摘要
安徽向山地区铁、硫矿床中黄铁矿属火山沉积型。黄铁矿的热电系数为- 16 3.2 5μV/℃ 。化学成分上具有明显富硫特点。Co/Ni比值平均为 6 .6 9。REE含量低 ,平均为7.2 9× 10 - 6 ,大部分样品具有负铈异常 ,所有样品具有明显的负铕异常。黄铁矿晶胞参数a0 =5.4 1487～ 5.4 1883 A ,晶体化学式 :(Fe0 .994 6 Co0 .0 0 17Ni0 .0 0 37) 1.0 0 0 0 S2 .0 2 79。本文还列出了黄铁矿的红外吸收光谱、X射线衍射和硫同位素等资料。
Systematically described in this paper are characteristics of pyrites from the Xiangshan iron and pyrite deposits, such as their modes of occurrence, chemical composition, physical properties, unit cell parameters, infrared spectra and sulfur isotopic composition. The pyrites might be classified into two types. Type Ⅰ is statistically characterized by very fine_grained texture (0.01～0.1mm across), while Type Ⅱ is somewhat coarser (0.05～0.5 mm across) than Type Ⅰ. Four pyrite samples show N_type electric conduction pattern with large variable pyroelectric coefficients (-97.5～246.5 μV/℃), and one sample shows P_type. Unit cell parameters a 0=5.41487～5.41883, and the crystallochemical formula is (Fe 0.9946 Co 0.0017 Ni 0.0037 ) 1.0000 S 2.0279 . Different types of pyrites show apparently different strong key absorption peaks with high absorption value features. In this area, every type of pyrite has relatively rich sulfur but poor Fe. Trace elements and REE geochemistry indicate that pyrites are enriched in Co, Ni, V, Ti, Cu, As, and Co/Ni ratios of all pyrites fall in a narrow range of 1～10; As/Se ratios of all pyrites range from 1.33 to 5.50. ∑REE values of all pyrites are from 2.2×10 -6 to 17.33×10 -6 , showing distinctly low Ce (δCe 0.62～0.78) and Eu (δEu 0.62～0.81). Sulfur isotopic compositions of all pyrites range from -2.11‰ to 17.11‰. These data further demonstrate that these pyrites were formed by volcanic hot water deposition and that the formation of Xianshan pyrite deposits is attributed mainly to volcanic deposition.
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
2000年第2期185-192,共8页
Acta Petrologica et Mineralogica
关键词
向山地区
铁矿床
硫矿床
黄铁矿
矿物学
pyrite
spectral characteristics
crystallochemistry
Xiangshan Anhui Province
