姜兴钰^1,2,,
田立柱^1,2,
李勇^1,2,
赵勇³,
商志文^1,2,
袁海帆^1,2,
伊布格勒³,
易亮⁴,
王宏^1,2,,
1. 中国地质调查局天津地质调查中心, 天津 300170
2. 中国地质调查局泥质海岸带地质环境重点实验室, 天津 300170
3. 内蒙古自治区 科尔沁(通辽市)博物馆, 内蒙古 通辽 028000
4. 同济大学海洋与地球科学学院, 海洋地质国家重点实验室, 上海 200092

基金项目: 国家自然科学基金面上项目（批准号：41476074和41372173）和中国地质调查局地质大调查项目（批准号：DD20189506）共同资助


详细信息

作者简介: 姜兴钰, 男, 37岁, 高级工程师, 海洋地质学专业, E-mail:jxingyu@cgs.cn或jiangxingyu2008@163.com

通讯作者: 王宏, E-mail:whong@cgs.cn

中图分类号: P534.63⁺2;P532

收稿日期:2018-05-11
修回日期:2018-08-26
刊出日期:2018-11-30

Late Holocene stratigraphy and palaeoenvironment of Sanyitang site, Horqin District

Jiang Xingyu^1,2,,
Tian Lizhu^1,2,
Li Yong^1,2,
Zhao Yong³,
Shang Zhiwen^1,2,
Yuan Haifan^1,2,
Yibu Gele³,
Yi Liang⁴,
Wang Hong^1,2,,
1. Tianjin Center, China Geological Survey(CGS), Tianjin 300170
2. CGS Key Laboratory of Muddy Coastal Geoenvironment, Tianjin 300170
3. Horqin(Tongliao) Museum, Inner Mongolia Autonomous Region, Tongliao 028000, Inner Mongolia
4. State Key Laboratory of Marine Geology, School of Ocean and Earth Science, Tongji University, Shanghai 200092


More Information

Corresponding author: Wang Hong,E-mail:whong@cgs.cn

MSC: P534.63⁺2;P532

--> Received Date: 11 May 2018
Revised Date: 26 August 2018
Publish Date: 30 November 2018


摘要
摘要:通过对西辽河中游科尔沁区三义堂剖面及相邻地区晚全新世沉积物组成、沉积相、地层层序、年代学（AMS ¹⁴C和考古断代）及宽浅河谷、沙地地貌的初步研究，揭示了古西辽河冲洪积砂、古科尔沁沙地风成砂、古湖泊泥质沉积与古土壤层的基本地层关系。尽管贮存库效应导致¹⁴C年龄存在明显颠倒，但考古学提供的断代证据及对贮存库效应的解释，对¹⁴C数据做出了尽可能合理的取舍，从而建立了自约1500 B.C.以来年代学的基本序列。据此，揭示了研究区晚全新世地层三分的基本格局：1）晚全新世早期，古西辽河冲洪积砂层在约1500 B.C.转为风成沙丘并发育良好的栗钙土（第1栗钙土层），标志着晚全新世科尔沁沙化的重新开始；随后，砂质沉积（冲洪积和风成）与（发育程度相对低的）多次栗钙土成壤反复交替。这一过程结束于约1250 A.D.时的第二次发育良好的栗钙土层（第6栗钙土层）。2）晚全新世中期（金元时期、"中世纪温暖期"后半期），是1250 A.D.之后的一次突然出现、而又突然结束的短暂湖泊发育期，经历黑钙土成壤作用的黑色泥质湖相层与上、下地层均为清楚的突变接触。3）晚全新世晚期，为冲洪积-风积砂层与栗钙土层的反复交替，直至现代。"湖泊-黑钙土成壤化"的突然出现与结束，暗示着干旱-湿润-干旱两次气候突变过程的存在。
关键词: 科尔沁区/
晚全新世/
湖相沉积/
快速变湿变干

Abstract:Sanyitang profile, 43°30'N, 122°30'E, 9.2 m thick, was investigated in a brickyard in Sanyitang site, Horqin District of Inner Mongolia Autonomous Region, in extensively wide and shallow channel of the middle reach of Xiliaohe River. It is located less than 200 km west to the margin of East Asian Summer Monsoon front, and is therefore sensitive to climate changes. However, most previous studies were focused mainly on eolian dune or endorheic depression environments while shallow and wide flooding plains, with various types of sedimentation, were less selected for palaeoenvironmental reconstruction.
In this study, depositional composition, facies, sequences and chronology (AMS ¹⁴C dating and archaeology)of the Late Holocene sediments were preliminarily investigated in the major site, Sayitang profile, with 12 additional profiles in the surrounding areas. The study was conducted with multiple approaches including: (1)An estimated reservoir age, ca. 600 ¹⁴C years, of the dated sedimentary organic materials. (2)A set of shards of pottery, found within the sequence, archaeologically determined around the late Neolithic. Consequently, ¹⁴C dated 1203 cal.B.C., obtained from the exact same position, is tenable. Based on such a combination of archaeological and radiocarbon dating, a local chronological framework of the Late Holocene is preliminarily established. (3)Both chestnut and chernozem soils were distinguished clearly on their differentiated origins. The former was developed from its parent C Horizon of eolian fine sand and silt sediments while the latter was directly formed from lacustrine clay sediment. (4)The lacustrine sediment, being chernozem-pedogenetically, was abruptly terminated determined by a sharp contact boundary with the overlying sediments.
Based on the aforementioned findings, the conclusions are drawn as follows. The local Late Holocene desertification, re-initiated slightly earlier than the first chestnut soil at ca.1500 B.C. The dune reactivation was followed by the soil complex, consisting of several chestnut soil horizons, alternated frequently with fluvial and eolian sands till around 1250 cal.A.D. Then, a lake environment suddenly occurred at the late half of Medieval Warm Period around 12^th~13^th century. This lacustrine environment occurred and disappeared abruptly. These two events may indicate rapid alternation between humidity and aridity besides relatively mild and smooth transition determined by the chestnut pedogenetic processes in the area. Thus, a hypothesis of 'Hurried humidity and hurried aridity' is proposed for further approaching. In the context of recent global warming and mid-latitude aridity, abrupt drought, as enlightened by the rapid termination of the lacustrine deposition in this study, is even much important to be better understood.
Key words:Horqin District/
Late Holocene/
lacustrine sediment/
rapid changes of humidity and aridity



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