中山大学学报(自然科学版)
中山大學學報(自然科學版)
중산대학학보(자연과학판)
ACTA SCIENTIARUM NATURALIUM UNIVERSITATIS SUNYATSENI
2014年
6期
27-36
,共10页
陈俊%张珂%梁浩%傅建利%李庶波
陳俊%張珂%樑浩%傅建利%李庶波
진준%장가%량호%부건리%리서파
鄂尔多斯西北缘%河流阶地%新构造运动%黄河%河湖相沉积
鄂爾多斯西北緣%河流階地%新構造運動%黃河%河湖相沉積
악이다사서북연%하류계지%신구조운동%황하%하호상침적
northwestern margin of the Ordos Plateau%river terrace%neotectonics%Yellow River%fluvi-al-lacustrine deposit
鄂尔多斯西北缘岗德尔山地处黄河中游,介于河套和银川盆地之间,山体西侧广泛发育河湖相沉积构成的阶地,留下了更新世以来黄河贯通两盆地的记录,是解剖新构造运动和水系关系的典型区域。作者实地详细考察了岗德尔山西侧的构造与地貌,发现了被抬升成阶地的河湖相沉积层,揭示了阶地高度沿现今黄河显示出“低-高-低”的拱形特征,T2阶地河湖相沉积层露头顶部和中部的光释光年龄分别为82.23±9.88 ka、116.76±11.41 ka,底部的电子自旋共振年龄为467±124 ka。阶地的时空分布特征表明,岗德尔山西侧中、晚更新世曾经存在过连接河套和银川两盆地的河湖地貌,岗德尔山沿着桌子山断裂带(主要是岗德尔山东麓断层)抬升的同时,山体还有向北扩展的趋势。由于构造抬升,湖泊缓慢萎缩,河流逐渐占优,留下了现今所见的两级河湖相阶地。研究揭示,银川与河套两盆地本已沟通,更新世构造抬升使两盆地之间的湖泊逐渐缩小,河流逐步壮大,最终形成现今所见的黄河。
鄂爾多斯西北緣崗德爾山地處黃河中遊,介于河套和銀川盆地之間,山體西側廣汎髮育河湖相沉積構成的階地,留下瞭更新世以來黃河貫通兩盆地的記錄,是解剖新構造運動和水繫關繫的典型區域。作者實地詳細攷察瞭崗德爾山西側的構造與地貌,髮現瞭被抬升成階地的河湖相沉積層,揭示瞭階地高度沿現今黃河顯示齣“低-高-低”的拱形特徵,T2階地河湖相沉積層露頭頂部和中部的光釋光年齡分彆為82.23±9.88 ka、116.76±11.41 ka,底部的電子自鏇共振年齡為467±124 ka。階地的時空分佈特徵錶明,崗德爾山西側中、晚更新世曾經存在過連接河套和銀川兩盆地的河湖地貌,崗德爾山沿著桌子山斷裂帶(主要是崗德爾山東麓斷層)抬升的同時,山體還有嚮北擴展的趨勢。由于構造抬升,湖泊緩慢萎縮,河流逐漸佔優,留下瞭現今所見的兩級河湖相階地。研究揭示,銀川與河套兩盆地本已溝通,更新世構造抬升使兩盆地之間的湖泊逐漸縮小,河流逐步壯大,最終形成現今所見的黃河。
악이다사서북연강덕이산지처황하중유,개우하투화은천분지지간,산체서측엄범발육하호상침적구성적계지,류하료경신세이래황하관통량분지적기록,시해부신구조운동화수계관계적전형구역。작자실지상세고찰료강덕이산서측적구조여지모,발현료피태승성계지적하호상침적층,게시료계지고도연현금황하현시출“저-고-저”적공형특정,T2계지하호상침적층로두정부화중부적광석광년령분별위82.23±9.88 ka、116.76±11.41 ka,저부적전자자선공진년령위467±124 ka。계지적시공분포특정표명,강덕이산서측중、만경신세증경존재과련접하투화은천량분지적하호지모,강덕이산연착탁자산단렬대(주요시강덕이산동록단층)태승적동시,산체환유향북확전적추세。유우구조태승,호박완만위축,하류축점점우,류하료현금소견적량급하호상계지。연구게시,은천여하투량분지본이구통,경신세구조태승사량분지지간적호박축점축소,하류축보장대,최종형성현금소견적황하。
The Gangdeer Mountains,located in the northwest margin of the Ordos Plateau,is a key area for understanding the formation and evolution of the drainage system in response to neotectonic movement. Two terraces (T1 and T2 )composed of fluvial-lacustrine deposits have been formed along the west pied-mont of the Gangdeer Mountains.Dating of T2 yields ages of 82.23 ±9.88 ka (OSL),1 16.76 ±1 1.41 ka (OSL)and 467 ±124 ka (ESR)for the upper,middle and lower deposit cropout,respectively.The longitudinal profile of both terraces indicates an arch-form,high in the middle of the Gangdeer Mountains and low in the area adjacent to Hetao and Yinchuan basins,suggesting the effects of mountain uplift. Lakes coexisting with rivers in the Middle to Late Pleistiocene,gradually shrank as the Gangdeer Mountains were uplifted along the Zhuozi Mountains Fault Zone (mainly along the Eastern Piedmont Fault of Gangdeer Mountains)and the zone of uplift propagated northward.Eventually,the rivers gradually prevailed over the lakes,leading to formation of the Yellow River,and its two terraces and their fluvio-la-custrine deposits.