discussion of zoning in hydrothermal districts, reference should be made to the work of W. H. Emmons (1937, 1940), one of the chief advocates of the zoning concept. The purpose of this paper is to report some new examples of zoning in pegmatite districts, to examine critically others recorded in scattered
Zoning in pegmatite districts - GeoScienceWorld
In numerous pegmatite districts the size, shape, external and internal structure, texture and mineral content of an individual pegmatite can be shown to be functions of the distance of the body from its batholith source.
A petrologic assessment of internal zonation in granitic pegmatites
2014年1月1日 · Zonation in pegmatites occurs at two scales: (1) regional zonation, manifested as increasing chemical complexity with distance from their granitic or other thermal source, and (2) internal zonation, the mineralogical and textural changes within individual pegmatite bodies.
Regional Zoning of a Li-Cs-Ta Pegmatite Field: Insights from …
2023年6月21日 · The Renli-Chuanziyuan pegmatite field (South China) displays a well-developed regional zonation sequence, involving a core of biotite-, two-mica- and muscovite monzogranites (MMs) that grades outward into microcline (K-zone), microcline-albite (K-Na-zone), albite (Na-zone) and albite-spodumene (Na-Li-zone) pegmatites.
Most LCT pegmatite bodies are concentrically, but irregularly, zoned (fig. 2). Zoning is both mineralogical and textural. Generalizing from detailed, deposit-scale mapping of hundreds of U.S. pegmatites, Cameron and others (1949) identified four main zones: the border, wall, intermediate, and core zones; the following is a synopsis from that study.
Regional Zoning of a Li-Cs-Ta Pegmatite Field: Insights from …
2023年6月21日 · From the spatial–temporal, source and differentiation relationships between the Renli pegmatites and the Mufushan granites, we propose that type I pegmatites originates from biotite...
Regional Zoning of a Li-Cs-Ta Pegmatite Field: Insights from …
Li-Cs-Ta (LCT) rare-element pegmatites occur as late-stage and highly fractionated bodies at the margins of regionally zoned granite pegmatite fields.
“Peraluminousfertile (S-)granites generating LCT pegmatites are derived by partial melting of upper/middle crustal rocks undergoing their first anatexis, and the pegmatites commonly show regional zoning. Metaluminous granites yielding poorly zoned groups of NYF pegmatites are largely of the A type, generated by second melting of
ZONING IN PEGMATITE DISTRICTS* - Semantic Scholar
Several types of pegmatites are distributed in zones, thought to reflect differences in temperature of formation. In general, plagioclase predominates over microcline, and crystallized first; the…
Many pegmatite fields show a zoning in paragenesis, mineral composition and grade of fractionation of the individual pegmatite bodies. This zoning is mostly due to fractionated crystallization of melt during upward migration from its source region. It can be used for prospecting rare element pegmatites, but also for unraveling