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青藏高原东缘最高山地—贡嘎山是横断山最大的现代冰川作用中心,第四纪冰期中冰川有较大规模的扩张,留下了形态较完整的冰川和冰水沉积地形.根据冰碛物的分布与风化程度、冰碛地层的接触关系以及表面土壤发育状况等,应用ESR和OSL测年技术,对该地区的第四纪冰川沉积进行了定年,其年龄分别为(2.2±0.5),(11.9±0.6),(35.9±2.7)~(58.0±6.3)与(119.2±15.9)~(194.2±32.8)ka.应用地貌地层学原理并结合已有的研究资料,确认贡嘎山东坡至少经历了5次规模较大的冰进,可分别对应于小冰期、新冰期、MIS2,MIS3中期和MIS6.本区的末次冰期冰川规模最大不是发生在末次冰期最盛期,而是气候较为冷湿的MIS3中期.早期划定的贡嘎、南门关和雅家埂冰期分别对应于末次冰期晚冰阶、中冰阶和倒数第二次冰期(MIS6).磨西台地中上部、两侧阶地及尾部均为MIS3至全新世的混杂有泥石流堆积的冰水沉积;而底部主要是南门关冰期(MIS3中期)的冰川沉积,其中包含有冰水砂砾石层透镜体和冰湖相等沉积.
The highest mountain in the eastern margin of the Qinghai-Tibet Plateau - Gongga Mountain is the largest center of modern glaciation in the Hengduan Mountains, with large-scale expansion of glaciers during the Quaternary glacial period, leaving a relatively complete glacier and ice-water sedimentary topography. According to the moraine The distribution and degree of weathering, the contact relationship between moraine strata and the development of surface soils, the ESR and OSL dating techniques were used to date the Quaternary glacial sediments in this area with ages of (2.2 ± 0.5) , (11.9 ± 0.6), (35.9 ± 2.7) ~ (58.0 ± 6.3) and (119.2 ± 15.9) ~ (194.2 ± 32.8) ka, respectively.Using the principle of geomorphologic stratigraphy and the existing research data, At least five large ice inlets have been observed, corresponding to the small ice age, the new ice age, MIS2, MIS3 and MIS6, respectively. The last glacial glacier scale in this area did not occur at the peak of the last ice age, but at a colder climate Wet MIS3 mid-term.The early delineation of Gongga, Nanmenguan and Yajiaye glacials correspond to the late glacial, intermediate glacial and second-penultimate glaciations (MIS6) in the last glacial period respectively. Terraces and tails are MIS3 to Holocene mixed with debris flow accumulation Depositing water; the bottom is mainly glacial Off Gate (OF MIS3 medium) of glacial, which contains an equal depositing gravel layer in ice-water and frozen lake lens.