摘要
In 1984, the authors carried on a geological survey around Jianfengpo tin field which is bounded within gravel-bearing sandstone of Nantuo Formation of the Middle Sinian and discovered some rounded fossil cassiterites deposited both in the wall rock and in the orebody. This discovery is of important significance for revealing genesis of the deposit and taking further steps to look for ore deposit in the area in ques-tion.
