摘要
钙华滩、钙华池与钙华瀑是黄龙自然风景区冷水型钙华地表堆积地貌的主要类型,文章描述了沟内这三类堆积地貌的形态,并探讨了它们的形成、钙华滩和钙华池的转化关系。对钙华池的地貌演化进行了深入分析,从池面积、最大地深、相对池深、周比、池埂高度、厚度、坡度的参数论证地貌演化规律,划分出雏形期、兼并期、稳定期、消亡期四个阶段。初步推证出该区钙华的沉积速率。
Huanglonggou is a well-known scenic spot in West Sichuan, China. This gully was initiallyformed from a glacial valley. After the mountain glacier ablated during the Late Pleistocene, there oc-curred three principal landforms consisting of travertine beaches, ponds and cascades. Travertine depo-sition relied mainly on chemical deposition while making biological (plant) deposition subsidiary.Travertine ponds could be divided into three types after we surveyed the formation and characteristics.of the pond dams and bottoms. The height, thickness and slope of pond dams were measured. The pa-rameters of the pond area, maximum depth, relative depth, ratio of the length of pond's marginon perarea of circle's margin and the length of pond's margin were estimated. The evolution law of traver-tine pond landforms was proved. Four stages were divided as Initial Stage, Capture Stage, Stable Stageand Old Stage. It was proved that travertine beaches and ponds could be transformed from each to theother. Concerning the speed of travertine accumulation we made an observation of deposition on a pieceof wood submerged in water during a bridge construction. From Spring 1985 until June 1986, traver-tine deposition of 1～4mm was accumulated on the wood for more than one year. Its thickest placereached 5.5mm. The sample made from travertine deposition 11.28 meters deep was tested by ^(14)C andidentified as 23422±1465 year. Therefore its speed of accumulation was 0.482±0.03mm/year. Thethickest travertine body in gully was about 19.5 meters and the interval deposition geochoronology was0.0406±0.0001 million years. From field exploration, it was discovered that a single layer of traver-tine deposition was 1.7～2.20mm, which showed a speed of one year deposition. All these evidencessuggested that some of pond dams began to develop only in Ming Dynasty.
关键词
钙华
冷水型
地表
堆积
地貌
Huanglonggou
cold-water travertine
depositional landforms
