地理学报 ›› 2011, Vol. 66 ›› Issue (11): 1562-1573.doi: 10.11821/xb201111012

• 水文地貌与第四纪 • 上一篇    下一篇

汉江上游谷地全新世风成黄土及其成壤改造特征

庞奖励, 黄春长, 周亚利, 查小春, 王朝建   

  1. 陕西师范大学旅游与环境学院,西安 710062
  • 收稿日期:2011-06-13 修回日期:2011-09-09 出版日期:2011-11-20 发布日期:2011-12-24
  • 作者简介:庞奖励(1963-), 男, 西安市人, 博士, 教授, 中国地理学会会员(S110005769M), 主要从事土地利用与土壤演变的研究。E-mail: jlpang@snnu.edu.cn
  • 基金资助:

    国家自然科学重点基金项目(41030637);国家社会科学基金重点项目(11AZS009)

Holocene Aeolian Loess and Its Pedogenic Modification in the Upper Hanjiang River Valley, China

PANG Jiangli, HUANG Chunchang, ZHOU Yali, ZHA Xiaochun, WANG Chaojian   

  1. College of Tourism and Environmental Sciences, Shaanxi Normal University, Xi'an 710062, China
  • Received:2011-06-13 Revised:2011-09-09 Online:2011-11-20 Published:2011-12-24
  • Supported by:

    NationalNatural Science Foundation of China, No.41030637; National Social Science Foundation of China, N0.11AZS009

摘要: 对汉江上游郧县—郧西段一级阶地物质上堆积的黄土状覆盖层的剖面构型、粒度、矿物组合、元素分布、微形态及形成时代进行了研究,并与渭河谷地全新世黄土—古土壤序列对比。结果表明,这些“黄土状覆盖层”是晚更新世以来沙尘暴在区内连续堆积的结果,具有TS-L0-S0-Lt-L1-AD剖面构型;这些风积物在不同时期受到了不同程度的成壤改造作用,晚更新世受到弱成壤改造→全新世中期受到强烈成壤改造→全新世晚期较弱成壤改造。汉江上游地区在晚更新世末期(11500 a BP),气候比较冷湿,沙尘暴频繁出现,形成较厚的黄土层L1;全新世初期(11500-8500 a BP),气候从冷湿向暖湿方向转变,沙尘暴活动减弱,形成了过渡黄土层位Lt;全新世中期(8500-3000 a BP),气候达到全新世最为暖湿的阶段,沙尘暴沉积物受到强烈成壤改造而形成了古土壤S0;全新世晚期(3000 a BP以来),气候暖湿程度降低,越过秦岭的沙尘暴又明显增强,形成了近代黄土L0

关键词: 沙尘暴堆积物, 成壤改造, 全新世, 汉江上游谷地

Abstract: Loess-like sediments over the first level river terraces of the Upper Hanjiang River Valley between Yunxian and Yunxi were surveyed in detail and then sampled systematically. Pedogenic modification characteristics and the structure of soil profiles were observed in the field survey. Particle-size distribution, mineral assemblage, major elements and trace elements, magnetic susceptibility, CaCO3, micromorphology and OSL age were analyzed in laboratory and compared with Holocene loess-paleosol sequences in the Weihe River Valley. Results are shown as follows. (1) The loess-like sediments have aeolian features due to continuous accumulation of dust storms since the Late Pleistocene, with the profile structure TS-L0-S0-Lt-L1-AD. They are the same as the Holocene loess-paleosol sequences in the Weihe River Valley in these aspects, including stratigraphic structure, color, physical and chemical properties. (2) The dust storm sediments went through different degrees of pedogenic modification in different periods, namely weak pedogenic modification in the late Pleistocene, very strong pedogenic modification during the mid-Holocene and weaker pedogenic modification during the late Holocene. (3) It was cold and wet during the late Pleistocene (11500 a BP) and frequent dust storms led to the formation of Malan loess layer L1. It is a climate shift from cold-wet to warm-humid during the early Holocene (between 11500-8500 a BP) and dust storm activity gradually decreased to form a transitional loess layer Lt. It was warm and humid during the mid-Holocene (between 8500-3000 a BP), and dust storm sediments were strongly modified to form paleosol S0. It tended to be cooler and drier during the late Holocene (since 3000 a BP), and dust storms were obviously inrensified to form modern loess L0.

Key words: aeolian sediments, pedogenic modification, Holocene, Upper Hanjiang River Valley