Filtering by Subject: Sedimentology
Published: 2019-12-03
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Sedimentology
A sediment core spanning the last ~50 ka from Lake Junín (Peru) in the tropical Andes reveals abrupt climatic events on a centennial-millennial time scale. These events, which involved the near-complete disappearance of glaciers below 4700 masl in the eastern Andean cordillera and major reductions in the level of Peru’s second largest lake, occurred during the abrupt warmings recorded in [...]
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 [...]
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 [...]
Published: 2019-09-30
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 [...]
Published: 2019-09-30
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. [...]
Published: 2019-09-17
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Tectonics and Structure
Local low-density basement anomalies are an important part of a rift basin’s inherited structural framework that can influence basin stratigraphy. Large granitic intrusions can cause local alterations in the basement’s density and often spatially correlate with fault-bounded highs (blocks) or convex-shaped regional flexural highs due to their isostatic responses. We investigate the influence of [...]
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 [...]
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 [...]
Published: 2019-08-17
Subjects: Earth Sciences, Geochemistry, Paleontology, Physical Sciences and Mathematics, Sedimentology
The Chicxulub impact caused a crash in export productivity in much of the world’s oceans which contributed to the extinction of 75% of marine species. In the immediate aftermath of the extinction, local export productivity was highly variable, with some sites, including the Chicxulub crater, recording elevated export production. The long-term transition back to more stable export productivity [...]
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 [...]
Published: 2019-08-08
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Social and Behavioral Sciences
Mass-transport complexes (MTCs) dominate many salt-influenced sedimentary basins. Commonly in such settings, halokinesis is invoked as the primarily trigger for MTC emplacement. Despite being very well-imaged in seismic reflection data, we know little of how MTCs vary in terms of their sedimentological character, which may relate to their provenance, or their triggers. We use high-quality 3D [...]
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 [...]
Published: 2019-07-31
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
Mouth bars are the fundamental architectural elements of proximal deltaic successions. Understanding their internal architecture and deciphering the relative impact and complex interaction of coastal processes (fluvial-, tide- and wave-dominated) is paramount to the interpretation of ancient deltaic successions. This is particularly challenging in low-accommodation systems, because they are [...]
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 [...]
Published: 2019-07-18
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Environmental Engineering, Geology, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
Accepted open-access publication available at: https://doi.org/10.1029/2019GL085524 Barrier island response to sea-level rise depends on their ability to transgress and move sediment onto and behind the barrier, either through flood-tidal delta deposition, or via overwash. Our understanding of these processes over decadal or longer timescales, however, is limited. Here we [...]