Record of Geology of Texas, 1887-1896. 
37 
Comstock^ Theo. B. 
posed to l)e ca-pped by the iCretaceous. The maps accompanying the pres- 
ent Report include only enough of the territory outlying to give a fair 
idea of the relations of the Pre-Cariboniferous terranes to those of more 
recent origin. These sheets represent an area of six thousand square miles, 
of which considerably more than five thousand square miles contain ex- 
posures of an earlier date than the Oarboniferous.” P. 556. 
“There are representatives of the Archean, Eparchean, and Paleozoic 
groups in the 'Central Mineral Region, which, as we now understand them, 
are regarded as the geologic equivalents of the Laurentian, Ontarian, 
Algonkian, Cambrian, iSilurian, and Devonian systems of other parts of 
the United iStates.” 'P. 556. 
Numerous analyses of dron Ores, Magnetites, Hematites, Sandy Ores, 
Segregated Ores, Soft (hydrated) Ores and Titaniferous Ore, are given on 
ipp. 634-635. 
Report of. 
(A Preliminary Report on Parts of the Counties of Menard, 
Concho, 'Tom Green, 'Sutton, 'S'chleicher, Crockett, Val Verde, 
Kinney, Maverick, Gvalde, Edwards, Bandera, Kerr, and Gilles- 
pie.) 
Geological Survey of Texas Second Report of Progress, 1891, 
pp. 43-54. Austin, 1892. 
Contents : 'Introduction. The 'General Geologic Section. Topographic 
'Features. Agricultural Possibilities. Water Supply — 'Artesian •Water. 
Mineral Resources — ^Ores of Metals other than Iron; Iron Ores; Koalin; 
■As.phaltum; ‘Coal or Lignite; Building Materials. Conclusion. 
“The rocks which lie at surface in the counties immediately bordering 
the Central Mineral Region are of Lower iCretaceous or Jurassic time. 
The settle'ment of the real horizons of the beds must be relegated to the 
specialists who are 'still debating the question. It is sufficient for our 
immediate purpose to warn investors that, in any event, no valuable deposit 
of coal or lignite may be expected within this range, although worthy peo- 
ple have proiposed boring to test the matter. All the important lignite 
layers lie in a geologic position considerably above this.” P. 44. 
“The topography of the Cretaceous area is distinctive and pronounced, 
a characteristic example of simple drainage erosion carried to a numerical 
extreme without widespread denud-ation. To express it otherwise, the 
results are those accomplished by myriads of streams of small extent, which 
have cut deep and narrow canyons, leaving innumerable peaks, buttes, and 
‘hog-backs’ in the intervening spaces. Thus the plateau levels correspond- 
ing to successively exposed hard layers are extensive, but so badly out up 
by ramifying streams that it is impossible to travel across them except 
by frequent ascent and descent of steep inclines. This peculiarity gives 
to one following the valley roads of the country only an idea about as 
erroneous as is obtained by one who pursues , the cross-eountry course, 
although either one will be liable to regard the region as more compli- 
cated in structure than it really is.” Pp. 45-46. 
