Preprints
Filtering by Subject: Geology
Stepwise chemical abrasion–isotope dilution–thermal ionization mass spectrometry with trace element analysis of microfractured Hadean zircon
Published: 2019-06-16
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
The Hadean Jack Hills zircons represent the oldest known terrestrial material, providing a unique and truly direct record of Hadean Earth history. This zircon population has been extensively studied via high spatial resolution, high throughput in situ isotopic and elemental analysis techniques such as secondary ionization mass spectrometry (SIMS), but not by comparatively destructive, [...]
Technical note: Limitations on the use of space borne differential SAR interferometry for systematic monitoring and failure forecast of alpine landslides
Published: 2019-06-16
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Geology, Geotechnical Engineering, Physical Sciences and Mathematics
Recent advances on satellite geodesy have boosted our capabilities to map and monitor landslides globally with unprecedented resolutions. In this scenario, differential interferometry of space borne synthetic aperture radar imagery (DInSAR) plays a major role in identifying surface displacements associated to slope instabilities and in monitoring their spatial and temporal evolution. However, [...]
Evaluating the relationship between the area and latitude of large igneous provinces and Earth’s long-term climate state
Published: 2019-06-12
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Tectonics and Structure
One of the hypothesized effects of large igneous provinces (LIPs) is planetary cooling on million-year timescales associated with enhanced silicate weathering of the freshly-emplaced basalt. This study combines reconstructions of the original surface extent and emplacement ages of LIPs, a paleogeographic model, and a parameterization of LIP erosion to estimate LIP area in all latitudinal bands [...]
A Stratigraphic Approach to Inferring Depositional Ages From Detrital Geochronology Data
Published: 2019-06-04
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
With the increasing use of detrital geochronology data for provenance analyses, we have also developed new constraints on the age of otherwise undateable sedimentary deposits. Because a deposit can be no older than its youngest mineral constituent, the youngest defensible detrital mineral age defines the maximum depositional age of the sampled bed. Defining the youngest `defensible age in the [...]
Physically consistent modeling of dike induced deformation and seismicity: Application to the 2014 Bárðarbunga dike, Iceland
Published: 2019-06-03
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Dike intrusions are often associated with surface deformation and propagating swarms of earthquakes. These are understood to be manifestations of the same underlying physical process, although rarely modeled as such. We construct a physics-based model of the 2014 B\ar{\dh}arbunga dike, by far the best observed large dike ($> 0.5$ km$^3$) to date. We constrain the background stress state [...]
How erosive are submarine landslides?
Published: 2019-05-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
Submarine landslides (slides) are ubiquitous on continental margins. They can pose a major hazard by triggering tsunami and damaging essential submarine infrastructure. Slide volume, which is a key parameter in hazard assessment, can change after initiation through substrate and/or water entrainment. However, the erosive capacity of slides is uncertain. Here, we quantify slide erosivity by [...]
Slab Rollback Orogeny model for the evolution of the Central Alps: Seismo-Thermo-Mechanical test
Published: 2019-05-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Forces associated with subduction of cold and dense oceanic plates control the motions and deformations of convergent margins. However, how these forces sustain mountain building processes — especially after slab breakoff — is still poorly known. Here we investigate this conundrum by performing 2-D, visco-elasto-plastic, seismo-thermo-mechanical numerical modeling, which simulates both tectonic [...]
Lake Level Fluctuations in the Northern Great Basin for the Last 25,000 years
Published: 2019-05-30
Subjects: Climate, Earth Sciences, Environmental Sciences, Geology, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
During the Last Glacial Maximum (LGM; ~23,000 to 19,000 years ago or ka) and through the last deglaciation, the Great Basin physiographic region in the western United States was marked by multiple extensive lake systems, as recorded by proxy evidence and lake sediments. However, temporal constraints on the growth, desiccation, and timing of lake highstands remain poorly constrained. Studies aimed [...]
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 [...]