...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Catena: An Interdisciplinary Journal of Soil Science Hydrology-Geomorphology Focusing on Geoecology and Landscape Evolution >Late Quaternary paleosols and their paleoenvironmental significance along the Andean piedmont, Eastern Bolivia.
【24h】

Late Quaternary paleosols and their paleoenvironmental significance along the Andean piedmont, Eastern Bolivia.

机译：玻利维亚东部安第斯山前地带晚第四纪古土壤及其古环境意义。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The Andean piedmont of eastern Bolivia is situated at the southern margin of Amazonia characterized by an overall humid climate regime with a marked contrast between the rainy and dry seasons. The nearby Subandean foothills deliver abundant sandy sediments to the piedmont, leading to a complex array of sediments and paleosol horizons. Within this setting, the presented study analyzes four profiles of paleosol-sediment-sequences along incised ephemeral streams near Santa Cruz de la Sierra with a focus on past pedogenic variability in the context of the regional late Quaternary geomorphic and environmental evolution. Based on field observations, micromorphological analysis, geochemical and clay mineralogical data five classes of paleosol horizons could be distinguished. The individual paleosol horizons as well as the sediments, in which they developed, were interpreted regarding their paleoenvironmental significance, taking into consideration the various controls on soil formation with particular focus on changes of local environmental conditions through time. Thus, three different pathways of soil formation were established. On the late Quaternary timescale, the results suggest a strong relation between paleoenvironmental conditions (climate, vegetation etc.), soil environment (soil water flow, micro-environment) and the type of paleosol horizons developed in the study area. The formation of "red beds" (Bw horizons) implies very dry soil environments under dominantly dry conditions, which seem to have prevailed in the study area some time before ~18 cal ka BP. Moderately dry but markedly seasonal environmental conditions with a long dry season and strong seasonal contrasts in soil water flow could explain the formation of moderately developed Bwt horizons around ~18 cal ka BP and much of the mid-Holocene. The formation of Bt horizons and/or clay lamellae in relation to intense neoformation of clay and dominant clay illuviation by soil water points to wet conditions similar to today, which have probably prevailed in the study area before ~8 cal ka BP and since ~5 cal ka BP.
机译：玻利维亚东部的安第斯山麓位于亚马孙地区的南部边缘，其特征是整体湿润的气候状况，在雨季和旱季之间形成鲜明对比。附近的Subandean山麓将大量的沙质沉积物输送到山前，导致一系列复杂的沉积物和古土壤层。在此背景下，本研究分析了沿圣克鲁斯-德拉塞拉附近的临时短暂河流切割的古土壤-沉积物序列的四个剖面，重点是区域第四纪晚期地貌和环境演化背景下的过去成岩作用的变化。根据现场观察，微观形态分析，地球化学和粘土矿物学数据，可以区分出五类古土壤层。解释了各个古土壤层及其沉积物的古环境意义，并考虑了对土壤形成的各种控制，特别关注随时间变化的当地环境条件。因此，建立了三种不同的土壤形成途径。在第四纪后期，研究结果表明古环境条件（气候，植被等），土壤环境（土壤水流，微环境）与研究区古土壤层位的类型之间存在密切关系。 “红色层”（B w 层位）的形成意味着在显着干燥条件下非常干燥的土壤环境，这似乎在〜18 cal ka BP之前的某个时间在研究区域盛行。中度干燥但季节明显的环境条件，干燥期长，土壤水流强烈的季节差异，可以解释约18 cal ka BP和中全新世大部分附近中等发育的B wt 层位的形成。 。 B t 层位和/或黏土薄片的形成与黏土的强烈新形成和土壤水对主要黏土的浸润有关，这表明与今天类似的湿润条件，这可能在〜 8 cal ka BP，从约5 cal ka BP开始。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号