Preprints
Filtering by Subject: Stratigraphy
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: 2019-10-31
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 [...]
Holocene relative sea-level changes and glacial isostatic adjustment of the U.S. Atlantic coast
Published: 2019-10-01
Subjects: Climate, Earth Sciences, Environmental Sciences, Geomorphology, Glaciology, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
The first quality-controlled Holocene sea-level database for the U.S. Atlantic coast has been constructed from 686 sea-level indicators. The database documents a decreasing rate of relative sea-level (RSL) rise through time with no evidence of sea level being above present in the middle to late Holocene. The highest rates of RSL rise are found in the mid-Atlantic region. We employ the database to [...]
Repeated degradation and progradation of a submarine slope over geological timescales
Published: 2019-10-01
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Submarine slopes prograde via accretion of sediment to clinoform foresets, and degrade in response to channel or canyon incision, or mass-wasting processes. The timescales over which progradation and degradation occur, and the large-scale stratigraphic record of these processes, remain unclear due poor age constraints in subsurface-based studies, and areally limited exposures of exhumed systems. [...]
NSB: an expanded and improved database of marine planktonic microfossil data and deep-sea stratigraphy
Published: 2019-09-20
Subjects: Computer Sciences, Databases and Information Systems, Earth Sciences, Paleontology, Physical Sciences and Mathematics, Stratigraphy
Thirty years ago, the Neptune Database was created to synthesize microfossil occurrences from the deep-sea drilling record. It has been used in numerous studies by both biologists and paleontologists of the evolution and distribution in space and time of marine microplankton. After decades of discontinuous development in various institutions, a significant overhaul of the system was made during [...]
Miniature paleo-speleothems from the earliest Ediacaran (635 Ma) Doushantuo cap dolostone in South China and their implications for terrestrial ecosystems
Published: 2019-09-15
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Speleology, Stratigraphy
Speleothems can offer insights into terrestrial life because their formation is critically dependent on soil-microbial ecosystems. Here we report the wide distribution of miniature paleo-speleothems from the ~635 Ma Doushantuo cap dolostone in South China in order to understand the recovery of terrestrial life after the terminal Cryogenian Marinoan snowball Earth glaciation. The cap dolostone was [...]
Comparing Aggradation, Superelevation, and Avulsion Frequency of Submarine and Fluvial Channels
Published: 2019-08-31
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
IN REVIEW IN "FRONTIERS IN EARTH SCIENCE" (30 Aug 2019). Constraining the avulsion dynamics of rivers and submarine channels is essential for predicting the distribution and architecture of sediment, organic matter and pollutants in alluvial, deltaic, and submarine settings. Submarine channels are well known to be more aggradational than rivers, and aggradation of the channel, levee, and [...]
Grain-Size and Discharge Controls on Submarine-Fan Depositional Patterns From Forward Stratigraphic Models
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Submarine fans are important components of continental margins; they contain a stratigraphic record of environmental changes and host large accumulations of oil and gas. The grain size and volume of sediment supply to fans is thought to control the heterogeneity of deep-water deposits; predicting spatial variability of sandy and muddy deposits is an important applied challenge in the [...]
Deep-water reservoir distribution on a salt-influenced slope, Santos Basin, offshore Brazil
Published: 2019-08-08
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Studies of near-seabed datasets show that salt tectonics controls the distribution and architecture of deep-water reservoirs in many salt-influenced basins. It is typically difficult, however, to study the distribution and stratigraphic evolution of depositional systems preserved at deeper, economically significant depths, reflecting poor seismic imaging of steeply dipping strata flanking [...]
The Byers Basin: Jurassic-Cretaceous tectonic and depositional evolution of the forearc deposits of the South Shetland Islands and its implications for the northern Antarctic Peninsula
Published: 2019-07-31
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
This paper addresses the Jurassic–Cretaceous stratigraphic evolution of fore-arc deposits exposed along the west coast of the northern Antarctic Peninsula. In the South Shetland Islands, Upper Jurassic deep-marine sediments are uncomformably overlain by a Lower Cretaceous volcaniclastic sequence that crops out on Livingston, Snow and Low islands. U-Pb zircon ages are presented for the upper [...]
Giant meandering channel systems controlled by sediment supply to the deep-water Campos basin
Published: 2019-07-24
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Stratigraphy
Large meandering submarine-channel systems are important conduits for mass transfer to continental margins; wider and deeper channels, with larger meanders, reflect larger sediment discharge. Some large meandering channel systems are known to receive voluminous sediment from the largest rivers in the world, such as the Ganges-Brahmaputra, Amazon, Indus, Mississippi, and Zaire (Congo); however, [...]
Tectonic controls on the Maastrichtian-Danian transgression in the Magallanes-Austral foreland basin (Chile): Implications for the growth of the Southern Patagonian Andes
Published: 2019-07-05
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
The Maastrichtian-Danian transgression was one of the most extensive Atlantic-derived marine incursions in Patagonia. This study examines its stratigraphic record and origin in the Magallanes-Austral Basin, revealing an interplay of sedimentation, tectonism, and base-level changes, which contribute to our understanding of foreland basin dynamics. We present a multidisciplinary approach from a [...]
The stratigraphic evolution of onlap in siliciclastic deep-water systems: Autogenic modulation of allogenic signals
Published: 2019-04-10
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Seafloor topography affects the sediment gravity flows that interact with it. Understanding this interaction is critical for accurate predictions of sediment distribution, paleogeography, and structural reconstructions of deep-water basins. The effects of seafloor topography can be seen from the bed scale, through facies transitions toward intra-basinal slopes, to the basin scale, where onlap [...]
McHargue et al Architectural Diversity of Submarine Lobes
Published: 2019-02-15
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The most popular model for submarine unconfined lobate deposits has the following attributes: (1) a single feeder channel that delivers sediment, (2) a set of distributary channels present only in the proximal part of the lobate body, and (3) unchannelized tabular deposits present in the middle and distal part of the lobate deposit. This model has become a standard to guide interpretation of [...]
The Stratigraphic Record of Minibasin Subsidence, Precaspian Basin, Kazakhstan
Published: 2019-02-14
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
Minibasins are fundamental components of many salt-bearing sedimentary basins, where they may host large volumes of hydrocarbons. Although we understand the basic mechanics governing their subsidence, we know surprisingly little of how minibasins subside in three-dimensions over geological timescales, or what controls such variability. Such knowledge would improve our ability to constrain initial [...]