新疆肖尔布拉克（XEBLK剖面）重矿物记录数据集（3万年以来）

中亚黄土沉积物记录了亚洲内陆干旱化过程，然而，黄土古气候指标通常会受到源区和沉积过程的影响，具有明确物源和沉积过程的敏感的古气候指标对准确重建古环境的演化有着重要意义。本研究中，选取我国伊犁盆地一个30- ka以来的黄土剖面，开展重矿物组合和沉积速率的研究。发现在MIS2阶段，沉积速率的变化趋势与黄土高原的一致，与北半球夏季太阳辐射呈现出反相位变化。角闪石和绿帘石比值（含量和平均粒径）在冷期（LGM晚期和H1）的时候比较低，在相邻的暖期比较高。这主要与角闪石和绿帘石的风动力分选有关。即在暖期，角闪石和绿帘石有更强的分选，在冷期，角闪石和绿帘石有更弱的分选。角闪石和绿帘石比值因此可以作为反映风动力强度的指标，进一步可以用来反映西伯利亚高压的强度。角闪石和绿帘石的比值比沉积速率对风强度的变化更加敏感，因为沉积速率也与沉积物的可及性有关。更高的角闪石和绿帘石的比值对应偏负的东亚石笋δ18O，表明了MIS2阶段，西伯利亚高压和东亚夏季风强度的反相位变化。

Central Asian loess sediments record the aridification process of inland Asia. However, loess paleoclimatic proxies are usually affected by source areas and depositional processes, so sensitive paleoclimatic proxies with well-constrained provenance and depositional processes are of great significance for accurately reconstructing paleoenvironmental evolution. In this study, we selected a loess section spanning the past 30 ka in the Yili Basin of China, and conducted research on heavy mineral assemblages and sedimentation rate. We found that during Marine Isotope Stage 2 (MIS2), the variation trend of sedimentation rate is consistent with that of the Loess Plateau, and shows out-of-phase changes with Northern Hemisphere summer solar radiation. The ratio of amphibole to epidote (both in content and mean grain size) is relatively low during cold phases (late Last Glacial Maximum and Heinrich Event 1) and high during adjacent warm phases. This is mainly related to the wind-driven sorting of amphibole and epidote: during warm phases, amphibole and epidote undergo stronger sorting, while during cold phases, the sorting is weaker. Thus, the amphibole-to-epidote ratio can serve as an indicator reflecting wind intensity, and further be used to reflect the intensity of the Siberian High. The amphibole-to-epidote ratio is more sensitive to changes in wind intensity than sedimentation rate, because sedimentation rate is also related to the availability of sediments. Higher amphibole-to-epidote ratios correspond to more negative East Asian stalagmite δ¹⁸O values, indicating out-of-phase changes in the intensity of the Siberian High and East Asian Summer Monsoon during MIS2.

搜集汇总

背景与挑战

背景概述

该数据集记录了新疆肖尔布拉克剖面3万年以来重矿物含量、粒度和磁化率等地质学数据，用于研究亚洲内陆干旱化过程和风动力强度变化。数据质量可靠，严格按照实验规范采集。