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河套地区新生代湖泊演化与“吉兰泰-河套”古大湖形成机制的初步研究 被引量:62
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作者 陈发虎 范育新 +3 位作者 d.b.madsen 春喜 赵晖 杨丽萍 《第四纪研究》 CAS CSCD 北大核心 2008年第5期866-873,共8页
研究发现,河套地区在距今5~6万年前存在一个统一的"吉兰泰-河套"古大湖,覆盖吉兰泰和河套盆地的大部分地区。本研究试图依据钻孔资料和湖泊沉积物的测年结果,讨论新生代以来河套盆地的湖泊演化和古大湖的形成机制。结果表明... 研究发现,河套地区在距今5~6万年前存在一个统一的"吉兰泰-河套"古大湖,覆盖吉兰泰和河套盆地的大部分地区。本研究试图依据钻孔资料和湖泊沉积物的测年结果,讨论新生代以来河套盆地的湖泊演化和古大湖的形成机制。结果表明,新生代以来,特别是早更新世以来吉兰泰盆地和河套平原的3个坳陷盆地就已经处于湖泊环境,但没有证据显示存在统一的湖泊。湖泊沉积及其OSL测年显示,"吉兰泰-河套"古大湖大约在距今10万年前后开始发育,至距今5~6万年之前湖面达到海拔1080m上下,随后湖泊衰退。我们认为,鄂尔多斯高原东北边缘距今12万年前后开始的快速构造隆升,可能导致了晋陕峡谷黄河外流受阻,最终在河套盆地积水形成统一湖泊,末次冰期中期(深海氧同位素3阶段)相对湿润的气候环境进一步促进了"吉兰泰-河套"古大湖的发育。 展开更多
关键词 湖泊演化“吉兰泰-河套”古大湖 构造运动 形成机制
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晚第四纪“吉兰泰-河套”古大湖的初步研究 被引量:69
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作者 陈发虎 范育新 +5 位作者 春喜 d.b.madsen C.G.Oviatt 赵晖 杨丽萍 孙洋 《科学通报》 EI CAS CSCD 北大核心 2008年第10期1207-1219,共13页
通过野外考察、探坑剖面观测和遥感影像分析,发现吉兰泰盐湖周围存在高湖面遗留的地貌、沉积和生物证据.在海拔1060,1050,1044和1035m共有4道古湖岸堤,分别高出现代盐湖37,27,21和12m.在海拔1070-1080m之间(高出现代盐湖47-57m)存在... 通过野外考察、探坑剖面观测和遥感影像分析,发现吉兰泰盐湖周围存在高湖面遗留的地貌、沉积和生物证据.在海拔1060,1050,1044和1035m共有4道古湖岸堤,分别高出现代盐湖37,27,21和12m.在海拔1070-1080m之间(高出现代盐湖47-57m)存在古湖滨砂砾石沉积,若干地点保存有古湖岸堤形态;在乌兰布和沙漠腹地的贺日木西尼也发现1080m高程及其以下的湖滨砂砾石和典型湖相沉积,以及从海拔1050-1035m,长11km的典型砂嘴.河套黄河南岸黄河水文站砂场、什拉召砂场也发现古湖岸堤,杭锦旗巴拉贡砂场发现发育在冲洪积砂砾石层上的湖滨砾石沉积.沿狼山-阴山南麓若干剖面点发现湖岸侵蚀台地及湖滩岩和湖滨相沉积.在黄河进入河套的乌海附近发现水下三角洲沉积,黄河出口的托克托台地存在典型湖相沉积.在湖滨沉积物中,普遍保存有蓝蚬、萝卜螺和扁卷螺等水生软体动物壳体,部分湖相细粒沉积物中也可见到介形虫壳体.出露较好的湖相沉积剖面具有典型的进积型垂向层序,较高湖岸堤普遍保存有湖滩岩.这些证据说明,曾存在一个覆盖吉兰泰和河套平原大部分地区的巨大古湖,湖面海拔可达1080m,建议称作“吉兰泰-河套”古大湖.光释光测年结果表明,该古大湖存在于距今5-6万年前.海拔1060-1035m间的4道湖岸堤代表了5-6万年到全新世早期间的湖面波动,而真正吉兰泰盐湖状态仅形成于距今5500年以来.“吉兰泰-河套”古大湖的发现,对进一步深入研究河套地区晚第四纪黄河发育、乌兰布和-库布齐沙漠的形成演化以及区域气候变化和新构造运动都具有重要意义. 展开更多
关键词 “吉兰泰-河套”古湖 湖岸堤 湖相沉积 晚第四纪 高湖面
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阿拉善高原中全新世干旱事件的湖泊记录研究 被引量:74
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作者 陈发虎 吴薇 +4 位作者 朱艳 J.A.Holmes d.b.madsen 金明 C.G.Oviatt 《科学通报》 EI CAS CSCD 北大核心 2004年第1期1-9,共9页
中国国内普遍流行的观点认为,中国中全新世是一个夏季风盛行的温暖湿润时期,称作全新世“最宜期”或“大暖期”.内蒙古西部阿拉善高原的湖泊沉积和湖泊地貌则显示了一种相反的状况,这一区域中全新世气候干旱,黑河的终闾湖泊居延泽、石... 中国国内普遍流行的观点认为,中国中全新世是一个夏季风盛行的温暖湿润时期,称作全新世“最宜期”或“大暖期”.内蒙古西部阿拉善高原的湖泊沉积和湖泊地貌则显示了一种相反的状况,这一区域中全新世气候干旱,黑河的终闾湖泊居延泽、石羊河的终闾湖泊潴野泽和腾格里沙漠东缘的头道湖均经历了湖泊缩小或干涸过程,时代为距今7000-5000日历年.潴野泽高分辨率(50年)的孢粉记录显示,季风边缘区的石羊河流域,特别是祁连山地的植被发生显著衰退,降水减少.中全新世的干旱事件存在于现代夏季风边缘区的较大范围,包括阿拉善高原、鄂尔多斯高原、内蒙古高原中东部,甚至黄土高原南部,指示了东亚夏季风在全新世期间的一次大衰退.中全新世东亚夏季风衰退期间气候寒冷,这在青藏高原及其周边山地尤为明显. 展开更多
关键词 阿拉善高原 中全新世 干旱事件 湖泊记录 中国 气候变化
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A mid-Holocene drought interval as evidenced by lake desiccation in the Alashan Plateau,Inner Mongolia,China 被引量:67
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作者 CHENFahu WUWei +4 位作者 J.A.Holmes d.b.madsen ZHUYan JINMin C.G.Oviatt 《Chinese Science Bulletin》 SCIE EI CAS 2003年第14期1401-1410,共10页
The mid-Holocene in China is traditionally thought to be a warm and humid period with a strong summer monsoon, and is often termed the Holocene Climatic Optimum or Megathermal Period. Here we present lake geomorpholog... The mid-Holocene in China is traditionally thought to be a warm and humid period with a strong summer monsoon, and is often termed the Holocene Climatic Optimum or Megathermal Period. Here we present lake geomorphologic and lithological evidence from the Alashan Plateau, part of the Mongolian Plateau, that indicates strong lake desiccation during the mid-Holocene. High resolution pollen data from Zhuyeze Lake, at the present summer monsoon margin, is also presented. These data show that present lakes and wetlands in the Juyanze Lake basin west of the Badain Jaran desert, in the Zhuyeze Lake basin between the Badain Jaran and Tengger deserts, and in lakes in the eastern Tengger desert, dried or experienced low lake levels in the mid-Holocene around 5000—7000 cal yr BP. Pollen data further indicate that the vegetation cover declined in both the local areas and in the Qilian Mountains, suggesting the climate was drier than that associated with the present Asian summer monsoon. This mid-Holocene drought interval was present throughout a quite large region of the south Inner Mongolian Plateau. The period was also probably colder, at least in the high Asian plateaus and mountains. 展开更多
关键词 中全新世 中国 内蒙古 蒙古高原 古气候 干旱气候 湖泊干涸
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Speculation on the timing and nature of Late Pleistocene hunter-gatherer colonization of the Tibetan Plateau 被引量:16
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作者 P.J.Brantingham MAHaizhou +3 位作者 J.W.Olsen GAOXinq d.b.madsen D.E.Rhode 《Chinese Science Bulletin》 SCIE EI CAS 2003年第14期1510-1516,共7页
Hunter-gatherer populations in greater northeast Asia experienced dramatic range expansions during the early Upper Paleolithic (45—22 ka) and the late Upper Paleolithic (18—10 ka), both of which led to intensive occ... Hunter-gatherer populations in greater northeast Asia experienced dramatic range expansions during the early Upper Paleolithic (45—22 ka) and the late Upper Paleolithic (18—10 ka), both of which led to intensive occupations of cold desert environments including the Mongolian Gobi and northwest China. Range contractions under the cold, arid extremes of the Last Glacial Maximum (LGM, 22—18 ka) may have entailed widespread population extirpations. The high elevation Qinghai-Tibetan Plateau is significantly more extreme in both climate and environment than either the Gobi or the Siberian taiga forests, and provides an ideal setting to test fundamental models of human biogeog- raphy in the context of regional population fluctuations. The area is presently occupied primarily by nomadic pastoralists, but it is clear that these complex middle Holocene (<6 ka) economic adaptations were not a necessary prerequisite for successful colonization of the high elevation Plateau. Exploratory field-work in 2000—2001 has established that Upper Paleolithic hunter-gatherers were present on the Qinghai-Tibetan Plateau by at least 12 ka and possibly much earlier. A speculative model for the colonization process is developed and preliminary archaeological data in support of the model are presented. 展开更多
关键词 青藏高原 晚更新世 猎人 聚集者 定居 时间 自然环境 人类地理学
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Late Pleistocene/Holocene wetland events recorded in southeast Tengger Desert lake sediments,NW China 被引量:11
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作者 d.b.madsen CHENFahu +4 位作者 Ch.G.Oviatt ZHUYan P.J.Brantinaham R.GoElston R.L.Bettinger 《Chinese Science Bulletin》 SCIE EI CAS 2003年第14期1423-1429,共7页
The area along the eastern and southeastern margins of the Tengger Desert, NW China, which is sensitive to the summer monsoon variations, was selectedfor studying the environmental conditions surrounding the transitio... The area along the eastern and southeastern margins of the Tengger Desert, NW China, which is sensitive to the summer monsoon variations, was selectedfor studying the environmental conditions surrounding the transition between Paleolithic foragers and Neolithic farmer/pastoral- ists. Short cores were obtained from four lake basins in the southwestern Tengger using a hand-driven piston coring device. Proxies from these cores were supplemented by ra- diocarbon ages obtained from lake sediment cores, shoreline features and spring mound deposits. Together these records provide evidence of millennial-scale climate change events from the Pleistocene-Holocene transition to the present. Lake/wetland events, representing periods of more intensive summer monsoon, occur in the records at ~12.7-11.6, ~10.1, ~9.3, ~8.0, ~5.4, ~1.5, and ~0.8 ka BP. They do suggest that century- to millennial-scale climatic cycles are characteristic of the Holocene in the southeastern Tengger Desert although the chronology must be considered extremely tentative. 展开更多
关键词 中国西北地区 腾葛尔沙漠 晚更新世 全新世 湖泊沉积物 古气候
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