琼北地区石山组玄武岩及其熔洞形成机理初探

Preliminary Study on Basalt's Mineral Composition and Cave Formation of Shanshi in North Hainan Island

介绍了琼北地区石山组玄武岩的化学成份,初步认为石山组玄武岩形成的构造环境属大陆板内裂谷环境。分析了玄武岩熔洞的形态特征和分布规律,初步认为沉积蜂窝型熔洞是熔岩流(舌)在冷凝沉积过程中,挥发成份无法释放到大气中,产生气泡冷凝形成空洞,分布在熔岩流(舌)底部或侧部的内接触带中。隧道型熔洞为残留的岩流空洞或岩流管道,它是岩浆运移的残留通道。

This paper introduces the basalt＇ s mineral composition and chemical component of Shanshi formation in north Hainan island and preliminarily thinks that geological environment, in which the basalt of Shanshi formation is formed, is mainland intraplate rift. This paper also analyzes the morphological characteristics and distribution law of basalt karst caves and preliminarily considers that the honeycomb -type karst cave, which is an empty cave condensed by air bubbles produced by lava flow＇ s volatile element which can not be released to atmosphere during the condensation of lava flow, distributes in the contact belts of the bottom or side of the lava flow. The tunnel - type lava, which is residue empty cave or pipeline of lava flow, is the residue pathway of magma movement.