Review of Recent Geological Literature. 55 
The Geology of the San Jose District, Tamaulipas, Mexico. By Geo. 
1. FiNLAY. (Contributions from the Geological Department of 
Columbia University, vol. xi. No. 100.) 
In December of 1901, Mr. Finlay went to San Jose, Mexico, for 
the purpose of studying the copper ore and eruptive rocks of that 
district; this paper gives the result of his investigations of the 
eruptives. 
The town of San Jose lies in a spacious amphitheatre which 
is enclosed on three sides, the north, east and west, by limestone 
mountains. Between these mountains the drainage of the valley 
finds an outlet to the north and east. The hight of the peaks varies 
from 3,000 to 3,500 which is about 1,000 feet above the valley level. 
The Baril range closes the vaLey on the south and forms a divide 
between the San Jos6 valley and that of the Arroyo Grande to the 
south. 
The valley climate approaches aridity; the rain supply of the 
year is concentrated in one or two weeks and finds its way to the 
streams at once, and with little diminution from ground storage, 
converting them into torrents and intensifying corrasion. V-shaped 
valleys and steep slopes result from these climatic conditions. 
The stratigraphic relations of the rock formations are as fol- 
lows: Underlying the town of San Jose and surrounding 
district is a laccolitic mass of andesyte which has intruded 
into limestone and shale on the north, east and west, and 
into nephelite syenyte to the south. The limestone cover has been 
almost wholly removed by erosion but the quaquaversal dip of the 
sedimentary rock indicates the laccolitic character of the igneous 
mass. At a short distance from the contact the limestone is hori- 
zontal and there the result of the intrusive action is recorded by 
pressure effects on the shaly member of the formation. The nephe- 
lite-syenyte appears in the Baril mountains and extends southward 
more than fifteen miles. It is older than the andesyte which lies 
to the north of it. Dioryte is found in three rounded bosses enclos- 
ed by the andesyte and it too is older than the andesyte by which 
it is penetrated. There are also numerous dyke rocks younger 
than these igneous masses, found as intrusions in all of them. 
The limestone is Cretaceous, the andesyte and subsequent 
dykes post-Cretaceous. The author was unable to determine the 
relations of the nephelite-syenyte and the limestone and makes no 
statement as to their relative ages. 
The remiander of the paper is devoted to the petrography of 
the igneous rocks. The author distinguishes, 
A. — Granitoid Types. 
1. Nephelite Syenyte. The San Jose rock is very uniform 
in character. Four types are described: The Baril type, the Ar- 
royo Grande type, the Mesa Verde type and a basic facies of it. By 
