Results 31 to 40 of about 75,440 (306)

Significance of the study of sedimental rock-forming evolution in the Earth history for the reconstruction of the changes of geochemical settings on its surface

open access: yesИзвестия высших учебных заведений: Геология и разведка, 2019
The distribution in the geological section of two groups of sedimentary rocks, siliceous and carbonate rocks of different composition — has been examined.
V. G. Kuznetsov
doaj   +1 more source

Early Cambrian U-Pb zircon age and Hf-isotope data from the Guasayán pluton, Sierras Pampeanas, Argentina: implications for the northwestern boundary of the Pampean arc [PDF]

open access: yes, 2016
An Early Cambrian pluton, known as the Guasayán pluton, has been identified in the central area of Sierra de Guasayán, northwestern Argentina. A U?Pb zircon Concordia age of 533 ± 4 Ma was obtained by LA-MC-ICP-MS and represents the first report of ...
Alasino, Pablo Horacio   +8 more
core   +2 more sources

The late Mesozoic-Cenozoic tectonic evolution of the South China Sea: A petrologic perspective [PDF]

open access: yes, 2014
This paper presents a review of available petrological, geochonological and geochemical data for late Mesozoic to Recent igneous rocks in the South China Sea (SCS) and adjacent regions and a discussion of their petrogeneses and tectonic implications. The
Castillo, PR, Shi, X, Yan, Q
core   +2 more sources

Uranium in alkaline rocks

open access: yes, 1978
Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to ...
Murphy, M.   +5 more
openaire   +4 more sources

Sulphur isotopes of alkaline magmas unlock long-term records of crustal recycling on Earth

open access: yesNature Communications, 2019
Sulphur isotopes track recycling of subducted crustal material, yet few igneous rocks preserve these signals over Earth history. Here, the authors investigate a billion-year-old alkaline province in Greenland and are able to reconstruct a recycled mantle
William Hutchison   +9 more
doaj   +1 more source

Petrology and geochemistry of volcanic and subvolcanic rocks in the south of Asagi igneous complex, northwest of Zahedan, Sistan Suture Zone [PDF]

open access: yesپترولوژی
IntroductionThe Asagi igneous complex is located in the northwest of Zahedan city (Figure 1A) and is part of a southeast–northwest trending magmatic belt. The igneous rocks of this belt were formed during at least two distinct periods.
Mohammad Bameri   +2 more
doaj   +1 more source

Mesozoic-Cenozoic mafic magmatism in Sanandaj-Sirjan Zone, Zagros Orogen (Western Iran): geochemical and isotopic inferences from Middle Jurassic and Late Eocene gabbros [PDF]

open access: yes, 2017
One of the consequences of Neo-Tethys ocean subduction beneath the Central Iranian Micro-continent (CIMC) is the development of rare gabbroic intrusions in the Malayer-Boroujerd Plutonic Complex (MBPC) located in the Sanandaj-Sirjan Zone (SaSZ) of the ...
Deevsalar, Reza   +8 more
core   +1 more source

GEOCHRONOLOGY OF ALKALINE ROCKS FROM THE BURPALA MASSIF (NORTHERN PRIBAIKALYE): NEW U-Pb DATA

open access: yesГеодинамика и тектонофизика
Geochronological studies have been made on the main types of rocks from the Burpala alkaline massif and two gabbro and gabbro-diorite dikes located nearby.
I. А. Izbrodin   +8 more
doaj   +1 more source

Glass in the submarine section of the HSDP2 drill core, Hilo, Hawaii [PDF]

open access: yes, 2004
The Hawaii Scientific Drilling Project recovered ~3 km of basalt by coring into the flank of Mauna Kea volcano at Hilo, Hawaii. Rocks recovered from deeper than ~1 km were deposited below sea level and contain considerable fresh glass. We report electron
Baker, Michael   +4 more
core   +1 more source

Facial accessory of high-titanium magnezium-ferruginous micas as one of evaluation criteria of metamorphic and magmatic rocks rare-metall specialization

open access: yesЛитосфера, 2015
Type-chemical features of high-titanium magnezium-ferruginous micas of granulites, mafite-ultramafites, alkaline rocks, and carbonatites are considered.
A. I. Belkovsky
doaj   +2 more sources

Home - About - Disclaimer - Privacy