Environmental constraints on lake sediment mineral compositions from the Tibetan Plateau and implications for paleoenvironment reconstruction
Environmental constraints on lake sediment mineral compositions from the Tibetan Plateau and implications for paleoenvironment reconstruction
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青藏高原湖泊沉积矿物成分的环境约束及其对古环境重建的意义
DOI：
10.1007/s10933-011-9549-2
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发表时间：
2011
影响因子：
2.1
通讯作者：
Herzschuh, Ulrike
中科院分区：
文献类型：
--
作者：
Wang, Yongbo;Liu, Xingqi;Mischke, Steffen;Herzschuh, Ulrike
无机矿物是湖泊沉积物的主要组成部分，有可能揭示有关以前气候和水文条件的详细信息。然而，由于对矿物与环境之间关系的了解有限，提取此类信息的能力受到了限制。为了填补这一知识空白，对青藏高原146个湖泊的146个表层沉积物样品进行了调查。用X射线衍射仪(X射线衍射仪)分析了这些样品的矿物组成，以考察矿物组成与每个地点所确定的环境变量之间的关系。基于矿物光谱和环境变量的多元回归树(MRT)和冗余分析(RDA)等统计技术表明，湖水电导率(EC)和镁钙比是控制内生矿物组成的最重要因素。在超淡水条件下(EC低于0.13毫秒/厘米)没有内生矿物沉淀，方解石通常在EC值大于0.13毫秒/厘米的水中形成。在EC值为0.13和26毫秒/厘米之间，湖泊沉积物的矿物组成可以用镁/钙比的变化来解释：当镁/钙比小于33时，方解石占主导地位，而当镁/钙比大于33时，通常形成文石。EC值在26-39毫秒/厘米之间时，一水解石与方解石、文石一起沉淀；高于39毫秒/厘米时，通常形成石膏和岩盐。关于当地地质地层的信息表明，异质(碎屑)矿物成分主要受集水区内基岩成分的影响。通过将这些关系应用于查卡盐湖的晚冰期和全新世矿物记录，已识别出五个湖泊阶段，并推断了与之相关的EC条件。该湖由冰川晚期(11.4世纪以前)的淡水湖演化而来。Ka BP)，以最低的EC值(<；0.13亿毫秒/厘米)为代表，到全新世早、中期(约11.4-5.3百万卡)EC值略高于3900万毫秒/厘米的盐湖。Ka BP)，最后到达盐湖(在5.3千卡之后。Ka BP)。这些结果说明了我们的矿物环境模型在根据湖泊沉积物记录定量重建过去的环境条件方面的实用性。
Inorganic minerals form a major component of lacustrine sediments and have the potential to reveal detailed information on previous climatic and hydrological conditions. The ability to extract such information however, has been restricted by a limited understanding of the relationships between minerals and the environment. In an attempt to fill in this gap in our knowledge, 146 surface sediment samples have been investigated from 146 lakes on the Tibetan Plateau. The mineral compositions derived from these samples by X-Ray Diffraction (XRD) were used to examine the relationships between mineral compositions and the environmental variables determined for each site. Statistical techniques including Multivariate regression trees (MRT) and Redundancy Analysis (RDA), based on the mineral spectra and environmental variables, reveal that the electrical conductivity (EC) and Mg/Ca ratios of lake water are the most important controls on the composition of endogenic minerals. No endogenic minerals precipitate under hyper-fresh water conditions (EC lower than 0.13 mS/cm), with calcite commonly forming in water with EC values above 0.13 mS/cm. Between EC values of 0.13 and 26 mS/cm the mineral composition of lake sediments can be explained in terms of variations in the Mg/Ca ratio: calcite dominates at Mg/Ca ratios of less than 33, whereas aragonite commonly forms when the ratio is greater than 33. Where EC values are between 26 and 39 mS/cm, monohydrocalcite precipitates together with calcite and aragonite; above 39 mS/cm, gypsum and halite commonly form. Information on the local geological strata indicates that allogenic (detrital) mineral compositions are primarily influenced by the bedrock compositions within the catchment area. By applying these relationships to the late glacial and Holocene mineral record from Chaka Salt Lake, five lake stages have been identified and their associated EC conditions inferred. The lake evolved from a freshwater lake during the late glacial (before 11.4 cal. ka BP) represented by the lowest EC values (<0.13 mS/cm), to a saline lake with EC values slightly higher than 39 mS/cm during the early and mid Holocene (ca. 11.4–5.3 cal. ka BP), and finally to a salt lake (after 5.3 cal. ka BP). These results illustrate the utility of our mineral-environmental model for the quantitative reconstruction of past environmental conditions from lake sediment records.
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影响因子：
5.8
作者：
Daniel C. Pope;S. Willett
通讯作者：
Daniel C. Pope;S. Willett
DOI：
--
发表时间：
2002
期刊：
--
影响因子：
--
作者：
C. Braak;P. Šmilauer
通讯作者：
C. Braak;P. Šmilauer
DOI：
10.1016/s0166-2481(08)x0001-7
发表时间：
2009
期刊：
Developments in soil science
影响因子：
--
作者：
T. Hengl;H. Reuter
通讯作者：
T. Hengl;H. Reuter
影响因子：
2.1
作者：
I. Campbell;W. Last;C. Campbell;Stephen M. Clare;J. McAndrews
通讯作者：
I. Campbell;W. Last;C. Campbell;Stephen M. Clare;J. McAndrews
影响因子：
3
作者：
Aichner, Bernhard;Herzschuh, Ulrike;Boehner, Juergen
通讯作者：
Boehner, Juergen