论文部分内容阅读
晚新生代以来黄土高原古气候参数的定量、半定量重建一直是黄土古气候领域研究的热点问题.通过利用磁化率一古降水和红度a.值一古温度转换函数.并结合古植被重建结果对黄土高原灵台剖面古气候参数的综合重建,初步结果表明:7.1~4.5Ma可能受到青藏高原隆升的驱动,气候变的相对暖湿.年均温度和年均降水从9.8±4.3℃和456±98mm增加到晚新生代以来最大的12.5±4.2℃和531±170mm;4.5~2.6Ma随着全球降温和上新世青藏高原隆升,气候趋于千冷.年均温度和年均降水变为10.4±3.9cI=和508±43lnm:2.6~1.8Ma年均温度降低到为8.4±3.4℃,年均降水减小为462±113mm;1.8~0.5Ma,随着全球降温的进一步持续,以及中更新世青藏高原的再次隆升,气候变的相对干冷,年均温度和年均降水分别变为8.5±1.7℃和457±118mm;0.5~0Ma,可能受到高原隆升和冰期旋回的共同作用,黄土高原干冷化显著.年均温度和降水分别减小为7.4±2.6℃和44±78mm. “,”Quantitative reconstruction of pMeo-climatic parameters of late Cenozoic has been a hot topic during the loess-paleoclimate realm. Combining the MS-paleoprecipitation model and redness-paleotemperature model with paleo-vegetation reconstruction results, comprehensively quantitative reconstruction of paleoclimatic parameters of Lingtai profile in Loess Plateau is accomplished. The preliminary results show that: During 7.1 -4.5 Ma, the mean annual temperature(MAT) and mean annuM precipitation(MAP) increased from 9.8 ±4.3℃ and 456 ± 98 mm to maximum of late Cenozoic ( 12.5± 4.2℃ and 531 ± 170 mm) driving probably by Tibetan Plateau uplift; Then, with the global cooling and the rapid uplift of the Tibetan Plateau, the climate of Loess Plateau tends to be arid and cold during 4.5 - 2.6 Ma, with MAT and MAP declining to 10.4 ± 3.9℃ and 508 ± 43 mm, respectively ; In the early quaternary from 2.6 to 1.8 Ma, the MAT and the MAP reduced to 8.4 ±3.4℃ and 462 ±113 mm, respectively; Moreover, from 1.8 to 0.5 Ma, ahmg with the global cooling further continuous and the rapid uplift of Tibetan plateau again during the mid-Pleistocene, the climate get relatively dry and arid, with MAT and MAP changing to 8.5± 1.7℃ and 457 ± 118 mm ; Finally, when the Tibetan Plateau further uplift and the initiation of global long glaciM-interglaciM cycle during 0.5 - 0 Ma, the MAT and MAP deceased significantly to 7.4±2.6℃ and 442 ±78 mm, respectively.