Results 51 to 60 of about 13,572 (229)

Exhumation of the Koktokay rare-metal pegmatite group in the China Altai: insights from low-temperature thermochronology of the No. 3 pegmatite and Aler S-type granitic batholith

Frontiers in Earth Science
The China Koktokay Pegmatite Group is an important metallogenic region where major rare-metal ores are mined. Here, we present new low-temperature thermochronological data to contribute to the understanding of the Koktokay Pegmatite Group’s exhumation ...
Haoyu Wang, Haoyu Wang, Guangming Ren, Yong Tang, Hui Zhang, Zhenghang Lv, Zhilong Huang   +6 more
doaj   +1 more source

The Sveconorwegian Pegmatite Province – Thousands of Pegmatites Without Parental Granites [PDF]

The Canadian Mineralogist, 2017
Abstract The Late-Proterozoic Sveconorwegian pegmatite province in southern Norway and southwest Sweden hosts seven rare-element pegmatite districts with more than 5000 rare-element pegmatites. Most of these pegmatites with Niobium-Yttrium-Fluorine (NYF) signature are not related to a parental granite, but instead occur in areas of high-grade ...
Müller, Axel, Romer, Rolf L., Pedersen, Rolf B.   +2 more
openaire   +4 more sources

Ambiguities in Assigning Single‐Crystal NMR Data to Individual Atoms in the Crystal Structure: A Case Study of Hambergite, Be2BO3OH, by 9Be and 11B NMR Spectroscopy, XRD Measurements and DFT Calculations

Magnetic Resonance in Chemistry, Volume 64, Issue 4, Page 400-415, April 2026.
The fundamental question of how to assign NMR resonances to specific atoms in the unit cell is addressed by using the 9Be and 11B spectra of the natural mineral hambergite as a model system. ABSTRACT The NMR interaction tensors of 9Be and 11B of hambergite, Be 2BO 3OH, were derived from single‐crystal NMR experiments.
Jennifer Steinadler, Georg Krach, Kristian Witthaut, Tobias Stürzer, Rupert Hochleitner, Wolfgang Schnick, Thomas Bräuniger   +6 more
wiley   +1 more source

First discovery of highly fractionated tourmaline-bearing leucogranite-pegmatite in Duxiushan, Anqing ore-cluster region, middle and lower Yangtze metallogenic belt: A clue to strategic metal exploration

Solid Earth Sciences, 2022
A suite of highly fractionated granites and associated pegmatite, were revealed through drill hole in the Anqing ore-cluster region in the Lower Yangtze River Belt (MLRB), Eastern China, for the first time. The pegmatite has abundant tourmaline.
Zhuang Zhao, Xiaoyong Yang, Beicai Zhang, Dongqing Wang, Jiancheng Xie, Tuyan Zhang, Wanying Li   +6 more
doaj   +1 more source

Pegmatites of Southern California [PDF]

, 1954
For many years the southern California region has attracted the attention of geologists interested in pegmatites and pegmatite deposits, largely because of the well-known gem and lithium occurrences in San Diego and Riverside Counties. These world-famous
Jahns, Richard H.
core  

Chemical diffusivity of boron in melts of haplogranitic composition [PDF]

, 1993
Chemical diffusivities of B in synthetic melts of haplogranitic composition have been measured by the diffusion couple technique at 1 atm between 1200–1600°C.
Chakraborty, Sumit, Chaussidon, Marc, Dingwell, Donald B.   +2 more
core   +1 more source

Supervised Swin Transformer‐Based Predictive Lithological Mapping and Uncertainty Quantification Using Aeromagnetic and Gravity Data

Journal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 2, April 2026.
Abstract Lithological mapping is essential for the exploration of critical minerals supporting energy transition and national defense. Although recent advancements have incorporated multi‐source data sets and leveraged machine learning and deep learning (DL) methods, lithological mapping continues to face significant challenges, such as data imbalance,
Liang Ding, Gilles Bellefleur, Olivier Boulanger, Phuong Vo   +3 more
wiley   +1 more source

A New Concept for an Integrated Mapping of Rare‐Earth Elements using Laser–Induced Fluorescence and Reflectance Spectroscopy

Advanced Sensor Research, Volume 5, Issue 3, March 2026.
We introduce a new integrated line‐scan sensor system that combines hyperspectral and laser‐induced fluorescence imaging as a non‐invasive alternative characterization technique specifically suited for rare‐earth element (REE) mapping and identification. We investigate in detail the potential and limitations in comparison to state‐of‐the‐art approaches
Titus Abend, Margret Fuchs, Jan Beyer, Sandra Lorenz, Nadine Schüler, Kay Dornich, Johannes Heitmann, Richard Gloaguen   +7 more
wiley   +1 more source

Inclusions of Amorphous and Crystalline SiO₂ in Minerals from Itrongay (Madagascar) and Other Evidence for the Natural Occurrence of Hydrosilicate Fluids

Geosciences, 2022
Experimental studies increasingly often report low-temperature (200–800 °C) and low-pressure (0.05–3 kbar) hydrosilicate fluids with >40 wt.% of SiO2 and >10 wt.% of H2O.
Daniil V. Popov, Richard A. Spikings, Théodore Razakamanana   +2 more
doaj   +1 more source

Minerals in Afghanistan : gemstones of Afghanistan [PDF]

, 2007
Afghanistan and gemstones have been inextricably linked for 6500 years and the country remains rich in precious and semiprecious gemstone deposits (Figure 1). Lapis lazuli, mined in the Hindu Kush since the Neolithic Period, was transported along the
Benham, Antony John, McIntosh, Robert
core