Microfossils in a specimen of Cambrian (?) sandstone from Karstula, Central Finland

Fragments of sandstone, believed to be of Cambrian age, occur in the Pleistocene glacial drift at Karstula. The microfossils contained in one pebble were analysed under the microscope and with the aid of scanning electronmicrographs. Four types were defined. They possibly represent blue-green algae and fungi. The tentative dating of the sandstone could not be confirmed, but the results seem to suggest a late Precambrian age.