江西“灵山式”花岗岩地貌景观特征及成因探讨

Characteristics and genesis of the “Lingshan-style” granite landscapes, Jiangxi Province

以上饶市幅1∶250000区域地质调查资料为基础,通过野外地质调查和室内综合研究,探讨江西灵山大型环状花岗岩的地貌景观特征及成因,并与黄山、三清山、天柱山花岗岩地貌景观进行对比。灵山花岗岩地貌景观主要分布在环形构造东南外环,海拔1000~1400 m,岩性为中粗粒黑云母碱长花岗岩,为世界罕见的大型环状花岗岩地貌景观,控制地貌形成的主要因素为构造作用、岩浆活动、风化侵蚀和重力崩塌作用。黄山、三清山是锥状峰林地貌景观的典型代表,天柱山以崩塌堆积地貌景观为特色,灵山以大型环状花岗岩峰林地貌景观为特色。天柱山、灵山锥状峰林和石锥地貌景观不如黄山和三清山发育,主要原因是天柱山、灵山比黄山、三清山海拔低400 m左右,冰川、融冻侵蚀作用不如黄山和三清山强烈。

Based on the 1∶50 000 regional geological reconnaissance data in Shangrao, the characteristic and genesis of the large ring-shaped structure and geomorphologic landscape of the Lingshan granitic complex are studied through field geology survey and indoor comprehesnive study. Meanwhile, comparison study of the Lingshan geomorphologic landscape with Mt. Huangshan, Mt. Sanqingshan and Mt. Tianzhushan was undertaken. The results show that the Lingshan geomorphologic landscape with an altitude of 2 500~3 000 m is mainly distributed to the southeast of the loop-shaped structure and is composed of medium-coarse biotite alkali granite. It is tectonism, magmatic activity, weathering and erosion, combined with gravitational collapse controlling the formation of the rare large ring structure in Lingshan area. The comparative study reveals that the Mt. Huangshan and Mt. Sanqingshan represent the typical granitic cone, the Mt. Tianzhushan is characteristics of granite collapse pile landforms, and the Mt. Lingshan is characteristics of the geomorphologic landscape of large ring structure. The reason causing the hoodoo and cone of Mt. Tianzhushan and Mt. Lingshan less spectacular than that of the Mt. Huangshan and Mt. Sanqingshan as follows:(1) the altitude of the Mt. Tianzhushan and Mt. Lingshan is 400 m lower than that of the Mt. Huangshan and Mt. Sanqingshan;(2) the erosion is weaker in the Mt. Tianzhushan and Mt. Lingshan area than that of the Mt. Huangshan and Mt. Sanqingshan area. Our investigations not only provide new information for study on granitic landscape, but also offer new data for the geopark protection and development.