依据牙形刺确定的内蒙古苏尼特左旗泥盆系泥鳅河组的时代

AGE OF THE NIQIUHE FORMATION IN SUNITEZUO QI,INNER MONGOLIA BASED ON CONODONTS

内蒙古苏尼特左旗泥鳅河组一段下部产Caudicriodus woschmidti hesperius等牙形刺,时代为Lochkovian(洛赫考夫期)期最早期。泥鳅河组二段最下部产牙形刺Masaraella pandora W new morph,Pandorinellinacf.miae等,时代为Pragian(布拉格期)期最早期,或由Lochkovian晚期pandora beta-gilberti带到Pragian期早期的steinachensis带。依据牙形刺确定的泥鳅河组一段—二段的时代为早泥盆世早、中期,即Lochkovian期到Pragian期的沉积。本文还首次确认了Masaraella属在中国的存在,并描述了Masaraella pandora W新的形态型。

The lower part of the Lower Niqiuhe Formation in Sunitezuo Qi, Inner Mongolia, yields conodonts Caudi- criodus zvoschmidti hesperius and its age should be the earliest Lochkovian. The lowermost part of the Upper member of the Niqiuhe Formation contains conodonts= Masaraella pandora W new morph, Pandorinellina el. miae etc. Its age should be the earliest Pragian or from the late Lochkovian pandora beta-gilberti Zone to Early Pragian steinachen sis Zone. The age of whole Niqiuhe Formation should be the lower-middle Lower Devonian, namely, Lochkovian and Pragian deposits. The present paper first recognizes the exist of genus Masaraella in China and describe a new W morphotype of Masaraella pandora