Results 61 to 70 of about 741 (232)

Electron Microprobe Reintegration Method for Clinopyroxene Breakdown with Lamellae Exsolution

open access: yesYankuang ceshi
Pyroxene is an important rock-forming mineral in magmatic to metamorphic rocks, which often possesses certain breakdown texture with lamellae exsolution under temperature and pressure changes.
Xiaoli LI, Lifei ZHANG
doaj   +1 more source

Volcanostratigraphic Sequences of Kebo-Butak Formation at Bayat Geological Field Complex, Central Java Province and Yogyakarta Special Province, Indonesia

open access: yesIndonesian Journal on Geoscience, 2016
DOI:10.17014/ijog.3.2.77-94Bayat Complex is usually used as a work field for students of geology and other geosciences. The study area is located in the southern part of the Bayat Complex.
Sri Mulyaningsih
doaj   +1 more source

Origin and formation of a chondritic xenolith in Krymka (LL3.2, breccia): Indications for a late formation of the accretionary breccia

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract An unusual chondritic xenolith was found in two sequentially prepared thin sections of a sample from the Krymka (LL3.2) chondrite. The xenolith has a rounded, slightly deformed shape of about 5 mm in apparent diameter and is partially surrounded by a double rim made of an inner fine‐grained silicate‐rich rim and an outer sulfide‐rich rim.
Aelita Girich   +6 more
wiley   +1 more source

Petrography and mineral chemistry of metamorphosed mantle peridotites of Nain Ophiolite (Central Iran)

open access: yesJournal of Economic Geology, 2017
Introduction Study of the petrology of the ophiolites as the relics of ancient oceanic lithosphere, is a powerful tool to reconstruct Earth’s history. Mantle peridotites have mostly undergone alteration and serpentinization to some extent.
Nargess Shirdashtzadeh   +2 more
doaj   +1 more source

Sedimentology of silica granules and haematite in the 3.47 Ga Antarctic Creek Member, Mount Ada Basalt, Western Australia

open access: yesSedimentology, EarlyView.
ABSTRACT The Paleoarchean Antarctic Creek Member of the Mount Ada Basalt, Eastern Pilbara Terrane, Western Australia, includes beds of jasper and white chert composed of sand‐sized silica granules that often contain or are mixed with silt‐sized particles of haematite.
Donald R. Lowe, Gary R. Byerly
wiley   +1 more source

Petrology of Oligocene Ghaleh Yaghmesh granitoids in the west of Yazd province

open access: yesJournal of Economic Geology, 2017
Introduction The generation and evolution of granitic magmas has been a hot debated subject among petrologists. The diversity of their origin has led different authors to propose that these rocks are not simple in their origin and might be generated in
Bahareh Fazeli   +4 more
doaj   +1 more source

A Triassic chronostratigraphic and palaeogeographic framework for the Utsira High area, northern North Sea: Reconstructing a basin‐scale drainage divide

open access: yesSedimentology, EarlyView.
ABSTRACT The Triassic succession of the northern North Sea comprises a series of interbedded sandstones, mudstones and conglomerates deposited under a fluctuating arid to semi‐humid climate regime, which are often difficult to correlate regionally due to differing lithostratigraphic schemes and poor age control. Despite existing regional studies on the
Riccardo Sordi   +3 more
wiley   +1 more source

Essentials of Igneous and Metamorphic Petrology [PDF]

open access: yesAmerican Mineralogist, 2015
B. Ronald Frost and Carol D. Frost (2013) Cambridge University Press, U.K. ISBN: 9781107696297, 314 pages. Essentials of Igneous and Metamorphic Petrology , which is easy to recommend, is presented in a concise and compelling manner. The book is about 300 pages and is subdivided into eighteen chapters that convey the fundamental principles that govern
openaire   +1 more source

Porosity Preservation in Deeply Buried (8500 m) Jurassic Calcareous Mudstones of the Vienna Basin (Austria)

open access: yesTerra Nova, EarlyView.
ABSTRACT Significant porosity of more than 5% was found at depths of more than 8500 m in poorly sorted, calcareous mudstones of the Malmian Mikulov Formation. These overpressured rocks are the main hydrocarbon source rock in the Vienna Basin. Core samples from present‐day depths of 8150 m to 8550 m were analysed using X‐ray diffraction and scanning ...
Susanne Gier   +3 more
wiley   +1 more source

Fault‐Controlled Permeability: A Key Parameter in Geothermal Electricity Production Assessment

open access: yesTerra Nova, EarlyView.
ABSTRACT Geothermal energy is central to the global green energy transition, but its development has long focused on regions with positive thermal anomalies. Through a semi‐quantitative global‐scale review and spatial analysis of 361 geothermal sites, we show that 56.2% of global geothermal electricity production occurs in regions with thermal ...
Vincent Roche, Gaétan Milesi
wiley   +1 more source

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