摘要
雪峰降起区主要由中、上元古界冷家溪群和板溪群组成,是湖南重要的石英脉型金矿成矿区。该区沉积建造是扬子地块东南缘裂陷槽演化的结果。该裂陷槽是在全球性第二裂谷期(800～1200Ma)裂谷作用影响下,沿扬子地块东南缘形成的陆缘裂陷带,本文称“雪峰裂谷”,其构造演化由拉张沉陷—裂陷,局部收缩、回返,再裂陷一再褶皱、回返,演化过程较为完整。在拉张沉陷—裂陷期,形成金的矿源层、含矿层;在裂谷褶皱、回返期,形成含金变质热液,形成金矿化;在裂谷封闭、雪峰期后多期次构造岩浆旋回中,再造、叠加形成金矿床。
Xuefeng upwarped zone in western Hunan, composed mainly of Middle, Upper Protorozoic Lengjiaxi Group and Banxi Group, is an important quartz vein type gold mineralization province in Hunan. The sedimentary formation in this province results from evolution of the aulacogen in the southeast margin of Y angtze massif. This aulacogen is a continental marginal rift depression zone formed along the southeast margin of Yangtze massif, influerpced by the rifting during the second global rifting period (800～1200Ma), which is considered as＂Xuefeng rift＂in this paper. Its tectonic evolution includes a relatively complete process from tensile sagging-rifting, local shrinkage and inversion, to re-rifting-re-folding and inversion. During sagging-rifting, source beds and ore-bearing horizon for gold formed; during rifting folding and inversion, gold-bearing metamorphic hydrothermal fluid and gold mineralization formed; and they were transformed and telescoped during the close down of the rift and in the polyphases tectono-magmatic cycles after Xuefeng orogeny to form gold ore deposits.
出处
《湖南地质》
1992年第1期1-6,共6页
Hunan Geology
关键词
地壳
构造
演化
金矿
成矿
Continental rift
Xuefeng upwarping zone
Gold mineralization
