Preprints
Filtering by Subject: Geology
A constant Chinese Loess Plateau dust source since the Late Miocene
Published: 2019-05-30
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
The Pliocene-Pleistocene boundary marks a major change in global climate and East Asian monsoon dynamic. However, the role of the global atmospheric dust-cycle over this time is unclear; in particular, whether, changes in the dust cycle influenced climate change, or resulted from it. Chinese loess records past dust-cycle history and the influences of aridification and monsoon circulation over the [...]
On the stability of deep-seated landslides. The cases of Vaiont (Italy) and Shuping (Three Gorges Dam, China)
Published: 2019-05-24
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geology, Geotechnical Engineering, Physical Sciences and Mathematics
Deep-seated catastrophic landslides are among the most powerful natural hazards on earth. These devastating events are not possible to be prevented yet, because of their large volumes and sudden acceleration phase. The present study suggests a new method to detect when a landslide will turn unstable, giving both a time-window to evacuate the area that is going to be affected and critical values [...]
Forced folding and fracturing induced by differential compaction during post-depositional inflation of sandbodies: insights from numerical modelling
Published: 2019-05-15
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Three series of numerical models based on the discrete element method were constructed to simulate forced folding and fracturing triggered by postdepositional inflation of fludised sandbody. The models consist of numerous particles that have relatively low to high interparticle bonds to represent overburden sediments with a relatively low to high cohesion, and cohesionless, frictionless particles [...]
Low-temperature thermochronology as a control on vertical movements for semi-quantitative Source-to-Sink analysis: A case study for the Permian to Neogene of Morocco and surroundings
Published: 2019-05-15
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics
Continental passive margins and their hinterlands in the Atlantic realm are the locus of a significant amount of studies that evidence pre-, syn-, and post-rift episodic km-scale exhumation and burial episodes. We submit a 3-steps workflow to obtain 1) exhumation/burial rates, 2) eroded material flux, and 3) paleoreconstructions of source and sink domains. We apply this workflow in onshore [...]
Overburden deformation induced by dyke-fed conical sandstone intrusions: insights from numerical experiments
Published: 2019-05-10
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Conical sandstone intrusions, as a distinct type of hydrocarbon reservoirs and carbon sequestration sites, remain poorly understood regarding their emplacement mechanics. Here, we report a numerical modelling study of conical sandstone intrusions using the two-dimensional discrete element method. We built simplified numerical models that contain bonded elastic particles with predefined mechanical [...]
Controls on structural styles and decoupling in stratigraphic sequences with double décollements during thin-skinned contractional tectonics: insights from numerical modelling
Published: 2019-05-10
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Six series of particle-based numerical experiments were performed to simulate thin-skinned contractional tectonics in stratigraphic sequences with double décollements during horizontal shortening. The models were assigned with varying rock competence, depth and thickness of the upper décollement, which resulted in significantly different styles of deformation and decoupling characteristics above [...]
Influence of nodular structures on fracture development in fine-grained rocks: numerical simulations based on the discrete element method
Published: 2019-05-10
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Discrete element experiments were performed to simulate fracturing processes in nodule-bearing, fine-grained rocks. Two models that contain a collection of bonded circular particles were subjected to uniaxial compression to yield shortening and fracturing of the particle assembly. Model I with soft nodules produced incremental amount of microfractures within nodules during the early stage of [...]
Global distribution of sediment-hosted metals controlled by craton edge stability
Published: 2019-05-07
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Sustainable development and the transition to a clean-energy economy drives ever-increasing demand for base metals, significantly outstripping the discovery rate of new deposits and necessitating dramatic improvements in exploration success. Rifting of the continents has formed widespread sedimentary basins, some of which contain large quantities of copper, lead and zinc. Despite over a century [...]
Identification and Characterization of a Buried Volcanic Field Using Seismic Reflection and Borehole Data
Published: 2019-05-06
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Buried volcanoes occur in great numbers within sedimentary basins globally. Knowledge of ancient buried volcanic systems has improved significantly over the past two decades. The in-depth understanding of these buried systems was mainly possible due to increasing availability of high-quality seismic reflection and sub-surface borehole data. This paper examines a cluster of Miocene volcanoes now [...]
Paleogeographic and Morphologic Reconstroction of a Buried Monogenetic Volcanic Field
Published: 2019-05-06
Subjects: Earth Sciences, Geology, Life Sciences, Physical Sciences and Mathematics
Technological advances of our modern society motivated an unprecedented necessity to find natural resources in the subsurface of our planet. The search for these valuable resources has revealed an unexpected number of ancient volcanoes buried and preserved within sedimentary basins globally. Continuous improvements in remote sensing techniques such as seismic reflection can provide a valid [...]
Pre-existing intra-basement shear zones influence growth and geometry of non-colinear normal faults, western Utsira High–Heimdal Terrace, North Sea
Published: 2019-05-06
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Pre-existing intra-basement shear zones can induce mechanical and rheological heterogeneities that may influence rifting and the overall geometry of rift-related normal faults. However, the extent to which physical and kinematic interaction between pre-existing shear zones and younger rift faults control the growth of normal faults is less-well understood. Using 3D reflection seismic data from [...]
Microstructural Constraints on Magmatic Mushes under Kīlauea Volcano, Hawaiʻi
Published: 2019-05-06
Subjects: Earth Sciences, Geochemistry, Geology, Mineral Physics, Physical Sciences and Mathematics, Volcanology
Distorted olivines of enigmatic origin are ubiquitous in erupted products from a wide range of volcanic systems (e.g., Hawaiʻi, Iceland, Andes). Investigation of these features at Kīlauea Volcano, Hawai’i, using an integrative crystallographic and chemical approach places quantitative constraints on mush pile thicknesses. Electron back-scatter diffraction (EBSD) reveals that the microstructural [...]
Terrestrial environmental change across the onset of the PETM and the associated impact on biomarker proxies: a cautionary tale
Published: 2019-04-28
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
The Paleocene-Eocene Thermal Maximum (PETM; ~ 56 million years ago (Ma) is the most severe carbon cycle perturbation event of the Cenozoic. Although the PETM is associated with warming in both the surface (~up to 8°C) and deep ocean (~up to 5°C), there are relatively few terrestrial temperature estimates from the onset of this interval. The associated response of the hydrological cycle during the [...]
A long-term, high-latitude record of Eocene hydrological change in the Greenland region
Published: 2019-04-26
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
A range of proxy approaches have been used to reconstruct short-term changes to Earth’s hydrological cycle during the early Eocene hyperthermals. However, little is known about the response of Earth’s hydrological and biogeochemical systems to long-term Cenozoic cooling, which began following the Early Eocene Climatic Optimum (53.3 – 49.4 million years ago; Ma). Here, we use the molecular [...]
Stratigraphy of Architectural Elements of a Buried Monogenetic Volcanic System and Implications for Geoenergy Exploration
Published: 2019-04-26
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Large volumes of magma emplaced and deposited within sedimentary basins can have an impact on their architectural style and geological evolution. Over the last decade, continuous improvement in techniques such as seismic volcano-stratigraphy and 3D seismic visualization of igneous rocks buried in sedimentary basins has helped increase knowledge about these “volcanic basins”. Here, we unravel the [...]