Results 41 to 50 of about 5,023 (118)

The Mata Azul pegmatitic field, Tocantins/Goiás, central Brazil: geology, genesis and mineralization

Brazilian Journal of Geology
: In Goiás and Tocantins States, Central Brazil, several granitic pegmatites were characterized and grouped for the first time. These pegmatites had been intensely explored by hand in the past, producing mainly gemstone varieties of tourmaline and beryl.
Hudson de Almeida Queiroz, Nilson Francisquini Botelho   +1 more
doaj   +1 more source

Assessment and Correction of Non‐Linearity Effects for In Situ Rb‐Sr Geochronology Applied to High 87Rb/86Sr Mica

Geostandards and Geoanalytical Research, Volume 50, Issue 3, Page 601-624, September 2026.
Key Points Measurement of 86Sr at count rates < 1500 cps can result in statistical bias. Non‐linear signals in analogue detection mode (e.g., Rb) present a challenge for accurately dating high 87Rb/86Sr mica (> 1000). Accounting for these considerations, high 87Rb/86Sr mica are dated here with accuracies of ∼ 1%.
Duane C. Petts, William J. Davis, Simon E. Jackson, Jamie A. Cutts, Janina Czas, Alfredo Camacho   +5 more
wiley   +1 more source

RADIOACTIVITY AND MINERALOGICAL INVESTIGATIONS ON YOUNGER GRANITES OF GABAL SHEIKH EL-ARAB AREA, SOUTHERN SINAI, EGYPT [PDF]

Delta Journal of Science, 2006
The younger granites of the studied area vary in composition from monzogranite, syenogranite to alkali feldspar granite. They exhibit silicification, kaolinitization and ferrugination as a result of the post-magmatic hydrothermal alteration.
ABDEL MONEM M. OSMAN, IBRAHIM E. AASSY, AND OSAMA R. SALLAM, ALI A. EL MOWAFY, SALAH S. EL BALAKSSY   +4 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

Pegmatite lithium deposits formed within low-temperature country rocks

Nature Communications
The global climate crisis is likely to lead to a potential supply risk of lithium (Li) over the coming decades. More than half of the world’s production of Li is derived from Li-bearing pegmatites.
Jinsheng Zhou, Qiang Wang, He Wang, Jinlong Ma, Guanhong Zhu, Le Zhang   +5 more
doaj   +1 more source

Petrochemical Characteristics and Age of Rare Metal (Ta-Nb) Mineralization in Precambrian Pegmatites, Komu, Nigeria [PDF]

International Journal of Economic and Environment Geology, 2010
The Precambrian pegmatites of Komu area intrude semi discordantly older rock types, such as biotite gneiss, amphibolites and pelitic schists. The pegmatites occur as near flat lying bodies.
A. OLUGBENGA, G. OKUNLOLA, B. OFONIME UDOUDO   +2 more
doaj  

Uranium- and thorium-bearing pegmatites of the United States

, 1980
This report is part of the National Uranium Resource Evaluation (NURE) Program designed to identify criteria favorable for the occurrence of the world's significant uranium deposits.
Parrish, I. S., Arengi, J. T., Adams, J. W.   +2 more
core   +1 more source

Surface ages of alluvial fans in the southern Central Andes recorded by ground‐ and space‐based hyperspectral reflectance

Earth Surface Processes and Landforms, Volume 51, Issue 8, August 2026.
Secondary weathering of alluvial‐fan surfaces records the relative, and even absolute, ages of deposited sediments up to 300 ka. Hyperspectral imagery quantifies evolving mineral‐weathering pathways to unlock high‐resolution mapping and dating of these sedimentary landscapes.
Henry T. Crawford, Mitch K. D'Arcy, Andreas Ruby, Ana Laura Martínez López, Philippa J. Mason, Taylor F. Schildgen, Ricardo N. Alonso   +6 more
wiley   +1 more source

Giant lithium-rich pegmatites in Archean cratons form by remelting refertilised roots of greenstone belts

Communications Earth & Environment
Around 80% of the world’s hard-rock lithium supply comes from pegmatites formed in the Archean Eon, yet our understanding of how Lithium-pegmatites form assumes magma source compositions not relevant to those Archean cratons hosting most of the giant ...
Robert H. Smithies, Yongjun Lu, David C. Champion, Marcus T. Sweetapple, Jack R. Lowrey, Nathan H. Bowman, Kevin F. Cassidy, Tim J. Ivanic, Anthony I. S. Kemp, Rose E. Turnbull, Klaus Gessner, Fawna J. Korhonen   +11 more
doaj   +1 more source

Post‐Collisional Evolution in the Southern Variscan Belt: Insights From Numerical Modeling of the Valpelline Series (Western Alps)

Tectonics, Volume 45, Issue 8, August 2026.
Abstract The post‐collisional evolution of orogenic belts is commonly marked by high‐temperature metamorphism and widespread magmatism, yet the processes linking collision to post‐collisional dynamics remain difficult to reconstruct due to limited exposure of deep‐crustal levels and uncertainties in the determination of pressure‐temperature conditions ...
Alessandro Regorda, Marco Filippi, Manuel Roda, Fabiola Caso, Federico Farina, Chiara Benedetta Piloni, Michele Zucali   +6 more
wiley   +1 more source