Preprints
Filtering by Subject: Earth Sciences
How do sea-level curves influence modeled marine terrace sequences?
Published: 2018-11-07
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Sequences of uplifted marine terraces are widespread and reflect the interaction between climatic and tectonic processes at multiple scales, yet their analysis is typically biased by the chosen sea-level (SL) curve. Here we explore the influence of Quaternary SL curves on the geometry of marine terrace sequences using landscape evolution models (LEMs). First, we modeled the young, rapidly [...]
A PCA-based framework for determining remotely-sensed geological surface orientations and their statistical quality
Published: 2018-11-07
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Planetary Geology, Planetary Sciences, Planetary Sedimentology, Statistical Methodology, Statistics and Probability, Stratigraphy, Tectonics and Structure
The orientations of planar rock layers are fundamental to our understanding of structural geology and stratigraphy. Remote-sensing platforms including satellites, unmanned aerial vehicles (UAVs), and LIDAR scanners are increasingly used to build three-dimensional models of structural features on Earth and other planets. Remotely-gathered orientation measurements are straightforward to calculate [...]
Preservation of autogenic processes and allogenic forcings within set-scale aeolian architecture II: the scour-and-fill dominated Jurassic Page Sandstone, Arizona, USA
Published: 2018-11-07
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
The stratigraphic architecture of aeolian sandstones is thought to record signals originating from both autogenic dune behavior and allogenic environmental boundary conditions within which the dune field evolves. Mapping of outcrop-scale surfaces and sets of cross-strata between these surfaces for the Jurassic Page Sandstone near Page, Arizona, USA, demonstrates that the stratigraphic signature [...]
Growth folds above propagating normal faults
Published: 2018-11-07
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
Growth folds above the upper tips of normal faults are ubiquitous in extensional settings, especially during the early phases of extension and in salt-rich basins. As slip accumulates on the underlying normal fault, the geometry and size of the fold changes. These changes reflect the dip, throw, displacement and propagation rate of the underlying normal fault, as well as the thickness and [...]
Spatial variability of late Holocene and 20th century sea-level rise along the Atlantic coast of the United States
Published: 2018-11-06
Subjects: Climate, Earth Sciences, Environmental Sciences, Geology, Geomorphology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
Accurate estimates of global sea-level rise in the pre-satellite era provide a context for 21st century sea-level predictions, but the use of tide-gauge records is complicated by the contributions from changes in land level due to glacial isostatic adjustment (GIA). We have constructed a rigorous quality-controlled database of late Holocene sea-level indices from the U.S. Atlantic coast, [...]
Palaeoenvironmental and tectonic significance of Miocene lacustrine and palustrine carbonates (Ait Kandoula Formation) in the Ouarzazate Foreland Basin, Morocco.
Published: 2018-11-06
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Sedimentology
The Ouarzazate Basin is the southern foreland basin to the High Atlas Mountains in Morocco. The sedimentary fill records a sequence from the Eocene to Pleistocene that records the interplay between tectonics and climate. This study presents the first stable isotope and facies analyses of the Middle to Late Miocene Aït Ibrirn lacustrine Member (Aït Kandoula Formation). These data test whether [...]
Strike-slip reactivation of segmented normal faults: implications for basin structure and fluid flow
Published: 2018-11-05
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Reverse reactivation of normal faults, also termed ‘inversion’, has been extensively studied, whereas little is known about the strike-slip reactivation of normal faults. At the same time, recognizing strike-slip reactivation of normal faults in sedimentary basins is critical, as it may alter and impact basin physiography, accommodation and sediment supply and dispersal. Motivated by this, we [...]
Grain friction controls characteristics of seismic cycle in rough faults with granular gouge
Published: 2018-11-02
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Mature faults with rough surface at their core contain granular gouge, however, the presence of fault gouge is mostly disregarded in the analysis of effect of fault’s surface roughness on the mechanics and stability of faults. In this work, we consider a rough fault system with constant roughness at the wall-gouge interaction and study the effect of grain friction on the characteristics of [...]
Burial-related Compaction Modifies Intrusion-induced Forced Folds: Implications for Reconciling Roof Uplift Mechanisms using Seismic Reflection Data
Published: 2018-11-02
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Space for shallow-level sills and laccoliths is commonly generated by bending and uplift of overlying rock and sediment. This so-called ‘roof uplift’ produces forced folds, the shape and amplitude of which reflect the geometry of underlying intrusions. The surface expression of forced folds can therefore be inverted to constrain intruding magma body properties, whilst ancient forced folds provide [...]
Implications of ambiguity in Antarctic ice sheet dynamics for future coastal erosion estimates: a probabilistic assessment
Published: 2018-11-02
Subjects: Earth Sciences, Engineering, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Probability, Statistical Models, Statistics and Probability
Sea-level rise (SLR) can amplify the episodic erosion from storms and drive chronic erosion on sandy shorelines, threatening many coastal communities. One of the major uncertainties in SLR projections is the potential rapid disintegration of large fractions of the Antarctic ice sheet (AIS). Quantifying this uncertainty is essential to support sound risk management of coastal areas, although it is [...]
Preservation of autogenic processes and allogenic forcings within set-scale aeolian architecture I: numerical experiments
Published: 2018-10-31
Subjects: Earth Sciences, Physical Sciences and Mathematics, Stratigraphy
A reduced complexity aeolian dune stratification model is developed and applied to explore the role of dune morphodynamics in the creation of synthetic sections of aeolian stratigraphy originating from three sets of environmental forcing: 1) steady wind transport capacity, 2) steady bed aggradation and variable wind transport capacity, and 3) steady wind transport capacity and bed aggradation. In [...]
New constraints from Central Chile on the origins of enriched continental compositions in thick-crusted arc magmas
Published: 2018-10-31
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Volcanology
Magmas from continental arcs built on thick crust have elevated incompatible element abundances and “enriched” radiogenic isotope ratios compared to magmas erupted in island and continental arcs overlying thinner crust. The relative influence of the slab, mantle, and upper plate on this variability is heavily debated. The Andean Southern Volcanic Zone (SVZ; 33-46° S) is an ideal setting to [...]
Overpressure Transfer Through Interconnected Igneous Intrusions
Published: 2018-10-30
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Paper looking at the transference of overpressure through interconnected igneous intrusions within sedimentary basins. The manuscript highlights the current under-recognized hazard in both scientific and hydrocarbon drilling in vicinity of subsurface igneous complexes.
Intermediate-magnitude postseismic slip follows intermediate-magnitude (M 4 to 5) earthquakes in California
Published: 2018-10-29
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The magnitude of postseismic slip is useful for constraining physical models of fault slip. Here we examine the postseismic slip following intermediate-magnitude (M 4 to 5) earthquakes by systematically analyzing data from borehole strainmeters in central and northern California. We assess the noise in the data and identify 36 records from 12 earthquakes that can be interpreted. We estimate [...]
Radiolysis via radioactivity is not responsible for rapid methane oxidation in subterranean air
Published: 2018-10-29
Subjects: Earth Sciences, Geochemistry, Life Sciences, Physical Sciences and Mathematics
Atmospheric methane is rapidly lost when it enters humid subterranean critical and vadose zones (e.g., air in soils and caves). Because methane is a source of carbon and energy, it can be consumed by methanotrophic methane-oxidizing bacteria. As an additional subterranean sink, it has been hypothesized that methane is oxidized by natural radioactivity-induced radiolysis that produces energetic [...]