Sheet 51. 10 The exposures from 9 to 16 are all of Archaean rocks. No Cam- brian is shown but the exposure of Archaean are so much in line and they seem as well to carry on the strike shown by the contacts far further north, and the exposures present so much the same configuration that unless positive evidence of the Archaean farther west can be adduced I should be unwilling to admit that this line of Ar- chaean could represent any- things else than the kind of con- tact between the Archaean and the Cambrian sandstones.