Abstract

Based on new materials, the structure and origin of a huge (up to 2-km-thick) massif of acid volcanic rocks, which occur in the volcanotectonic depression in the upper reaches of the Chegem River in the North Caucasus, is considered. The issue of the lava, rather than the pyroclastic origin of the main part of the massif, is discussed. This massif was formed due to multiple eruptions of lava flows that composed a series of the acid volcanic rocks without gaps and with a well-pronounced columnar jointing in a limited volume of a deep volcanotectonic depression formed synchronously to eruptions in the Late Pliocene. The volcanic rocks were formed as a result of the boiling of a silicate melt and its exit from the vent of the volcano, which could be due to the phase transition of a supercritical aqueous fluid.

中文翻译：

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Chegem高地（北高加索地区）的流纹岩断层的起源

摘要

基于新材料，考虑了北高加索地区切格姆河上游的火山构造隆起中发生的巨大（高达2公里厚）酸性火山岩地块的结构和成因。讨论了熔岩的问题，而不是地块主要部分的火山碎屑成因。形成该断层的原因是熔岩流多次喷发，熔岩流由一系列无间隙的酸性火山岩组成，并在有限体积的深火山构造凹陷中形成了发音清楚的柱状节理，该凹陷与上新世爆发同时形成。火山岩是由于硅酸盐熔体的沸腾及其从火山喷口的出口而形成的，这可能是由于超临界水性流体的相变所致。