Results 11 to 20 of about 1,498 (118)

Depositional and Hydrological Relationships Between Buried Dead Ice and the Active Layer in the McMurdo Dry Valleys, Antarctica: A Study of Sediment Geochemistry and Cation Concentrations

open access: yesPermafrost and Periglacial Processes, EarlyView.
ABSTRACT The McMurdo Dry Valleys, the largest ice‐free region in Antarctica, are home to a cold‐desert hydrologic system of glaciers, snowbanks, streams, and lakes. Freshwater is also stored as dead glacial ice, which is poorly constrained in terms of ion concentrations and interactions with both in situ and overlying sediments.
Matthew C. Witscheber, Kate M. Swanger
wiley   +1 more source

New Results From the Pre‐Pottery Neolithic Site of Al Uyaynah, Tabuk, in Northwestern Saudi Arabia

open access: yesArabian Archaeology and Epigraphy, EarlyView.
ABSTRACT Al Uyaynah is a low sandstone mound on an alluvial plain, long known for its extensive surface remains of stone‐built circular and rectangular structures. Following test excavations in 2012, more detailed excavation was undertaken in 2016 within one of the largest rectangular stone structures.
Khalid Alasmari   +6 more
wiley   +1 more source

Spatial and temporal evolution of a coastal erg margin: the Middle Jurassic Page Sandstone, southern Utah, USA

open access: yesSedimentology, EarlyView.
ABSTRACT Aeolian deflationary events are erosive to static stages where sediment supply is insufficient to support bedform migration and preservation in the rock record. In the vicinity of shallow‐marine environments, inland rises of relative water table and associated generation of deflationary super surfaces may be driven by the onset of ...
Victor J. P. Hême de Lacotte   +4 more
wiley   +1 more source

Recognition of fossil keratose sponges in carbonates using petrographic and machine‐learning classification

open access: yesSedimentology, EarlyView.
ABSTRACT Filamentous, anastomosing spar‐filled networks in Phanerozoic carbonates have been interpreted as the mineralised remains of keratose (non‐spiculate) sponges, yet their recognition remains contested because fabrics of broadly similar appearance may arise from microbial, diagenetic or physical processes. This study combines direct fossil–modern
Jeong‐Hyun Lee   +2 more
wiley   +1 more source

Salt Range Formation of Pakistan Preserves Unique Record of Volcanic Fertilization During the Ediacaran Shuram Excursion

open access: yesTerra Nova, EarlyView.
ABSTRACT Thin, discontinuous, organic‐rich oil shale beds in the siliciclastic‐evaporitic Salt Range Formation (SRF) of Pakistan are of approximate Neoproterozoic to Cambrian age based on stratigraphic constraints. The beds are enriched (26–43 wt.% total organic carbon, TOC) in aliphatic organic matter (OM) of low thermal maturity despite their ...
Paul C. Hackley   +4 more
wiley   +1 more source

Upper Ordovician formations in the Maysville area, Kentucky [PDF]

open access: yes, 1966
Upper Ordovician strata in the Maysville area, Kentucky, are divided into five formations. The basal Kope Formation is overlain by the Fairview Formation. Above the Fairview are two newly defined map units, the Grant Lake Limestone and the overlying Bull Fork Formation. The Preachersville Member of the Drakes Formation overlies the Bull Fork.
openaire   +1 more source

Reconnaissance study of watershed and cave sediment sources discharging from a karst spring, Iowa

open access: yesAgrosystems, Geosciences &Environment, Volume 9, Issue 3, September 2026.
Abstract Springs discharging from karst landscapes provide sustainable flows to natural ecosystems and support productive fish hatcheries but sediment discharging from springs threatens the long‐term sustainability of hatcheries. In this study, we conducted a reconnaissance study to evaluate watershed and cave sediment sources discharging to Siewers ...
Keith E. Schilling   +4 more
wiley   +1 more source

Fish Scales: A Multifunctional Biomaterial from Nature

open access: yesENERGY &ENVIRONMENTAL MATERIALS, Volume 9, Issue 5, September 2026.
Fish scales demonstrate nature's solution to impact protection through overlapping multilayered architecture. This biological design combines mineralized surfaces with collagen networks to achieve both flexibility and fracture resistance. The structural principles inspire advanced protective materials and biomedical implants, where damage tolerance ...
Liyao Dong, Xiaojie Sun, Xiguang Chen
wiley   +1 more source

Geochronological Constraints on Diachronous Post‐Collisional Slab Breakoff Along the Paleo‐Tethyan Sutures

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 9, September 2026.
Abstract The slab breakoff model is a preferred geodynamic interpretation for post‐collisional exhumation and associated magmatic flare‐ups. In this study, rutile U–Pb dating of retrograde eclogites revealed distinct stages of exhumation along the Paleo‐Tethyan sutures in southwest China. The studied samples yielded ages of 246.7 ± 8.5 and 239.7 ± 14.0 
Min Liu   +7 more
wiley   +1 more source

Surface ages of alluvial fans in the southern Central Andes recorded by ground‐ and space‐based hyperspectral reflectance

open access: yesEarth Surface Processes and Landforms, Volume 51, Issue 8, August 2026.
Secondary weathering of alluvial‐fan surfaces records the relative, and even absolute, ages of deposited sediments up to 300 ka. Hyperspectral imagery quantifies evolving mineral‐weathering pathways to unlock high‐resolution mapping and dating of these sedimentary landscapes.
Henry T. Crawford   +6 more
wiley   +1 more source

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