Preliminary paleomagnetic dating of the metalliferous(Zn-Pb rich),Stark black shale,Kansas City region,U.S.A.

摘要

The Stark metalliferous black shale is a member of the Dennis Formation,which is a cyclothemic limestone and shale unit in the Missourian(Upper Pennsylvanian)Kansas City Group.Paleomagnetic analysis of 96 specimens from 7 sites indicates that the characteristic remanent magnetization of the Stark Shale yields a Late Mississippian to Early Pennsylvanian age.This age is close to,but slightly older than,the Middle Pennsylvanian host rock age and implies that the metalliferous content of the shale is syngenetic in origin.