| 摘要: |
| 对山东省淄博市寨里镇佛村黄土剖面（FC剖面）进行粒度、磁化率及色度等沉积学指标分析，结果表明：（1）FC剖面6个光释光样品年龄结果介于3.02 ± 0.45 — 100.99 ± 13.58 ka，说明FC剖面是末次间冰期以来的沉积物；（2）根据沉积物粒度频率分布曲线和粒度组成特征，并与伊犁黄土、黄土高原黄土对比，可判知FC剖面为风成沉积物；（3）FC剖面磁化率与色度曲线具有相似的变化趋势，较好指示了黄土沉积时的冷暖干湿变化；（4）根据粒度中值粒径（Md）、低频磁化率（χlf）、土壤颜色（L*，a*）、环境敏感组分（56.23 — 112.20 μm）等气候代用指标并结合光释光测年结果，将FC剖面划分为5个部分，分别对应于深海同位素MIS1 — MIS5时期。1、3、5部分分别对应MIS1、MIS3早期、MIS5阶段，夏季风强盛，气候较暖湿，发育古土壤；2部分对应MIS2和MIS3中晚期阶段，4部分对应MIS4阶段，冬季风强盛，气候较干冷，堆积黄土。 |
| 关键词: FC剖面 粒度 磁化率 色度 环境演变 |
| DOI：10.7515/JEE201705004 |
| CSTR： |
| 分类号: |
| 基金项目:国家自然科学基金项目(41472159，41172160) |
|
| Climatic and environmental evolution with multi-index records of the loess in the Focun, Zibo, Shandong Province |
|
KONG Fanbiao, XU Shujian, JIA Guangju
|
|
1. Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection, College of Resources and Environment, Linyi University, Linyi 276005, China
2. School of Geography and Environment, Shandong Normal University, Jinan 250014, China
|
| Abstract: |
| Background, aim, and scope Study on the evolution of Paleoclimatic and paleoenvironment in Shandong Province by Sedimentary Indicators. Shandong is located in the eastern part of China, land and sea transition zone, which is sensitive to global climate and environmental changes. As a result, the Shandong loess records a richer climate and climate evolution information with its unique geographical location. However, the study of loess in Shandong area is relatively weak, lack of systematic chronological framework, its causes, provenance and other research still need further. In this paper, we select the artificial disturbance is small and well-preserved loess profile in Shandong Province to study the sedimentary environment information. Materials and methods On the basis of extensive field investigation and previous research, we choose the loess section with rich and thicker piles in the village of Zhaili Town, Zichuan City, which is the object of study on the age, grain size, magnetic susceptibility and chromaticity. In this study, drilling core sampling method is used, and the core 7 m can be obtained. A total of 175 samples were collected at 4 cm intervals. According to the profile stratification, 6 light-emitting samples were collected at 70 cm, 140 cm, 267 cm, 427 cm, 547 cm and 617 cm respectively. Results Analysis of Sedimentary Indexes of Particle Size, Magnetic Susceptibility and Chromaticity of the FC profile in the Zibo, Shandong Province, the results show (1) The age of 6 light releasing samples in FC profile is 3.02 ± 0.45 — 100.99 ± 13.58 ka, indicating that the loess section of fo village is a sediment formed during the last interglacial period of late quaternary; (2) According to the grain size distribution curve and grain size composition of the sediments, and compared with the Loess of Yili and Loess Plateau, it can be concluded that the FC profile is wind deposition; (3) The variation of magnetic susceptibility and chromaticity curve of FC profile shows a similar trend, which indicates the change of temperature and humidity; (4) According to the size of the median diameter (Md ), low frequency magnetic susceptibility (χlf), soil color (L*, a*), environmental sensitive components (56.23 — 112.20 μm) to analyze the climatic indicators, combined with the OSL dating results can be divided into modern farming layer, 3 paleosol layer and 2 loess layer. Discussion By analyzing the change characteristics of sedimentary indicators and combining the data of OSL, the FC profile is divided into 5 parts, which correspond to the deep-sea oxygen isotope MIS1-MIS5 period respectively. 1, 3 and 5 correspond to the periods of MIS1, MIS3 and MIS5 respectively, the summer monsoon increased, the winter wind decreased, the climate was warm and humid, and the ancient soil was developed. 2 and 4 correspond to the MIS2 and MIS4 phases respectively, the summer monsoon weakened, the winter monsoon increased, the climate is dry and cold, the accumulation of loess. Conclusions The FC profile has typical characteristics of aeolian loess, and records the warm or cold climate of Shandong region since the last interglacial, basically consistent with global change. However, the change characteristics of sedimentology indicators reflect the regional characteristics of its formation environment. Recommendations and perspectives The study of loess and island loess in the east coast of China is relatively weak, so it is necessary to carry out multidisciplinary comprehensive analysis, strengthen the mutual verification of multiple indicators, then we can get a better understanding of the climate and environment change in this area. |
| Key words: FC profile grain size magnetic susceptibility chroma environmental evolution |
