序号:03

       地理坐标:E102° 54' 13.172",N31° 6' 43.495"

       地质时期:新生代

       地学价值类型:地貌学

       重要性等级:世界级

       地质遗迹点描述:由大峰、二峰、三峰、幺妹峰四座毗连的雪峰组成,均为海拔大于5000m的山峰,其中幺妹峰海拔6247.80m,为四川第二高山峰,素有“蜀山王后”之称。幺妹峰和三峰(5355m)山体由花岗岩组成,二峰(5276m)山体由石英岩与石英砂岩组成,大峰(5025m)山体由灰岩与砂岩、板岩组成。

       约2.20亿~1.90亿年前,由于松潘-甘孜等地块挤压扬子地块,导致本区约20km深的上地壳深部发生部分熔融,形成了道孚-金川-小金-黑水构造岩浆带,中酸性岩浆侵入地壳所形成的花岗岩体构成了四姑娘山的主体,奠定了四姑娘山的物质基础。因侵入岩的岩性差异,导致第四系冰川侵蚀后形成不同形态的角峰。

       构成四姑娘山主体的复式花岗岩体分布于邛崃山中段四姑娘山主峰一带。该复式岩体呈近南北向岩基出露地表,侵入于古生代变质砂泥岩和碳酸盐岩、火山岩、三叠系变质砂板岩中,岩体南北长约30km,东西宽10~20km,面积约420km2。主要由四姑娘山岩体和牛心沟岩体的多个侵入体组成,侵入体间呈脉动接触关系。其岩石类型复杂,主要有黑云母花岗岩、二长花岗岩、正长岩、云闪正长岩、黑云角闪二长岩、角闪正长岩、二长岩、石英二长岩、斑状二长闪长岩等组成。

四姑娘山极高山群峰图与松潘-甘孜地块东部花岗岩分布图(据Roger et al., 2004; Zhang et al., 2006; Xiao et al., 2007; Yuan et al., 2010, 2011; Duan et al., 2013; Chen et al., 2017; Zheng et al., 2020; Zhou et al., 2020; Liu et al., 2021; Gao et al., 2023

       世界级价值的明确理由:四姑娘山地处青藏高原向四川盆地陡跌的关键区域,位于中国松潘-甘孜地块与扬子地块的结合部,完整地记录了青藏高原的隆升过程与机制,四姑娘山的复式花岗岩体记录了松潘-甘孜造山带形成过程的深部动力学信息,为揭示造山带岩浆的活动机制、壳幔作用过程、地壳属性、造山带演化等关键问题提供了研究对象。

 

代表性文献:
a) Pei, S., Niu, F., Ben-Zion, Y., Sun, Q., Liu, Y., Xue, X., ... & Shao, Z. (2019). Seismic velocity reduction and accelerated recovery due to earthquakes on the Longmenshan fault. Nature Geoscience, 12(5), 387-392.

b) Wang, J., Wang, W., Cao, B., Cui, H., Chen, X., Qiu, J., ... & Liao, J. (2023). Millennial-scale glacier fluctuations on the southeastern Tibetan Plateau during MIS 2. Earth and Planetary Science Letters, 601, 117903.

c) Pan, Y., & Shen, W. B. (2017). Contemporary crustal movement of southeastern Tibet: Constraints from dense GPS measurements. Scientific Reports, 7(1), 45348.

d) Zhao, H., Zhang, Y., Li, Q., Du, W., Zhang, Y., & Guo, Z. (2020). Early Jurassic I-type garnet leucogranite in the Siguniangshan pluton, eastern margin of the Songpan-Ganze terrane (NE Tibet), and its tectonic implications. Journal of Asian Earth Sciences, 188, 104079.

e) Xiao, L., Zhang, H. F., Clemens, J. D., Wang, Q. W., Kan, Z. Z., & Wang, K. M., et al. (2007). Late triassic granitoids of the eastern margin of the tibetan plateau: geochronology, petrogenesis and implications for tectonic evolution. Lithos, 96(3-4), 436-452.

f) Sigoyer, J. D., Vanderhaeghe, O., Duchene, S., & Billerot, A.. (2014). Generation and emplacement of triassic granitoids within the songpan ganze accretionary-orogenic wedge in a context of slab retreat accommodated by tear faulting, eastern tibetan plateau, china. Journal of Asian Earth Sciences, 88(jul.1), 192-216.