摘要
临汾盆地的第四纪调查发现,在湖相沉积层之上广泛覆盖着部分L3黄土层或S2古土壤层,表明在S2古土壤发育前后时期盆地内发生了一次显著湖退;在海拔稍低的一些区域,出现晚期灰绿色湖相层覆盖在L2黄土层之上的现象,表明在L2黄土堆积时期盆地内发生了一次小幅湖侵;广大的盆地区域都存在S1古土壤广泛覆盖晚期湖相地层现象,表明这次小幅湖侵结束于S1古土壤开始发育之时.盆地的湖退—湖侵变化证明,盆地深部"上地幔强烈上隆→减弱或渐趋稳定→再次强烈上隆……"这样的构造循环是存在的.同时,盆地的湖退时序差异也初步证明了"青藏高原的阶段性隆升对其广大外围地区的地貌发育有着重大影响和控制作用".
Field work in Linfen Basin found （ 1 ） the lacustrine sediment was widely capped by Loess L3 or Paleosol S2 ,indicating the basin experienced a distinct paleolake regression during the formation of L3 or S2 ; （ 2 ） Loess L2 in some lower areas in the basin was covered by younger lacustrine sediment, showing there exist a paleoplake transgression with small vertical extent during the period when L2 was forming; （3） Paleosol S1 widely covered the younger lacustrine sediment in the basin, indicating an intensive paleolake regression took place when S1 began to develop. These changes in paleolake regression-transgressions proved the tectonic cycles ＂upper mantle intensively uplifled→the uplift of the upper mantle became weak or stable→intensive uplift of the upper mantle came out again→exist under the deep of the earth in the basin. Besides, the difference in the time when the paleolake regression occurred in the west and the east of the basin also provided some evidences that the periodic uplifts of the Tibet Plateau played important roles in the landform development of the outer areas around the plateau.
出处
《上海师范大学学报（自然科学版）》
2011年第5期454-459,共6页
Journal of Shanghai Normal University(Natural Sciences)
基金
国家自然科学基金项目(41071004)
上海市教委"地理学与城市环境"重点学科(CZL702)
关键词
临汾盆地
湖退-湖侵
地幔上隆
青藏高原
Linfen Basin
lake regression-transgression
uplift of upper mantle
tibet plateau
