【摘要】 裂变径迹研究显示中新世早期(23±3Ma)现今吕梁山及周缘地区发生了一次整体性快速隆升。中新世晚期(约8Ma前),吕梁山前、鄂尔多斯盆地及东部宁武—沁水盆地结束了长期剥蚀历史,开始广泛接受新生代沉积。沉积物的垂向叠置关系及横向展布特征显示:8.35～6.7Ma为吕梁山快速差异隆升期,在山前(东西两侧)堆积了冲积扇相芦子沟组砾岩层,暗示了吕梁山已经地貌上成山;与此同时地势相对平坦且摆脱地表水流影响的鄂尔多斯盆地广泛堆积了风尘堆积—红黏土(保德组)。中新世晚期—早更新世早期(6.7～1.8Ma),吕梁山西部山前及鄂尔多斯地区整体缓慢隆升,堆积了新近纪保德组上部、静乐组红黏土及早更新世午城组黄土—古土壤序列。受西部六盘山快速抬升作用影响,鄂尔多斯西部抬升速率略高于东部,于早更新世中期(1.8～1.4Ma)形成现今西高东低的地势格局和南北向晋陕谷地,进而黄河及其支流顺流而下。中更新世以来,鄂尔多斯地区沉积与抬升并重,最终形成现今黄土高原。吕梁山以东的沁水盆地中新世演化史与西部相似,上新世起盆地开始断陷,汾河地堑开始形成。断陷一直持续到早更新世,自下而上依次沉积了下土河组、小白组、大沟组、木瓜组湖相地层,盆地边缘则持续抬升堆积了静乐组和午城组风成堆积。中更新世以来,断陷结束,盆地整体抬升。更多还原

【Abstract】 Fission track dating indicates that the region represented by the modern Lüliang Mountains and djacent areas was uplifted rapidly as a block in the early Miocene ( 23±3 Ma ),, although the Lüliang Mountains were not geomorphologically formed at that time.In the late Miocene ( about 8Ma ), the Erdos Basin , Ningwu-Qinshui Basin , and the piedmont zone of the Lüliang Mountains ended their long-term deudation history and began to receive Cenozoic sedimentation.Based on stratigraphic data , it is inferred hat rapid differential uplifting in the Lüliang Mountains started 8.35～6.7 Ma and foothill alluvial fan onglomerates ( the Luzigou Formation ) were deposited , indicating that the Lvliang Mountains were ormed geomorphologically.At the same time , the Erdos Basin , which was relatively flat and had not been ffected significantly by surface fluvial processes , began to receive eolian deposits ( red clays of the Baode Fm ) .From the late Miocene to early Pleistocene ( 6.7～1.8Ma ), the foothills of the Lüliang Mountains( western part ) and the Erdos Basin have uplifted slowly and accumulated red clays of the upper Baode Formation and the Jingle Formation as well as loesses and paleosols of the early Pleistocene Wucheng Formation.In the middle part of the early Pleistocene ( 1.8～1.4 Ma ), due to the uplift of the Liupan Mountains , the western Erdos rose slightly faster than the eastern Erdos , leading present geomorphological pattern ( i.e. , western Erdos is higher than eastern Erdos ) and the formation of the north-south-trending Shanxi-Shaanxi valley.These geomorphological features also affected the paths of the Yellow River and its tributaries.From the middle Pleistocene to the present , sedimentation was companied with continual uplifting , leading to the final formation of the Loess Plateau in the Erdos basin.The Miocene evolution history of the Qinshui Basin to the east of the Lüliang Mountains is similar to that of the Erdos Basin. Faulting and subsidence of the Qinshui Basin in the Pliocene and early Pleistocene allowed the accumulation of the Xiatuhe , Xiaobai Dagou , and Mugua formations , whereas eolian deposits of the Jingle and Wucheng formations were deposited in the margin of the basin which continued uplifting.Since the middle Pleistocene , faulting and subsidence came to a halt , and the Qinshui Basin has been uplifted as a block.更多还原