华北煤田陷落柱的地下水内循环形成机理——以峰峰矿区为例

分析了华北型煤田,特别是峰峰矿区陷落柱的发育规律,提出了陷落柱的地下水内部循环形成机理。认为莫霍面抬高和火成岩体产生的地热异常使得奥灰水产生内部对流循环,导致岩溶发育;论证了地热,特别是亚临界和超临界水对CaCO3 溶解的加速作用,认为封闭环境中矽卡岩矿物在形成过程中产生的CO2 和灰岩在热解过程中产生的CO2 造成CO2 分压升高,导致了CaCO3 溶解速度的提高。文章还提出了灰岩内对流散热过程中“烟囱”效应,认为强烈对流区的“火苗”形溶洞进一步发展成为最有利于对流的“烟囱” ,上覆岩层垮落后即形成陷落柱。据此,还解释了陷落柱边缘导水的原因。 

Mechanism of groundwater inner circulation in sinking column formation in North China coal field-A case study at Fengfeng mine

The forming law of sinking column in Huabei type coal field,especially at the Fengfeng coal mine is analyzed and the mechanism of groundwater inner cycle in sinking columns is put forth.The igneous intrusion and Mohorovicic discontinuity lift are considered as the main causes to generate abnormal geothermal to energize groundwater circulation and karst development in limestone.The CaCO3 dissolution accelerated by geothermal abnormality,by sub-critical and supercritical water is discussed.High content of CO2 generated by CaCO3 decomposition and relieving when the skarn minerals form is considered to raise CO2 partial pressure and consequently enhance the dissolution of carbonate rocks.Chimney effect during hot water convection in the limestone aquifers was proposed.The paper assumes that the flame shaped cave in intensive convection areas developed into chimney that were favorable to convection.The overburden of the chimney collapsed and became sinking column.According to this,the causes that some sinking columns have permeable edge are explained.It is deduced that the above factors result in karst development with sinking column formation.