24 PLEISTOCENE OF INDIANA AND MICHIGAN. 



remainder of the State. Those by C. R. Dryer present exceptionally clear descriptions of the 

 several moraines of the northeastern counties. These and other contributions by the Indiana 

 Survey are reviewed in connection with the discussion of features on which they have bearing. 

 The work of the Indiana Survey under the State geologist, W. S. Blatchley, has been directed 

 toward the investigation of certain commercial products and, except in the report on road 

 materials issued in 1906, has been little concerned with the glacial deposits. 



As reference to townships is commonly made by number and range rather than by civil 

 names, and as the numbering is connected with more than one meridian and base line, a brief 

 explanation of the system is given. 



Most of the townships of Indiana are numbered east and west from the second principal 

 meridian, which runs through the State about 86° 28' W. from Greenwich. A small triangular 

 area in the southeast part of the State, however, is numbered west from the first principal 

 meridian, which follows the State line of Indiana and Ohio. All the townships are numbered 

 north and south from a base line that crosses the southern portion of the State 1 to 2 miles 

 south of latitude 38° 30' N. The State extends from T. 9 S. to T. 38 N. of this base line. 



The townships of Michigan are numbered east and west from the Michigan meridian, 

 which leads from Sault Ste. Marie south to the Ohio State line, and north and south from a 

 base line that follows the parallel 42° 30'. Tho State extends from T. 8 S. to T. 39 N. in the 

 southern peninsula and to T. 66 N. on Isle Koyal in Lake Superior. 



Each township has 36 sections numbered back and forth in tiers of six, the numbering 

 beginning at the northeast and ending at the southeast corner of the township. 



GLACIAL GATHERING GROUNDS AND ICE LOBES. 



Studies by the Canadian Geological Survey have brought to fight several large gathering 

 grounds with smaller gathering grounds on their peripheries. The larger ice fields have been 

 named from their places of occurrence, the Cordilleran, the Keewatin, the Patrician, and the 

 Labrador. The Cordilleran field at its maximum occupied much of Canada west of the Rocky 

 Mountains, but did not extend far south into the United States. The Keewatin field occupied 

 central Canada, extended southward into the United States across Minnesota, the Dakotas, 

 Iowa, and Nebraska into southeastern Kansas and central Missouri, and encroached on western 

 Wisconsin and western Illinois. The Patrician 1 lay between Hudson Bay and Lake Superior 

 and may have extended over Michigan. The Labrador ice field extended from the Labrador 

 Peninsula southward and southwestward to the limits of glaciation in the district between the 

 Atlantic seaboard and the Mississippi Valley; it encroached slightly on southeastern Iowa and 

 caused a temporary •displacement 2 of the part of Mississippi River touching eastern and 

 southeastern Iowa. It is with the Labrador ice field that the present monograph is chiefly 

 concerned, and with that part of it which covered the southern peninsula of Michigan and the 

 glaciated portion of Indiana . As indicated later (pp. 64-65) the Patrician ice field may prove to 

 have spread southeastward across Michigan into Indiana and Ohio before the Labrador ice field 

 had entered this region. 



The Labrador ice field developed two large lobes west of the Appalachians in its extension 

 beyond the great basins through which it passed. The western lobe spread from the Lake 

 Michigan basin over much of Illinois, forming the Illinois glacial lobe, the theme of Monograph 

 XXXVIII. Itsi neighbor on the east extended through the Huron-Erie basin and on across 

 western Ohio and eastern Indiana to the edge of Kentucky, forming another large glacial lobe. 

 Between these two great lobes there is a conspicuous reentrant angle in the glacial boundary in 

 southern Indiana. East of the eastern lobe there is a reentrant on the west slope of the Alle- 

 ghenies which extends as far north as western New York. East of the Alleghenies there was 

 less extensive lobing, though the border of the ice conformed markedly to the marginal 

 topography. 



i Tyrrell, J. B., Hudson Bay exploring expedition, 1912: Twenty-second Ann. Rept. Ontario Bur. Mines, pt. 1, 1913. 

 2 Mon. U. S. Geol. Survey, vol. 38, 1899, p. 89. 



