摘要
桃花赤铁矿位于川东褶皱带与川湘凹陷的过渡带,矿区出露一套以砂岩、泥岩、灰岩为主的沉积层。上泥盆统黄家蹬组(D3h)为桃花赤铁矿的赋矿地层,矿体呈层状、似层状、透镜状分布于黄家蹬组上部,矿体与顶底板围岩界线清楚。黄家蹬组含Fe1和Fe2两层矿体,其中Fe1矿体无工业价值,Fe2矿体为矿区主矿体(层厚1.07m～5.89m)。矿区矿石为高磷、低杂质、较低品位酸性鲕状赤铁矿矿石,矿石因含泥质不同而呈紫红色或暗紫色,发育条带状构造和块状构造。依据矿床地质特征分析,桃花赤铁矿的分布主要受岩相古地理影响,矿体产出形态受褶皱构造控制。桃花赤铁矿属渝东鄂西"宁乡式"铁矿成矿区的西延部分,矿区泥盆系中统云台观组(D2y)和泥盆系上统黄家蹬(D3h)为一套海进过程中形成的滨海相沉积序列,矿体分布于细砂岩、粉砂岩、粉砂质页岩向页岩或碳酸盐岩过渡的层位。湿热气候和邻近海盆是形成赤铁矿矿的有利古环境,古海盆周围的古陆风化碎屑物是成矿的物质来源。矿区及其外围上泥盆统地层分布区是宁乡式赤铁矿的找矿远景区,褶皱是良好的构造找矿标志。
The Taohua hematite deposit is located in the transition belt of the eastern Sichuan fold zone and Sichuan-Hunan hollow zone,where the exposed rocks are mainly sandstone,mudstone and limestone.The orebodies are preserved in the Huangjiadeng formation of upper Devonian（D3h,which exhibit layered and lenticular shape with distinct boundaries between the orebody with surrounding rock in roof.The Huangjiadeng formation contains two layers of orebodies（Fe1 and Fe2）,of which Fe1 has no economic value,and Fe2 is the main ore body with thickness 1.07 m^5.89 m.The type of the ore is acid oolitic hematite which has low grade,high phosphorus and low impurities.The ore is magenta or dark purple due to the difference of pelitic content,with banded and massive structures.Based on the study of geological characteristics of the deposit,this paper indicates that Palaeogeography and lithofacies have major influence on the distribution of Taohua deposit,where the occurrences of orebodies are controlled by fold structure.The Taohua iron ore area is the westward extending part of the Ningxiang-type hematite metallogenic area in East Chongqing and West Hubei province.The Yuntaiguan formation of middle Devonian and Huangjiadeng formation of upper Devonian are littoral facies depositional sequence which formed in the transgressive process.The orebodies occur in the transitional horizon from fine sandstone,siltstone,silty shale to shale or limestone.Warm-wet climate and ancient sea basins were favorable for the generation of hematite.The metallogenic materials are mainly derived from the weathered terrigenous clastics.The Taohua area and its outer zone which have the upper Devonian are the prospect areas for Ningxiang-type hematite,where folds in are the structural indicator for ore exploration.
出处
《地质与勘探》
CAS
CSCD
北大核心
2010年第2期230-237,共8页
Geology and Exploration
基金
国家自然科学基金资助项目(40972225)
关键词
鲕状结构
临滨相
成矿规律
桃花赤铁矿
oolitic texture
offshore facies
metallogenic regularity
Taohua hematite deposit
