Results 41 to 50 of about 13,572 (229)

A new occurrence of samuelsonite in the Buranga Pegmatite, Rwanda [PDF]

Bulletin of the Geological Society of Finland, 1992
A new occurrence of the rare mineral species, samuelsonite, is reported from the Buranga pegmatite, Rwanda, in close association with gatumbaite and burangaite, as aggregates of bladed crystals imbedded in trolleite and in bertossaite.
A.-M. Fransolet, O. von Knorring, F. Fontan   +2 more
doaj   +1 more source

Minerals in Afghanistan : rare-metal deposits [PDF]

, 2007
In Afghanistan rare metals (lithium, caesium, tantalum and niobium) occur in three main deposit types: pegmatites, mineralised springs and playa-lake sediments (Figure 1).
Benham, Antony John, Coats, Stan
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Thermochronologic Constraints on the Extensional History of the Ibex Hills, Southeastern Black Mountains, Death Valley, California

Geological Journal, EarlyView.
A. Modeled T‐t paths for samples in the northern Ibex Hills, showing steady cooling throughout much of the Cenozoic, until rapid Miocene cooling. B. Weighted mean paths for each sample in this study. Note that all show a rapid cooling event at or just after 10 Ma, which is interpreted to represent exhumation as a result of regional extenstion ...
Zachariah D. Fleming
wiley   +1 more source

Quartz deformation characteristics, deformation temperature, and their constraints on pegmatites of the 509 Daobanxi lithium deposit in the West Kunlun area, Xinjiang

Dizhi lixue xuebao
Objective   The 509 Daobanxi deposit in the West Kunlun orogenic belt is a newly discovered large pegmatite-type lithium-polymetallic deposit in northwestern China.
HUO Hailong, CHEN Zhengle, ZHANG Qing, WANG Yong, MA Huadong, WANG Wei, ZHANG Wengao, LI Yong, HAN Fengbin, DU Xiaofei, MIN Zhuang, MENG Xiangpeng   +11 more
doaj   +1 more source

Do Pegmatites Crystallise Fast? A Perspective from Petrologically-Constrained Isotopic Dating

Geosciences, 2023
Most recent studies consider the formation of individual pegmatite bodies to be a fast process with estimated crystal growth rates reaching a walloping 10 m/day. This opinion is presumably underpinned by the traditional way of thinking of them as the end
Daniil V. Popov
doaj   +1 more source

Ancient tin production: Slags from the Iron Age Carvalhelhos hillfort (NW Iberian Peninsula) [PDF]

, 2018
Provenance and production of tin in the Ancient World has since long been a major topic of discussion among archaeologists. In Western Europe, where significant tin ore (cassiterite) deposits are known, only a few remains of ancient tin production, such ...
Figueiredo, Elin, Fonte, João, Lima, Alexandre, Mirão, José, Silva, Rui J.C., Veiga, João Pedro   +5 more
core   +1 more source

A geophysical investigation of the Roter Kamm impact crater, Namibia

Meteoritics &Planetary Science, EarlyView.
Abstract The Roter Kamm impact crater is located in the southern Namib Desert. The crater has a diameter of 2.5 km and belongs to the category of simple, bowl‐shaped impact craters, with an elevated rim of fractured target rock. The crater's interior is completely buried beneath sediments, preventing extensive surface investigations of the bedrock ...
Hannah Nienhaus, Pritam Yogeshwar, Wiebke Mörbe, Bülent Tezkan, Yajun Liu, Bufelo Lushetile, Martin Melles   +6 more
wiley   +1 more source

Preliminary site report for the 2005 ICDP-USGS deep corehole in the Chesapeake Bay impact crater [PDF]

, 2006
First report for the ICDP-USGS 1.7-km-deep corehole drilled into the central part of the Chesapeake Bay impact crater during ...
Browning, J. V., Cockell, C. S., Dypvik, H., Edwards, L. E., Gohn, G. S., Horton Jr., J. W., Koeberl, C., McLaughlin, P. P., Miller, K. G., Ormö, J., Plescia, J. B., Powars, D. S., Reimold, W. U., Sanford, W. E., Self-Trail, J. M., Voytek, M. A.   +15 more
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The effect of fluorine on viscosities in the system Na2O-Al2O3-SiO2: implications for phonolites, trachytes and rhyolites [PDF]

, 1985
The effect of fluorine on melt viscosities of five compositions in the system Na2O-Al2O3- SiO2h as been investigateda t one atmospherea nd 1000-1600'Cb y concentric-cylinder viscometry.
Cronin, David J., Dingwell, Donald B., Scarfe, Christopher M.   +2 more
core   +1 more source

Geologic Guide for the Northern Part of the Peninsular Range Province, Southern California [PDF]

, 1954
This geologic guide deals with parts of Los Angeles, San Bernardino, Riverside, and San Diego Counties, in southern California, and in effect is a sampling of the geology and mineral deposits in the northern part of the Peninsular Range province.
Jahns, Richard H.
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