Abstract

Paleoreconstruction of events involved in the bottom sedimentation has been carried out on the basis of mineral composition of the section of the minor lake IV (Lake Fumarolnoe, Kamchatka) bottom sediments. The lower sediments are composed mainly of smectite in association with gypsum and jarosite; they are overlain by smectite–kaolinite with a large amount of framboidal pyrite and diatom shells. There is also a layer of sinter opal–pyrite units and calcite. It is concluded that initially the minor lake IV was a mud pit with sulfide-bearing solutions. Then, after the lowering of the water level and the partial exposure of the bottom sediments on the surface, the latter were oxidized. The subsequent phreatic explosion provided the covering of oxidized sediments with the reduced substance from the lower horizons of the pit. Further setting of sediment accumulation corresponded to a source with cyanobacterial community developing around the gryphon, and then it changed to that of a shallow-water lake similar to a contemporary one. Sediments also include two layers of pyroclastic material originated from eruptions of neighboring volcanoes.

中文翻译：

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富马洛尔诺热湖（堪察加乌桑火山口）的现代矿物形成是古构造的关键

摘要

底部沉积事件的古构造已经根据IV号次要湖（富马洛诺湖，堪察加湖）底部沉积物的矿物组成进行了构造。下层沉积物主要由蒙脱石，石膏和黄钾铁矾组成。它们被蒙脱石-高岭石覆盖，并带有大量的黄铁矿黄铁矿和硅藻壳。还有一层烧结蛋白石-黄铁矿单元和方解石。可以得出结论，最初的IV号小湖是一个含硫化物溶液的泥坑。然后，在水位降低并且底部沉积物部分暴露在表面上之后，后者被氧化。随后的潜水爆炸使来自坑底较低层的还原性物质覆盖了氧化的沉积物。沉积物积累的进一步设置对应于狮ry周围发展蓝细菌群落的来源，然后变为类似于现代湖泊的浅水湖泊。沉积物还包括两层火山碎屑物质，它们是由邻近的火山喷发产生的。