Temporal and spatial distribution of various granites in North China and the northern margin of Northeast China

It has long been known that there is a Triassic-Early Jurassic granite belt in the northern margin of North China, which is mainly composed of peraluminous granite and alkaline granite (Yan Guohan et al., 2001; Tao, 2003; Ren Kangxu et al., 2005). Our research shows that there are different types of granites in northern North China (including Northeast China), and their distribution is very regular: adakite and Himalayan granite are the main ones in the northern margin of North China, and Zhejiang-Fujian granite and Nanling granite are developed in the northern part.

65,438+04 adakite has been identified in this area, with ages ranging from 236 to 65,438+080 Ma. The oldest is Guzuizi granite in Hebei (236 Ma, Miao et al., 2002), and the youngest is alkaline granite in Liaoning (182 ~ 190Ma, Wu Fu). As can be seen from Figure 7. 1, adakite is distributed in a long and narrow east-west direction, located between east longitude 1 15 ~ 128 and north latitude 40 ~ 44, and mostly concentrated in North China and Northeast China to the east of Zhangjiakou, with only one rock mass in Beishan, Gansu (Maanshan North Granite, 238 Ma). Himalayan granite is widely developed in this area, exposed in a narrow range of east longitude 105 ~ 129 and north latitude 40 ~ 43 (fig. 7. 1). The age is from early Triassic to early Jurassic (247 ~ 182 Ma). Zhejiang-Fujian type granite is rare, only found in Qianjin field of Inner Mongolia and Wangqing area of Jilin Province (Figure 7. 1), with an age of 196 ~ 220 Ma (Pei Fuping, 2004; Wang Wanjun et al., 2005): Nanling-type granites are widely distributed (Figure 7. 1), with a large age span from the Early Triassic to the Early Jurassic (25 1 ~ 182 Ma).

Fig. 7. 1 Temporal and spatial distribution of early Mesozoic granites in northern North China