230 Harmon A. Nixon and Dexter J. Tight 
Summary 
1. Piracy is not competent to account for these changes, be- 
cause the present stream drainage is not sufficient to have cut the 
gorges found in the area, and because the streams are superim- 
posed upon glacial drift for a large part of their courses. 
2. Diastrophism is not competent to account for these changes, 
because at the present time the rock floor dips to the west, pre- 
cluding the possibility of a differential tilt diverting to the east 
the normal drainage of the area. 
3. These drainage reversals are of Pleistocene age, because of 
the fact that the supposed diastrophic movement took place in 
the late Cretaceous or Pliocene period. 
4. The distribution of moraine shows that a tongue of ice halted 
in the MooPs Pun area and diverted the drainage, causing it to 
take a course along the ice margin. This drainage cut the second 
tributary and MooPs Run below their junction at the rock gorge. 
5. Evidence also shows that the so-called MooPs Run in its 
upper course was nothing more than a tributary to its second main 
auxiliary, but has cut through a less resistant material, glacial 
drift, and has eroded its bed much faster, thus becoming the main 
stream. 
6. The present drainage of the MooPs Run area has been super- 
imposed upon a heavy recessional moraine, largely independent 
of preglacial drainage lines. 
