250 The American Geologist. ^i^'"- ^'-^^^ 
Geology of the Vicinity of Little Falls, Herkimer County, [New York], 
New York State Museum, bulletin 77, 1905. By H. P. Gushing, 
The central portion of the Mohawk river beginning west of 
Schenectady and extending to Utica has cut a deep trench in what 
professor Tarr has called the Mohawk valley physiographic pro- 
vince, to the north of which the land rises moderately and then 
sharply to the slopes of the Adirondack mountains. This valley is 
the eastern gateway between the tide water of the Hudson, at 
whose mouth lies greater New York, and the great agricultural 
west. Up the Mohawk valley passed the early explorers and pio- 
rieers who built the ancient highv/ays which in time were followed 
by the Erie Canal and the steam and electric railways. The beau- 
tiful scenery of this valley is well known and during the last cen- 
tury has been admired by thousands of travelers between the east 
and the west. The upper gorge of the Mohawk river at Little 
Falls has been for many years a region of interest to the physio- 
grapher and geologist. This well written and interesting account 
of 90 pages describing the geology of the Little Falls region by 
professor Gushing accompanies his geologic map of that qua<l- 
rangle. It is illustrated by 15 plates, most of which are excellent 
half-tones, giving views of interesting exposures of the formations 
or geologic structure; by 14 text-figures and a sheet of colored geo- 
logic sections. This region has suffered deformation by faulting 
which has produced the conspicuous cliff east of Little Falls and 
the geologic map shows two fault lines near that city and another 
east of Dolgeville. The Little Falls fault is said to be the most 
westerly known one in the state with "a throw of nearly or quite 
800 feet." To the east of this quadrangle numerous faults cross 
the Mohawk valley, and the reviewer has shown that the throw 
of the Hoffman fault, about nine miles northwest of Schenectady, 
is some 1,600 feet. The geologic map, which is clearly printed, 
shows areas of both Pre-Gambrian igneous and sedimentary rocks, 
nearly all the Lower Silurian formations found in the Mohawk val- 
ley and Pleistocene deposits. The Pre-Cambrian sedimentary 
rocks, which are referred to the Grenville formation, are mapped 
separately. The Lower Silurian formations in ascending order are 
mapped under the following divisions: Beekmantown formation; 
Trenton formation composed of the Lowville, Black river and Tren- 
ton limestones; Trenton-Utica passage beds and the Utica shale. 
Considerable attention is devoted to the character and slope of the 
Pre-Cambrian floor and the evidence of a Beekmantown overlap 
appears clear and decisive. c s. p. 
Recent studies in the Cambrian of Bohemia. 
In connection with the International Geological Congress at 
Vienna, Dr. J. .T. Jahn has published several short articles on the 
geology of the Palaeozoic Basin in Middle Bohemia. One entitled 
"Geologische exkursionen im Altern Palaozoikurn Mittel-Bohmens," 
