Abstract

The Ushkatyn-III in Central Kazakhstan is a weakly metamorphosed hydrothermal–sedimentary ore deposit of the Atasu type. For such objects, an assemblage of stratiform bodies of iron–manganese and polymetallic (lead–zinc and barite–lead) ores is typical. At the Ushkatyn-III deposit, there are iron, manganese, and barite–lead ores located in the Upper Devonian limestones. Iron and manganese ore have been the study objects. Iron ores are composed of hematite, calcite, and quartz. Two mineralogical types of manganese ores are distinguished: hausmannite and braunite. Hausmannite ores are composed of hausmannite, rhodochrosite, calcite, tephroite, sonolite, alleghanyite, and friedelite. Braunite ores include braunite, calcite, quartz, albite, rhodonite, friedelite, and rhodochrosite. The mineral composition of these ores was formed during transformation of metalliferous deposits that initially accumulated iron and manganese in form of oxides and hydroxides of Fe³⁺ and Mn³⁺/Mn⁴⁺ at T ≈ 250° and P ≈ 2 kbar. The organic matter content in the rocks controlled postdepositional processes. Braunite ores were formed under oxidizing conditions, while hausmannite ores were formed under reducing ones. Hydrated silicates, such as caryopilite, friedelite, pennantite, clinochlore, chamosite, and parsettensite, are indicators of low temperatures of metamorphism. There are a large number of accessory minerals found in iron and manganese ores. Among them, minerals containing B, F, S, V, Cu, Zn, As, Sr, Ag, Sb, Te, Ba, Hb, Pb and rare-earth elements, including Mn–Zn and Mn–Pb phases – zinc-bearing hausmannite and jacobsite, hetaerolite, kentrolite, and pyrobelonite—are widely distributed. The spatial–age relationships between the minerals indicate the synchronous accumulation of Fe, Mn, Zn, As, Ba, Pb, and other elements in the primary metalliferous sediments and their subsequent local redistribution during metamorphism, which led to crystallization of their phases. Presence of minerals of nonferrous metals and barium makes manganese ores related to barite–lead ores occurring in their immediate vicinity. Both ore types were likely formed simultaneously as products of the evolution of the single hydrothermal system.

中文翻译：

---

哈萨克斯坦中部 Ushkatyn-III 矿床铁锰矿石矿物学

摘要

哈萨克斯坦中部的 Ushkatyn-III 是 Atasu 类型的弱变质热液沉积矿床。对于此类物体，铁锰和多金属（铅锌和重晶石铅）矿石的层状体组合是典型的。在 Ushkatyn-III 矿床，有铁、锰和重晶石-铅矿石位于上泥盆统石灰岩中。铁和锰矿一直是研究对象。铁矿石由赤铁矿、方解石和石英组成。锰矿石有两种矿物学类型：hausmannite 和 braunite。Hausmannite矿石由hausmannite、菱锰矿、方解石、tephroite、sonolite、alleghanyite和fridelite组成。Braunite矿石包括braunite、方解石、石英、钠长石、rhodonite、friedelite和rhodochrosite。³⁺和 Mn ³⁺ /Mn ⁴⁺在T ≈ 250° 和P≈ 2 千巴。岩石中的有机质含量控制着沉积后过程。布劳恩石矿石在氧化条件下形成，而豪斯曼矿石在还原条件下形成。水合硅酸盐，如石竹、橄榄石、彭南特石、斜绿石、水辉石和帕赛特石，是变质作用低温的指标。在铁矿和锰矿中发现了大量的副矿物。其中，含有B、F、S、V、Cu、Zn、As、Sr、Ag、Sb、Te、Ba、Hb、Pb和稀土元素的矿物，包括Mn-Zn和Mn-Pb相——锌-含高锰矿和镍钴锰矿、黑铁辉石、孔雀石和辉绿辉石——分布广泛。矿物之间的空间年龄关系表明Fe、Mn、Zn、As、Ba、Pb、和原始金属沉积物中的其他元素及其随后在变质过程中的局部重新分布，导致它们的相结晶。有色金属和钡矿物的存在使得与重晶石-铅矿石相关的锰矿石出现在其附近。作为单一热液系统演化的产物，这两种矿石类型很可能同时形成。