| 黄土高原河谷阶地黄土地层结构模式 |
| |
| 引用本文： | 雷祥义.黄土高原河谷阶地黄土地层结构模式[J].海洋地质与第四纪地质,2006,26(2):113-122. |
| |
| 作者姓名： | 雷祥义 |
| |
| 作者单位： | 西北大学,大陆动力学教育部重点实验室,西安,710069 |
| |
| 基金项目： | 国家自然科学基金项目(49472132) |
| |
| 摘 要： | 流经黄土高原的黄河及其支流因受地壳不断间歇性隆升的影响而形成了5—6级阶地,这些阶地多系黄土覆盖阶地。以六盘山为界,河谷阶地黄土地层结构可分为东、西阶地地层区。六盘山以西河流阶地一般为6级。第6级阶地(T6)冲积黄土状土之上全系无层理黄土,厚310~505 m,含21—23层古土壤,是迄今世界上最厚的黄土剖面,黄土开始堆积的时间不早于1.43 MaBP。T5上的黄土厚200~400 m,含14—16层古土壤,黄土最早是在1.23 MaBP开始堆积的。T4上的黄土厚100~200 m,含5—6层古土壤,开始沉积时间为0.62 MaBP。T3上的黄土包括L1和S1,厚40~65 m,形成于0.12 MaBP。T2冲积黄土状土之上的风积黄土厚20~35 m,形成时间约为0.03 MaBP。T1冲积黄土状土之上为S0、L0及MS,厚1.5~2.5 m,形成时间不早于0.01 MaBP。六盘山以东的河谷阶地一般为5级。T5风积黄土厚70~90 m,含11—16层古土壤,黄土开始堆积时间不早于1.23 MaBP。T4黄土厚40~70 m,含8—9层古土壤,形成时间不晚于0.80 MaBP。T3的黄土包括L1—S6之间的土层,厚25~45 m,形成于0.62 MaBP。T2的黄土由L1和S1构成,厚10~17 m,形成于0.12 MaBP。T1冲积黄土状土之上为S0、L0及MS,厚1.5~2.5 m,形成时间不早于0.01 MaBP。
|
| 关 键 词： | 阶地 黄土地层 结构模式 黄土高原 |
| 文章编号： | 0256-1492(2006)02-0113-10 |
| 修稿时间： | 2005年9月11日 |
MODELS OF LOESS STRATIGRAPHICAL STRUCTURE ON THE TERRACES IN THE LOESS PLATEAU OF CHINA |
| |
| LEI Xiang-yi.MODELS OF LOESS STRATIGRAPHICAL STRUCTURE ON THE TERRACES IN THE LOESS PLATEAU OF CHINA[J].Marine Geology & Quaternary Geology,2006,26(2):113-122. |
| |
| Authors: | LEI Xiang-yi |
| |
| Abstract: | There are generally 5~6 terraces along the main rivers and their affluents in the Loess Plateau.The loess is overlying these terraces like mantles.Divided by the Liupanshan Mts.,the loess stratigraphical structure on the terraces may be subdivided into two stratigraphical regions:the west and the east. In the west region,the highest terrace is terrace VI,on which loess section is about 310~505 m thick with 21~23 layers of paleosol,being the thickest loess deposits in the world at present.The loess on terrace VI began to form during 1.43 MaBP.Loess on the terrace consists of layers of soil from L_(1) to S_(14)or S_(16),200~400 m in thickness,and dated at about 1.23 MaBP.Terrace IV loess is made up of layers of soil from L_(1) to S_5 or S_6,100~200 m in thickness and dated at about 0.62 MaBP.Terrace III loess consists of L_(1) and S_(1),about 40~65 m in thickness and dated at about 0.12 MaBP.Terrace II loess is about 20~35 m thick and dated at about 0.03 MaBP.Terrace I loess consists of black loam(S_(0)),and upper loess(L_(0)),2~3.5 m in thickness,and dated at about 0.01 MaBP. In the east region,there are generally I-V terraces,which are overlaid by loess,but loess thickness is thinner.Terrace V loess:about 70~90 m thick,with 11~16 layers of paleosol,and dated at about 1.23 MaBP.Terrace IV loess:layers of soil from L_(1) to S_(8) or S_(9),about 40~70 m thick and dated at about 0.80 MaBP.Terrace III loess:layers of soil from L_(1) to S_(6),about 25~45 m thick and dated at about 0.62 MaBP.Terrace II loess:L_(1) and S_(1),10~17 m thick,and dated at 0.12 MaBP.Terrace I loess consists of S_(0),L_(0) and MS,about 2.0 m in thickness and dated at about 0.01 MaBP. |
| |
| Keywords: | terrace loess strata structure model Loess Plateau |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
|
