地理学报

地理学报 ›› 1994, Vol. 49 ›› Issue (1): 64-72.doi: 10.11821/xb199401008

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黄河源区更新世冰盖初步研究

周尚哲, 李吉均, 潘保田, 张叶春   

  1. 兰州大学中国第四纪冰川与环境研究中心
  • 收稿日期:1992-06-01 修回日期:1993-04-01 出版日期:1994-01-15 发布日期:1994-01-15
  • 基金资助:
    国家自然科学基金

A PRELIMINARY STUDY ON THE LOCAL ICE SHEET OF PLEISTOCENE IN THE SOURCE AREA OF YELLOW RIVER

Zho Shangzhe, Li Jijun, Pan Baotian and Zhang yechun   

  1. Quaternary Glacier & Environment Research Center. Lanzhou University Lanzhou 730000
  • Received:1992-06-01 Revised:1993-04-01 Online:1994-01-15 Published:1994-01-15

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被引次数

21

摘要： 黄河源区广泛分布的冰川遗迹，如流线型地形、贯穿型谷地、浑圆状山顶、冰碛沉积、花岗闪长岩漂砾、带擦面的擦痕石、冰砾阜等表明本区曾发育过更新世冰盖。据上述各种地貌和沉积物复原，冰盖面积约达到８００００km2，中心厚度约１３６０ｍ，发育时间在倒数第二或第三次冰期。现代黄河源区是青藏高原最寒冷和降水相对丰裕的地区，倒数第二和第三次冰期时雪线降低到了４３００ｍ以下，有条件形成冰盖。

关键词: 黄河源区, 更新世小冰盖

Abstract: The source area of the Yellow River (33°-36°N. 95°-100°E. and higher than 430, on an average) is located in the east part of Qinghai-Xizang Plateau. Widespread glacial relics.such as streamlined landforms including roches moutonnees and whale back. glaciated troughs. smoothed hill tops, till deposits. qranodiorite erratics stria stones. kame deposits and so on. indicate that there was an ice sheet in this region during Pleistoene. The ice sheet covered an area of about 80000km2 and the centred of it is near the peak of Bayan Har mountain. south of which is the Changjiang drainage basin. Calculating by the equations H=3. 4L1/2and logv=1.23 (logs-1) (where H is thickness of centre of ice sheet. L is radius. V is ice volume and S is area). the thickness of the centre and the ice volume of the ice sheet were up to about 1360m and 63000km3 respectivily. We cna deduce that the glacier began to develop around the mountains and gradually covered all the area.The snowline of the modern glaciers on the Anyemagen Mountain, situated in the east of the area. lies at 5090m. and it was 4600m high during last glaciation and 4300m high during Penultimate ice age in the Ela Mountain, which is situated in northeast of the area. So we think that the ice sheet was developed not later than penultimate ice age when the plateau surface was much lower than that of today. and the snowline at that time was also lower than 4300m, Climatic data shows that. at present. the temperature is the lowest and the precipitation is relatively abundant in this area in the Qinghai-Xizng Plateau because of the influence of the monsoon. This is probably the reason why the ice sheet was formed only in this area but not in the west part of the plateau where the land surface is much higher. Some ice wedges developed at 135. 7±10.5 kaB. P. were found near Xinghai County (350m).which indicate that the mean annual temperature was approximately 10℃ lower than today.This Pleistocence ice sheet was the largest one found so far at present in the Qinghai Xizang Plateau. 

Key words: Local, ice, sheet., Source, area, of, Yellow, River., Pleistocene