum at tropical ODP Site 865 in the Pacific Ocean
Published: 2020-02-20
Subjects: Earth Sciences, Geology, Paleontology, Physical Sciences and Mathematics, Stratigraphy
The Middle Eocene Climatic Optimum (MECO) at ca. 40 Ma is one of the largest of the transient Eocene global warming events. However, it is relatively poorly known from tropical settings as few sites span the entirety of the MECO event and/or host calcareous microfossils, which are the dominant proxy carrier. Ocean Drilling Program (ODP) Pacific Ocean Site 865 in the low-latitude North Pacific [...]
Entangled external and internal controls on submarine fan evolution: an experimental perspective
Published: 2020-02-02
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Submarine fans are formed by sediment-laden flows shed from continental margins into ocean basins. Their morphology represents the interplay of external controls such as tectonics, climate, and sea-level with internal processes including channel migration and lobe compensation. However, the nature of this interaction is poorly understood. We used physical modelling to represent the evolution of a [...]
Discriminating stacked distributary channel from palaeovalley fill sand bodies in foreland basin settings
Published: 2020-01-10
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Stratigraphy
Stacked fluvial distributary channel deposits and palaeovalley fills can form major, multi-storey sand bodies with similar thicknesses, and with lateral extents often greater than a single exposure. Consequently, they can be difficult to tell apart from one another using outcrop data. This study addresses this problem by quantitatively analysing the architecture of five stacked fluvial [...]
Stratigraphic reservoir compartmentalization: causes, recognition, and implications for the geological storage of carbon dioxide
Published: 2019-11-22
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
The impact of carbon capture and storage (CCS) in mitigating anthropogenic emissions of greenhouse gases is potentially great, but its success is strongly dependent on identifying suitable geological storage sites. One of the key uncertainties in this regard is the degree of compartmentalization of the target storage horizon. Many studies have examined reservoir compartmentalization in oil and [...]
Revised timing of Cenozoic Atlantic incursions and changing hinterland sediment sources during southern Patagonian orogenesis
Published: 2019-11-21
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Stratigraphy
New detrital zircon U-Pb geochronology data from the Cenozoic Magallanes-Austral Basin in Argentina and Chile ~51°S establish a revised chronostratigraphy of Paleocene – Miocene foreland synorogenic strata and document the rise and subsequent isolation of hinterland sources in the Patagonian Andes from the continental margin. The upsection loss of zircons derived from the hinterland Paleozoic and [...]
Does fluvial channel belt clustering predict net sand to gross rock volume? Architectural metrics and point pattern analysis of a digital outcrop model
Published: 2019-10-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Spatial point-pattern analyses (PPAs) are used to quantify clustering, randomness, and uniformity of the distribution of channel belts in fluvial strata. Point patterns may reflect end-member fluvial architecture, e.g., uniform compensational stacking and avulsion-generated clustering, which may change laterally, especially at greater scales. To investigate spatial and temporal changes in fluvial [...]