Preprints
There are 7996 Preprints listed.
Tempo of magma degassing and the genesis of porphyry copper deposits
Published: 2017-10-25
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Volcanology
Porphyry deposits are copper-rich orebodies formed by precipitation of metal sulphides from hydrothermal fluids released from magmatic intrusions that cooled at depth within the Earth’s crust. Finding new porphyry deposits is essential because they are our largest source of copper and they also contain other strategic metals including gold and molybdenum. However, the discovery of giant porphyry [...]
Tuning sedimentation through surface charge and particle shape
Published: 2020-10-22
Subjects: Engineering, Physical Sciences and Mathematics
Mud forms the foundation of many coastal and tidal environments. Clay suspensions carried downstream from rivers encounter saline waters, which encourages aggregation and sedimentation by reducing electrostatic repulsion among particles. We perform experiments to examine the effects of surface charge on both the rate and style of sedimentation, using kaolinite particles as a model mud suspension [...]
Seismicity Induced by Longwall Coal Mining at the Thoresby Colliery, Nottinghamshire, U.K.
Published: 2017-10-24
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The U.K. has a long history of deep coal mining, and numerous cases of mining-induced seismicity have been recorded over the past 50 years. In this study we examine seismicity induced by longwall mining at one of the U.K.’s last deep coal mines, the Thoresby Colliery, Nottinghamshire. After public reports of felt seismicity in late 2013 a local seismic monitoring network was installed at this [...]
Turbulence, displacement, death and worms: a day in the life of a fluvial Carboniferous bivalve
Published: 2017-10-24
Subjects: Earth Sciences, Paleontology, Physical Sciences and Mathematics, Sedimentology
In the Pennsylvanian Rough Rock Flags and Rough Rock of northern England, trace fossils attributed to the non-marine bivalve Carbonicola are found. Carbonicola, recorded by Lockeia and associated trace fossils, lived a semi-infaunal lifestyle and thus were influenced by both the sediment in which they were hosted, and the currents which supplied their nutrients and oxygen. A number of [...]
Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current
Published: 2017-10-24
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Volcanology
Thermohaline oceanic currents influence global heat transfer, controlling local and global variations in climate, biodiversity, and the terrestrial biosphere. Paleoceanographic studies typically use biostratigraphic and geochemical proxies to reconstruct the dynamics of these currents in Earth’s ancient oceans, although seismic reflection data have also been successfully employed, most commonly [...]
Modelling silicon supply during the Last Interglacial (MIS 5e) at Lake Baikal
Published: 2017-10-24
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics
Throughout the Quaternary, lake productivity has been shown to be sensitive to drivers such as climate change, landscape evolution and lake ontogeny. In particular, sediments from Lake Baikal, Siberia, provide a valuable uninterrupted and continuous sequence of palaeoproductivity, which document orbital and sub-orbital frequencies of regional climate change. Here we augment these records through [...]
The stratigraphic record and processes of turbidity current transformation across deep-marine lobes
Published: 2017-10-24
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
Sedimentary facies in the distal parts of deep-marine lobes can diverge significantly from those predicted by classical turbidite models, and sedimentological processes in these environments are poorly understood. This gap may be bridged using outcrop studies and theoretical models. In the Skoorsteenberg Fm., a downstream transition from thickly-bedded turbidite sandstones to argillaceous, [...]
An alternative review of facts, coincidences and past and future studies of the Lusi eruption
Published: 2017-10-24
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
The cause of the Lusi mud eruption remains controversial. The review by Miller and Mazzini (2017) firmly dismisses a role of drilling operations at the adjacent Banjarpanji-1 well and argues that the eruption was triggered by the Mw6.3 Yogyakarta earthquake 254 km away. We disagree with both of these conclusions. We review drilling data, and specifically the daily drilling reports, which clearly [...]
Lake Baikal isotope records of Holocene Central Asian precipitation
Published: 2017-10-23
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Climate models currently provide conflicting predictions of future climate change across Central Asia. With concern over the potential for a change in water availability to impact communities and ecosystems across the region, an understanding of historical trends in precipitation is required to aid model development and assess the vulnerability of the region to future changes in the hydroclimate. [...]
Metrology and Traceability of U-Pb Isotope Dilution Geochronology (EARTHTIME Tracer Calibration Part I)
Published: 2017-10-23
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Mixed 235U–233U–205Pb(–202Pb) tracers for U–Pb isotope-dilution isotope ratio mass spectrometry have been prepared under the auspices of the EARTHTIME Initiative. The methods and results for the preparation and calibration of the U/Pb ratio and isotopic abundances are given, and the various sources of uncertainty are discussed and quantified. The accuracy of the EARTHTIME U–Pb tracer isotopic [...]
The Effect Of Clay Type On The Properties Of Cohesive Sediment Gravity Flows And Their Deposits
Published: 2017-10-23
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
The present knowledge of cohesive clay-laden sediment gravity flows (SGFs) and their deposits is limited, despite clay being one of the most abundant sediment types on earth and subaqueous SGFs transporting large volumes of sediment into the ocean. Lock-exchange experiments were conducted to contrast SGFs laden with noncohesive silica flour, weakly cohesive kaolinite, and strongly cohesive [...]
A New Synergistic Approach for Monitoring Wetlands Using 1 Sentinels -1 and 2 data With Object-based Machine Learning 2 Algorithms
Published: 2020-03-30
Subjects: Earth Sciences, Life Sciences, Other Earth Sciences, Physical Sciences and Mathematics
In this work the synergistic use of Sentinel-1 and 2 combined with the System for Automated Geoscientific Analyses (SAGA) Wetness Index in the content of land use/cover (LULC) mapping with emphasis in wetlands is evaluated. A further objectivehas been to a new Object-based Image Analysis (OBIA) approach for mapping wetland areas using Sentinel-1 and 2 data, where the latter is also tested [...]
Active deformation of Malawi Rift’s North Basin hinge zone modulated by reactivation of pre-existing Precambrian shear zone fabric
Published: 2018-02-19
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Key Points: 1. Filtered aeromagnetic data elucidates the relationship between earthquake surface ruptures and buried faults along the North Basin hinge-zone, Malawi Rift. 2. Fault segments align with basement shear zone fabric. 3. Strain accommodation in the North Basin hinge zone is modulated by reactivation of the underlying Precambrian shear zone fabric. Abstract: We integrated temporal [...]
3-D seismic interpretation with deep learning: a brief introduction
Published: 2020-10-21
Subjects: Physical Sciences and Mathematics
Understanding the internal structure of our planet is a fundamental goal of the Earth Sciences. As direct observations are restricted to surface outcrops and borehole cores, we rely on geophysical data to study the Earth’s interior. Especially, seismic reflection data showing acoustic images of the subsurface, provide us with critical insights into sedimentary, tectonic and magmatic systems. The [...]
Amphibole Control on Copper Systematics in Arcs: Insights from the Analysis of Global Datasets
Published: 2020-10-21
Subjects: Earth Sciences, Geochemistry, Geology, Volcanology
Copper, sourced from porphyry deposits formed in arc settings, is a critical resource, and is primarily sourced from magmas. However, the processes that shape the copper contents of arc magmas are up for debate. Existing models place emphasis on different petrological agents that explain large-scale trends in copper systematics. Previous studies have noted the 'Cu paradox,' where the magmas with [...]