Results 41 to 50 of about 63,261 (236)

Devonian Sandstone Lithostratigraphy, Northern Arkansas [PDF]

open access: yes, 1977
Two areas of Devonian sandstone development may be recognized in northern Arkansas. In northwestern Arkansas, the Clifty Formation comprises a massively bedded, super mature quartz arenite of Middle Devonian age overlain by thinner bedded, phosphatic ...
Hall, Jeffery D., Manger, Walter L.
core   +2 more sources

The fossil record of early tetrapods: worker effort and the end-Permian mass extinction [PDF]

open access: yes, 2010
It is important to understand the quality of the fossil record of early tetrapods (Tetrapoda, minus Lissamphibia and Amniota) because of their key role in the transition of vertebrates from water to land, their dominance of terrestrial faunas for over ...
Bebber D.F.   +18 more
core   +3 more sources

An ontological morphological phylogenetic framework for living and extinct ray‐finned fishes (Actinopterygii)

open access: yesThe Anatomical Record, EarlyView.
Abstract The ray‐finned fishes include one out of every two species of living vertebrates on Earth and have an abundant fossil record stretching 380 million years into the past. The division of systematic knowledge of ray‐finned fishes between paleontologists working on extinct animals and neontologists studying extant species has obscured the ...
Jack Stack
wiley   +1 more source

Geochemical and ecological aspects of lower Frasnian pyrite-ammonoid level at Kostomłoty (Holy Cross Mountains, Poland) [PDF]

open access: yes, 2004
The lower Frasnian (transitans Zone with Ancyrodella priamosica = MN 4 Zone) rhythmic basin succession of marly limestones and shales (upper Szydlówek Beds) at Kostomloty, western Holy CrossMts., Central Poland, contains a record of the transgressive ...
Bond, D.P.G.   +3 more
core  

A new species of Lonchidiidae (Hybodontiformes) from the Late Jurassic of Brazil (Aliança Formation, Jatobá Basin)

open access: yesThe Anatomical Record, EarlyView.
Abstract The Aliança Formation (Jatobá Basin) represents lacustrine deposits formed in oxygenated waters that hosted a diverse fauna, including Hybodontiform sharks. Within this group, the Family Lonchidiidae comprises 11 valid genera, with Parvodus previously reported in Brazilian deposits from the Brejo Santo Formation (Araripe Basin, Late Jurassic ...
Larissa de Souza Ribeiro   +1 more
wiley   +1 more source

Gamma-ray spectrometry across the Upper Devonian basin succession at Kowala in the Holy Cross Mountains (Poland) [PDF]

open access: yes, 2003
The Upper Devonian sequence at Kowala in the Holy Cross Mountains was logged using gamma-ray spectrometry, for investigating the changes of oxygenation level in the Late Devonian basin.
Bond, D.P.G., Zaton, M.
core   +1 more source

Multi‐Method Geophysical Surveys Between and Around the Kerlescan and the Manio Megalithic Alignments in Carnac (Morbihan, France)

open access: yesArchaeological Prospection, EarlyView.
ABSTRACT The Carnac alignments in Morbihan (France) are among the most famous Neolithic sites of the world. Paradoxically, they have benefited little from a thorough renewal of archaeological data over the past century. There are many reasons for this, but it is mainly because the site has been regarded more as a monument to visit and protect than as ...
Guillaume Bruniaux   +6 more
wiley   +1 more source

First U–Pb LA-ICP-MS Radioisotopic Ages of the Devonian–Carboniferous Boundary Black Shales (Domanik Facies) in the Kama–Kinel Trough System, Volga–Ural Petroleum Province, East European Platform

open access: yesGeoresursy
For the first time, zircons from thin volcanic ash layers contained within organic-rich black shales (Domanik facies) at the Devonian–Carboniferous boundary have been dated using the U–Pb LA-ICP-MS method.
V. V. Silantiev   +7 more
doaj   +1 more source

Geologic quadrangle map no. 47 [PDF]

open access: yes, 1978
Process Steps: 1. Either: a) a Portable Document Format (PDF) version of the map provided the Bureau of Economic Geology, University of Texas at Austin was converted from pdf to Tagged Image File Format (TIFF) or b) a paper map was scanned and saved in ...
Barnes, Virgil E. (Virgil Everett), 1903-1998
core   +1 more source

Slip versus dilation tendency parameter space as a tool for prospecting structurally controlled geothermal systems in greenfield: insights from the greater Ruhr region

open access: yesDeep Underground Science and Engineering, EarlyView.
This study highlights that with the static and time‐dependent evolution of slip versus dilation tendency parameter space, structurally controlled deep geothermal systems can be selected within areas of higher permeability and lower seismic hazard. Abstract Faults play a vital role in the Earth's hydraulic system by facilitating fluid flow when dilating
Michal Kruszewski   +4 more
wiley   +1 more source

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