Results 91 to 100 of about 2,650 (213)

Distribution and rare earth element abundances of apatite in Bennu samples determined by synchrotron X‐ray fluorescence spectroscopy

Meteoritics &Planetary Science, EarlyView.
Abstract Apatite is often the most rare earth element (REE)‐enriched mineral in chondritic meteorites. REE enrichment and fractionation levels in apatite grains can give insight into the aqueous fluids in which they formed and the conditions prevailing within the host body. In this study, we applied synchrotron X‐ray fluorescence (SXRF) spectroscopy to
B. J. Tkalcec, P. Tack, T. Baert, J. Herthogs, B. Vekemans, B. Bazi, E. De Pauw, M. Di Michiel, G. Falkenberg, J. Garrevoet, G. Libourel, M. Portail, V. Guigoz, C. Collin, H. C. Connolly Jr., D. S. Lauretta, L. Vincze, F. E. Brenker   +17 more
wiley   +1 more source

Fluid-Mineral Partitioning of REE in Critical Mineral Deposits [PDF]

Goldschmidt Abstracts, 2020
openaire   +1 more source

‘Chrystalline Talk’: Thomas Browne's Poetics of Concretion and Mineral Plain Style

Renaissance Studies, EarlyView.
ABSTRACT This article charts the figuration, both material and rhetorical, of mineral bodies in early modern natural philosophy, paying particular attention to the second book of Thomas Browne's Pseudodoxia Epidemica (1646). It argues that concretions (stony calculi and crystals formed through the aggregation of physical matter) make manifest a mineral
Jess Dunmore
wiley   +1 more source

Coupled plagioclase dissolution and K‐feldspar overgrowth precipitation preserve anomalously high permeability in deeply buried sandstones

Sedimentology, EarlyView.
ABSTRACT This study investigated the formation mechanism responsible for anomalously high permeability (AHP) observed in the Eocene sandstones at depths from 3824 to 3832 m in the Huizhou Sag, Pearl River Mouth Basin, China, using helium porosity and permeability measurements, thin section, scanning electron microscopy, electron probe X‐ray ...
Changgui Xu, Huan Li, Wei Wang, Yangdong Gao, Guangrong Peng, Lin Ding, Eric O. Ansah, Pei Liu, Xiaoyan Li, Saju Menacherry, Hongtao Zhu, Xianghua Yang, Zhiwei Zeng   +12 more
wiley   +1 more source

REE minerals in Catalão II, Goias, Brazil

, 2012
The REE minerals pyroxenites and sövites of Catalão II show a substantial enrichment in REE from the magmatic stage. The activity of carbonate and CO32-/ PO43- ratio have played an important role in the formation of REE-carbonate-phosphates, which are an intermediate form between REE-rich apatite and REE-rich carbonate.
Bilal, Essaïd, de Mello, Fernando Machado, Soubiès, François, Bounakhla, Moussa   +3 more
openaire   +1 more source

Application of multisensor remote sensing and Machine Learning for mapping alteration minerals in the Mountain Pass District, California, USA

Discover Geoscience
Mapping alteration minerals in carbonatite-hosted mineral systems is challenging because diagnostic spectral responses are distributed across multiple lithologic units, structurally controlled zones, and hydrothermal overprints.
Nima Esmaeilzadeh, Nahid D. Gani, Amin Beiranvand Pour   +2 more
doaj   +1 more source

Conditions and timing for the precipitation of early marine diagenetic dolomite in the Triassic Dolomia Principale (northern Italy)

Sedimentology, EarlyView.
ABSTRACT Thermodynamic constraints and empirical evidence often suggest that fabric‐retentive replacement dolomites are stable carbonate minerals that preserve ancient seawater properties. This study evaluates this hypothesis by examining the Upper Triassic Dolomia Principale in Northern Italy.
Vivien Folliot, Giovanna Della Porta, Mathias Mueller, Fabrizio Berra, Benjamin F. Walter, Aratz Beranoaguirre, Sylvia Riechelmann, Oskar Schramm, Adrian Immenhauser   +8 more
wiley   +1 more source

Chemical Textures on Rare Earth Carbonates: An Experimental Approach to Mimic the Formation of Bastnäsite

Global Challenges
The interaction between multi‐component rare earth element (REE) aqueous solutions and carbonate grains (dolomite, aragonite, and calcite) are studied at hydrothermal conditions (21–210 °C).
Melanie Maddin, Remi Rateau, Adrienn Maria Szucs, Luca Terribili, Brendan Hoare, Paul C. Guyett, Juan Diego Rodriguez‐Blanco   +6 more
doaj   +1 more source

Siliceous sponges or seawater as a silicon source? Tracing silicon burial pathways of the Upper Cretaceous opal‐CT deposits using δ30Si and δ7Li

Sedimentology, EarlyView.
ABSTRACT Classical models of formation of sedimentary siliceous rocks (flint, chert, opoka) commonly assume that the Cretaceous marine silicon (Si) cycle was primarily biologically controlled, broadly analogous to the modern ocean. In this framework, siliceous sponges are regarded as the principal source of dissolved silica (dSi) to sediment porewaters,
Agata Jurkowska, Ewa Świerczewska‐Gładysz, Marek Szczerba, Tomáš Magna, Szymon Kowalik Filipowicz   +4 more
wiley   +1 more source

RARE EARTH MINERALS IN ALKALINE AND SUBALKALINE ROCKS OF THE BALBUK COMPLEX (SOUTH URALS) [PDF]

Минералогия, 2016
Mineral composition of alkaline and subalkaline rocks of the Balbuk complex (South Urals) is characterized. The major REE minerals are monazite-(Ce), allanite-(Ce), and rhabdophane-(Ce).
E.P. Makagonov, V.A. Kotlyarov
doaj