摘要
广东南雄享有“中国恐龙之乡”的美誉。本文对南雄市下坪恐龙蛋化石保护点花岗岩基底开展了单颗粒锆石U-Pb年代学研究,获得中粒斑状黑云母二长花岗岩岩浆结晶年龄217.1 ±2.2 Ma (MSWD = 1.3),表明下坪红层与印支期花岗岩(γ15)基底呈侵蚀不整合接触。南雄盆地周围发育众多印支期岩浆岩,结合区域资料,表明粤北南雄地区中生代早期(T3-K1)处于长期的风化剥蚀状态,于早白垩世南雄地区现今盆山地貌才略具雏形。
The Nanxiong city, Guangdong province, has a famous reputation for being named “Chinese Dino-saur Town”. This paper carries out research on single grain zircon U-Pb geochronology of underlying granite basement of Xiaping red stratum in Nanxiong basin, and gets the middle grained porphyritic biotite monzonitic granite magma crystallization age of 217.1 ±2.2 Ma (MSWD = 1.3), and it shows that the contact relationship between Xiaping red stratum and underlying Indosinian granites (γ15) is erosion unconformity. There are lots of Indosinian granite bodies around Nanxiong basin;combined with regional geological data, it shows that the Nanxiong area in Northern Guangdong province was in the state of long-term weathering and denudation in the early Mesozoic in (T3-K1), and the basin and mountain topography of Nanxiong area just began to appear in the early Cretaceous.
作者
李宏卫
Hongwei Li(Guangdong Geological Survey, Guangzhou Guangdong)
基金
中国地质调查局、中国地质环境监测院“华南地区重要地质遗迹调查(广东) (项目编码:1212011220047)”项目成果。
