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我国东部中低山区第四纪冰川的存在与否一直存在争议,但冰川必然对山体进行冰蚀作用形成冰蚀地貌。为了分析我国东部中低山区的山体地貌是否具有冰蚀特征,该文选取了现代冰川集中发育区-喜马拉雅山脉作为冰蚀地貌的研究对象,通过宏观分析,除了由缩口、三角脊、残弧组成的冰斗系统外,还发现冰蚀作用过程存在避谷、吞脊、切壁、穿梁等特殊习性。分析认为冰蚀过程主要受制于雪线高程、积雪高程与坡向坡角三方面因素的控制。以此为基础,对我国东部的江西庐山、山东蒙山、大兴安岭主峰黄岗梁三个地区的山体地貌进行对比分析,发现这些山区的山体地貌与喜马拉雅山脉的冰蚀地貌具有一致性。文章从冰蚀过程的角度确认了我国东部中低山区存在第四纪冰川的事实。 相似文献
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笔者观察了豫西罗圈组下伏若干处出露良好的基岩侵蚀面和伴存的构造遗迹,认为是一个典型的古冰蚀面,而非构造滑动面。其上遗留的如钉子擦痕、新月形凿坑、新月形裂缝和羊背石等,与现代冰蚀遗迹可完全类比。这是冰川运动腐蚀与掘蚀机制所成。 相似文献
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东北是否发育第四纪冰川及其范围、性质与冰期问题,始终没有定论。在对长白山及大兴安岭冰川遗迹厘定基础上,进行了专项调查,并采用地理信息系统(GIS)、遥感(RS)及全球定位系统(GPS)的3S技术,采取钻探测图、孢粉、泥砾粒度与渗透性分析及14C定年等方法,在长白山及大兴安岭发现了冰蚀谷及泥砾堆积等新的冰川遗迹,进一步肯定了两座山地第四纪冰川的存在及其多期性。在小兴安岭首次发现冰蚀岩墙等冰川遗迹,填补了研究空白,证明小兴安岭也曾发育第四纪冰川。综合多种信息,确定长白山与大兴安岭分别有4次冰期和3次间冰期,小兴安岭至少有1次冰期。最后构建了可以与国际对比的冰期序列,重建了区域第四纪冰川环境演化模式:早更新世早期冷干,中晚期偏暖湿;中更新世早期冷湿,中晚期暖湿;晚更新世早期冷稍湿,中期暖湿,晚期冷干。 相似文献
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冰斗系统是冰斗作用以山体为载体进行剥蚀作用形成的结果,其在山体上形成的以缩口、三角脊、残弧等为代表的冰斗遗迹很难被后期的风化作用所消解,因此冰斗系统在解读古冰川作用中具有极为重要的意义。在对全球冰斗系统进行研究的过程中,发现了雪球事件,根据深海沉积物研究获得的环境变化信息,初步确定最近的一次雪球事件发生在渐新世,也即33.7~23.8Ma之间。研究发现雪球事件发生时,全球仅在赤道附近形成了4处陆生生物避难区,分别为刚果盆地、亚马逊盆地、阿拉弗拉海以及新加坡东部海域。研究认为,渐新世雪球事件塑造的冰斗地貌,是全球现代山区地貌的本底与基础。 相似文献
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针对山东蒙山发育的第四纪冰川遗迹,采用光释光的测年方法,获得了8.2ka冰期年龄值,以此为基础建立了拦马冰期,属于全新世早期。为了能够获得其他测年成果的相互验证,该次研究采用了宇生核素的测年方法,获得了3个年龄值:7.01ka,8.57ka,9.95ka,均属于全新世早期,与光释光方法获得的年龄值具有较高的一致性。在海拔752m的清荣峡谷内的冰碛表面,获得了5.27ka的全新世中期的年龄,对应冰碛建立了清荣冰期。通过该项研究,结合蒙山冰川遗迹的特征及其风化程度,反映了冰川遗迹、测年数据与环境气候之间的吻合性,综合确认了我国东部全新世早期拦马冰期、全新世中期清荣冰期的存在,也证明了全新世,在山东蒙山及我国东部中低山区受到东亚冷槽的影响,曾经存在冰川作用。 相似文献
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豫西甘山第四纪冰斗系统的发现及其与MIS的耦合关系分析 总被引:1,自引:0,他引:1
在调查东亚冷槽西壁冰川遗迹及其海拔梯度的过程中,发现了甘山冰斗系统与磨光面、擦痕、漂砾等冰川遗迹。进而对该冰斗系统进行成因分析的过程中,发现了冰斗系统的"冰斗环退"的形成方式。以此为基础,就甘山冰斗系统与MIS之间的耦合关系进行了对比分析。研究表明,甘山冰斗系统是以"冰斗环退"方式形成的,该冰斗环退系统完整展现了我国东部第四纪冰川作用的过程,对研究冰期的雪线高程、环境演化规律、冰川作用的进退等,都有着极其重要的意义。在"冰斗环退"的研究基础上,发现了对应的"冰斗环进"机制。冰斗环进代表了冰川作用由高向低推进过程,冰斗环退代表了冰川作用由低向高撤退过程。通过影像分析,初步将甘山冰斗系统划分四段,共解析出了50余套冰斗环,冰川作用的时代可追溯到2.56 Ma。根据冰斗的环进、环退特征,进而发现C28冰斗环所对应MIS56,也即1.60Ma,可能为我国第四纪冰川作用过程中的冰进向冰退演化的重要拐点。 相似文献
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依据地貌、孢粉、岩性沉积特征,划分巴颜喀拉山地区第四纪冰期。并与珠穆朗玛峰、唐古拉山、昆仑山地区进行对比。确定巴颜喀拉山地区第四纪以来有:哈拉滩冰期;巴颜喀拉山冰期;洛曲冰期;汪藏因姆措冰期;折尕考钦新冰期。 相似文献
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青藏高原冰川变化遥感监测研究综述 总被引:1,自引:0,他引:1
在全球变暖影响下,青藏高原冰川消融造成的冰川径流增大、冰湖溃决等问题威胁着山区及其周边居民的生命财产安全,对青藏高原冰川变化的研究日益紧迫。本文综述了国内外山地冰川变化遥感监测手段的发展、冰川面积及冰面高程变化的遥感监测研究现状、存在问题与发展趋势,并总结了中国青藏高原冰川变化遥感监测研究的主要成果。此外,本文基于2003-2009年ICESat/GLAS数据,计算了青藏高原各山区冰面高程变化及其冰川消融量。结果显示:青藏高原冰川面积持续减少,青藏高原冰面高程的平均变化为-0.24±0.03 m/a,冰川融水量为-14.86±11.88 km3/a,冰川变化呈现从青藏高原东、南外缘山区往内陆与西、北部山区减慢的时空特征。 相似文献
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古雪线直接反映了冰期时的气候特征,因此雪线是古冰川研究最终要解决的问题。2017年笔者等基于蒙山雪线的初步研究,发现东亚地区存在的雪线低洼区,采用了东亚冷槽的概念来表述该槽状雪线低洼区,并初步绘制了东亚冷槽的雪线高程。本文主要介绍了山东段(蒙山-崂山)的研究情况。根据山东蒙山、崂山34个光释光、宇生核素等方法获得的冰碛年龄数据及对应冰期雪线高程研究,表明崂山的雪线比蒙山要低,且在MIS6之前的冰期,崂山东侧冰碛多被现代海面淹没。研究表明,我国东部的气候敏感度要明显强于西部高原区,冰期时强劲的北路寒潮是我国东部地区冰川形成的核心气候因素。 相似文献
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Since the late 1950’s, many Chinese scientists have explored the remains of the Quaternary glaciation in the Qinghai-Xizang
(Tibet) Plateau and its surrounding mountains. In the main, 3–4 glaciations have been recognized. The largest one occurred
in the Late Middle Pleistocene with piedmont glaciers, ice caps and trellis valley glaciers in many high peak regions. But
here is no evidence of a unified ice sheet covering the whole plateau as described by M. Kuhle. Due to the further uplifting
of the Himalayas and Qinghai-Xizang Plateau the climate became progressively driver, diminishing the extension of glaciers
during the Late Pleistocene. The elevation of the snow line during the Last Glaciation was about 4,000 m on the south, east
and northeast edges of the plateau and ascended to 5500 m on the hinder northwest of the plateau. The thermal effect of the
big plateau massif, the sharp increase of aridity from the southeast rim to the northwest inland area and the abrupt decrease
of precipitation during the Ice Age largely account for the distribution of the Quaternary glaciers in the Qinghai-Xizang
Plateau. The neglect of Chinese literature may be one of the causes accounting for M. Kuhle’s misinterpretation on the environment
of the Quaternary glaciations in the Qinghai-Xizang Plateau. 相似文献
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LAST GLACIATION AND MAXIMUM GLACIATION IN THE QINGHAI-XIZANG (TIBET) PLATEAU: A CONTROVERSY TO M. KUHLE,S ICE SHEET HYPOTHESIS 总被引:1,自引:0,他引:1
Since the late 1950's, many Chinese scientists have explored the remains of the Quaternary glaciation in the Qinghai-Xizang (Tibet) Plateau and its surrounding mountains. In the main, 3-4 glaciations have been recognized. The largest one occurred in the Late Middle Pleistocene with piedmont glaciers, ice caps and trellis valley glaciers in many high peak regions. But here is no evidence of a unified ice sheet covering the whole plateau as described by M. Kuhle. Due to the further uplifting of the Himalayas and Qinghai-Xizang Plateau the climate became progressively drier, diminishing the extension of glaciers during the Late Pleistocene. The elevation of the snow line during the Last Glaciation was about 4,000 m on the south, east and northeast edges of the plateau and ascended to 5500 m on the hinder northwest of the plateau. The thermal effect of the big plateau massif, the sharp increase of aridity from the southeast rim to the northwest inland area and the abrupt decrease of precipitation during the 相似文献
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Quaternary glacio-erosional landforms in Laoshan Mountain and their constraints on the origin of Jiaozhou Bay, Qingdao, east of China 总被引:2,自引:0,他引:2
A field investigation on Quaternary glacial landforms in Laoshan Mountain has discovered many glacial potholes, scouring grooves on top of granite ridges, and large boulders. These erosional landforms were formed by the meltwater from the overlying ice cap, suggesting that there was at least an ice cap covering Laoshan Mountain and the surrounding areas or even a continental ice sheet over the vast area of Shandong Province in the Late Pleistocene. The ice sheet was obstructed by the Laoshan Mountain, Dazhu Mountain and Xiaozhu Mountain in the coastal areas as it moved toward the Yellow Sea. The ice flows eroded the bedrock and carved the weak intersection of the fault systems in the NE and NW directions into a deep channel, which gradually formed a fjord in the area of the Jiaozhou Bay basin by 20.00 ka BP. The seawater gradually invaded the fjord from the beginning of the Holocene (11.00 ka BP) and Jiaozhou Bay was eventually formed. Similar fjords are easily found along the east of China and they share a similar origin because of the Quaternary glaciation in the region. 相似文献
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QUATERNARY GLACIATION SERIES ANDGLACIAL LANDFORM IN GONGWANG MOUNTAINS INNORTHEAST PART OF YUNNAN PROVINCE, CHINA 总被引:1,自引:0,他引:1
况明生 《中国地理科学(英文版)》1997,7(2):180-190
Therearemanyquaternaryglaciallandformsinalpineareasahave3100ma.s.1.intheGongWangMountainsinthenortheastpartofYunnanProvinceofChina.TheglaciationseriesandtheglaciallandformsoftheQuaternaryhaveoncebeencoveredinanarticlesketchily(Yietal.,1991).Onthebasisoffieldinvestigationsinrecentyears,we'11goastepfurthertodiscusstheQuaternaryglaciationseriesandtheglacierlandfo~sthereinthisPaper.I.TabsQU~ANANYG~W~TheGOngWangMountainsissituatedbetweentwobranchesoftheJinshaRiver,theXiaojiangandthePudu… 相似文献