Timing of the last Deglaciation in the Sierra Nevada of the Mérida Andes, Venezuela
Timing of the last Deglaciation in the Sierra Nevada of the Mérida Andes, Venezuela
复制标题
委内瑞拉梅里达安第斯山脉内华达山脉最后一次冰消期的时间
DOI：
10.1016/j.yqres.2013.08.001
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发表时间：
2013
影响因子：
2.3
通讯作者：
C. Beck
中科院分区：
文献类型：
--
作者：
J. Carcaillet;I. Ángel;E. Carrillo;F. Audemard;C. Beck
在热带的梅里达安第斯山脉（委内瑞拉西北部），在海拔2600米至5000米之间发现了冰川地貌，相当于最大冰川延伸期间600平方公里的冰盖。然而，由于缺乏足够的绝对年龄数据，无法详细重建最后一次冰消期的时间。在Mucuñuque地块的西北侧，连续的冰碛和条纹状侵蚀基底表面取样进行宇宙成因10 Be调查。他们的汇编与公布的数据允许建立一个详细的年表后LGM冰川的历史。最古老的冰碛（18.1和16.8 ka）对应于最古老的仙女木。连续的冰碛脊表明在LGM和新仙女木之间的整体撤退的停止。寒冷和短暂的旧仙女木stadial已被确定。结果表明，大部分的冰在更新世撤退。该数据集支持的垂直后退速率从25米/ka在晚更新世到更新世/全新世的310米/ka的加剧。之后，冰川被限制并位于较高的海拔地区。Mucubají、La维多利亚和Los Zerpa山谷中新仙女木冰碛的海拔差异表明，山谷方向对冰碛发育的海拔有很强的影响。
In the tropical Mérida Andes (northwestern Venezuela), glacial landforms were found at altitudes between 2600 and 5000 m, corresponding to 600 km2 of ice cover during the maximum glacial extension. However, the lack of sufficient absolute age data prevents detailed reconstruction of the timing of the last deglaciation. On the northwestern flank of the Mucuñuque Massif, successive moraines and striated eroded basement surfaces were sampled for cosmogenic 10Be investigation. Their compilation with published data allows the establishment of a detailed chronology of the post-LGM glacier history. The oldest moraines (18.1 and 16.8 ka) correspond to the Oldest Dryas. Successive moraine ridges indicate stops in the overall retreat between the LGM and the Younger Dryas. The cold and short Older Dryas stadial has been identified. Results indicate that most of the ice withdrew during the Pleistocene. The dataset supports an intensification of the vertical retreat rate from ~ 25 m/ka during the late Pleistocene to ~ 310 m/ka during the Pleistocene/Holocene. Afterwards, the glacier was confined and located in the higher altitude zones. The altitude difference of the Younger Dryas moraines in the Mucubají, La Victoria and Los Zerpa valleys indicates a strong effect of valley orientation on the altitude of moraine development.
影响因子：
5.3
作者：
Kaplan, Michael R.;Strelin, Jorge A.;Travis, Scott G.
通讯作者：
Travis, Scott G.
影响因子：
2.7
作者：
Putnam, A. E.;Schaefer, J. M.;Kelley, S. E.
通讯作者：
Kelley, S. E.