共查询到19条相似文献，搜索用时 125 毫秒
1.
关于南国冰臼群成因的商榷之二 总被引：7，自引：1，他引：7
南国冰臼群分布区大量冰川堆积、冰川条痕石及变形砾石的发现，再次有力地证明是“冰臼”不是“壶穴”的正确结论，由冰川漂砾经融冻作用形成的“石海”，与化学风化作用产生的花岗岩“石蛋”地貌特征，有天渊之别，不应混为一谈；边滩是由河流冲积物组成，不能与基岩冰床相提并论；圆滚水钻与急流旋涡及风蚀作用，形成的动力学性质、方向和方式完全不同，不该阴错阳差；节理、构造只影响冰臼的形态和发育程度，不是控制形成的动力学性质、方向和方式完全不同，不该阴错阳差；节理、构造只影响冰臼的形态和发育程度，不是控制冰臼的发育部位，不致于是非不辨，南国地区古冰川遗迹的大量发现，证明距今约二三百万年的第四纪早期确实曾发生过大规模的古冰川运动，为争论了半个多世纪的中国东部中低山区有无第四纪冰川问题，从此画上一个圆满的句号。 相似文献
2.
质疑粤西北的冰川遗迹 总被引：1，自引：1，他引：1
从地貌、沉积物、第四纪地层关系、古气候、古环境等方面论证了广东封开-怀集-带所谓的冰川谷、冰蚀三角面、悬谷、角峰、刃脊、冰半、鼻山尾、冰碛砾石、蛇形丘以及近百万年来发生过3次冰期，是既不符合地学基础理论也不符合野外实际，所以是不确实的，那里没有第四纪冰川遗迹。 相似文献
3.
内蒙古满洲里地区,北部与俄罗斯赤塔洲接壤.隶属于内蒙古自治区呼伦贝尔市满洲里市与新巴尔虎右旗管辖.地处内蒙古高原的北东缘,属高原低山——丘陵草原区.海拔高度一般在600-1,000m之间,地势较平坦,牧草丛生.
上世纪80年代以来,地质专家已先后发现了上更新统冰水堆积、第四纪冰臼、冰河时期动物猛犸象与披毛犀化石等冰川遗迹.进一步证明了冰川遗迹与第四纪冰川的形成有密切的关系. 相似文献
4.
内蒙古满洲里地区自上世纪80年代开展1∶20万区域地质调查工作以来,已先后发现了上更新统冰水堆积、第四纪冰臼、冰河时期动物猛犸象与披毛犀化石等冰川遗迹.这些遗迹直接反映了第四纪古冰川的存在,再次推翻了“大兴安岭没有经历第四纪冰川时代”的论断.并对预测未来区域气候、环境演化趋势提供了依据. 相似文献
5.
中国科学院院士施雅风谈"冰臼"与"壶穴" 总被引：7，自引：0，他引：7
广东不具备形成古冰川的气候条件 ,因此不可能有“冰臼”存在 ;通过理论研究和实地考察 ,认为庐山不存在第四纪冰川 ;科学也必须打假 ,近年来有关广东“冰臼”的报道是失实的 ,利用“冰臼”论发展旅游业是一种误导行为 ,应消除由此所产生的不良社会影响 ;新闻报道应尊重事实 ,注重深入调查研究 ,类似“冰臼”报道的教训值得记取 相似文献
6.
秦岭太白山古冰川发育与黄土高原气候变迁 总被引：4，自引：1，他引：3
本文通过古冰川遗迹的系统分析,揭示了太白山雪线变化和冰川发育过程,将其与黄土高原晚第四纪气候变化模式对比,阐明了太白山雪线变化和冰川发育的时代和时间序列问题。 相似文献
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中国第四纪冰川作用与深海氧同位素阶段的对比和厘定 总被引：1，自引：0，他引：1
随着冰期(阶)与间冰期(阶)旋回的不断细化,第四纪冰期系列与深海氧同位素阶段(MIS)对比之间所反映的问题开始逐步显现。通过中国第四纪冰期与MIS阶段对比,结合分析气候旋回与构造运动对地貌演化的控制作用,研究表明:①冰期(阶)或者间冰期(阶)发生的时段应尽可能对应于MIS的偶数或奇数阶段,有助于MIS框架下新的冰期(阶)的发现;②中更新世以来,中国第四纪冰期-间冰期旋回可能受控于100 ka轨道偏心率变化的气候大背景,昆仑冰期-倒数第二次冰期的冰川规模总体上与全球冰量变化一致。然而,末次冰期早、中期的冰川规模却与MIS所记录的全球冰量变化不尽一致,强烈显示气候与构造环境对冰川作用的影响;③目前在中国第四纪冰期划分方案中,存在着冰期系列由时间和地点双重命名的现象,建议用大理冰期、古乡冰期分别代替末次冰期和倒数第二次冰期。 相似文献
12.
Adrian M. Hall Karin Ebert Clas Hättestrand 《Geografiska Annaler: Series A, Physical Geography》2013,95(1):33-49
We seek to quantify glacial erosion in a low relief shield landscape in northern Sweden. We use GIS analyses of digital elevation models and field mapping of glacial erosion indicators to explore the geomorphology of three granite areas with the same sets of landforms and of similar relative relief, but with different degrees of glacial streamlining. Area 1, the Parkajoki district, shows no streamlining and so is a type area for negligible glacial erosion. Parkajoki retains many delicate pre‐glacial features, including tors and saprolites with exposure histories of over 1 Myr. Area 2 shows the onset of significant glacial erosion, with the development of glacially streamlined bedrock hills. Area 3 shows extensive glacial streamlining and the development of hill forms such as large crag and tails and roches moutonnées. Preservation of old landforms is almost complete in Area 1, due to repeated covers of cold‐based, non‐erosive ice. In Area 2, streamlined hills appear but sheet joint patterns indicate that the lateral erosion of granite domes needed to form flanking cliffs and to give a streamlined appearance is only of the order of a few tens of metres. The inheritance of large‐scale, pre‐glacial landforms, notably structurally controlled bedrock hills and low relief palaeosurfaces, remains evident even in Area 3, the zone of maximum glacial erosion. Glacial erosion here has been concentrated in valleys, leading to the dissection and loss of area of palaeosurfaces. Semi‐quantitative estimates of glacial erosion on inselbergs and palaeosurfaces and in valleys provide mean totals for glacial erosion of 8 ± 8 m in Area 1 and 27 ± 11 m in Area 3. These estimates support previous views that glacial erosion depths and rates on shields can be low and that pre‐glacial landforms can survive long periods of glaciation, including episodes of wet‐based flow. 相似文献
13.
Kevin Kiernan 《The Australian geographer》1990,21(2):113-125
The Mt Anne massif is characterised by spectacular erosional landforms of glacial origin. Evidence of at least two separate Pleistocene glaciations is preserved in valleys that extend east and south of the massif, and also on nearby Schnells Ridge. There is evidence of a much older glaciation beneath the western slopes of the Mt Anne massif. Dense vegetation in the eastern valleys has inhibited mapping of the Quaternary geology there. These glaciations have influenced postglacial evolution of the landscape, including the advent of prominent karst features and Holocene landslip activity. 相似文献
14.
哈巴雪山(5 396 m)位于横断山脉中北段,与玉龙雪山(5 596 m)以金沙江相隔,受西南季风影响强烈。在哈巴雪山3 100 m以上保存第四纪冰川侵蚀与堆积地貌,主要沿哈巴雪山西北脊两侧分布。应用相对地貌法,对比邻近山地尤其是玉龙雪山,将哈巴雪山冰期系列初步划分为:倒数第二次冰期、末次冰期早期和末次冰盛期(LGM)。以哈巴雪山哈巴河谷的冰碛物为研究对象,其末端海拔高度在倒数第二次冰期、末次冰期早期、末次冰盛期分别约为3 100 m、3 500 m、3 900 m。应用TSAM法、MEIM法、CF法计算得出哈巴雪山古雪线高度在倒数第二次冰期、末次冰期早期、末次冰盛期分别为3 675 m、4 000 m、4 200 m。 相似文献
15.
According to the glacial landforms and deposits with the optically stimulated luminescence (OSL) dating results, two glacial
stages of the last glacial cycle (LGC) and Late Glacial were identified. The Late Glacial stage (Meteorological Station glacier
advance) took place about 11 ka (11.3±1.2 ka), and the last glacial maximum (LGM), named Black Wind Mouth glacier advance,
occurred at 20 ka (20.0±2.1 ka). Based on the Ohmura’s formula in which there is a relationship between summer (JJA) atmospheric
temperature (T) and the annual precipitation (P) at ELA, the present theoretical equilibrium line altitude (ELAt) in Changbai Mountains was 3380±100 m. Six methods of accumulation-area ratio (AAR), maximum elevation of lateral moraines
(MELM), toe-to headwall altitude ratios (THAR), the terminal to summit altitudinal (TSAM), the altitude of cirque floor (CF),
and the terminal to average elevation of the catchment area (Hofer) were used for calculation of the former ELAs in different
stages. These methods provided the ELA for a range of 2250–2383 m with an average value of 2320±20 m during the LGM, which
is 200 m higher than the value of previous investigation. The snowlines during the Late Glacial are 2490 m on northern slope,
and 2440 m on western slope. The results show that the snowline on northern slope is 50 m higher than that on western slope
during the Late Glacial, and the average snowline is 2465m. The ΔELA values were more than 1000 m during the LGM, and about
920 m lower than now during the Late Glacial stage respectively. Compared with Taiwanese and Japanese mountains in East Asia
during the LGM, the effect of the uplift on ELA in Changbai Mountains during the glaciations (i.e. 20 m uplift in the LGM
and 11 m in the Late Glacial) is not obvious.
Foundation: National Natural Science Foundation of China, No.40571016
Author: Zhang Wei (1969–), Ph.D and Professor, specialized in Quaternary environment and climate geomorphology. 相似文献
16.
气候和地貌对晚第四纪冰川发育差异性的影响 总被引：1，自引：1，他引：0
中国第四纪冰川作用极大地推动了高亚洲乃至全球冰川形成机制的探讨。青藏高原以及喜马拉雅山地冰川作用的时限和规模研究得到了广泛关注,为西风带与西南季风带对晚第四纪冰川作用差异性问题的解决提供了有利条件。然而,对于中亚西风环流与东亚季风环流影响下的冰川演化差异性关系不甚明确,两大气候系统控制下的山地第四纪冰川的冰进时序、冰期历史和冰川规模显示出不同特点,其差异性主要体现在:西部山地的冰期启动时间早,冰川规模随时间而逐渐缩小,冰川历史较为完整,绝对年代证据显示冰川作用的启动时间是450 ka 左右的中梁赣冰期(MIS12);东部山地的冰期历史较短,仅保留末次冰期(~75 ka)的冰川遗迹,冰川作用的阶段性明显;冰川演化时间与空间的差异性表明,影响冰川发育的因素不仅仅是区域气候,构造因素也起着相当重要的作用。 相似文献
17.
Yeong Bae Seong Michael P. Bishop Andrew Bush Penny Clendon Luke Copland Robert C. Finkel Ulrich Kamp Lewis A. Owen John F. Shroder 《Geomorphology》2009,103(2):251-267
The Central Karakoram, which includes K2 in Pakistan, is one of the most rapidly rising areas on Earth and exhibits complex topography and extreme relief. Impressive valley fills and glacial landforms are present throughout the valleys. The dynamics of landscape evolution of the region are currently not well understood. Consequently, the landforms were mapped and assessed in the Skardu, Shigar, and Braldu valleys, to elucidate the spatio-temporal scale dependencies of surface processes active in the region. These valleys were examined using geomorphic field methods, remote sensing, geomorphometry, and terrestrial cosmogenic nuclides (TCNs) surface exposure dating. The glaciers in this region have oscillated considerably throughout the Late Quaternary, and four glacial stages have been recognized including at least six glacial advances. Surface processes readjusted after glacier retreat, and ubiquitous mass movements and catastrophic landsliding transported material from steep slopes to valley bottoms, while glaciofluvial meltwater and glacier outburst floods redistributed sediment down valley. Glacier geochronology and late Holocene ages of the outburst flood deposits indicate that landscape evolution has been dominated by glaciation and paraglaciation during the late Quaternary. 相似文献
18.
According to the glacial landforms and deposits with the optically stimulated luminescence (OSL) dating results, two glacial stages of the last glacial cycle (LGC) and Late Glacial were identified. The Late Glacial stage (Meteorological Station glacier advance) took place about 11 ka (11.3±1.2 ka), and the last glacial maximum (LGM), named Black Wind Mouth glacier advance, occurred at 20 ka (20.0±2.1 ka). Based on the Ohmura’s formula in which there is a relationship between summer (JJA) atmospheric temperature (T) and the annual precipitation (P) at ELA, the present theoretical equilibrium line altitude (ELAt) in Changbai Mountains was 3380±100 m. Six methods of accumulation–area ratio (AAR), maximum elevation of lateral moraines (MELM), toe–to headwall altitude ratios (THAR), the terminal to summit altitudinal (TSAM), the altitude of cirque floor (CF), and the terminal to average elevation of the catchment area (Hofer) were used for calculation of the former ELAs in different stages. These methods provided the ELA for a range of 2250–2383 m with an average value of 2320±20 m during the LGM, which is 200 m higher than the value of previous investigation. The snowlines during the Late Glacial are 2490 m on northern slope, and 2440 m on western slope. The results show that the snowline on northern slope is 50 m higher than that on western slope during the Late Glacial, and the average snowline is 2465m. The ELA △ values were more than 1000 m during the LGM, and about 920 m lower than now during the Late Glacial stage respectively. Compared with Taiwanese and Japanese mountains in East Asia during the LGM, the effect of the uplift on ELA in Changbai Mountains during the glaciations (i.e. 20 m uplift in the LGM and 11 m in the Late Glacial) is not obvious. 相似文献
19.
云南千湖山第四纪冰川发育特点与环境变化 总被引：2，自引：0，他引：2
千湖山(4249 m) 是横断山脉中段保存确切第四纪冰川遗迹的山地,受西南季风影响强烈。对于研究青藏高原边缘山地冰川发育与气候和构造之间的耦合关系具有十分重要的科学意义。在千湖山海拔3500 m以上保存着古冰川侵蚀与堆积地貌,冰川发育依托海拔4000~4200 m的夷平面及其支谷地形。冰川形态类型为小型的冰帽以及由冰帽边缘溢流进入山谷的山谷冰川。应用相对地貌法,光释光(OSL) 年代测试,本文确定千湖山地区的冰进系列:末次冰盛期(LGM,22.2±1.9 ka BP)、末次冰期中期(MIS3b,37.3±3.7 ka BP、45.6±4.3 ka BP45.6±4.3 ka BP)、末次冰期早期(MIS4)。千湖山冰川前进规模是MIS3b 阶段大于末次冰盛期,主要原因是末次冰期中期(MIS3b) 时本区气候相对湿润,而在末次冰盛期(MIS2) 时气候条件比较干燥。在总体相似的气候背景下,与横断山其它存在多期次冰川作用的山地相比,千湖山只发育末次冰期的冰川作用,其差异性说明该地区冰川发育主要受山体构造抬升控制。 相似文献