Petrology of granitic rocks in Dan Chang District, Suphan Buri Province, Thailand

Granitic rocks in Thailand and South East Asia have been divided into Eastern belt granite, Central belt granite, and Western belt granite.The Central belt granite widely expose in Thailand including Dan Chang area. According to the field investigation, there are two granitic bodies in Dan Chang area. The main granitic body is composed of mainly K-feldspar, plagioclase, quartz, and biotite with some accessory minerals of opaque mineral and zircon. The granitic rocks are obviously characterized by porphyritic texture of coarse-grain K-feldspar.Another granitic body is small body which is similar mineral assemblage to those granite in the main body with different proportion of K-feldspar. The amount of K-feldspar in the small body granite is less than the main body granite. However, both granitic bodies are generally characterized by porphyritic texture of K-feldspar. Moreover, aplite and pegmatite are associated with both of them. The results of field investigation and petrographic study of the granitic rocks in Dan Chang District, Suphan Buri Province, Thailand can be compared with the Central belt granite which may be resulted from the Sibumasu and Indochina collision in Late Triassic.