Supergene and exotic Cu mineralization occur during periods of landscape stability in the Centinela Mining District,Atacama Desert

The Centinela Mining District (CMD), Atacama Desert (northern Chile), includes several mid‐late Eocene porphyry Cu deposits that contains supergene mineralization and provides access to a record of gravel deposits that host syn‐sedimentary exotic Cu mineralized bodies. By studying these gravels, we reconstruct the unroofing history and constrain the geomorphological conditions that produced supergene and exotic Cu mineralization. We present an integrated study based on stratigraphic and sedimentological data, lithology clast counts, ⁴⁰Ar/³⁹Ar and U/Pb ages from interbedded tuff layers and U/Pb detrital zircon geochronology data. To relate the gravel deposition episodes to the timing of the supergene mineralization, we provide in‐situ and exotic supergene mineral ages (40Ar/39Ar and K‐Ar). Six gravel units were deposited between the mid‐Eocene and the mid‐Miocene. The Esperanza gravels were deposited concurrently with the emplacement of porphyry Cu deposits at depth. The subsequent Tesoro I, II and III and Atravesado gravels register the unroofing of these deposits, from the advanced argillic zone to the sericitic and prophylitic hypogene zones. The Arrieros gravels register landscape pediplanation, that is, denudational removal and wear of the landscape to base level on a relatively stable tectonic regime, occurring roughly contemporaneous with supergene activity. The supergene mineral ages of the CMD define a time span (ca. 25–12 Ma) during which most of the supergene ages cluster in northern Chile. This time span corresponds with a period of warm and humid climate conditions in the southern hemisphere. We conclude that landscape pediplanation favours supergene mineralization and helps preserve the former supergene mineralized zones from significant erosion. Low erosion rates during pediplanation may constitute a necessary condition for the efficiency of the supergene processes in such semi‐arid climate.     

Climatic and halokinetic controls on alluvial–lacustrine sedimentation during compressional deformation,Andean forearc,northern Chile

The Salar de Atacama forms one of a series of forearc basins developed along the western flank of the Central Andes. Exposed along the northwest margin of the basin, a salt‐cored range, the Cordillera de la Sal, records the Mid‐Miocene to recent sedimentological and structural development of this basin. Sediments of the Mid‐Miocene Vilama Formation record the complex interaction between regional/local climate change, halokinesis and compressional deformation. This study reveals how these factors have controlled the facies development and distribution within the Salar de Atacama. Detailed sedimentary logging, cross‐sections and present day geomorphology through the northern Cordillera de la Sal have been used to establish a lithostratigraphy, chronostratigraphy and the regional distribution of the Vilama Formation. The Vilama Formation documents an increase in aridity with a hiatus in sedimentation from Mid‐Miocene to 9 Ma with initial uplift of the Cordillera de la Sal. From 9 Ma to 8.5 Ma deposition of a meandering fluvial system is recorded followed by a rapid decrease in sedimentation till 6 Ma. From 6 to 2 Ma, the deposition of extensive palustrine carbonates and distal alluvial–mudflat–lacustrine demonstrates the existence of an extensive lake within the Salar de Atacama. Post 2 Ma, the lake decreased in size and braided alluvial gravels associated with alluvial fans were widespread through the region suggesting a final shift to hyperarid conditions. By comparing the Vilama Formation with similar age facies throughout northern Chile and southern Peru, several shifts in climate are recognized. Climate signatures within northern Chile appear to be largely diachronous with the last regional event in the Mid‐Miocene. Since that time, humid events have been restricted to either Precordillerian basins or the Central Atacama. Within the Central Atacama, the final switch to hyperarid conditions was not till the earliest Pleistocene, much later than previously estimated within the region.     

Late Cenozoic geomorphologic signal of Andean forearc deformation and tilting associated with the uplift and climate changes of the Southern Atacama Desert (26°S–28°S)

We analyze remarkable examples of the large ( 10,000 km²) and local-scale ( 100 km²) landscape forms related to Late Cenozoic geomorphologic evolution of the Andean forearc region in the Southern Atacama Desert. We also consider the continental sedimentary deposits, so-called “Atacama Gravels”, which are related to the degradation of the landscape during the Neogene. Our analysis integrates 1:50,000 field cartography, Landsat TM images observations,  1:1000 sedimentary logging data, and 50 m horizontal resolution topographic data to reconstruct the Late Cenozoic geomorphologic evolution of this region and discuss the factors that control it, i.e., Miocene aridification of the climate and Neogene Central Andean uplift. We determine that the Precordillera was already formed in the Oligocene and most of the present-day altitude of the Precordillera was reached before that time. Afterward, five episodes of geomorphologic evolution can be differentiated: (1) the development of an Oligocene deep incised drainage system cutting the uplifted Precordillera (up to 2000 m of vertical incision) and connecting it to the Ocean; followed by (2) the infilling of deep incised valleys by up to 400 m of Atacama Gravels. This infill started in the Early Miocene with the development of fluvial deposition and finished in the Middle Miocene with playa and playa lake depositions. We propose that playa-related deposition occurs in an endorheic context related to tectonic activity of the Atacama Fault System and Coastal Cordillera uplift. However, the upward sedimentologic variation in the Atacama Gravels evidences a progressive aridification of the climate. Subsequently, we have identified the effects of the Middle–Upper Miocene slow tectonic deformation: the Neogene Andean uplift is accommodated by a tilting or flexuring of the inner-forearc (Central Depression and Precordillera) related to some hundreds of meters of uplift in the Precordillera. This tilting or flexuring results in (3) the Middle Miocene re-opening of the valley network to the Pacific Ocean. Upper Miocene aridification, from arid to hyperarid, induces alluvial fans backfilling in the Central Depression (4) resulting in up to 50 m of Atacama Gravel deposition. Finally, in response to an increase in the rate of tilting, a new phase of vertical incision (up to 800 m in the Precordillera) allows the development of the canyon that crosses the forearc (5).     

新疆硝酸盐矿床地质特征及成因研究进展

硝酸盐矿产资源在工农业领域应用广泛,世界范围内大规模的硝酸盐矿床主要分布于国内新疆和智利阿塔卡玛沙漠地区。目前,国内外学者就硝酸盐矿床氮来源与富集成矿的解释仍存有争议,尚未形成一个完善的硝酸盐成矿理论体系。简述了国内新疆硝酸盐矿床的地质特征与成因研究进展,通过与智利阿塔卡玛硝酸盐成因与成矿模式的对比,认为新疆硝酸盐矿床的成因成矿过程更复杂,进一步研究硝酸盐矿床有助于完善成矿理论体系,具有现实意义。     

Interdecadal fluctuation of dry and wet climate boundaries in China in the past 50 years

Based on the mean yearly precipitation and the total yearly evaporation data of 295 meteorological stations in China in 1951-1999, the aridity index is calculated in this paper. According to the aridity index, the climatic regions in China are classified into three types, namely, arid region, semi-arid region and humid region. Dry and wet climate boundaries in China fluctuate markedly and differentiate greatly in each region in the past 50 years. The fluctuation amplitudes are 20-400 km in Northeast China, 40-400 km in North China, 30-350 km in the eastern part of Northwest China and 40-370 km in Southwest China. Before the 1980s (including 1980), the climate tended to be dry in Northeast China and North China, to be wet in the eastern part of Northwest China and very wet in Southwest China. Since the 1990s there have been dry signs in Southwest China, the eastern part of Northwest China and North China. The climate becomes wetter in Northeast China. Semi-arid region is the transitional zone between humid and arid regions, the monsoon edge belt in China, and the susceptible region of environmental evolution. At the end of the 1960s dry and wet climate in China witnessed abrupt changes, changing wetness into dryness. Dry and wet climate boundaries show the fluctuation characteristics of the whole shifts and the opposite fluctuations of eastward, westward, southward and northward directions. The fluctuations of climatic boundaries and the dry and wet variations of climate have distinctive interdecadal features.     

Interdecadal fluctuation of dry and wet climate boundaries in China in the past 50 years

Based on the mean yearly precipitation and the total yearly evaporation data of 295 meteorological stations in China in 1951–1999, the aridity index is calculated in this paper. According to the aridity index, the climatic regions in China are classified into three types, namely, arid region, semi-arid region and humid region. Dry and wet climate boundaries in China fluctuate markedly and differentiate greatly in each region in the past 50 years. The fluctuation amplitudes are 20–400 km in Northeast China, 40–400 km in North China, 30–350 km in the eastern part of Northwest China and 40–370 km in Southwest China. Before the 1980s (including 1980), the climate tended to be dry in Northeast China and North China, to be wet in the eastern part of Northwest China and very wet in Southwest China. Since the 1990s there have been dry signs in Southwest China, the eastern part of Northwest China and North China. The climate becomes wetter in Northeast China. Semi-arid region is the transitional zone between humid and arid regions, the monsoon edge belt in China, and the susceptible region of environmental evolution. At the end of the 1960s dry and wet climate in China witnessed abrupt changes, changing wetness into dryness. Dry and wet climate boundaries show the fluctuation characteristics of the whole shifts and the opposite fluctuations of eastward, westward, southward and northward directions. The fluctuations of climatic boundaries and the dry and wet variations of climate have distinctive interdecadal features.     

中国干湿格局对未来高排放情景下气候变化响应的敏感性

气候变化影响下干湿状况的区域分异格局如何变化是一个重要科学问题。基于参与耦合模式比较计划第五阶段（CMIP5）的5个全球气候模式（GCM）,预估了RCP 8.5情景下未来百年中国干湿区面积的变化趋势,分析了干湿格局变化的敏感地区以及对气候变化响应的敏感性。结果表明：未来干湿格局变化以湿润区显著减少、干湿过渡区显著扩张为主要特征,特别是半湿润区面积在远期（2070-2099年）相对基准期（1981-2010年）增加了28.69%。升温2 ℃~4 ℃条件下,全国发生干湿类型转变的面积从10.17%增加至13.72%,尤其在淮河流域南部,这里主要受未来潜在蒸散增加的影响,湿润区向南明显退缩从而转变为半湿润区。总体上,随着未来升温加剧,中国干湿格局对气候变化响应的敏感性将可能增强。     

南岭同纬度带典型区域气候特征差异与成因分析

基于91个气象站观测值和大气环流模型CCSM3,对南岭同纬度典型区域的气候特征参数进行分析,并对未来不同区域的温度和降水进行预测,进一步探索净初级生产力对温度和降水的敏感性,并分析导致南岭同纬度带典型区域气候差异的可能原因。结果表明：1）南岭和同纬度其它区域呈现不同的干旱期和湿润期,撒哈拉沙漠、阿拉伯半岛沙漠和塔尔沙漠仅存在干旱期,墨西哥荒漠和南岭均存在湿润期,但两者湿润期出现的季节有差异。南岭在植物生长的春季和夏季雨热同期,而墨西哥荒漠雨水充沛的季节多在秋季。墨西哥除湿润期外,一年有两次干旱期,其中冬旱持续的时间较长。2）撒哈拉沙漠、阿拉伯半岛沙漠和塔尔沙漠的潜在蒸散、风速和日照百分率均高于墨西哥荒漠和南岭,但降水正好相反。墨西哥荒漠干季的水汽压与撒哈拉沙漠和阿拉伯半岛沙漠接近,低于该区域湿季及塔尔沙漠与南岭的值。3）在B1气候情景下,对2000―2099年5个阶段（每20年为一个阶段）与1981―2010年的温度和降水数据进行T-test检验发现,南岭同纬度5个典型区域的未来温度均呈极显著上升趋势（P＜0.001）,降水总体呈增加趋势,然而在不同阶段和区域也存在不同比例的显著减少和显著增加情况。4）通过比较5个区域是否存在温度或降水成为潜在生产力限制因子发现,南岭及同纬度的其它区域均为降水限制因子区域。其中,撒哈拉沙漠和阿拉伯半岛沙漠对降水的敏感性显著高于墨西哥荒漠、塔尔沙漠和南岭。5）南岭与同纬度其它区域气候迥异的原因除气候变化外,还包括海陆位置、人类活动干扰的强弱、地形地貌特征等因素。     

中国戈壁综合自然区划研究

中国戈壁广泛分布于北方的干旱与极干旱区域,直至目前尚未系统地开展戈壁分区研究。本文在综合分析戈壁特征与形成发生机制关系后认为,我国戈壁的最主要特征是地表砾质覆盖;表层具孔状漆漠结皮,其下具棕红色紧实层及石膏层;植物覆盖度极低,生长旱生极旱生灌木—半灌木。戈壁形成发生的区域仅限于干燥度4以上的干旱、极干旱区域。根据戈壁特征及发生条件的区域分异,选取干温指标、区域地质地貌建造指标、地表物质成因形态指标,将中国戈壁分布区划分为温性干旱极干旱戈壁区、暖性干旱极干旱戈壁区和青藏高原北部亚寒干旱极干旱戈壁区3个一级区(区),其下按区域地质地貌建造特征划分出9个二级区(地区),再按戈壁地表物质成因与形态差异划分出19个三级区(亚地区)。还可根据土壤和植被的地域分异进一步划分出若干个四级区(小区)。     

新疆地区沙漠形成与演化的古环境证据

通过回顾新疆沙漠形成演化过程的研究与进展,指出新疆构造地貌特征使塔里木和准噶尔两大盆地区域受行星系西风、海陆季风或地形山谷风等的焚风效应的影响,第四纪以来的气候环境格局总体表现为持续的干旱化过程并伴随次级规模的波动过程;盆地及其边缘风成沉积的形成,是对青藏高原隆升引起的全球气候环境变化尤其是亚洲内陆干旱化的响应。在塔克拉玛干沙漠的形成时代上,由于研究方法、对象和信息载体的不同,目前存在较多争议;来自沙漠边缘及腹地的古风成沉积及其年代学证据指示塔里木盆地边缘或腹地在第三纪时即已存在干旱性的气候和地表的风营力过程;但在沉积规模和连续性上,它们的存在是否代表大范围沙丘地乃至古塔克拉玛干沙漠的出现以及其后是否与现今规模的塔克拉玛干沙漠有继承关系,需要进一步的研究来解释。来自沙漠外围昆仑山北坡和天山北坡的风成黄土沉积表明现代规模的塔克拉玛干和古尔班通古特沙漠都是在中更新世以后形成的,并在末次冰期时经历了显著的气候变化,但不同区域有不同的干湿波动过程。     

中国气候和构造运动对花岗岩地貌的影响

Present granite landform characteristics and distribution are the integrated result of climate, tectonics and lithology. Various types of granite landforms in China signify climate zonality and differential vertical movement of earth surface, while published research results on Chinese granite landforms are very rare, especially in international journals. Based on the process analysis of chemical weathering and physical disintegration, four granite landform regions in China are classified according to the present climate regime. On the Tibetan Plateau, the cold and freezing climate induced periglacial landscapes; the northeast region is characterized by physical disintegration and low round mounds are widespread; in the northwest region controlled by arid climate, wind-carved minor landscapes are extremely prominent. The most spectacular granite landscapes in China are presented in southeast as a result of longtime chemical weathering under humid and warm conditions, as well as the differential uplift after Neogene. Correlating the weathering crust in southern China, Tibetan Plateau and India, a possible unified planation surface in Neogene is proposed. With corestones as indicators of original weathering front, the differential uplift extent of dissected planation surfaces can be estimated. At least three landforms implying uplift can be identified in southeastern China, with elevations of 300–400 m, 2000 m and 3600 m above the sea level respectively.     

Influence of climate and tectonic movements on granite landforms in China

Present granite landform characteristics and distribution are the integrated result of climate, tectonics and lithology. Various types of granite landforms in China signify climate zonality and differential vertical movement of earth surface, while published research results on Chinese granite landforms are very rare, especially in international journals. Based on the process analysis of chemical weathering and physical disintegration, four granite landform regions in China are classified according to the present climate regime. On the Tibetan Plateau, the cold and freezing climate induced periglacial landscapes; the northeast region is characterized by physical disintegration and low round mounds are widespread; in the northwest region controlled by arid climate, wind-carved minor landscapes are extremely prominent. The most spectacular granite landscapes in China are presented in southeast as a result of longtime chemical weathering under humid and warm conditions, as well as the differential uplift after Neogene. Correlating the weathering crust in southern China, Tibetan Plateau and India, a possible unified planation surface in Neogene is proposed. With corestones as indicators of original weathering front, the differential uplift extent of dissected planation surfaces can be estimated. At least three landforms implying uplift can be identified in southeastern China, with elevations of 300–400 m, 2000 m and 3600 m above the sea level respectively.     

试论青藏高原多年冻土类型的划分

本文采用综合分析与主导因素相结合的原则，以干燥度作为主要指标并参考年降水量，年平均相对湿度及气温较差等，结合地形因素将青藏庙的多年冻土划分为：湿润，亚湿润，半干旱，干旱和极干旱５种类型，并对各类型代表性和冻土地区进行分别论述。     

浑善达克沙地全新世中晚期地层化学元素特征及其气候变化

在系统考察浑善达克沙地的基础上,选择沙地北部锡林浩特全新世地层剖面样品进行全量化学元素分析和¹⁴C年代测定;并根据地球化学特征的变化,推论8kaBP以来的气候变化过程。结果表明,8kaBP以来区域气候具有干旱化的趋势,并经历了6个冷干暖湿变化旋回,气候变化可划分为4个阶段:8060~7100aBP,气候寒冷干旱;7100~5500aBP,气候温暖半湿润;5500~3500aBP,气候发生频繁的干湿波动;3500aBP特别是2200aBP以来气候以干旱为主。     

阿拉善东南部自然环境演变与地面流沙路径的分析

阿拉善东南部包括腾格里和吉兰泰两区。腾格里和吉兰泰两区在晚更新世均是一个湖域广阔的淡水大湖。之后 ,吉兰泰大湖和腾格里大湖在封闭状态下 ,一方面因气候转为干旱、蒸发致使湖域减小直至完全干涸 ,露出的湖底在风的吹蚀作用下形成沙漠 ;另一方面在“狭管效应”作用下 ,由吉兰泰西部来自雅玛雷克沙漠和在腾格里西部来自巴丹吉林沙漠的风吹沙沿着地形上狭窄通道的侵进是加剧这两个湖盆沙漠化的另一个重要因素。对此 ,基于遥感的研究提出了研究区西缘挡沙固沙 ,建立生态保护带 ,区内分块治理、有效控制流沙的侵进和扩张以及通过改善下垫面性质来控制沙尘的发生与强度 ,逐步改善生态环境的措施。研究区风沙的治理 ,对于缓解京津沙尘灾害具有重要的意义。     

末次盛冰期以来库布齐沙漠环境变化

中国北方季风边缘区沙漠/沙地如何响应气候变化及其反馈研究对于理解干旱半干旱地区现代地表过程及其未来环境演变趋势有重要的科学意义。库布齐沙漠作为中国北方季风边缘区中东部唯一的以流动、半流动为主的沙漠,现代地表景观与周围沙地（如毛乌素沙地、浑善达克沙地、科尔沁沙地等）明显不同。晚第四纪以来库布齐沙漠与季风边缘区中东部沙地环境演化过程到底是否一致,其湿润期究竟发生于何时,尚存颇多争议。区域风成沉积和湖泊沉积记录研究得出的结论明显不同,存在中晚全新世和早中全新世湿度最优期的分歧。对库布齐沙漠风成沉积年代-岩性的概率密度分布（Probability Density Function,PDF）进行处理,与周边沙地风成沉积和湖泊沉积古环境记录进行了对比分析。结果表明：末次盛冰期以来库布齐沙漠与季风边缘区中东部沙地环境演化过程总体一致,27.6—10 ka和晚全新世（2—0 ka）,风沙堆积强烈,气候相对干旱;早全新世（10—6 ka）古土壤渐次发育,沙丘逐渐被固定,湿度增加,环境状况有所改善;中全新世（6—2 ka）古土壤广泛发育,沙丘经历固定成壤,气候最为湿润。区域环境演变过程受控于低纬太阳辐射和高纬冰量变化的双重制约。     

Evolution of the great river systems of southern Asia during the Cenozoic India–Asia collision: Rivers draining north from the Pamir syntaxis

During uplift of the Tibetan plateau and surrounding ranges, tectonic processes have interacted with climatic change and with local random effects (such as landslides) to determine the development of the major river systems of Asia. Rivers draining northward from the Pamir syntaxis have three distinctive patterns that are controlled by different tectonic and climatic regimes. West of the Pamir, the rivers have moderate but irregular gradients and drain northwards to disappear into arid depressions. Relatively steady uplift of the Hindu Kush in northern Afghanistan allowed rivers to cut across the rising ranges, modified by the shear along the Harirud fault zone, local faulting, and by increasing rain-shadow effects from the rising Makran. In the transition to the Pamir the rivers have steeper but more even gradients suggesting more even flow and downcutting during uplift, possibly related to larger glacial sources. In the central Pamir, only one antecedent river, the Pyandzh appears to have kept its northward course with compression and uplift of the indenter, and its course strangely corresponds with a major geophysical boundary (a distorted subducted slab) but not a geological boundary: the other rivers are subsequent rivers developed along deformation fronts during development and northward displacements of the Pamir structural units. The above areas have sources north of the Cretaceous Karakorum–South Pamir Andean margin. On the eastern flank of the Pamir, in the Kunlun and northern Tibetan plateau, the rivers rise similarly north of the Cretaceous Andean margin of southern Tibet, but then flow with low gradients across the plateau, before cutting and plunging steeply down across the Kunlun to disappear into the arid Tarim. These steep profiles are the result of late Neogene uplift of the northern Tibetan plateau and Kunlun possibly modified by glacial diversion and river capture. The drainage history of the Pamir indenter can be reconstructed by restoring the gross movements of the plates and the tectonic displacements, uplift, and erosion of individual tectonic units. Most important changes in drainage took place in the last 10 million years, late Miocene to Quaternary times, as the Pamir syntaxis developed.     

Holocene climatic change reconstructed from trace elements of an aeolian deposit in the southeastern Mu Us Desert,northern China

In semi-arid and arid desert regions of northern China, aeolian deposits document the framework variation of an Asian monsoon during the late Quaternary. However, there is still a lack of detailed data pertaining to Holocene Asian monsoonal variation especial in the modern Asian summer monsoonal boundary belt. In this study, we reconstructed Holocene millennial-scale climatic changes in the Mu Us Desert, northern China, through systematic analysis of the variation of trace elements(324 samples) in different lithological units of the palaeosol-aeolian sand deposit, in combination with14 C and OSL chronology. Statistical results, correlation and clustering analysis indicate that the high content of 11 trace elements(V, Y, Cr, Nb, P, Mn, Cu, Zr, As, Ni and Rb, represented by P) and lower Sr content corresponding to periods of palaeosol development, marked increase of vegetation, weathering degree, and enhanced Asian summer monsoonal strength. In contrast, their opposed variation are coincident with accumulated aeolian sand layers, implying weaker summer monsoons and less geochemical weathering and degraded vegetation. These associations can be considered as signaling regional humid and dry changes of the Holocene environment. Accordingly, relatively arid conditions dominated the region before 7.2 ka, and there was an optimal humid climate in 7.2-4.6 ka. Afterwards, the climate became obviously dry, accompanied with several cycles of relatively wet and dry, such as relatively wet intervals around 4.1-3.7 ka, 3.5-3.3 ka and 2.5 ka. In addition, six millennial-scale dry events were recorded, and these events were consistent with weaker Asian summer monsoonal intervals in low latitudes, declined palaeosol development and precipitation in middle latitudes, as well as increased winter monsoon and periodic ice-rafting events in high latitudes of the Northern Hemisphere, within limits of accuracy of existing dating ages. This possibly suggests a noteworthy synchronism between millennial-scale climatic changes in this region and on a global scale.     

塔克拉玛干沙漠腹地晚冰期以来的环境与气候变化

通过对塔克拉玛干沙漠腹地地层剖面的沉积类型、孢粉、ｐＨ值、有机质、ＣａＣＯ＿３和地球化学气候指标Ｃ等分析，认为本区晚冰期以来一直处于荒漠环境，气候变化可划出四个阶段：１３－１０ｋａＢ．Ｐ．气候寒冷。温凉，干旱，湿度相对后期较大；１０－８ｋａＢ．Ｐ．气候温暖干旱，湿度相对减小；８－３ｋａＢ．Ｐ．气候炎热干旱，湿度最小；３ｋａＢ．Ｐ．至今气候温暖干旱，湿度较前增大，气候及环境与今相似。     

青藏高原东北部共和盆地末次冰消期以来古植被和环境演变(英文)

Paleoenvironmental history in the monsoonal margin in the northeast Tibetan Pla-teau provides important clue to the regional climate. Previous researches have been limited by either poor chronology or low resolution. Here we present a high-resolution pollen record from a 40.92-m-long sediment core (DLH) taken from Dalianhai, a terminal lake situated in the Gonghe Basin, the northeast Tibetan Plateau for reconstructing the vegetation and climate history since the last deglacial on the basis of a chronology controlled by 10 AMS 14C dates on plant remains preserved in the core sediments. The pollen assemblages in DLH core can be partitioned into 6 pollen zones and each zone is mainly characterized by the growth and decline of tree or herb pollen percentage. During the periods of 14.8-12.9 ka and 9.4-3.9 ka, the subalpine arboreal and local herbaceous pollen increased, indicating the subalpine forest developed in the surrounding mountains and a desert steppe or typical steppe developed in Gonghe Basin under a relatively moister climate. During the periods of 15.8-14.8 ka, 12.9-9.4 ka and 3.9-1.4 ka, the forest shrank or disappeared according to different degrees of aridity, and the desert steppe degraded to a more arid steppe desert in the basin, indicating a dry climate. After 1.4 ka, vegetation type around Dalianhai was mainly dominated by steppe suggested by increased Artemisia. Our results suggested the climate history in this region was dry from 15.8-14.8 ka, humid from 14.8-12.9 ka and dry from 12.9-9.4 ka, after which the climate was humid during 9.4-3.9 ka, followed by dry conditions during 3.9-1.4 ka and humid conditions in the last 1.4 ka. The change of pollen percentage and the evolution of palaeovegetation in Dalianhai since the last deglacial were similar to those recorded in Qinghai Lake. The forest expanded in the mountains around Dalianhai during the B?l-ling-Aller?d period, shrank during the Younger Dryas and the early Holocene, then it devel-oped and reached its maximum in the mid-Holocene. During the late Holocene, the vegetation began to shrink till disappearance. However, the timing of forest expansion in the Holocene lagged behind that of Qinghai Lake, and this spatial heterogeneity was probably caused by the different forest species between these two places. The maximum of forest development in the mid-Holocene was inconsistent with the period of stronger summer monsoon in the early Holocene indicated by stalagmite records, the reason might be related to the complexity of vegetation response to a large-scale climatic change.