FIFTH REPORT OF THE DIRECTOR I908 



Introduction to Geology [1907. p. 384] is the most satisfactory. 1 

 It reads : " Inliers differ from outliers in not necessarily being 

 isolated masses of rock, but merely isolated outcrops of older beds 

 which are surrounded by newer strata, though underground they 

 may be continuous with very extensive areas of beds. An inlier 

 is thus a larger or smaller mass of rock surrounded by beds 

 which are geologically younger than itself." Three groups of 

 inliers are recognized by Scott, viz those produced by folding 

 (anticlines, domes), by faults ("horsts") and the buried outliers. 



A survey of all outcrops of rocks within the State which, being 

 surrounded by beds geologically younger, fall under this definition 

 of inliers, has furnished various expressions of these phenomena 

 which naturally fall into two fundamentally different larger groups 

 as regards their primary causes. The first group is produced solely 

 by the agency of water in its different forms, in either depositing 

 or eroding. We distinguish these as deposition and erosion inliers. 

 The other group is caused by the diastrophism of the earth, re- 

 sulting in folds and faults. 



We will now proceed to consider these groups separately. It 

 may, however, be mentioned at the outset that, since nature does 

 not recognize the clean and simple division lines drawn by man, 

 the examples which she furnishes us in this instance are mostly 

 the result of several of the processes here cited as producing 

 inliers, and they will be placed under those agencies which appear 

 to have been most active in their production. 



1 Deposition inliers. The inliers which are produced by the 

 deposition of newer beds around outliers comprise that form 

 originally and still now most generally understood under the term 

 inliers. As Scott states, " the isolated ' stacks ' and pillars on the 

 seacoast are outliers but a movement of depression submerging 

 them in the sea would eventually result in their being buried in 

 newer deposits, thus changing them into inliers." Inliers which 

 originate from true outliers i. e. detached portions of formations, 

 will, in practice, be difficult to distinguish from the second group 

 of deposition inliers, namely, those resulting from the deposition 

 of newer rocks around mere erosional irregularities of still con- 

 tinuous strata, a case that must prevail in all folded regions. We 

 are not aware of instances of the first kind in this State, although 

 the required conditions, i. e. slightly disturbed strata buried by an 

 advancing sea, would seem to have been fulfilled repeatedly in the 



1 See also Geikic, J. Structural and Field Geology. 1908. 



