摘要
山东沂源土门地区具有三种岩溶形态组合类型,其形态、分布和发育的地质年代明显不同。结合区域地质发展史初岩溶相关沉积物的测年研究,揭示它们分别形成于晚第三纪以后的仰平期、早更新世中期以后的土门期和晚更新世以来的临城期。其相应的岩溶环境在气候和水文网两方面存在明显差异。气候环境由晚第三纪的湿热→更新世的冷干与暖湿交替变化→向现代的半湿润一半干早环境变迁;河流水文网则由无→有→越来越清楚,使岩溶区能够获得越来越集中的外源水补给。
The karst feature complex of Tumen region could be distinguished into three
The first set is characterized by solution cap rock, closed depression, conduit
, red clay and outside stalactite They are distributed nearby higher
top about 600-800m in the altitate Most of them can be regarded as
palenkarst forms due to they formed mainly in Neogene period. The set similae
to the karst feature complex in the area of the middle and lower reaches of
Yangtze River, occurred under subtropical humid environment conditions The
second set is composed of such feature as hill peak, even mountain ridge,cave in
shape of branch passage, stone tooth, lapie, brown-red clay, speoleothem, cement
quart sand and conglomerate and ape man and mammals fossils. They lie at 450
600m a.s.l.,i.e in the middle level of the limestone mountains or near hill top. It is proved that they were formed mainly in the Middle Pleistocene, with the environment of the alternation cold or warm, and arid or humid. Mean while, the hydrogeologic pattern that karst area can get lots of allogenic water recharge had developed. The third set can recognized as following forms, normal shape mountain, dry valley, karst spring, shelter rock, single passage but long cave, shollow karren, limestone screen, fluvial and collapse deposits in the cave. Their elevation is generally lower than that of the first and second sets. The important distribution range is near modern river erosion base level.Some evidences suggest that they were formed after the Late Pleistocene, and most of them are continuing to develop up to now.The karst feature especially surface karst. forms is accordance with the geomorphic process under modern semiarid and semihumid climate conditions, While the features of the long and large cave with subterranean river show that the allogenic water recharge is getting more and more concentrative
出处
《中国岩溶》
CAS
CSCD
北大核心
1992年第4期356-365,共10页
Carsologica Sinica
关键词
岩溶
形态组合
类型
形成环境
Karst feature complex
Environmental change
Yiyuan Tumen
