摘要
大洞所在的十里坪地区的喀斯特地貌在形态结构上属湿热带喀斯特。新第三纪是本区碳酸盐岩体一次强烈的喀斯特化和洞穴化时期。第四纪以来新构造运动强烈的间歇性抬升，喀斯特垂直方向发育，外源水补给区流水喀斯特的解体成为峰丛洼地（谷地）形成的基本动力，外源水的垂直方向渗透和侧向运移为洞穴初始形成并呈层状分布提供基本条件。干湿冷暖交替的气候变迁使这些峰丛洼地、谷地表现出许多残余特征和相应的洞内沉积类型。
The Shiliping area where Panxian Dadong cave site is located at is situated in southeastern Panxian County of Guizhou Province. This area is on the dividing crest between the Wuduhe River of the Beipanjiang drainage and the Mabiehe River of the Nanpanjiang drainage. The karst landscapes, in terms of morphometry, belong to the humid tropical karst. They are characterised by a combination of clustered cones and depressions, valleys and poljes, a typical karst of peak cluster depression in China. The cones are found to be almost constant in slope angle (41°—44°)and generally symmetrical in plan. The Late Tertiary was a very karstic and caverous period in the carbonate rocks of this area. The later tectonics are significant. With the great uplift of the neotectonics accompanied by the active incision of major rivers, the karstification by erosion and corrosion proceeded vertically rather than horizonally as the surface and ground water in this area try to follow a lowering of the base level and a thicking of the vadose zone. Under conditions of this increasing available relief and hence potential energy driving groundwater circulation, it is possible for any types of karst landforms at any stages to evolve toward peak cluster depression karst in an abnormal sequence and to exist in a steady state of developments. With the intermittent uplift accompanied by the frequent changes of base level, alternating karstification in both vertical and lateral ways resulted in many times of headwater erosion and subsequent surface levelled landforms and caves. The effects then spread from the lower reaches of trunk river to the upper reaches and from the major gorges to the plateau interfluves. In this uplifted and mountainous area, when the overlying classic rocks were stipped, the major rivers would at first cut across the limestone surface. Eventually, large faults or fissures will become foci for infiltration of water and a part or all of the stream will disappear underground. This break up of the fluvial system will be accelerated by the neotectonic uplift, which will lower the water table, empty the caverns and allow more water well seep into the rock. The infiltration points then will develop into a series of dolines and hence enclosed depressions. As a result, the disappearance of fluvial karst in allogenic area is a major hydrodynamic factor in the formation of peak cluster depression (valley). The vertical infiltration and lateral movement of the allogenic water are basically sure of cave formation and passage leveled features. The alternations of dry wet and cool warm climates in Quaternary may have played an important part in the relic features of peak cluster depressions, valleys, and in the related speleothem types in caves. However, the landscape is still a sort of the tropical karst.
出处
《人类学学报》
CSCD
北大核心
1997年第3期247-253,共7页
Acta Anthropologica Sinica
