Filtering by Subject: Stratigraphy

Towards an astrochronological framework for the lower Paleoproterozoic Kuruman and Brockman Iron Formations

Margriet L Lantink, Joshua HFL Davies, Rick Hennekam, et al.

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

Pete Rowley, Rebecca Williams, Matthew Johnson, et al.

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

Adrian Broz, Devin Pritchard-Peterson, Sarah Schneider, et al.

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

James K. Muller, Marc-Antoine Longpré

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

Adam Matthew Forte, Eric S. Cowgill, Dawn Y. Sumner, et al.

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

Michal Šujan, Kishan Aherwar, Rastislav Vojtko, et al.

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).

Josep Maria Puig Lopez, Miquel Poyatos-Moré, John Howell

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

Christopher Michael Lowery, Ligia Perez Cruz, Jaime Urrutia Fucugauchi, et al.

Published: 2023-06-08
Subjects: Geophysics and Seismology, Oceanography, Sedimentology, Stratigraphy

The Loop Current is a key component of 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 multichannel seismic survey of sediment drifts [...]

Structure and Morphology of an Active Conjugate Relay Zone, Messina Strait, Southern Italy

Rebecca Dorsey, Sergio Longhitano, Domenico Chiarella

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

Lauren O'Connor, Emily Dearing Crampton-Flood, Rhodri Jerrett, et al.

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

Euan Soutter, Ander Martinez-Donate, Ian Kane, et al.

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

Pierre-Henri BLARD, Baptiste SUCHERAS-MARX, Guillaume SUAN, et al.

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

Valentin Zuchuat, Miquel Poyatos-Moré, Bjorn Nyberg, et al.

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 [...]

Correlation of geological complexes of the Khan-Tengri Mountain massif

Alexander Mikolaichuk, Farid Apayarov, Dmitry Gordeev

Published: 2022-12-09
Subjects: Earth Sciences, Geology, Stratigraphy, Tectonics and Structure

Researchers of the border regions of Xinjiang and the Central Asian countries are actively discussing two alternative models for the relationships between the main structural units of the Tianshan mountains. Most researchers believe that the Kyrgyz Middle Tianshan wedges out to the east along the Atbashi-Inylchek-Nalati marginal fault. According to the second hypothesis, the structures of the [...]

Evolution of intraplate magmatism atop a mantle plume: geochemical and chronological analysis of Shawahit Basalt, Harrat Rahat, Saudi Arabia

Gareth G Roberts, Patrick Ball

Published: 2022-11-15
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Stratigraphy, Tectonics and Structure, Volcanology

Harrat Rahat is the largest volcanic  eld in Saudi Arabia and has been active from ~10 Ma to the present day. Due to its close proximity to important population centres, Harrat Rahat's recent eruptions, the Medinah lava flows (< 1.7 Ma), have been extensively studied to identify volcanic risk. However, the evolution of Harrat Rahat's most extensive and oldest lava flows, known collectively as the [...]


You can search by:

  • Title
  • Keywords
  • Author Name
  • Author Affiliation