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南京汤山葫芦洞是著名的南京直立人化石发现地,洞穴碎屑堆积与演化研究是该地点研究中的薄弱环节。本文应用统计学方法分析了该洞穴4个剖面碎屑堆积氧化物和植硅体化石记录,结合洞穴堆积物特征厘清了各剖面间地层对比关系;借助地质雷达等物探技术反演了洞穴东部埋藏堆积的空间结构和特征,进而结合年代学研究成果,将洞穴碎屑堆积自下而上划分为7层,建立了洞穴碎屑堆积剖面与埋藏碎屑堆积间的对比框架。受气候环境演变、洞穴内部动力系统变化以及侵蚀基准面局部调整的影响,洞穴侵蚀堆积的发育可分为洞穴北侧堆积、东部堆积、南裂隙堆积、中部锥状体堆积和西部堆积5个阶段。洞穴演化过程时空上的显著迁移特征及洞穴宜居性差,暗示葫芦洞并非是早期直立人的居住地。 相似文献
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南京汤山猿人生存古环境重建探讨 总被引：7，自引：1，他引：6
由铀系法测定的５组化石年代数据表明,南京汤山猿人年代为２８０￣４３０ｋａＢ．Ｐ．之间;以剑齿象,李氏野猪,肿骨鹿,葛氏斑鹿、三门马等为主的古动物群化石,证实了南京猿人生活在中更新世中期偏晚,距今约３５０ｋａ左右。鉴定的孢粉主要为喜暖湿、暖干的落叶阔叶与针叶及蕨类混合林以及偏干凉的（松）针叶林、既未发现反映寒冷的云杉、冷杉、也未发现反映干旱的黄连木,表明本区猿人生存时并未经历中更新世冰期时的冰川环境 相似文献
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黄山第四纪泥砾沉积物分形结构特征与沉积环境分析 总被引：13，自引：0，他引：13
黄山第四纪泥砾沉积物粒度组成的分维值介于２．７０８￣２．７５３之间,非常接近古泥石流堆积物粒度组成的典型分维值２．７５。结合沉积特征,表明该类沉积物属第四纪间冰缘环境下的稀性泥石流沉积,其形成过程与季风型冰缘环境有关,是两种环境综合作用的结果。 相似文献
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青藏高原灰岩出露面积不广,但具多种成因的喀斯特形态。现代山区的石峰等是由寒冻风化和冰川作用所形成,属冰缘冰川喀斯特;高原内部的许多洞穴及其堆积物,以及东南部的丘陵洼地等由溶蚀侵蚀作用所形成,属古喀斯特;高原内部和边缘地区,在钙华或河成钙华形成中,生物残体仅起凝结核作用,喀斯特泉物理化学性质的变化起决定作用。因此青藏高原兼有在现代气候条件下和古气候条件下形成的喀斯特。 相似文献
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PER HOLMLUND BOGDAN P. ONAC MARGARETA HANSSON KARIN HOLMGREN MAGNUS MÖRTH MART NYMAN AUREL PERSOIU 《Geografiska Annaler: Series A, Physical Geography》2005,87(1):193-201
ABSTRACT. The ice block in Scarisoara Cave, NW Romania, is preserved due to unusual climate and permafrost conditions within the cave. The air temperature in the cave is governed by the winter cold, the cooling effect of the ice block, and only to a minor extent influenced by summer temperatures. At present, the ice block is slowly thinning, but the present-day climate is sufficiently cold to preserve the permafrost conditions caused by the cold air trapped in the cave. In February 2003 a 22.5 m long ice core was recovered from the ice block. Approximately 200 ice layers have been identified by visual examination. Ice crystallographic analyses indicate a steady growth of ice crystals with depth and there is no sign of deformation. Carbon-14 dates on wood-related samples collected from a natural vertical exposure of the ice block indicate that the ice spans more than 1000 years. Observations on the exposure indicate that a basal melting phase may have occurred in the past. 相似文献
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东南极大陆沿岸的维斯特福尔德丘陵(68°22'～68°40'S,77°55'～78°30'E)和西南极乔治王岛南端的菲尔德斯半岛(62°08'～62°20'S,58°45'～58°58'W)的气候条件不同。前者属于极地大陆性气候,气温低,冬季严寒,干燥、风大,夏季较短;后者属于极地海洋性气候,气温不很低,湿润、风小,夏季较长。因此,两地的冰缘地貌的组合类型及其发育过程存在明显的差异。前者冰缘地貌单一,发展速度较慢;后者冰缘地貌复杂多样,发展速度较快。 本文根据实地观测资料,对极地大陆型和极地海洋型两类冰缘地貌作一些比较,并且提出,年冻融日数是决定冰缘作用强弱的最重要指标。 相似文献
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Human-induced climatic warming will have major impacts on permafrost, which presently underlies half of Canada's land mass. The adaptation of the northern environment and its physical processes to the altered climate may be contemporaneous or may lag behind climatic change. The extent of permafrost will diminish, accompanied by modifications of the land surface through thermokarst or mass wasting. Streamflow regimes, sediment transport, coastal flooding and erosion will be affected. The magnitude of most components of the water balance will be altered. More research is needed to understand how the permafrost environment behaves during the transient phase, and the problem of permafrost adaptation should be addressed holistically. [Key words: climatic change, frozen ground, ground ice, hydrology, permafrost, periglacial geomorphology, water balance.] 相似文献
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南设得兰群岛是晚中生代以来古太平洋板块向南极板块俯冲消减过程中形成的,目前对整个群岛的地层特征及沉积演化无统一认识。通过归纳总结国内外研究成果,认为该群岛出露的地层具明显的时空规律。群岛主体的西南部出露上侏罗统-下白垩统,发育海底扇、深海、斜坡裙、扇三角洲等沉积相,相伴随的火山作用主要为钙碱性玄武岩和玄武安山岩的喷发,记录了弧前盆地-火山岛弧的演化过程;群岛主体的东北部主要出露上白垩统-下渐新统,其中上白垩统-始新统发育一套玄武质熔岩、火山碎屑-沉积岩建造,为温暖气候下的陆相沉积,火山活动具有岛弧拉斑玄武岩与钙碱性火山岩的过渡性质。渐新统-下中新统则记录了从间冰期正常海相到冰期冰海相沉积的转变过程。 相似文献
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《极地研究》1992,3(2):1-7
Some weathering observation sites were set up at different height and face in Great Wall Station area of King Geroge Island, Antarctica, since 1989. Baced on the data series obtained from 1987-1991, the relationship between physical weathering of rock and season, height, face are discussed in this paper. We also compare the results to that of other periglacial area in the world in order to know the special features of King George Island in physical weathering of rock. The rock weathering in south-east face of sea stack is higher than that of north-west face in same environment. Get rid of influence of elevation, rock type, weathering time and organisms, the main reason which caused physical weathering of this area is climate and orientation of rock. The King George Island of Antarctica belong to high latitude area. The temperature time of below zero is 6-8 months in a year, so the process of freeze-thow is restricted. Compared with other periglacial area in the world, the weathering rate of rock is midd 相似文献
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THE CASE STUDY ON THE EFFECT OF CO_2 IN CAVE ATMOSPHERE ON STABILITY OF SPELEOTHEM SCENERY IN YAOLIN CAVE, ZHEJIANG PROVINCE, CHINA 总被引：1，自引：0，他引：1
Song Linhua Yang Jingrong Lin Junshu Group of Karstology Speleology Institute of Geography CAS Beijing People’s Republic of ChinaWang Laihong Administration of Yaolin Cave Tonglu County Zhejiang Province People’s Republic 《地理学报(英文版)》1997,(3)
ＴｈｅｖｉｓｉｔｏｒｓｇｉｖｅｔｈｅｃａｖｅｅｎｖｉｒｏｎｍｅｎｔａｇｒｅａｔｄｅａｌｏｆＣＯ2.ＡｖｅｒａｇｅＣＯ2ｃｏｎｔｅｎｔｏｆｔｈｅｖｉｓｉｔｏｒｓｉｓ13,00015,000ｐｐｍｉｎｔｈｅｂｒｅｅｄｉｎｇａｎｄｏｎｅｖｉｓｉｔｏｒｂｒｅｅｄｓ40ｌｉｔｒｅｏｆＣＯ2ｐｅｒｈｏｕｒ.ＴｈｅｖｉｓｉｔｏｒｓｓｔｒｏｎｇｌｙｉｎｆｅｒｅｎｃｅｔｈｅＣＯ2ｃｏｎｔｅｎｔｉｎｔｈｅｃａｖｅａｔｍｏｓｐｈｅｒｅ.Ｉｎｓｐｒｉｎｇ,ＣＯ2ｃｏｎｔｅｎｔｗａｓ500-600ｐｐｍｉｎＮｏ.1ａｎｄＮｏ.2ｃｈａｍｂｅｒｓａｔ8:008:… 相似文献
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Characteristics and Altitudinal Distribution of Periglacial Decay Phenomena in the Massif of Rondane,Central Norway 
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下载免费PDF全文 Riwan Kerguillec 《Geografiska Annaler: Series A, Physical Geography》2015,97(2):299-315
The Norwegian massif of Rondane is part of the Scandes Mountains and is subject to polar, oceanic and continental influences. Because of its climatic context and its quartzitic structure, the massif has one of the thickest functional periglacial belts in Europe (1200 m). This belt is not fixed considering its translation in altitude since the end of the Little Ice Age. This mobility is continuing and involves periglacial decay dynamics which are revealed by numerous and various periglacial forms in the field. Because of their frequency in the massif and also their sensitivity to climate fluctuations, earth patches and small non‐sorted circles have a diagnostic value for current periglacial climate fluctuations. The major aim of this study is to propose several indicators of this periglacial decay and to highlight its consequences on periglacial belt mobility because these landforms enable the delimitation of a critical belt of decay in the massif. 相似文献
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利川南坪泥炭形成的环境分析 总被引：1，自引：0，他引：1
根据钻孔、孢粉分析、粘土矿物X射线分析、14C测年等资料,本文讨论了鄂西南山原利川一带玉木亚间冰期以来气候波动的历史,分析了在亚热带高压带喀斯特作用和山地条件下,泥炭形成的环境特点。 相似文献
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Located near the southeastern limit of Africa, the Lesotho‐Drakensberg and associated escarpment is the highest range of African mountains south of the massifs in Tanzania. At the escarpment summit and on the adjacent high peaks, the climate is generally interpreted as marginal periglacial yet few data, specifically rainfall and temperature, exist on record at these altitudes. Climatic data from two temporary field stations on the escarpment edge, one of which is the highest rainfall station yet on record in southern Africa, provide contemporary surface‐climate conditions. Mean annual rainfall recorded between 2001 and 2005 averages 767.8 mm at Sani Pass summit (three complete years), and 753.2 mm on Sentinel Peak (two complete years); these values are less than those recorded for the same period in the mountain foothills. Even though rainfall is slightly below long‐term rainfall averages for the area due to a marginally dry spell, the data show that earlier estimates of between 1000 mm and 2000 mm rainfall per annum on the escarpment are too high. A measured mean air temperature of 5.8°C at Sani Pass, however, falls within the range estimated for the escarpment summit. Frost cycles in air and at the soil surface are frequent in winter, but absent in soil for summer, and no long‐duration surface‐soil freeze was measured. Temperatures thus confirm the marginal periglacial nature as postulated for previously, but precipitation data indicate a dryer environment than anticipated. Palaeoenvironmental scenarios, notably arguments for former glaciation based on extrapolations from somewhat exaggerated contemporary precipitation values, thus require re‐consideration. 相似文献
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本区位于东昆仑山腹地,青藏高原多年冻土区的北缘。区内海拔高,地形相对高差较大,气候寒冷而较干旱。故冰缘作用强烈,冰缘现象种类繁多。本区冰缘作用及其形态类型的分布具明显的垂直地带性。自高至低有4个冰缘作用带,各带内冰缘现象不同。区内冰缘现象的动态变化相当复杂,这与环境条件有关,主要决定于自身的生成条件。 相似文献
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基于遥感与SRTM的青藏高原冰缘地貌信息提取方法——以1 ∶ 100万标准分幅拉萨幅(H46)为例 总被引：5，自引：0，他引：5
根据模型和分布函数,本文首先依据多年平均气温、地温和SRTM等数据对研究区域冰缘地貌的分布范围进行分别提取,并利用遥感数据和人工解译方式对其进行了修正。在此基础上,采用一定指标,利用SRTM数据对冰缘地貌次级类型(如起伏度、海拔高度和坡度等)进行了提取,从而完成研究区域冰缘地貌信息的提取。研究结果表明:①研究区域冰缘地貌总面积约5.15×104km2,主要分布在研究区域的西北部和西南部,另外在东北部也有少量分布;通过提取,研究区域中最重要的冰缘地貌类型是冰缘作用的中起伏缓极高山,面积约0.82×104km2,分布范围较广。②冰缘地貌的分布与海拔高度、气温和地温等有密切的关系,基于此提取的结果可为冰缘地貌的解译提供一定的参考;由于青藏高原气象站点较少,数据精度较低,自动提取精度受到很大限制,因此进行人工解译修正是非常重要和必不可少的。 相似文献
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试论青藏高原多年冻土类型的划分 总被引：5，自引：1，他引：5
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。 相似文献
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本文通过对西藏高原洞穴堆积物的粘土矿物组合特征的分析,初步探讨了喀斯特地貌形成的古地理环境。喜马拉雅山北坡旧定日东山洞穴堆积物是较温湿的森林草原环境下的产物,新定日西侧遮普若山北坡洞穴堆积物则是在高寒草甸环境下形成的;拉萨西南曲水大佛后溶洞堆积物形成于湿热的亚热带气候环境,而拉萨西山洞穴堆积物却形成于较温湿的草原环境;唐古拉山南坡安多一带的洞穴堆积物则是在高寒的草甸环境下形成的。并以此研讨了西藏高原喀斯特的成因和时代。 相似文献