宝丰县清凉寺铁矿床地质特征及成因分析
Geological Characteristics and Genesis of Iron Deposit in Qingliangsi, Baofeng
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摘要: 河南省宝丰县清凉寺铁矿,为一首次发现的中型山西式富铁矿床。该铁矿位于华北陆块南部,渑池-确山陷褶断束中段,属华北地层区,豫西地层分区,渑池—确山地层小区。该矿床含矿岩系为上石炭统本溪组。铁矿体呈较为稳定的层状-似层状产于本溪组下部,矿体内部结构简单,没有夹石和无矿天窗,属简单矿层。矿石自然类型为赤铁矿,矿石品位w(TFe)普遍较高,w(TFe)介于27.50%~59.75%,平均50.55%,w(TFe)>50%的样品占53%,有害元素S、P微量。矿石工业类型:以炼铁用铁矿石(高炉富矿)为主,占总资源量的66%;次为需选铁矿石,占总资源量的34%。矿床规模为一中型富铁矿床。该矿床成因为碎屑型浅海相环境下化学沉积的山西式铁矿。该矿区准平原化程度相对较高、岩溶漏斗不发育的地区,有利于山西式富铁矿床的形成。而在准平原化程度相对较低、岩溶漏斗发育的地区,则利于"漏斗状"铝土矿的形成。Abstract: Shanxi-typed medium-sized high-grade iron deposit is first discovered in Qingliangsi, Baofeng county, Henan province. The deposit is situated in the midpiece of the Mianchi-Queshan collapsed fold fault bundle, southern part of the North China Block. It belongs to the Mianchi-Queshan stratum minor region in the western Henan stratigraphic subregion of north China stratigraphic area. The ore serials are generated from Benxi formation of late Carboniferous. The iron deposit is relatively stable layered or stratum-like, which is from the lower part of Benxi formation. Without mix stone and the non-ore skylight, the deposit is simple in internal structure and thus belongs to a simple orebed type. The ores are naturally hematite, and the ore grade of w(TFe)is generally high between 27.50%-59.75%, with an average of 50.55%, while the samples with w(TFe)value higher than 50% take up 53% in total. The harmful elements containing in the mineral such as S,P are tiny. The major ore for industrial purpose are ironmaking iron ore, accounting for 66% of the resources;Taking up 34% of the whole, the minor iron ore are to be chosen upon necessity. Genesis of the deposit is a Shanxi-typed iron ore in detrital neritic facies chemical sediment. The high peneplaination degree and non-developed karst funnel in this region is beneficial to Shanxi-typed high-grade iron ore bed formation. In contrast, an area with lower peneplaination degree plus a developed karst funnel is in favour of forming the funnel-shaped bauxite deposit.