Rare earch element contents and patterns in major skarn minerals from Shizhuyuan W, Sn, Bi and Mo deposit, South China.

Abstract

Rare earth element (REE) contents and distribution patterns in the major rock-forming minerals (vesuvianite, wollastonite, garnet, pyroxene, hornblende, epidote and fluorite) from the Shizhuyuan W, Sn, Mo and Bi-containing skarn deposit of Hunan Province of South China have been determined. Three types of REE distribution patterns were found: 1) vesuvianite and wollastonite, formed at the ex pense of carbonates and shales of the Upper Devonian Shetianqiao Formation during thermal metamor phism stage, show linear light REE enrichment and small Eu anomalies; 2) garnet, the most abundant mineral in the skarn deposited at metasomatic stage, exhibits high REE enrichment and considerable negative Eu anomalies; 3) epidote and fluorite, precipitated during retrograde alteration stage, display very strong negative Eu anomalies. Comparison of relative REE abundances in these minerals with those in the carbonates and shales as well as in the Qianlishan Yanshanian granite suggests that REE compositions of the vesuvianite and wollastonite appear to have been inherited from precursor car bonates and shales, whereas REE contents and patterns in the metasomatic and the retrograde alteration products, such as garnet and epidote, seem to have been determined by the interactions between the reac ting minerals and hydrothermal solutions originated from Qianlishan granite.

Composition of Garnet from the Xianghualing Skarn Sn Deposit, South China: Its Petrogenetic Significance and Exploration Potential

“…This is consistent with many other hydrothermal Sn deposits in China and worldwide, which are commonly related to highly reduced granitic system [1,60,61]. [53], Shizhuyuan [51] and Huanggangliang [55], which have been shown here for comparison. All data were normalized to the C1 chondrite values [50].…”

“…As shown in Figure 6, the chondrite-normalized REE patterns [50] of the garnets from the Xianghualing skarn Sn deposit indicate that the garnets are generally enriched in heavy REE (HREE) relative to light REE (LREE), with pronounced negative Eu anomalies. This is also similar to the garnets from many other Sn-bearing skarn deposits in China, such as the Shizhuyuan skarn W-Sn-Mo-Bi deposit [51,52] and the Jinchuantang skarn Sn-Bi deposit [53] in Hunan Province, the Gejiu skarn Sn deposit in Yunnan Province [54], and the Huanggangliang skarn Sn-Fe deposit in Inner Mongolia [55]. As documented in previous studies, such REE patterns indicate that the incorporation of the REEs into garnets was controlled by crystal chemistry through isomorphic substitution [19,53], and that the HREEs with smaller ionic radii are more compatible to be accommodated in the octahedral coordination site of garnet lattice than the LREEs with larger ionic radii [56,57].…”

origin of the Canton Saint-Onge wollastonite deposit, Lac-Saint-Jean, Québec /

“…At the Traversella Fe, W, Cu skarn deposit at Ivrea, Italy the skarned rock is enriched in REE as compared to the protolith marble (Auwera and Andre, 1991). The skarned rocks at the Shizhyuan W, Sn, Bi, and Mo deposit in South China also show an increase in REE (Chen et al, 1992). At the Bergell and Adamello contact aureoles in Italy, Ti, Zr, U, Th, Y and REE were found to have migrated in a potassium-rich fluid (Gieré, 1989).…”

Metal Sources of World-Class Polymetallic W–Sn Skarns in the Nanling Range, South China: Granites versus Sedimentary Rocks?

“…Since the 1990s, the trace element (and particularly rare earth element; REE) characteristics of skarn-associated plutons and their constituent minerals have been the focus of much research given that these signatures reveal much about deposit genesis [5][6][7][8][9][10]. Major and accessory mineral phases in skarns (such as garnet and scheelite) inherit their REE patterns from magmatic fluids and they control the REE signatures of the host skarn [11]. However, Giuliani et al [12] propose that strong REE variations in skarns, characterized by a pronounced negative Eu anomaly and low propose that ore-forming metals such as W and Sn are extracted from country rocks by high temperature circulating water and metamorphic fluids released from deep crustal rocks.…”

“…Cross-sections of (a) the Huangshaping deposit, (b) the Shizhuyuan deposit (modified from[11]); and (c) the Xianghualing deposit, respectively.Minerals 2018, 8, x FOR PEER REVIEW 6 of 20…”