(reology of the St. Croix Dalles. — Berkeij. H47 
Part 1.— GEOLOGY. 
(Plates XX, XXI and XXII.) 
Chapter I. Topofiraphy and Special Surface Features. 
Topofiraphij. The elevation of each of the points estab- 
lished as a basis for the topographic map of the district 
studied was obtained by aneroid barometer readings. Pub- 
lished altitudes above mean sea level, determined by the sur- 
veys of the Saint Paul and Duluth and the Minneapolis, Saint 
Paul and Sault Ste. Marie railways, were used as primary sta- 
tions. The existence of one road on each side of the river 
gave ample opportunity for correction of readings. About 900 
aneroid readings were recorded and perhaps as many more 
taken at intermediate points and used for immediate correc- 
tion of contour lines in the tield. The following points were 
used as primary stations: 
Taylor's Falls depot 791 feet 
Taylor's Falls freight house 750 " 
Francooia station 915 " 
Steamboat landing at Taylor's Falls 687 " 
St. Croix Falls depot 920 " 
Summit of grade 1010 " 
Dresser Junction 950 " 
Osceola station 806 '• 
The following additional points have been selected from the 
list of those determined by aneroid readings, as representing 
different parts of the area : 
Highest diabase knob— Taylor's Falls, S.W. '4, N. 
W. Ml S. E. 14, Sec. 25, T. .34 N.. R. 19 W . . . . 1040 feet 
Colby lake, Sec. 23, T. .34 N., R. 19 W 940 " 
Cemetery, Sec. 24, T. 34 N., R. 19 W 960 " 
Residence of Senator Deedon, Sec. 13, T. 34 X.. 
R. 19 W 1100 " 
School house. Sec. 11, T. .34 N.. R. 19 W 980 " 
Diabase knob, N. E. I4, N. E. 14^, Sec. 1, T. 34 N. 
R. 19 W 1120 " 
Rock lake. Sec. 4, T. .34 N., R. 18 W 1025 " " 
Trout mere, Sec. 6, T. 34 N., R. 18 W 920 " 
Fair grounds, Sec. 20, T. .34 N., R. 18 W 1025 " 
Summitof morainic ridge,Sec. 21, T. .34 N., R. 18 W. 1215 " 
Summit of morainic ridge, Sec.6, T. ,33 N., R. 18 W. 1165 " 
Poplar lake. Sec. 4, T. 33, R. 18 W 1135 " 
East lake, Sec. 16 and 21, T. .33, R. 18 W 940 " 
Trout mere, Sec. 14, T. .'33, R. 18 W 835 " 
