Results 41 to 50 of about 1,482 (183)

Crystallization conditions of two adjacent epidote + diopside-bearing granitic stocks, northeastern Brazil

Anais da Academia Brasileira de Ciências, 2021
The Tamboril and Olho d’Água granitic stocks are part of the abundant calc-alkalic magmatic epidote-bearing granitic rocks in the Cachoeirinha–Salgueiro Terrane (CST) in the Transversal Zone Domain, northeastern Brazil. The equigranular Olho d’Água stock
RENAN SIQUEIRA, ALCIDES N. SIAL, VALDEREZ P. FERREIRA   +2 more
doaj   +1 more source

Stardust Mine: A 2024 gabbroic shergottite from Arizona, USA

Meteoritics &Planetary Science, EarlyView.
Abstract This study provides an initial characterization of Stardust Mine, a fresh gabbroic enriched shergottite collected in Arizona, USA, in September 2024 and is the first Martian meteorite to be unequivocably collected on US soil. Analysis was conducted on the type specimen and finds that Stardust Mine is composed of equal proportions of pyroxene ...
Jennifer T. Mitchell, Natasha R. Stephen, Zsuzsanna P. Allerton, Weiming Ding, Xin‐Yuan Zheng   +4 more
wiley   +1 more source

The use of predominance area diagrams (PAD) to determine the oxygen and sulfur fugacities prevailing during historical metallurgical processes: the case of fifteenth to seventeenth century copper slags from Polichno (Old Polish industrial district)

Heritage Science
The study presents the first use of predominance area diagrams (PADs) to determine oxidation–reduction conditions during reconstructing historical copper smelting processes.
Krzysztof Kupczak, Rafał Warchulski, Aleksandra Gawęda, Marta Ślęzak, Piotr Migas   +4 more
doaj   +1 more source

Mineralogy, mineral chemistry, and redox equilibria in ten aggregate particles from asteroid Bennu

Meteoritics &Planetary Science, EarlyView.
Abstract Examination of 10 Bennu aggregate particles has revealed the presence of many phases which taken together can provide constraints on the oxygen fugacity (fO2) of Bennu samples. Phyllosilicates (saponite and serpentine), carbonates, oxides (magnetite, chromite), sulfides (pyrrhotite, pentlandite), phosphate (hydroxyapatite, Na‐Mg‐phosphate ...
K. Righter, J. Gorce, L. Le, K. Thomas‐Keprta, Z.E. Wilbur, L.P. Keller, Z. Gainsforth, T.J. McCoy, T.J. Zega, S.S. Russell, H.C. Connolly Jr., D.S. Lauretta   +11 more
wiley   +1 more source

Oxygen fugacity of Alto Paranaíba kimberlites and diamond instability: Três Ranchos IV and Limeira I intrusions

Brazilian Journal of Geology, 2020
Oxygen fugacity (ƒO2) conditions were established for Três Ranchos IV (TR-IV, diamond-bearing) and Limeira I (LM-I, barren) kimberlite intrusions, in Alto Paranaíba Alkaline Province, to constrain a possible correlation between fO2 and diamond ...
Bruna Coldebella, Rogério Guitarrari Azzone, Luanna Chmyz, Excelso Ruberti, Darcy P. Svisero   +4 more
doaj   +1 more source

Evaluating maturity of organic matter in hydrated C1 and CM‐like clasts and a dehydrated clast within a polymict eucrite and a howardite

Meteoritics &Planetary Science, EarlyView.
Abstract Volatile‐rich xenolithic clasts in different types of brecciated meteorites represent unique pristine solar system material. This study investigates the maturity and thermal history of organic matter using Raman spectroscopy and aqueous alteration effects using infrared spectroscopy in the matrix of 15 volatile‐rich clasts (C1 and CM‐like ...
Swarna Prava Das, Alessandro Maturilli, Aurélie Van den Neucker, Markus Patzek, Dipak Kumar Panda, Gopal K. Pradhan, Guneshwar Thangjam, Surya Snata Rout   +7 more
wiley   +1 more source

Contrasting apatite geochemistry between ore-bearing and ore-barren intrusions of the giant Kalmakyr gold-rich porphyry Cu deposit, Tien Shan, Uzbekistan

Frontiers in Earth Science, 2023
The Kalmakyr deposit in Uzbekistan is one of the world’s largest gold-rich porphyry Cu deposits, and mineralization was proposed to be closely associated with the emplacement of the latest intrusive phases, that is, granodiorite porphyry.
Yangtao Liu, Xiaobo Zhao, Chunji Xue, Chunji Xue, Bakhtiar Nurtaev, Jing Chen   +5 more
doaj   +1 more source

Potassium isotopic compositions and exposure ages of evolved and silica‐rich achondrites

Meteoritics &Planetary Science, EarlyView.
Abstract Some of the oldest igneous rocks in the Solar System include evolved and silica‐rich achondrites that originate from parent bodies less than 1000 km in diameter, referred to as planetesimals. While Earth was initially in a molten state and required continental crust formation and plate tectonics to generate andesite bulk compositions, evolved ...
Z. Vaci, Z. Tian, P. Koefoed, M. Habermann, M. Humayun, K. Ziegler, H. Busemann, D. Krietsch, J. M. D. Day, K. Wang   +9 more
wiley   +1 more source

Redox control of the partitioning of platinum and palladium into magmatic sulfide liquids

Communications Earth & Environment
The partitioning behavior of platinum group elements in magmas is critical for their use as tracers of planetary accretion and in understanding magmatic sulfide deposits.
Wanying Wang, Yuan Li
doaj   +1 more source

EPMA Analysis of Hydrothermal Biotite from the Bangpu Porphyry Mo-Cu Deposit of Tibet, China and the Characteristics of Early Ore-forming Fluids

Yankuang ceshi, 2016
The chemical composition of hydrothermal biotite is important in revealing the physiochemical conditions and evolution of early ore-forming fluids. The Bangpu deposit is a large porphyry Mo(Cu) deposit in the eastern part of the Gangdese metallogenic ...
WANG Yong, TANG Ju-xing, WANG Li-qiang
doaj   +1 more source