引言笔者在1963年初冬参加联合专题组解决区测工作遗留的疑难问题过程中,在祁连山东部天祝自治县西南15公里马营沟(参阅图1)前人命名为“白坡子复理石岩系”中,首次发现了大量志留纪笔石化石。经过全组同志详测剖面,发现笔石层达五十余层之多,从 INTRODUCTION In the early winter of 1963, the author participated in the joint task force to solve the difficult problems left behind by the area survey. In the Mayinggou (see Figure 1), 15 kilometers southwest of Tianzhu Autonomous County in the eastern part of the Qilian Mountains, Department ", for the first time found a large number of Silurian pen stone fossils. After the whole group of comrades detailed test section, found that more than fifty layers of pen and stone, from