青藏高原东北部——黄土高原过去250万年土壤易溶盐含量数据集

中国黄土高原（CLP）的黄土保存了有关亚洲沙尘循环的丰富信息。
然而，黄土的来源和成分随时间的变化仍然存在争议。可溶性盐是一种重要的粉尘成分，与粉尘动员、运输和沉积有关的地形和环境有关。通过对中、西部两个黄土层序可溶性盐含量的研究，发现中国黄土的可溶性盐含量在~1和~ 0.5 Ma时主要呈阶梯式增加。
多种证据表明，可溶性盐供应的增加主要来源于粉尘的输入，表明亚洲粉尘盐度的增加。丰富的地貌和沉积学证据证实，潜在源区的湖床演化驱动了可溶性含盐粉尘的增强。中更新世过渡带（与青藏高原隆升有关）引起的潜在源区干旱化和中布伦什过渡带引发的东亚夏季风的加剧，分别在~1 Ma和~ 0.5 Ma形成了潜在源区湖床的阶梯式演化，并成为重要的含盐粉尘储集层。这些发现为认识过去和未来区域沙尘排放的演变及其可能的环境影响提供了新的证据。
数据来源：样品分别来自黄土高原中部的灵台剖面和西部的九州台剖面，灵台剖面共采集133份样品，九州台剖面共采集90份样品进行可溶性盐测定。在灵台和九州台剖面，每个黄土和古土壤层选取3-5个代表性样品。
加工方法：在测定可溶性盐之前，所有样品都在玛瑙砂浆中干燥和研磨，并通过100 μm的筛子。取10g样品称重，与蒸馏水(1:5)混合，充分混合，离心，提取上清液测定可溶性盐含量。上清液采用美国DIONEX公司的ICS-2500离子色谱仪进行测量，该色谱仪可测量溶液中的7种主要离子，包括阴离子Cl-、NO3-、So42-和阳离子Na+、K+、Mg2+和Ca2+，测量精度为0.1% ~ 0.3%。所有实验均在兰州大学西部环境重点实验室进行。

Loess deposits on the Chinese Loess Plateau (CLP) preserve abundant information regarding Asian dust cycles. However, temporal changes in the provenance and composition of loess remain controversial. Soluble salts are a critical dust component, associated with terrain and environmental conditions that govern dust mobilization, transport, and deposition. Based on analyses of soluble salt contents from two loess sequences in the central and western CLP, we found that the soluble salt content of Chinese loess exhibited prominent stepwise increases at ~1 Ma and ~0.5 Ma, respectively. Multiple lines of evidence indicate that the increased supply of soluble salts primarily stems from enhanced dust inputs, suggesting elevated salinity of Asian dust. Abundant geomorphic and sedimentological evidence confirms that lake bed evolution in potential dust source regions drives the amplification of salt-bearing soluble dust. The aridification of potential source regions induced by the Mid-Pleistocene Transition (MPT, linked to Tibetan Plateau uplift) and the intensification of the East Asian Summer Monsoon (EASM) triggered by the Mid-Brunhes Event (MBE) drove the stepwise evolution of lake beds in potential source regions at ~1 Ma and ~0.5 Ma, respectively, turning these regions into major salt-bearing dust reservoirs. These findings provide novel insights into the evolution of regional dust emissions and their potential environmental impacts, both in the past and under future scenarios.

Data Source: Samples were collected from the Lingtai section in the central CLP and the Jiuzhoutai section in the western CLP. A total of 133 samples were obtained from the Lingtai section and 90 samples from the Jiuzhoutai section for soluble salt analysis. For both sections, 3–5 representative samples were selected from each loess and paleosol layer.

Sample Preparation and Analytical Methods: Prior to soluble salt determination, all samples were dried and ground in an agate mortar, then passed through a 100 μm sieve. Approximately 10 g of each sample was weighed, mixed with deionized water at a solid-to-liquid ratio of 1:5, thoroughly stirred, and centrifuged to extract the supernatant for soluble salt quantification. The supernatant was analyzed using an ICS-2500 ion chromatograph (DIONEX Corporation, USA), which can detect 7 major ions: anions Cl⁻, NO₃⁻, SO₄²⁻, and cations Na⁺, K⁺, Mg²⁺, and Ca²⁺, with a measurement precision ranging from 0.1% to 0.3%. All experiments were conducted at the Key Laboratory of Western China’s Environmental Systems, Lanzhou University.

搜集汇总

背景与挑战

背景概述

该数据集提供了青藏高原东北部——黄土高原过去250万年的土壤易溶盐含量数据，时间分辨率为1000年，空间分辨率为100km - 1000km。数据来源于黄土高原的两个剖面，共223份样品，通过离子色谱仪测量了7种主要离子含量，旨在研究亚洲沙尘循环中可溶性盐的变化及其与环境的关系。