T. C. Chamberlin — Diversity of the Glacial Period. 189 



Turning now to the interpretation which Professor Wright 

 puts upon the High Bridge and Pattenbnrg deposits, it is to 

 be noted first, that the one occurs upon a spur as shown by 

 the New Jersey topographical maps and that to reach higher 

 ground a line running along the back of the spur must be fol- 

 lowed, rather than one down the maximum slope in the most 

 natural line of slide and creep. No height exceeding 460 feet 

 above the deposit in question occurs in the neighborhood, 

 except such as are separated from it by depression ; and to 

 reach even this moderate height, it is necessary to go one mile 

 back from the locality. In the other case, heights 500 feet 

 above the area in question occur within two miles to the north, 

 but they are separated by gentle slopes and a shallow valley. 

 The slope on which the deposit lies is composed of Triassic 

 rock. These facts bear upon the suggestion of Professor 

 Wright that these deposits are due to degradation, slide and 

 creep. Bearing more specifically upon that interpretation is 

 the fact that in these deposits there are bowlders and pebbles 

 of rock not now in the adjacent ridges, and these are polished 

 and scratched in a manner precisely similar in every respect to 

 the well-known polishings and scratchings of glaciated pebbles. 

 One or two in the collection of Mr. Kummel take rank among 

 the best examples of typical glaciation ; and if they were 

 passed through the hands of a hundred glacialists of the 

 greatest experience, not one could be expected to hesitate for 

 a moment to refer them to glacial action. Nothing at all 

 closely simulating them has ever been reported as the demon- 

 strable work of either land slide or creep. Furthermore, the 

 deposits in question are in part distinctly stratified, a feature 

 foreign to the products of landslide and creep. The deposit 

 at High Bridge is about 30 feet in maximum thickness, and 

 that at Pattenburg scarcely less. 



To refer to creep or landslide deposits having these con- 

 siderable thicknesses, containing derivatives from five forma- 

 tions, embracing nine recognizably different varieties of rock, 

 a part of the deposits being stratified, and. containing in both 

 localities scratched stones, the glacial origin of which no gla- 

 cialist would ever independently question, is most extraordi- 

 nary in what claims to be a demonstration of an illusion on 

 the part of one of our best trained and most critical observers. 



As another proof of alleged error on the part of Professor 

 Salisbury, Professor "Wright says, p. 364 : " The extensive 

 oxidation spoken of by Professor Salisbury in the quotation 

 made from his recent reports on the glacial deposits of New 

 Jersey is clearly of preglacial origin." That extensive oxida- 

 tion affected the old surface material that became a part of the 

 old drift, here as elsewhere, goes without saying. In a profes- 



