Geologie: Recent submissions
Anzeige der Dokumente 276-300 von 933
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Brittle-Ductile Deformation and Tensile Rupture of Dome Lava During Inflation at Santiaguito, Guatemala
(Journal of Geophysical Research: Solid Earth, 2019)Gas-and-ash explosions at the Santiaguito dome complex, Guatemala, commonly occur through arcuate fractures, following a 5- to 6-min period of inflation observed in long-period seismic signals. Observation of active faults ... -
Late Palaeozoic red beds elucidate fluvial architectures preserving large woody debris in the seasonal tropics of central Pangaea
(Sedimentology, 2020)Fluvial red beds containing anatomically preserved large woody debris shed new light on seasonally dry biomes of the Pennsylvanian–Permian transition and elucidate the concurrence of river depositional systems and vegetation. ... -
Comment on “A New One-Equation Model of Fluid Drag for Irregularly Shaped Particles Valid Over a Wide Range of Reynolds Number” by F. Dioguardi et al.
(Journal of Geophysical Research: Solid Earth, 2019)With this comment we want to clarify a number of aspects of the paper recently published by Dioguardi, Mele, and Dellino “A New One-Equation Model of Fluid Drag for Irregularly Shaped Particles Valid Over a Wide Range of ... -
Paired 10Be sampling of polished bedrock and erratic boulders to improve dating of glacial landforms: an example from the Western Alps
(Earth Surface Processes and Landforms, 2020)Cosmogenic nuclide dating of glacial landforms may lead to ambiguous results for ice retreat histories. The persistence of significant cosmogenic concentrations inherited from previous exposure may increase the apparent ... -
Salt-induced crestal faults control the formation of Quaternary tunnel valleys in the southern North Sea
(Boreas, 2020)Tunnel valleys are major features of glaciated margins and they enable meltwater expulsion from underneath a thick ice cover. Their formation is related to the erosion of subglacial sediments by overpressured meltwater and ... -
Plio-Pleistocene Variability of the East Pacific Thermocline and Atmospheric Systems
(Paleoceanography and Paleoclimatology, 2020)The transition from the Pliocene to the Pleistocene was accompanied by major tectonic reorganizations of key oceanic gateways. In particular, the gradual closure of the Panama Gateway and the constriction of the Indonesian ... -
Isostatic Control of Axial Rivers and Large Drainage Basins on Passive Margins
(Geophysical Research Letters, 2020)More than half of the world's large rivers flow towards the ocean crossing passive continental margins. Here using an analytical solution and numerical models, we demonstrate that on passive margins, river basins may be ... -
The Impact of Sediment Supply on the Initiation and Magnitude of Runoff-Generated Debris Flows
(Geophysical Research Letters, 2020)Rainfall intensity-duration (ID) thresholds are commonly used to assess the potential for runoff-generated debris flows, but the sensitivity of these thresholds to sediment supply, which can change rapidly with time, is ... -
On the Sensitivity of the Devonian Climate to Continental Configuration, Vegetation Cover, Orbital Configuration, CO 2 Concentration, and Insolation
(Paleoceanography and Paleoclimatology, 2019)During the Devonian (419 to 359 million years ago), life on Earth witnessed decisive evolutionary breakthroughs, most prominently the colonization of land by vascular plants and vertebrates. However, it was also a period ... -
Coastal Erosion Variability at the Southern Laptev Sea Linked to Winter Sea Ice and the Arctic Oscillation
(Geophysical Research Letters, 2020)Arctic coastal erosion experiences pronounced effects from ongoing climate change. The Laptev Sea figures among the Arctic regions with the most severe erosion rates. Here, we use unprecedentedly long records of almost ... -
Impact-Induced Porosity and Microfracturing at the Chicxulub Impact Structure
(Journal of Geophysical Research: Planets, 2019)Porosity and its distribution in impact craters has an important effect on the petrophysical properties of impactites: seismic wave speeds and reflectivity, rock permeability, strength, and density. These properties are ... -
Sediment Transit Time and Floodplain Storage Dynamics in Alluvial Rivers Revealed by Meteoric 10Be
(Journal of Geophysical Research: Earth Surface, 2020)Quantifying the time scales of sediment transport and storage through river systems is fundamental for understanding weathering processes, biogeochemical cycling, and improving watershed management, but measuring sediment ... -
Coastal landscape evolution in the Wilpattu National Park (NW Sri Lanka) linked to changes in sediment supply and rainfall across the Pleistocene–Holocene transition
(Geological Journal, 2020)Coastal sand dunes are sediment archives which can be used to reconstruct periods of aridity and humidity, past wind strength and variations in the sediment supply related to sea-level changes. In this manner, the sedimentary ... -
Lateglacial and Holocene environmental history of the central Kola region, northwestern Russia revealed by a sediment succession from Lake Imandra
(Boreas, 2020)Bolshaya Imandra, the northern sub-basin of Lake Imandra, was investigated by a hydro-acoustic survey followed by sediment coring down to the acoustic basement. The sediment record was analysed by a combined physical, ... -
Predictability of Antarctic Sea Ice Edge on Subseasonal Time Scales
(Geophysical Research Letters, 2019)Coupled subseasonal forecast systems with dynamical sea ice have the potential of providing important predictive information in polar regions. Here, we evaluate the ability of operational ensemble prediction systems to ... -
Cretaceous Evolution of the Central Asian Proto-Paratethys Sea: Tectonic, Eustatic, and Climatic Controls
(Tectonics, 2020)The timing and mechanisms of the Cretaceous sea incursions into Central Asia are still poorly constrained. We provide a new chronostratigraphic framework based on biostratigraphy and magnetostratigraphy together with ... -
Boundary condition control of fluvial obstacle mark formation – framework from a geoscientific perspective
(Earth Surface Processes and Landforms, 2020)Obstacle marks are sedimentary bedforms, typically composed of an upstream local scour hole and a downstream sediment accumulation in the vicinity of an obstruction that is exposed to a current. However, specific morphologies ... -
Polyphase Magmatism During the Formation of the Northern East Greenland Continental Margin
(Tectonics, 2019)New marine geophysical data acquired across the partly ice-covered northern East Greenland continental margin highlight a complex interaction between tectonic and magmatic events. Breakup-related lava flows are imaged in ... -
Impact of Eurasian Ice Sheet and North Atlantic Climate Dynamics on Black Sea Temperature Variability During the Penultimate Glacial (MIS 6, 130–184 ka BP)
(Paleoceanography and Paleoclimatology, 2020)Understanding hemisphere-wide millennial-scale temperature variability during past glacials in response to ice sheet dynamics and orbital forcing is one of the key targets for Quaternary climate research. While an inland ... -
Tajik Basin and Southwestern Tian Shan, Northwestern India-Asia Collision Zone: 3. Preorogenic to Synorogenic Retro-foreland Basin Evolution in the Eastern Tajik Depression and Linkage to the Pamir Hinterland
(Tectonics, 2020)The Tajik basin archives the orogenic evolution of the Pamir hinterland. Stratigraphic-sedimentologic observations from Cretaceous-Pliocene strata along its eastern margin describe the depositional environment and ... -
Characterizing Water Flow in Vegetated Lysimeters with Stable Water Isotopes and Modeling
(Groundwater, 2019)We have used stable water isotopes (δ18O, δ2H) in combination with lumped-parameter modeling for characterizing unsaturated flow in two lysimeters vegetated with maize. The lysimeters contained undisturbed soil cores ... -
Exhuming the Top End of North America: Episodic Evolution of the Eurekan Belt and Its Potential Relationships to North Atlantic Plate Tectonics and Arctic Climate Change
(Tectonics, 2019)We present the first low-temperature thermochronology data from northernmost Ellesmere Island (Canadian Arctic), along with palynological data from Paleogene sediments. Our study area is part of the >2,500-km-long Eurekan ... -
Wolfgang Beyer: A Groundwater Scientist from Dresden
(Groundwater, 2019)Wolfgang Beyer was a groundwater scientist in Dresden, whose work on the permeability of sediments is cited the world over, but who is otherwise little known. This article is to commemorate him on the occasion of his 90th ... -
Central uplift collapse in acoustically fluidized granular targets: Insights from analog modeling
(Meteoritics & Planetary Science, 2020)Depending on their sizes, impact craters have either simple or complex geometries. Peak-ring craters such as the Chicxulub impact structure possess a single interior ring of peaks and hills and a flat interior floor. The ... -
Using a Paleosurface to Constrain Low-Temperature Thermochronological Data: Tectonic Evolution of the Cuevas Range, Central Andes
(Tectonics, 2019)Dispersion of low-temperature thermochronologic data from nine samples collected on a deformed paleosurface preserved on the Cuevas range (Central Andes) can be exploited to unravel complex thermal histories. The nine ...