共查询到18条相似文献，搜索用时 171 毫秒
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云南石林洞穴发育特征初析 总被引：5，自引：0，他引：5
石林位于滇东喀斯特高原南部，喀斯特极其发育，以发育了典型的石林地形面闻名退途，倍受国内外喀斯特学者的关注。研究区内喀斯特洞穴极为发育，洞穴在发育分布上受到区域碳酸盐岩地层分布的控制，表现出洞穴分布的相对集中性、洞穴发育对地层的选择性和洞穴发育的成层性等特征。洞穴发育规模绝大多数为中小型洞穴；洞穴多为现代地下洞河，埋藏浅且多天窗，并且洞穴的发育延伸方向明显受裂隙构造的控制，有强烈的方向性。通过对石林地区喀斯特洞穴的发育延伸方向明显受裂隙构造的控制，有强烈的方向性。通过对石林地区喀林斯特洞穴发育条件、洞穴发育规模、分布特征和洞穴发育的古地理环境特征的条件，论述了石林地区洞穴的发育特征。 相似文献
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中国喀斯特地貌的演化模式 总被引：15，自引：0，他引：15
中国喀斯特地貌的发育与岩性密切相关,并受许多因素的影响与控制。特别是新生代的两个构造事件和更新世的五次气候变换,都影响了喀斯特的发育。在计算典型喀斯特地区的上升、沉降、溶蚀与沉积等速率的基础上,本文重点探讨了喀斯特地貌演化的八个模式。 相似文献
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贵州省独山南部喀斯特谷地、槽谷纵横交错,地下河系十分发育。本文从构造体系、构造应力场对喀斯特地貌发育的控制入手,着重探讨了不同期的构造应力场网络及构造节理变形网络对喀斯特地貌及喀斯特地下水网络的控制,并用数理统计的方法探讨了二者的相关性。 相似文献
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喀斯特地貌研究进展与趋势 总被引：30，自引：1，他引：29
我国喀斯特地貌研究在 2 0世纪后半叶取得了巨大进展 ,特别自 80年代 ,喀斯特与物理、化学、生物学、数学等学科相结合 ,借助于计算机和先进的测试技术 ,开辟了许多研究领域 ,加速了喀斯特地貌理论与应用的发展。本文着重评述了喀斯特地貌的演化 ,喀斯特溶蚀强度与速率 ,深部喀斯特发育机理 ,生物喀斯特和喀斯特与古环境等方面的新进展 ,展望了 2 1世纪初将在喀斯特生态系统、古环境与全球变化研究、风景旅游洞穴环境的改善与景观风化的防治、实验和量化喀斯特地貌的研究等方面将得到加强和取得丰硕成果。 相似文献
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The property, age and formation environment of the palaeokarst in Qinghai-Xizang Plateau 总被引：1，自引：0，他引：1
The karst landforms distributed on the Qinghai-Xizang (Tibet) Plateau can be genetically classed with the Tertiary underground
karst, which were gradually exhumed to the surface with the uplift of the plateau during Quaternary period. The relative deposits
of the Tertiary palaeokarst processes, such as the residuum and speleothem, were discovered recently in the southern and southeastern
fringe areas of the plateau, where has geological-currently been disintegrated by the headward erosion processes of the modern
river systems. The major chemical components of the clay portion of the residuum consist mainly of SiO2, A12O3 and Fe2O3. The clay minerals composition of the clay portion belongs to illite-kaolinite pattern for most of the residuum samples,
and kaoliniteillite pattern for a few of the samples. It can be judged from the silicic acid index and the clay minerals composition
that the formation of the residuum of the Plateau was in its initial phase. However, such a lower chemical weathering index
only reflected the weathering degree in the bottom or lower parts of the lateritic weathering crust. The relatively intensive
chemical weathering processes of the surface layers of the lateritic weathering crust could be logically speculated. The surface
feature textures of quartz grains in the residuum were formed mainly by the chemical erosion, which revealed a long-term humid-tropical
environment when the residuum and the palaeokarst formed. 相似文献
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Clearing up sediment and regolith on the foundation of the dam in the Three Gorges of the Yangtze River in 1999, riverbed
were exposed. On the basis of weathering granite regolith sampled from different portions of the valley landforms, by analysing
total chemical contents with X rays fluorescent slice and calculating proper value of chemical element transferring ratio
and intensity, the transferring law of chemical elements in different portions of the landforms were concluded: 1) In various
landforms of the river valley, the process of desilication is not distinct; 2) in weathering granite regolith of riverbed,
easy soluble CaO and MgO are relatively enriched whereas A12O3 tends to decrease. The enriching rate of Fe2O3 is the greatest in various landforms of the river valley; 3) in weathering granite regolith of flood-plain, K2O and MgO contents are relatively enriched; 4) the weathering granite regolith of valley slope is a typical north subtropical
weathering regolith, and its chemical weathering degree is in the transition phase from early to middle period; and 5) there
is an opposite layer where K2O is relatively leaching and Na2O relatively enriching in 6.5 m depth of all weathering granite regolith. 相似文献
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The varicolored hills in the northern foothills of the Qilian Mountains of northern China, in the Hexi Corridor of Gansu Province's Sunan Yugur Autonomous County, have given this region a unique geomor... 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
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Wei Ye Qu Chen Lidong Zhu Fengquan Li Tianyang Wang Longjuan Cheng Yunxia Zhang 《Journal of Paleolimnology》2018,59(2):263-278
A long-standing controversy exists concerning the spatial and temporal characteristics of Holocene climate change in China. Zhejiang is located in the southeast of China, where the East Asian monsoon dominates the climate and a Neolithic culture flourished. In recent years, geographers have debated the climatic conditions existing at the time of the Neolithic cultures. This study reconstructed the sedimentary environment between 11.30 and 4.17 cal ka BP based on a multi-proxy analysis of a 14.3 meter sediment core, drilled in Beihuqiao, Zhejiang Province, China. The results show: (1) The climate was getting warm between 11.50 and 8.77 cal ka BP. Grain size became finer from the bottom to the top layer, accompanied by an increase in the chemical index of alteration (CIA), Mg/Sr ratio, the percentage of clay, pollen concentrations, and a decrease in SiO2/Al2O3 ratio, and the value of bases–alumina (ba), as well as other trace elements. (2) Between 8.77 and 7.99 cal ka BP, the sediment is composed of gray-yellow and gray silt. The percentage of CaO and the ratio of CaO + Na2O + K2O to Al2O3 is much higher. The pollen concentration sharply decreases. The climate was cold and dry in the early stages of this period, but became relatively warmer and wetter in the later stages. (3) The Holocene Climatic Optimum occurred at 7.99–5.68 cal ka BP. Higher contents of clay, total Fe2O3, Al2O3, CIA, the chemical proxy of alteration, pollen concentration, evergreen pollens, and high values of Mg/Sr are observed at this stage, coinciding with a lower SiO2/Al2O3 value, (CaO + Na2O + K2O)/Al2O3 ratio, and an obvious reduction in silt/clay, and SiO2 and CaO concentrations. (4) During the period 5.68–4.17 cal ka BP, the temperature in the study area declined in a stepwise fashion. The grain size became finer, and the Mg/Sr ratio decreased gradually. 相似文献
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旧石器时代至商周时期贵州遗址空间分布及其自然环境背景 总被引：2，自引：0，他引：2
根据对贵州230 处遗址的时空变化分析发现, 贵州旧石器时代遗址集中分布在中部、西北部和黔西南等喀斯特发育的高海拔区域。至新石器时代, 遗址仍集中分布在中部、西北部和黔西南地区, 但南部、东部等沿河地带和中西部的山间坝子开始有遗址分布。到商周时期, 遗址主要分布在沿河地带和山间坝子里。其中, 东部和南部海拔低于1000 m的地区遗址多分布在沿河地带, 而西部和北部海拔高于1000 m的地区遗址则分布在山间坝子。贵州位于亚热带湿润气候区, 气候环境的冷暖干湿波动对从事渔猎、采集及原始农业生产的古人类影响不大, 人类居住空间变化更多的与贵州特殊的自然地理背景有关, 特别是喀斯特地貌发育及适宜农业生产地方的空间差异, 对贵州旧石器至商周时期的遗址分布影响显著。旧石器时代人类以采集和渔猎为生, 临近水源的天然溶洞是人类居住的首选。随农业的出现和发展, 便于农耕的沿河地带和山间坝子成为人类的生活居住地。故新石器时代, 贵州先民居住呈现洞穴和河流阶地或山间坝子并存;至商周时期, 农业成为人类的主要经济生产方式, 人类主要居住在沿河地带和山间坝子里。 相似文献
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中国地貌与第四纪研究的近今进展与未来展望 总被引：3，自引：0，他引：3
近年来,在来自国民经济建设巨大需求的推动下,我国地貌与第四纪学服务于国民经济建设,取得了长足的进展.本文对近年来(主要为2006-2008年间)我国在地貌与第四纪方面所取得的主要进展进行了综述,包括构造地貌、流水地貌、风沙地貌、冰川地貌、河口与海岸地貌和第四纪环境演变方面的进展.同时,还指出了学科发展中存在的问题.文中对未来发展进行了展望,提出了推动学科发展的若干建议:(1)加强地貌学基本理论研究;(2)加强应用地貌研究,更好地为国家建设的重大需求服务;(3)加强地貌学的实验研究;(4)加强人才队伍建设. 相似文献