欢迎您！东篱公司
退出
-
申报数据库
-
立项数据库
-
成果数据库
-
项目获奖数据库
中文摘要：
通过对汉江上游湖北郧县一郧西段河谷的野外考察，选择前坊村汉江第一级阶地典型的黄土覆盖层剖面进行了深入研究。我们系统进行采样，分选出40～63μm石英颗粒，利用单片再生剂量法（SAR）技术，测得这些样品的光释光（OSL）年龄在2．90±0．15～16．76±0．60ka之间。OSL年龄值与地层深度表现出良好的对应关系。其中，利用释光信号组分拟合得到3种指数组分，发现快速组分达80％以上，且不同积分区间获得的D。值处于一个坪区，各测片D。值呈正态分布，说明这些风成沉积物晒退比较彻底。结合粒度参数Y值分析，确定这些沉积物属于风成堆积物。利用样品OSL年龄与气候替代指标，结合与秦岭北侧黄土剖面的对比，表明汉江上游河谷第一级阶地的风成堆积物从18．0ka开始堆积形成。自全新世以来受到不同程度的成壤改造作用，形成了与渭河谷地相似的L1-L1-S0-L1-Ms土壤地层序列。同时发现在1．8ka（200A．D．）前后，汉江上游发生了一期特大古洪水事件。这些研究成果对于深入了解汉江上游水文气候变化具有重要意义。
英文摘要：
Geomorphological and sedimentological study was carried out in the upper Hanjiang River Valley. A typical eolian loess-palaeosol profile（QFC-B） was found on the first terrace land near the Qianfang village in the Yunxian reach （32°48＇13＂N, 110°35＇18＂E; 161m a. s. 1）. After detailed pedo-stratigraphic sub-divisions during the fieldwork,a group of 70SL dating samples and another group of 228 sediment samples were collected from the profile systematically. The results of sedimentological analysis showed that the profile was deposited by dust storms and dust falls and palaeosol was developed during the warm-humid period. OSL dating on quartz grains at the size of 40 - 63μm were carried out by using the single aliquot regenerative-dose （SAR） protocol. The OSL dates of the samples were ranged from 2.90±0. 15ka to 16.76±0.60ka and the ages changed linearly with the depth change in this profile. A depth-age relationship was therefore established in the profile with the OSL dates in combination with the archaeological dating and the loss-on-ignition and grain size distribution. It showed that the eolian loess was deposited from 18.0ka on the first terrace land along the upper Hanjiang River Valley. The loess（L1 ）was deposited between 18.0ka and 11.5ka under the dry and cold climate during the last glacial. The transitional loess（L1） was deposited during 11.5～8.5ka during the early Holocene climatic amelioration. During the middle Holocene climatic optimum between 8.5ka and 3.1 ka,palaeosol So（ Udic Luvisol）was developed on the eolian dust deposit. This palaeosol So was well correlatable to the palaeosol So （ Ustic Luvisol） in the Guanzhong Basin north of the Qinling Mountains. Recent loess L0 was deposited from 3. l ka in the cooler and drier climate during the late Holocene. Typical palaeoflood slackwater deposit was identified in the upper part of the profile. It has recorded an extraordinary palaeoflood event occurring in the upper Hanjiang River that was dated to 1.8ka（200A
同期刊论文项目
同项目期刊论文
Late Pleistocene and Holocene palaeoflood events recorded by slackwater deposits in the upper Hanjia
Holocene Palaeoflood Events recorded by slackwater deposits along the Lower Jinghe River Valley, Mid
Sedimentary and hydrological studies of the Holocene palaeofloods in the middle reaches of the Jingh
Extraordinary floods related to the climatic event at 4200 a BP on the Qishuihe River, middle reache
Sedimentological study of the stratigraphrat the site of Homo erectus yunxianensis in the upper Hanj
Palaeoenvironmental implications of the prehistorical catastrophes in relation to the Lajia Ruins wi
A luminescence dating study of the sediment stratigraphy of the Lajia Ruins in the upper Yellow Rive
Reconstructing the extraordinary palaeoflood events during 3200-2800 a BP in the upper reaches of Ha
Comparative study of the modern flood slackwater deposits in the upper reaches of Hanjiang and Weihe
期刊信息
位置：