Results 41 to 50 of about 238 (148)

Formation of black opal in the pegmatites from Volyn (Ukraine) – an example for interaction of silica with organic matter [PDF]

European Journal of Mineralogy
Black opal, a variety of opal pigmented by organic matter, from Volyn, western Ukrainian Shield, was investigated by means of scanning electron microscopy (SEM), electron microprobe analyses (EMPAs), μ-X-ray fluorescence (μXRF) element mapping, X-ray ...
G. Franz, V. Khomenko, V. Chornousenko, A. Zeh, F. Schiperski, S. Gouzy, U. Gernert, J. Nissen   +7 more
doaj   +1 more source

NEW FINDINGS OF RARE MINERALS IN PEGMATITES OF VISHNEVYE MOUNTAINS IN THE SOUTHERN URALS [PDF]

Минералогия, 2019
In addition to previously known 221 minerals, 11 new rare minerals were identified in alkali pegmatites of the Vishnevye Mountains. Yttrialite-(Y)Y2(Si2O7) and huanghoite-(Ce) aCe(CO3 2F were found for the first time in the Urals.
V.I. Popova, V.A. Popov, I.A. Blinov, V.A. Kotlyarov, A.V. Kasatkin, R. Škoda, S.M. Lebedeva   +6 more
doaj  

CONCENTRIC-ZONAL AGGREGATE OF REE MINERALS IN FELDSPAR PEGMATITE OF THE VISHNEVYE MOUNTAINS, SOUTH URALS [PDF]

Минералогия, 2019
A concentric-zonal texture of mineral aggregate observed in alkali pegmatite of the Vishnevye Mountains was formed as a result of melt-fluid crystallization in a closed system.
V.A. Popov
doaj  

Provenance of Middle Triassic sediments in the Southern Youjiang Basin: Insights from detrital zircon geochronology and tourmaline geochemistry

The Depositional Record, Volume 12, Issue 4, September 2026.
Middle Triassic turbidites in the Youjiang Basin were chiefly derived from a Late Palaeozoic continental arc along the southeastern South China Block, as revealed by detrital zircon U–Pb geochronology and tourmaline geochemistry, supporting a tectonic model driven by Paleo‐Pacific subduction rather than Paleo‐Tethyan closure.
Yumei Wei, Lanqiu Meng, Yu Zhang
wiley   +1 more source

PETROCHEMISTRY OF ROCKS IN THE PEGMATITE ZONE OF THE PRECAMBRIAN CENTRAL NIGERIA: AN ECONOMIC POTENTIAL PERSPECTIVE

Academy Journal of Science and Engineering, 2022
Pegmatites occur in association with amphibolites, minor granite-gneiss and quartzites in central Nigeria. Findings on their economic potentials are yet to reveal more representative and accurate depiction of their characteristics.
Adeyemi, O.O., Adebisi, N.O., Egbeyemi, O.R.   +2 more
doaj  

Relation of alkali-metasomatism and Ti-REE-U (Th) mineralization in the Saghand mining district, Central Iran

Journal of Economic Geology, 2019
Introduction The Saghand mining district is a part of Bafq-Saghand metallogenic zone in the Central Iranian geostructural zone which is located in northeast of city of Yazd.
Saleh Deymar, Mehrdad Behzadi, Mohammad Yazdi, Mohammad Reza Rezvanianzadeh   +3 more
doaj   +1 more source

Corundum Discovered by SuperCam and the Perseverance Rover at Jezero Crater, Mars

Geophysical Research Letters, Volume 53, Issue 16, 28 August 2026.
Abstract Mars is primarily composed of mafic mineral assemblages and their alteration products, but small, scattered rocks strewn across the landscape offer clues to greater petrological diversity. While traversing the Jezero crater rim, the Perseverance rover encountered several plagioclase‐rich light‐toned float rocks.
A. M. Ollila, O. Beyssac, A. Fau, O. Forni, E. Clavé, P. Beck, C. C. Bedford, V. Payre, E. Dehouck, S. A. Connell, J. A. Manrique, P. Pilleri, O. Gasnault, G. M. Martinez, A. Udry, S. Bernard, P. Gasda, T. Acosta‐Maeda, R. B. Anderson, T. S. J. Gabriel, F. Calef, J. F. Bell III, J. Maki, S. Schröder, C. Quantin‐Nataf, J. R. Johnson, B. Chide, K. Rammelkamp, F. Poulet, C. Royer, M. Rock, N. L. Lanza, S. K. Sharma, G. Lopez‐Reyes, T. Fouchet, J. Comellas, A. Zastrow, E. Cloutis, R. C. Wiens, A. Cousin, S. Maurice, S. Clegg, P. Bernardi, T. Nelson   +43 more
wiley   +1 more source

Crystal chemistry and trace-element behaviour in tourmalines from Minas Gerais, Brazil [PDF]

European Journal of Mineralogy
A series of 17 museum tourmaline samples from several pegmatites of Minas Gerais, Brazil, were investigated by several techniques including single-crystal X-ray structure refinements, electron microprobe, and laser ablation inductively coupled plasma ...
F. Bomal, F. Hatert, S. Philippo, M. Guennou, M. Depret, H. Wang, P. Lefèvre, M. Erambert   +7 more
doaj   +1 more source

Subduction Initiation and Early Subduction Zone Development: Insights From the P–T–t Path of the Bay of Islands Metamorphic Sole

Journal of Metamorphic Geology, Volume 44, Issue 7, Page 510-536, August 2026.
ABSTRACT The processes involved during subduction initiation (SI) remain poorly constrained, in part due to the rarity of geological archives. Ophiolites and their underlying metamorphic soles are thought to form during subduction zone infancy and may thus provide critical constraints. Metamorphic soles are derived from oceanic crust of the lower plate
François Fournier‐Roy, Carl Guilmette, Mark Coleman, Kyle Larson, Douglas K. Tinkham, Alana M. Hinchey, John Wakabayashi, Jean H. Bédard, Louise Mérit, Philippe Agard, Loïc Labrousse, Antoine Godet   +11 more
wiley   +1 more source

Thermodynamic Modeling of Lithium Enrichment During Partial Melting: The Importance of Partition Coefficients

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 7, July 2026.
Abstract Predicting the partial melting conditions that generate Li‐rich peraluminous melts is of major economic and societal importance. However, existing models disagree on the optimal conditions (e.g., pressure, temperature, protolith) and, consequently, on targets for exploration.
Nicolas Riel, Owen M. Weller, Caroline R. Soderman, Elisa O. Costa, Matthew C. Morris, Evangelos Moulas, Boris J. P. Kaus   +6 more
wiley   +1 more source