| 广西下雷晚泥盆世锰矿床沉积学研究 |
| |
| 引用本文： | 曾友寅.广西下雷晚泥盆世锰矿床沉积学研究[J].沉积学报,1991,9(1):73-80. |
| |
| 作者姓名： | 曾友寅 |
| |
| 作者单位： | 广西第四地质队 |
| |
| 摘 要： | 本文着重研究和探讨下雷层状锰矿床喷气热液沉积的特征和成因。热液沉积锰矿层产于浅海深水台沟沉积相中,分布面积小,但规模大,矿层由一系列热液硅酸盐矿物、碳酸锰矿物、氧化矿物及硫化物等组成,碳同位素组成表明碳酸锰矿物中的碳来自岩浆,热液矿物形成层状、豆鲕状同生沉积构造,在剖面上呈韵律层,在平面上以热液沉积为中心,往外逐渐变为分布较广的冷水沉积碳酸锰矿,滑坡重力流使锰矿再沉积富集。
|
| 关 键 词： | 层状和豆鲕状锰矿 浅海深水台沟 喷气热液沉积 |
| 收稿时间： | 1988-08-18 |
Study on the Sedimentology of Late Devonian Manganese Ore Deposit in Xialei,Guangxi |
| |
| Institution: | The Fourth Geological Brigade, Guangxi Province |
| |
| Abstract: | Xialei manganese ore deposit consists of three ore beds. And the microfacies of the ore beds can be grouped into three types: 1. Cold water autochthonous chemical sedimentary manganese carbonate orebeds. 2. Hydrothemal autochthonous colloidal- chemical sedimentary silicatemanganese carbonate orebeds.3. Allochthonous recleposited gravity folw silicate-manganese carbonate orebeds. In the hydrothemal sedimentary manganese ore deposit, besides of manganese carbonate minerals, the associated minerals are rhodonite, biotite, actinolite, chlorite, manganese epidote, and manganoferro antigorite.Minerals such as hcmatite. potash-feldspar, barite, garnet and braunite, often shown as minor or local accumulated minerals. These hydrothermal minerals are often mixed and formed laminae, thin beds, bands, oolitics of pisolitic grains, horizontal or fine wavy laminae.Oolites and pisolitic grains which rich in manganese orebeds show obvious boundary, their cores are constituted by manganese carbonate and silicate minerals, no elastics were found. The colloidal-chemical deposits as a core, continously deposition and growth around it and the grains were formed, Oolitic, pisolitic grains and hydrothermal minerals are roughly distributed over the same range, and they have genetic relationship. The ore deposit may be fall into three zones in horizontal, (1) inner-zone composed of manganese carbonate, silicate and oxide minerals mixture. (2) biotite-manganese carbonate transitional zone. (3) outer manganese carbonate zone. Muddy limestone in the bottom of orebeds has a δC13 value of 0.03 per mil, this proved that the carbon came from seawater.The δC13values of manganese carbonate has a range from-2.83 to -14.29 per mil, averaged about -7.06 per mil, this value is roughly accord with that of the carbonates originated from magma, thus, it can be considered that the carbon was from deep basic magma. The mineralization model is summariaed as follows: In the trough in platform, when basic magma intruded, hot juvenile gas, liquid and dissolved mineralizing material ascended along cracks, therefore, resulted in the convection of seawater and subsurface water. Some dissolvable matter were leached and extracted, then were carried to the segs located in the bottom of the trough and a hot water pool formed.The silicate-carbonates' manganese were deposited.The sediments on the low slope zone were transported by gravity flow to the trough and covered autochthonous deposits. |
| |
| Keywords: | |
| 本文献已被 CNKI 维普 等数据库收录！ |
| 点击此处可从《沉积学报》浏览原始摘要信息 |
| 点击此处可从《沉积学报》下载免费的PDF全文 |
|
