东南极拉斯曼丘陵区的风力地貌

A PRELIMINARY STUDY ON AEOLIAN LANDFORMS IN THE LARSEMANN HILLS, EAST ANTARCTICA

拉斯曼丘陵区风力强度大、频数高，各月平均风速均可起动粗砂级以上碎屑。高速气流的极不饱和挟砂（雪晶）状态限制了风力堆积作用和磨蚀作用，而风力吹蚀作用和雪粒（晶）堆积作用则构成本区风力地貌发育的主体。风积方式包括遇阻堆积和停滞堆积，其地貌形态主要有雪被（雪坝）、砂堆（砂地）和砾堤（砾滩）。风积物的沉积地球化学参数与本区母岩有极高的相似性。

The Larsemann Hills is ice free and formed in the Holocene. It consists of a series of rocky peninsulas and islets in the Prydz Bay. The most obvious geomorphic process operating on the landscape is aeolian and frost physical weathering. The intensity and frequency of wind force are very high. The monthly average wind spleed can start the coarse sand and fine gravel. The high speed air flow is not saturated with sand and snow grains.It restricts the aeolian sedimentary and erosion process. That is the principal reason for the characteristics of aeolian landforms. The aeolian sedimentation consists of barrier and standstill sedimentary processes. They mainly form three types of landforms:snow blanket(snow dam), sand drift(sand land) and gravel dyke (gravel shoal). Some landforms are special and only form in cold pole environment. The geochemical parameteres of aeolian sediments are very similar with those of the bedrock. That means the transplortation distance is very short and the sedimentary site is very closed to the weathering site.