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Crescentic dune migration and stabilization： Implications for interpreting paleo-dune deposits as paleoenvironmental records

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Journal of Geographical Sciences 2017年第11期27卷 1341-1358页

作者： XU Zhiwei Joseph A. MASON lu huayu YI Shuangwen ZHOU Yali WU Jiang HAN Zhiyong School of Geographic and Oceanographic Sciences Nanjing University Nanjing 210023 China Department of Geography University of Wisconsin Madison Wl 53706 USA School of Geography and Tourism Shaanxi Normal University Xi'an 710062 China

Paleo-dune deposits have been widely used as a proxy indicator of past dune ac- tivity, which is further used to reconstruct paleoclimates. However, recent studies have criti- cally examined the reproducibility of dune chronologies and the complexity of paleo-dune deposits as paleoenvironmental records. This paper addresses questions on the paleoenvi- ronmental implications of dune chronostratigraphies that have been raised by those reviews, in the specific case of crescentic dunes, using a case study from the Mu Us dune field, north-central China. The processes of turn-over and stabilization of relatively small crescentic dunes are first investigated by observational evidence. In combination with the analysis of a simplified sand preservation model and stratigraphic records, the effect of dune morphody- namics on sand preservation is demonstrated. It is especially evident that thick, nearly in- stantaneously deposited sand units record dune stabilization near the very end of a dune activity episode, while thin sand units may signal the preservation of sand deposited earlier in episodes of activity. Interpreting the distribution of luminescence ages that indicate sand deposition over time is not as simple as assumed in some previous work. Low frequency of sand ages could indicate an interval of either dune field stabilization or extensive dune activity but poor sand preservation. A peak of sand age frequency likely represents a shift in dune field activity towards stabilization, not a peak of active dune extent, especially if it partially overlaps with an independently identified interval of stabilization （e.g. one recorded by pa- leosols）. The nature and magnitude of these biases in the distribution of sand ages over time are strongly affected by the magnitude of net sand accumulation, which is in turn related to sand supply, transport capacity and sand availability, and ultimately climate change. Rela- tively short dune stabilization and turn-over time （101 to 102

关键词： dune activity dune chronologies dune morphodynamics dune turn-over time OSL dating paleoen- vironmental interpretation

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Chinese deserts and sand fields in Last Glacial Maximum and Holocene Optimum

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Chinese Science Bulletin 2013年第23期58卷 2775-2783页

作者： lu huayu YI ShuangWen XU ZhiWei ZHOU YaLi ZENG Lin ZHU FangYing FENG Han DONG LiNa ZHUO HaiXin YU KaiFeng MASON Joseph WANG XiaoYong CHEN YingYong lu Qi WU Bo DONG ZhiBao QU JianJun WANG XunMing GUO ZhengTang School of Geographic and Oceanographic Sciences Institute for Climate and Global Change Research Nanjing University College of Tourism and Environment Shaanxi Normal University Department of Geography University of Wisconsin Madison Institute of Desertification Studies Chinese Academy of Forestry Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Institute of Geology and Geophysics Chinese Academy of Sciences

The Last Glacial Maximum (LGM, c. 26-16 ka) and the Holocene Optimum (HO, c. 9-5 ka) were characterized by cold-dry and warm-wet climates respectively in the recently geological Earth. How Chinese deserts and sand fields responded to these distinctive climatic changes is still not clear, however. To reconstruct environments of the deserts and sand fields during the LGM and HO is helpful to understand the forcing mechanisms of environment change in this arid region, and to test paleoclimatic modeling results. Through our long-term field and laboratory investigations, 400 optically stimulated luminescence (OSL) ages and more than 100 depositional records in the Chinese deserts and sand fields were obtained; on the basis of these data, we reconstruct spatial distributions of the deserts and sand fields during the LGM and HO. Our results show that the sand fields of Mu Us, Hunshandake, Horqin and Hulun Buir in northern and northeastern China had expanded 25%, 37%, 38% and 270%, respectively, during the LGM; the sand fields of Gonghe in the northeastern Qinghai-Tibetan Plateau had expanded 20%, and the deserts of Badain Jaran, Tengger in central northern China had expanded 39% and 29% separately during the LGM; the deserts of Taklimakan, Gurbantünggüt and Kumtag in northwestern China had expanded 10%-20% respectively, compared to their modern areas. On the other hand, all of the sand fields were nearly completely covered by vegetation during the HO; the deserts in northwestern and central northern China were reduced by around 5%-20% in area during this time. Lakes in this arid region were probably expanded during the HO but this conclusion needs more investigation. Compared with the geological distributions of deserts and sand fields, human activity has clearly changed (expanded) the area of active sand dunes at the present time. Our observations show that environmental conditions of Chinese deserts and sand fields are controlled by regional climate together with human a

关键词：沙漠环境中国北部适宜期全新世末次冰期末次盛冰期库姆塔格沙漠干旱地区

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A preliminary quantitative reconstruction of precipitation in southern Mu Us sandy land at margin of Asian monsoon-dominated region during late Quaternary

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Journal of Geographical Sciences 2015年第3期25卷 301-310页

作者： CHEN Yingyong lu huayu YI Shuangwen ZHANG Enlou XU Zhiwei YU Kaifeng Joseph A. MASON School of Geographic and Oceanographic Sciences Nanjing University Jiangsu Collaborative Innovation Center for Climate Change Nanjing 210023 China State Key Laboratory of lake Science and Environment Nanjing Institute of Geography and Limnology CAS Nanjing 210008 China Department of Geography University of Wisconsin Madison Wl 53706 USA

We present the first quantitative estimation of monsoon precipitation during the late glaciaI-Holocene in the sandy land of northern China, based on organic carbon isotopic composition data from a loess-sand sequence at margin of the Mu Us sandy land. We use the relationship between monsoon precipitation and the carbon isotopic composition of modern soils as an analogue, with a minor modification, to reconstruct precipitation back to c. 47 ka ago. The preliminary results indicate that annual monsoon precipitation was high after 8 ka, with an average of 435 mm; and it decreased during 18 and 8 ka with a mean value of 194 mm. The precipitation value of 47-18 ka varied between the two. We compare the recon- structed precipitation with other records and paleoclimatic modeling results, showing that our record agrees with reconstructions of the monsoon precipitation from other sources, even capturing short climatic events such as the Younger Dryas. We suggest that solar irradiance, high-latitude temperature/ice volume and local evaporation have together modified moistures in the sandy land.

关键词： quantitative reconstruction organic carbon isotopic composition precipitation Mu Us sandy land Asian monsoon

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唐天宝间江南地区的麻布产量及社会需求

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中国经济史研究 2017年第4期 5-12页

作者：卢华语西南大学历史文化学院

江南是唐代最重要的麻布生产中心。据《新唐书·地理志》相关资料可知,唐天宝间江南地区每户实有麻田12亩;又据《通典·食货典》等资料推算得知,天宝十四载(755)江南地区课户与不课户的比例分别约占当时总户数的60%和40%,进而可计算出... 详细信息

江南是唐代最重要的麻布生产中心。据《新唐书·地理志》相关资料可知,唐天宝间江南地区每户实有麻田12亩;又据《通典·食货典》等资料推算得知,天宝十四载(755)江南地区课户与不课户的比例分别约占当时总户数的60%和40%,进而可计算出唐天宝间江南地区年产麻布凡27 626 745.6端。唐代江南地区对麻布的需求紧迫而多样,一是可输纳赋税,二是充着衣料,三是成为日常用品(如布囊、麻袋等)的材料,四是充当货币职能等。江南地区麻布的产量及社会需求,从一个方面反映了唐代江南地区经济的繁荣,也为我国古代经济重心的南移提供了有力的佐证。

关键词：唐天宝间江南地区麻布产量社会需求

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Newly discovered Palaeolithic artefacts from loess deposits and their ages in Lantian,central China

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Chinese Science Bulletin 2014年第7期59卷 651-661页

作者： Shejiang Wang huayu lu Hongyan Zhang Xuefeng Sun Shuangwen Yi Yingyong Chen Gaike Zhang luda Xing Weigang Sun Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences Institute of Vertebrate Palaeontology and Palaeoanthropology The Chinese Academy of Sciences School of Geographic and Oceanographic Sciences Institute for Climate and Global Change Research Nanjing University Guizhou Provincial Institute of Cultural Relics and Archaeology University of Chinese Academy of Sciences Shaanxi Provincial Institute of Archaeology

Eight new Palaeolithic open-air sites were identified and 770 stone artefacts were collected from 2009 to 2011 in the Lantian area of the Bahe River valley, central China. Because the famous Homo erectus fossils were unearthed at the Gongwangling and Chenjiawo localities, and more than 30 Palaeolithic open-air sites were investigated in the 1960s in this region, the catchment of Bahe River is regarded as one of the most important hominin sites from the late early Pleistocene to the middle Pleistocene. These eight newly discovered open-air sites are located at the second(n = 6), third(n = 1) or higher terraces(n = 1) of the Bahe River. The Diaozhai section on the second terrace was sampled in detail. Two samples were collected for optically stimulated luminescence dating(OSL). The OSL results suggest that a buried lithic artefact layer at the Diaozhai site spans approximately 70–30 ka. The lithic assemblage analysis suggests that the stone artefacts were made of local pebbles/cobbles such as greywacke, quartz, sandstone and igneous rocks. The main percussion techniques that were used were direct hard hammer percussion and bi-polar techniques. The lithic artefacts comprise hammer stones, cores, flakes, retouched tools and flaking debris. Acheulian-type large cutting tools(LCTs) such as hand-axes, picks and cleavers were indentified in the Lantian region as well. This is the first time Acheulian-type LCTs from the late Pleistocene have been identified in this region. This study distinguishes age gaps between Western world and East Asian Acheulian-type tools.

关键词：旧石器时代蓝田地区黄土沉积年龄文物中国古人类遗址晚更新世

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先秦时期编织业刍议

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中国经济史研究 2018年第5期 5-15页

作者：卢华语西南大学历史文化学院

编织业是华夏文明的重要组成部分,是我国传统文化的瑰宝。2002年9月至12月,考古工作者对浙江萧山跨湖桥遗址进行第三次发掘时,出土了距今7 000—8 000年的编织物,证明我国编织的肇始最迟不晚于距今7 000—8 000年前,而其实际,当更悠远... 详细信息

编织业是华夏文明的重要组成部分,是我国传统文化的瑰宝。2002年9月至12月,考古工作者对浙江萧山跨湖桥遗址进行第三次发掘时,出土了距今7 000—8 000年的编织物,证明我国编织的肇始最迟不晚于距今7 000—8 000年前,而其实际,当更悠远。先秦时期,编织生产分官营和私营两大类,官营包括中央和地方两亚类,一般都是规模生产,以作坊形式进行;私营也有营利和自用两亚类,前者以个体或作坊形式生产,后者则主要是个体生产。无论官营和私营,由于时代不同,生产条件和环境不同,各个时代的生产类型及经营管理又各有不同内容及特点。编织品为政治生活、军事装备所必备,日常生活亦不可或缺。编织业不仅催生了纺织业,而且是社会生产的助推器,其作用和影响不容忽视。

关键词：先秦时期编织业官营私营助推器

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六朝商人诗及所反映的商品经济

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中国经济史研究 2005年第4期 112-119页

作者：卢华语西南大学历史文化与旅游学院 400715

六朝商人诗含以商人为题者、商人所写者、不以商人为题而实写商人者、借叙事抒情而涉及商人者等四种类型,其传递出的信息是:1.商人社会地位的变化;2.城市商业畸形繁荣;3.封建政权不抑富商巨贾,抑商、贱商主要针对中小商人,这为研究六朝... 详细信息

六朝商人诗含以商人为题者、商人所写者、不以商人为题而实写商人者、借叙事抒情而涉及商人者等四种类型,其传递出的信息是:1.商人社会地位的变化;2.城市商业畸形繁荣;3.封建政权不抑富商巨贾,抑商、贱商主要针对中小商人,这为研究六朝的商人和商业提供了有力的佐证。

关键词：六朝商人诗信息商业

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风成沉积物叶蜡氢同位素在揭示东亚季风区干湿变化中的原理及应用

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地球科学进展 2021年第1期36卷 45-57页

作者：梁承弘鹿化煜南京大学地理与海洋科学学院自然地理学系南京大学关键地球物质循环前沿科学中心江苏南京210043

沉积物叶蜡正构烷烃氢同位素是指示气候和环境变化的一种新的生物地球化学指标,由于其存在广泛、成因机制清晰、易于保存等特点,被认为是具有很大潜力的重建古环境的替代指标。分析了正构烷烃的形成过程与其氢同位素的分馏机制,讨论了... 详细信息

沉积物叶蜡正构烷烃氢同位素是指示气候和环境变化的一种新的生物地球化学指标,由于其存在广泛、成因机制清晰、易于保存等特点,被认为是具有很大潜力的重建古环境的替代指标。分析了正构烷烃的形成过程与其氢同位素的分馏机制,讨论了叶蜡正构烷烃氢同位素在不同气候区指示湿度变化的能力,总结了在东亚季风区半干旱区的一些应用案例。相比于风成黄土中其他气候代用指标,沉积物正构烷烃氢同位素更直接地指示了区域干湿变化,对区域气候和环境变化响应敏感,在长时间尺度上记录了水汽变化过程,并存在显著的太阳辐射岁差周期。正构烷烃氢同位素是一种理想的东亚季风区干旱半干旱地区湿度重建的代用指标,未来需要进一步研究大气降水同位素和本地分馏过程对其变化的控制规律,加强其在古气候定量重建中的研究应用。

关键词：正构烷烃氢同位素湿度重建黄土半干旱区东亚季风

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