大厂是我国重要有色金属基地之一。冶金部215地质队在勘探实践中,首先发现该区龙头山一带中泥盆世早期生物礁;查明礁中蕴藏有丰富的锡石、铅、锌金属矿与沥青。1974年以来,我队曾多次前往调查研究。本文依据1979年对礁体地表露头以及八口钻井岩心的观察、300多块岩石薄片和100余件古生物鉴定报告写成。 Dachang is one of the important non-ferrous metal bases in China. In the exploration practice, the Geological Team of the Ministry of Metallurgy 215 first discovered the middle reefs of Middle Devonian in the area of ​​Longtoushan in this area; and found that there are rich cassiterite, lead and zinc metal deposits and bitumen in the reef. Since 1974, our team has repeatedly visited the survey. Based on the observation of the reef surface outcrop in 1979 and the drilling cores of eight wells, more than 300 pieces of rock slices and over 100 paleontological identification reports were written in this paper.