Results 31 to 40 of about 27,665 (229)

The Timan-Pechora basin. The structure and main stages of development

open access: yesGeoresursy, 2017
The lack of complete inheritance in the history of the Timan-Pechora basin development has led to a discrepancy between the basement surface plans and the individual sub-levels and their complexes. In the lower part of the section, the structures inherit
A.V. Stoupakova
doaj   +1 more source

Indigenous demosponge spicules in a Late Devonian stromatoporoid basal skeleton from the Frasnian of Belgium [PDF]

open access: yes, 2014
This paper records the first example of a demosponge spicule framework in a single specimen of a Devonian stromatoporoid from the Frasnian of southern Belgium.
Alvarez   +51 more
core   +1 more source

Rediscovery of the Type Specimens of the Sarcopterygian Fishes Onychodus sigmoides and Onychodus hopkinsi from the Devonian of Ohio, USA

open access: yesDiversity
John Strong Newberry described three species of the lobe-fin fish Onychodus (Osteichthyes, Sarcopterygii, Onychodontida) based on parasymphysial teeth, or tusks.
Loren E. Babcock
doaj   +1 more source

The geochemical characteristics, distribution of marine source rocks and gas exploration potential in the northwestern Sichuan Basin, China

open access: yesJournal of Natural Gas Geoscience, 2021
In recent years, the northwestern part of the Sichuan Basin has become a popular location for natural gas exploration. However, up to this point, the geochemical characteristics and distribution of marine source rocks in this area have not been ...
Guoyi Hu   +4 more
doaj   +1 more source

Middle–upper devonian terrigenous rocks of the Tsil’ma River basin and their palynological characteristics

open access: yesСтратиграфия, 2019
The results of biostratigraphic study of Givetian–Frasnian rocks of the Tsil’ma River basin (Middle Timan) are presented. The biostratigraphic division of the sections is based on palynological data: five palynocomplexes are distinguished in the Valsa, Tsil’ma, Ust’-Chirka, Ust’-Yarega, and Kraipol’e formations and are correlated with coeval ...
O. P. Tel’nova, I. Kh. Shumilov
openaire   +2 more sources

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

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

Influence of palaeoweathering on trace metal concentrations and environmental proxies in black shales [PDF]

open access: yes, 2017
The mineralogical and chemical compositions of Lower Carboniferous (Tournaisian) marine black shale from the Kowala quarry, the Holy Cross Mountains, Poland, were investigated.
Agnieszka Pisarzowska   +128 more
core   +1 more source

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

An assessment of the groundwater resources based on infiltration recharge hydrogeological modeling

open access: yesИзвестия высших учебных заведений: Геология и разведка, 2016
An assessment of the natural groundwater resources (GWR) of Devonian (middle and upper Famennian) aquifer was made in the area of research-assessment works for Smolensk city water supply.
S. O. Grinevskiy   +2 more
doaj   +1 more source

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