摘要
对松散沉积物中的大块地下冰已有多种成因假设,而基岩中的大块冰可以排除分凝,分凝—侵入及埋藏等成因机制。岩芯的破碎程度及水文地质条件分析表明,霍拉河盆地发育于泥岩及煤层之间的大块地下冰属侵入冰,即承压地下水侵入岩层裂隙后冻结而成。在冻结中,冰体的体胀力及地下水的侵入力使上覆岩层压密或有些抬升,由此为大块冰的生长创造空间条件。同时真空—渗透机制也不应忽视。
There have been several hypothses proposed for the origin of massive ground ice oc-curing in unconsolidated sediments of Quaternary. Some of the hypothese are reviewed in this paper. As to the origin of massive ground ice at depth within bedrock, the possibilities that the ice can be of buried glacier ice, segregation ice, and segregation-intrusion ice can be discounted. Another possibility is that the ice formed by the freezing of bulk water in an existing aquifer, i.e., a cavity infilled by groundwater under artesian pressure as permafrost aggraded. However, it is hard to explain why such a cavity existed in the first place, and why the overlying strata did not collapse before the ice formed because the rock were fractured by faulting. It follows that a more likely possibility is that the massive ground ice formed by the in-situ freezing of groundwater intruded under pressure(i.e.intrusive ice).
出处
《冰川冻土》
CSCD
北大核心
1990年第3期209-218,共10页
Journal of Glaciology and Geocryology
关键词
冰块
大型
地下冰
基岩
侵入冰
massive ground ice, sediments, bedrock,groundwater under artesian pressure, intrusive ice
