Results 21 to 30 of about 297,462 (204)

Seismic anisotropy in siliciclastic reservoir rocks [PDF]

open access: yes, 2006
The interpretation of geophysical field measurements of seismic anisotropy is presently limited by our knowledge of the controls of the elastic anisotropy of sedimentary rocks in the subsurface. Traditionally, laboratory ultrasonic velocity measurements
Maddock, Jamie Stewart
core   +7 more sources

GENETIC AND EXPLORATION IMPLICATIONS OF THE ZINC RATIO [100 Zn/(Zn + Pb)] IN THE RODRUIN PROSPECTING AREA OF THE GOLDEN TRIANGLE -EGYPT [PDF]

open access: yesDelta Journal of Science, 2022
Rodruin Prospecting Area (26o21/59//N, 33o20/32//) in the Golden Triangle -Egypt, was exploited by the Ancient Egyptian Miners. They exploited gold from gossans and gossanous gold-bearing quartz veins.
Hassan Harraz   +3 more
doaj   +1 more source

Geology, petrology and U-Pb geochronology of metavolcanic rocks in the Mundo Novo greenstone belt, eastern São Francisco Craton, NE Brazil: considerations about its tectonic setting

open access: yesBrazilian Journal of Geology, 2020
Field, petrological and LA-ICP-MS U-Pb geochronological data of metavolcanic rocks were used to interpret the petrological processes and to propose the tectonic setting for the Mundo Novo greenstone belt (MNGB) in the eastern São Francisco Craton.
Ricardo Ramos Spreafico   +3 more
doaj   +1 more source

Stratigraphy of the central parts of the Palaeoproterozoic Tampere Schist Belt, southern Finland: review and revision [PDF]

open access: yesBulletin of the Geological Society of Finland, 1998
The arc-type Palaeoproterozoic volcanic-sedimentary Tampere Schist Belt (TSB), close to the centre of the Svecofennian Orogen, comprises an E-W-striking major synform in its central parts.
Y. Kähkönen
doaj   +1 more source

PHYSICAL-MECHANICAL PROPERTIES OF METAVOLCANIC ROCKS OF THE MOUNTAIN CRIMEA

open access: yesEngineering Geology, 2018
The article considers the petrogenetic features of the volcanogenic rocks of the Middle Jurassic age of the Mountain Crimea and analyzes their influence on physical (density, porosity, water absorption, and magnetic susceptibility) and physical-mechanical properties (strength, modulus of elasticity, and Poisson's ratio). Among volcanogenic strata there
J. V. Frolova   +3 more
openaire   +1 more source

THE NEOPROTEROZOIC ISLAND-ARC ASSOCIATION OF THE MUKODEK GOLD-ORE FIELD, NORTHERN BAIKAL AREA

open access: yesГеодинамика и тектонофизика, 2015
Metamorphosed volcanic rocks of the Ushmukan suite were studied in the Mukodek gold-ore field located in the Baikal-Muya belt in the Northern Baikal area, Russia. The Ushmukan suite shows interleaving of ortoschists which compositions are widely variable.
V. A. Vanin   +2 more
doaj   +1 more source

The Encantada Granite: registration of a peraluminous intrusion in the Rondonian Province - San Ignacio, in SW Amazonic Craton, Mato Grosso, Brazil [PDF]

open access: yesGeologia USP. Série Científica, 2015
The Encantada Granite occurs on the extreme southwest of the state of Mato Grosso, SW of the Amazonian Craton, near the border of Brasil/Bolívia. It corresponds to an body oriented to NNW direction that intruded metasedimentary and metavolcanic rocks ...
Brena Verginassi do Nascimento   +2 more
doaj   +1 more source

U-Pb dating, Lu-Hf isotope systematics and chemistry of zircon from the Morro do Polvilho meta-trachydacite: constraints on sources of magmatism and on the depositional age of the São Roque Group

open access: yesGeologia USP. Série Científica, 2018
We present new in situ geochronological data of controversial silicic metavolcanic rocks from the lower terrigenous-metavolcanic sequence of the São Roque Group, Ribeira Belt, confirming that they are older than the rocks of higher-metamorphic grade ...
Renato Henrique-Pinto   +2 more
doaj   +1 more source

The Mesoproterozoic sub-Heddersvatnet unconformity, Telemark, South Norway [PDF]

open access: yesBulletin of the Geological Society of Finland, 2005
The 1.51 Ga Rjukan group,Telemark, S Norway, is divided into felsic volcanic rocks of the Tuddal formation and mafic rocks of the Vemork formation. It is overlain by the sedimentary rocks of the Vindeggen group (1.50-1.17 Ga), starting with the arkosic ...
K. Laajoki
doaj   +1 more source

Metagabbros, metasyenites and related rocks in the Outokumpu assemblage, east Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 1992
A diverse group of minor intrusive rocks in the early Proterozoic Outokumpu assemblage of eastern Finland include metagabbro, hornblendite, amphibolite, pyroxenite, syenite and chloritized dykes.
A.F. Park
doaj   +1 more source

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