Results 51 to 60 of about 68,053 (269)

The Upper Ordovician of Estonia: facies, sequences, and basin development [PDF]

open access: yesEstonian Journal of Earth Sciences
Sequence stratigraphic analysis of the Nabala–Porkuni regional stages (RSs; upper Katian–Hirnantian) of Estonia clarifies the Late Ordovician evolution of the Estonian Shelf–Livonian Basin.
Mark T. Harris   +7 more
doaj   +1 more source

Fish Scales: A Multifunctional Biomaterial from Nature

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
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

Machine Learning‐Driven Classification and Production Capacity Prediction of Tight Sandstone Reservoirs: A Case Study of the Taiyuan Formation, Ordos Basin

open access: yesEnergy Science &Engineering, EarlyView.
On the basis of core and log data, a Bayesian‐Optimized Random Forest model achieved 92.76% accuracy in classifying tight sandstone reservoirs. A gray relational analysis‐derived evaluation index shows > 80% consistency with actual gas zones. ABSTRACT Tight sandstone gas (TSG), an unconventional oil–gas resource, has heterogeneous reservoirs ...
Yin Yuan   +8 more
wiley   +1 more source

Global Series and Stages for the Ordovician System: A Progress Report

open access: yesGeologica Acta, 2005
There is no global standard set of chronostratigraphic/geochronologic subdivisions for the Ordovician System/Period. British series/epochs are often used as de facto nomenclature on stratigraphic correlation charts and geologic time scales. However, they
S. FINNEY
doaj   +1 more source

The Age and Origin of Block Deposits in the Victorian Alps, Australia

open access: yesPermafrost and Periglacial Processes, EarlyView.
ABSTRACT Large periglacial block deposits are found in the mountains of southeastern Australia. Despite their widespread distribution, their mode of formation and age are poorly understood. These landforms hold considerable potential to shed light on the nature of cooling during glacial periods. In this paper we present a new study of block deposits in
Timothy T. Barrows   +4 more
wiley   +1 more source

Internal framework and geochemistry of the Carboniferous Huaco granite pluton, Sierra de Velasco, NW Argentina [PDF]

open access: yes, 2018
The A-type Huaco granite pluton of the Velasco range (Sierras Pampeanas of northwest Argentina) is formed by three coeval granitic facies and contains subordinate coeval-to-late facies, as well as enclaves, dikes and stocks that show different temporal ...
Grosse, Pablo   +3 more
core   +2 more sources

Deciphering Freeze–Thaw Dynamics In Rockwalls: A Novel Approach for High Accuracy Regional‐Scale Modeling

open access: yesPermafrost and Periglacial Processes, EarlyView.
ABSTRACT Using a large and novel array of instruments on five rockwalls in northern Gaspesia, their respective surface energy balances were calculated and their thermal regimes were measured and modeled to depths exceeding the seasonal frost penetration.
Tom Birien, Francis Gauthier
wiley   +1 more source

Clay mineralogy, chemistry, and diagenesis of late devonian K-bentonite occurrences in northwestern Turkey [PDF]

open access: yes, 2015
Thin beds of tephra (K-bentonites) formed by the diagenesis of volcanic ash are exposed within the limestone-dolomitic limestone successions of the Yilanli formation at Zonguldak and Bartin in northwestern Turkey.
Bozkaya, Ömer   +5 more
core   +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

Late Ordovician Palynomorphs [PDF]

open access: yesJournal of Micropalaeontology, 1985
Abstract. ACRITARCHSOrdovician acritarchs have been recorded in five core samples collected between 2520 ft. and 3000 ft. in Well E1-81, and ten cutting samples taken between 12150 ft. and 13240 ft. in Well J1-81A. All the assemblages recovered are of Late Ordovician age; no Early Ordovician or Middle Ordovician assemblages have been identified ...
Molyneux, S. G., Paris, F.
openaire   +2 more sources

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