Review of Recent Geological Literature. 121 
and 26 from Australasia and the Sandwich Islands. Its total weight 
is 5,509 pounds, and the average weight of all kinds is 9V0 pounds, the 
total number of specimens large and small about 1,600. 
This collection is now "on deposit" at the American Museum of 
Natural History, Central Park, New York. N. H. w. 
The traces of the mountain building process in the coasts of the Don 
river between the z'illages Klctskaia and Trechostrovianskaia (in 
S. E. Russia), by Alexander W. Pavlow ("Semlevieocnie," 1902, 
N. II-III). 
The paper contains a brief description of one of the regions of the 
S. E. Russia studied by the author from the geotectonic side. 
The locality in question is the extreme eastern part of the Don river, 
where the river sharply changes its course from the eastern direction to 
the southwestern (a little northerly of the village Trechostrovianskaia). 
The investigations of the author show, that the series of Carboniferous, 
Jurassic, Cretaceous and, probably. Tertiary rocks, developed in this 
region, are compressed into a large unsymmetrical anticlinal fold, with 
strike in a N. E. direction (about 30°). This strike in general coin- 
cides with the principal direction of the portion of Don immediately 
below the extreme eastern point of the river. Thus, the part of the 
valley (with a W — E direction) is a transversal valley, the parts with 
the NE direction form a longitudinal. 
The described fold must be regarded as an extreme western por- 
tion of the "region of the pericaspian dislocations" (of the author), 
connected with the disturbed regions on the rivers Archeda and !Med- 
vieditza and perhaps with the inclined rocks near the village Tioplowka 
(in the government of Saratow) situated in the north of the city Sar- 
atow. 
The western part of the summit level of Volga-Don represents 
probably the eastern portion of the fold. 
According to the author there is no proof of the existence of any 
fault, as has been supposed by ]Mr. Leon Dru. If any fault exist, prob- 
ably one can find it on the summit level of Volga-Don. 
Notes on a Section across tlic Sierra Madre Occidental of Chihualiua 
and Sitialoa, Mexico. (Am. Inst. Min. Eng., Novl, 1901.) 
This paper contains an ideal cross section and description of the 
Sierra Madre between Parral and the Pacific coast. The results of 
these observations are new and important. It is shown that the 
Sierra Madre is not a mountain range, but a great plateau, deeply 
• trenched by river canyons, and bordered westward by a great abfall, 
w-ith a fringe of mountains carved by erosion from the edge of the 
plateau. The geologic structure shows a base of eroded Cretaceous 
shales and limestones, covered by andesitic rocks, partly lava flows, 
partly fragmental volcanic accumulations, which are cut and meta- 
morphosed by quartsmonzonyte, dioryte. and granite. The eroded 
surface of these earlier igneous rocks is covered by dacitic and rhy- 
