Preprints
Filtering by Subject: Stratigraphy
New insights into the Upper Pleistocene directed blast eruption, Popocatépetl volcano, México
Published: 2023-10-30
Subjects: Geology, Stratigraphy, Volcanology
Volcanic eruptions of the directed blast type can affect areas of hundreds of square kilometres and reach more than 25 km from the crater, as observed in the directed explosions of the Bezymianny (1956) and Mt. St. Helens (1980) volcanoes. These directed eruptions are characterized by powerful explosions with a significant lateral component that can travel at speeds above 100 m/s, which includes [...]
Sediment supply controls on Early Eocene delta sequences (South Pyrenean Foreland Basin; Spain)
Published: 2023-10-13
Subjects: Climate, Geochemistry, Geology, Sedimentology, Stratigraphy
Sediment supply variations are often overlooked when interpreting depositional sequences, which tend to emphasize changes in accommodation. Here, we focus on a temporally well-constrained shallow-marine succession in the South Pyrenean Foreland Basin to test the control of sediment supply on the development of deltaic sequences during the Early Eocene. We analyzed the paleoenvironmental record [...]
Towards an astrochronological framework for the lower Paleoproterozoic Kuruman and Brockman Iron Formations
Published: 2023-09-01
Subjects: Earth Sciences, Physical Sciences and Mathematics, Stratigraphy
Recent evidence for astronomical-induced cycles in banded iron formations (BIFs) hints at the intriguing possibility of developing astrochronological, i.e. precise time-stratigraphic, frameworks for the earliest Proterozoic as also reconstructed for parts of the Mesozoic and Paleozoic. The ca 2.47-Ga Kuruman Iron Formation (Griqualand West Basin, South Africa) and Dales Gorge Member of the [...]
Spontaneous Unsteadiness and Sorting in Pyroclastic Density Currents and their Deposits
Published: 2023-08-22
Subjects: Geology, Sedimentology, Stratigraphy, Volcanology
Pyroclastic density currents (PDCs) pose substantial risk to populations living on and around active volcanoes, but their structure and internal dynamics are poorly understood. Much of this understanding is derived from interpretation of their widespread deposits. Scaled experiments are able to probe different conditions, to explore how changing flow dynamics relate to the wide variety of [...]
Eocene (50-55 Ma) greenhouse climate recorded in nonmarine rocks of San Diego, CA, USA
Published: 2023-08-08
Subjects: Chemistry, Climate, Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Soil Science, Stratigraphy
Nonmarine rocks in sea cliffs of southern California store a detailed record of weathering under tropical conditions millions of years ago, where today the climate is much drier and cooler. This work examines early Eocene (~50-55 million-year-old) deeply weathered paleosols (ancient, buried soils) exposed in marine terraces of northern San Diego County, California, and uses their geochemistry and [...]
Tephra dispersal and composition reveal the explosive onset of a large basaltic fissure eruption: Timanfaya, Lanzarote, 1730–1736 CE
Published: 2023-08-03
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Stratigraphy, Volcanology
Basaltic fissure eruptions are chiefly characterized by sizable emissions of lava flows and volcanic gases, posing significant hazards. However, such eruptions may be punctuated by explosive episodes, which are comparatively poorly understood but may have important volcanic hazard and environmental implications. The 1730–1736 CE Timanfaya eruption on Lanzarote, Canary Islands, is a large basaltic [...]
Timing and Evolution of Structures within the Southeastern Greater Caucasus and Kura Fold-Thrust Belt from Multiproxy Sediment Provenance Records
Published: 2023-08-03
Subjects: Earth Sciences, Stratigraphy, Tectonics and Structure
The west-northwest trending Greater Caucasus (GC) mountains locally represent the main locus of post-Pliocene shortening within the north central Arabia-Eurasia collision. Although recent low-temperature thermochronology constrains the timing of orogen formation, the evolution of major structures remains enigmatic - particularly regarding the internal kinematics within this young orogen and the [...]
Application of the authigenic 10Be/9Be dating to constrain the age of a long-lived lake and its regression in an isolated intermontane basin: The case of Late Miocene Lake Turiec, Western Carpathians
Published: 2023-07-31
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The depositional record of intermontane basins provides a valuable archive of the temporal evolution of orogenic belts; their common isolated nature may, however, hinder the efficient usage of standard approaches to constrain the age of a basin fill. In this paper the authigenic 10Be/9Be dating method is employed and tested to construct an age model of the existence and regression of Lake Turiec, [...]
Sedimentology and sequence stratigraphy of shallow-marine, coarse-grained siliciclastic deposits in the southern Utsira High: the Late Jurassic intra-Draupne Formation sandstones in the Johan Sverdrup Field (Norwegian North Sea).
Published: 2023-06-30
Subjects: Earth Sciences, Geology, Sedimentology, Stratigraphy, Tectonics and Structure
Thin, condensed coarse-grained shallow-marine successions can be difficult to describe and interpret, especially in the subsurface because they commonly lack finer grained intervals which are typically associated with sequence stratigraphic surfaces. This lack of mudstones and siltstones means that they also typically make excellent reservoir intervals. The Oxfordian to Volgian intra-Draupne [...]
Seismic Stratigraphy of Contourite Drift Deposits Associated with the Loop Current on the Eastern Campeche Bank, Gulf of Mexico
Published: 2023-06-08
Subjects: Geophysics and Seismology, Oceanography, Sedimentology, Stratigraphy
The Loop Current is a key component of global circulation via the northward transport of warm, salty water and an important influence on Gulf of Mexico hydrography. Understanding how the Loop Current will respond to ongoing anthropogenic warming is critically important, but the history of the Loop Current is poorly known. Here, we present the results of a high resolution (3-8 m) multichannel [...]
Structure and Morphology of an Active Conjugate Relay Zone, Messina Strait, Southern Italy
Published: 2023-03-10
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Messina Strait is a narrow fault-bounded marine basin that separates the Calabrian peninsula from Sicily in southern Italy. It sits in a seismically active region where normal fault scarps and raised Quaternary marine terraces record ongoing extension driven by southeastward rollback of the Calabrian subduction zone. A review of published studies and new data shows that normal faults in the [...]
Steady decline in mean annual air temperatures in the first 30 ka after the Cretaceous-Paleogene boundary
Published: 2023-03-06
Subjects: Climate, Earth Sciences, Geochemistry, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Stratigraphy
The Cretaceous-Paleogene (K-Pg) boundary marks one of the five major mass extinctions of the Phanerozoic. How the climate system responded to a bolide impact and extensive volcanism at this time over different timescales is highly debated. Here we use the distribution of branched tetraether lipids (brGDGT) from fossil peats at two sites in Saskatchewan, Canada (paleolatitude ~55°N), to generate a [...]
Exceptional preservation of three-dimensional dunes on an ancient deep-marine seafloor: implications for sedimentary processes and depositional environments
Published: 2023-01-19
Subjects: Geology, Stratigraphy
Depositional and erosional bedforms can be used to reconstruct sedimentary processes and aid paleoenvironmental interpretations. Using exhumed deep-marine strata in the Eocene Aínsa Basin, Spain, we document a 3-dimensional package of dunes; a relatively rarely identified bedform in deep-marine environments. Our analysis shows that the dunes have curvilinear crests in planform, with smaller [...]
Are marl-limestone alternations mainly driven by CaCO3 variations at the astronomical timescale? New insights from extraterrestrial 3He
Published: 2023-01-07
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Sedimentology, Stratigraphy
Marl-limestone alternations are rhythmical inter-bedded deposits that commonly occur in many sedimentological environments. It is quite well established that these lithological variations originate from astronomically-driven climatic variations paced by the Milankovitch cycles of main periods 19, 23, 41, 100 and 405 ka. However, the sedimentological mechanisms involved are not clear: some models [...]
Use of remote-sensing to quantify the distribution of progradation/erosion along a forced-regressive modern coastline: driving factors and impact on the stratigraphic record
Published: 2022-12-13
Subjects: Geomorphology, Sedimentology, Stratigraphy
The long-term development of ancient and modern coastal distributary distributive fluvial systems (DFSs) during periods of relative sea-level highstand or fall usually drives net-progradation of shorelines. Such systems often develop in periods of relative sea-level highstand or fall and typically record annual to millennial-scale deviations in coastal trajectories. A new continental dataset [...]