Abstract

This paper discusses the conditions of generation for the Au–Ag epithermal mineralization in the Amguema–Kanchalan Volcanic Field (AKVF), which is situated at the western termination of the East Chukchi flank zone of the Okhotsk–Chukchi Volcanogenic Belt (OChVB). The AKVF contains the potentially large Valunistoe Au‒Ag deposit and several promising deposits and ore occurrences (Zhilnoe, Shakh, Gornoe, Ognennoe, and Osennee). Thermal and cryometric studies of fluid inclusions in quartz and calcite in epithermal veins showed that the solutions were dominated by Na and K chlorides. The epithermal mineralization was deposited by heterogeneous hydrothermal fluids with low salt concentrations (0.2–3.6 wt % equ. NaCl, under moderate temperatures 174–354°С). The fluid pressure reached values of 30–160 bars, which is proper to depths of generation of 0.1–0.6 km under hydrostatic conditions. These results classify the epithermal mineralization studied here as a low sulfide one. Meteoric waters and magma chambers of andesitic magmas are the most likely sources of ore-forming fluids. The information furnished in this paper is of practical value for regional metallogenic predictions, as well as the search for and assessment of epithermal Au–Ag deposits.

中文翻译：

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楚科奇东部Amguema-Kanchalan火山田中Au-Ag超热矿化的生成条件

摘要

本文讨论了安格玛-坎恰兰火山场（AKVF）中Au-Ag超热矿化的生成条件，该矿位于鄂霍次克-楚科奇火山带（OChVB）东楚科奇侧翼区的西端。AKVF包含可能很大的Valunistoe Au‒Ag矿床以及一些有前途的矿床和矿床（Zhilnoe，Shakh，Gornoe，Ognennoe和Osennee）。对超热脉中石英和方解石中的流体包裹体的热学和低温测量研究表明，溶液以氯化钠和氯化钾为主。超热矿化作用是由盐浓度低的非均质热液（在174-354°С的中等温度下，NaCl的含量为0.2-3.6 wt％）引起的。流体压力达到30–160 bar的值，适合于0.1–0的生成深度。在静水条件下为6公里。这些结果将这里研究的超热矿化归为低硫化物矿。流水和安山岩浆的岩浆室是成矿流体的最可能来源。本文提供的信息对于区域成矿预测以及寻找和评估超热金银沉积物具有实用价值。