Results 91 to 100 of about 2,363 (234)

Mineralogical Components of the Upper Jurassic Naokelekan Formation from Northeastern Iraq

المجلة العراقية الوطنية لعلوم الارض
The upper Jurassic Naokelekan Formation has been investigated using X-ray diffraction and scanning electron microscopy in two outcrop sections from Halabja and Barzinja areas in northeastern Iraq to determine mineralogical composition.
Sumaya Asghar Samad, Hasan A. Ali Al-Jumaily, Ali Ismail Al-Juboury, Harry Rowe, Giovanni Zanoni, Rebwar H. Rasool, Arkan O. Sharazwri   +6 more
doaj   +1 more source

Geochemical Aspects of Na-Metasomatism in Sargaz Granitic Intrusion (South of Kerman Province, Iran) [PDF]

Journal of Sciences, Islamic Republic of Iran, 2012
The Sargaz granitic intrusion has been emplaced in Sargaz ophiolitic suite, south-east of Sanandaj-Sirjan metamorphic zone, south of Kerman province.
H. Ahmadipour
doaj  

The Ames impact structure, Oklahoma: New radioisotopic constraints and implications for North American impact chronology

Meteoritics &Planetary Science, EarlyView.
Abstract The Ames impact structure (Oklahoma) is thought to have formed during the Ordovician Meteor Event, based on conodont biostratigraphy of its crater fill. Here, U–Pb zircon dates from its impact‐melt portion, conducted using secondary ion mass spectrometry and laser ablation–inductively coupled plasma–mass spectrometry (n = 37 spots), yield a ...
Elizabeth J. Catlos, Andrew F. Parisi, Michael E. Brookfield, Timmons Erickson, Sean P.S. Gulick, Axel K. Schmitt, Daniel F. Stockli, Daniel P. Miggins, Ben Ruchte, Mark Cloos   +9 more
wiley   +1 more source

Terms: alkali feldspar and “potassium feldspar”

The Journal of the Geological Society of Japan, 2023
openaire   +1 more source

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

Meteoritics &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, Addi Bischoff, Samuel Ebert, Kazuhide Nagashima, Andreas Morlok, Harald Hiesinger, Jasper Berndt   +6 more
wiley   +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

Impact provenance and age of a unique basalt found in Apollo 12 regolith

Meteoritics &Planetary Science, EarlyView.
Abstract Basaltic sample 12032,366‐18 from the Apollo 12 landing site is distinct among basalts collected at this site, other Apollo landing sites, and lunar meteorites in terms of its age, bulk rock composition, and isotopic composition. We present new Pb isotopic data obtained by in situ Secondary Ion Mass Spectrometry on multiple mineral phases in ...
C. Deligny, M. J. Whitehouse, R. E. Merle, H. Jeon, A. A. Nemchin, B. L. Jolliff   +5 more
wiley   +1 more source

Characterization of coesite‐bearing impact melt glass from the Hapcheon crater, Korea: Trimodal phase architecture, shock metamorphism, and implications for 40Ar/39Ar geochronology

Meteoritics &Planetary Science, EarlyView.
Abstract We present the first micrometer‐scale, phase‐resolved compositional characterization of impact melt glass from the Hapcheon crater (~1.4 km apparent diameter), the first confirmed impact structure on the Korean Peninsula, integrating EPMA‐WDS (5 μm spot), confocal Raman spectroscopy (<1 μm spot), XRD, and 40Ar/39Ar step‐heating geochronology ...
Jin‐Young Lee, Jeongmin Kim, Sei‐Sun Hong   +2 more
wiley   +1 more source

The effects of bioturbation on porewater chemistry and early marine diagenesis: Evidence from a modern intertidal zone in Abu Dhabi, U.A.E.

Sedimentology, EarlyView.
ABSTRACT Early marine carbonate cements generally form in CaCO3‐supersaturated seawater at the seabed or shallow burial depths, resulting in syn‐sedimentary cemented firmgrounds and hardgrounds. The processes controlling early marine diagenesis are complex, particularly in coastal environments where geochemistry is influenced by different water sources
Drew Brown, Tom Kibblewhite, Fiona Whitaker, Daniela Gutierrez‐Rueda, Daniel S. Alessi, John‐Paul Zonneveld, Murray Gingras, Hilary Corlett   +7 more
wiley   +1 more source

Fluid-driven element mobility resets plagioclase rubidium strontium and barium clocks while potassium feldspar resists

Communications Earth & Environment
Rubidium, cesium, strontium, barium and their isotopes are employed as tracers of magmatic differentiation and fluid-mediated metasomatism, but their mobility during mineral-scale alteration remains uncertain.
Hao-Xiang Zhang, Shao-Yong Jiang, Si-Qi Liu, Hui-Min Su, Wen-Tian Li   +4 more
doaj   +1 more source