722 TRANS-PECOS TEXAS. 



Metamorphism has gone on to such an extent that the organic remains 

 have been destroyed, if they have ever existed in it, for in fact the rock is 

 now a marble. Above this limestone comes the second horizon of gypsum, 

 with a thickness of one hundred • and ten feet. It is the same lithologically 

 as the first horizon, stratified, nearly pure, friable, granular gypsum. It con- 

 tains comparatively little earthy matter. On the east side of the southeast 

 end of Malone Mountain there is a development of gypsum, with a surface 

 area of about forty acres, that may be classed with one of these horizons, and 

 from its relations to the overlying conglomerates, it is probably the lowest. 

 The crumpling and displacement of the strata have been so great that it is 

 not possible to correlate positively. In character it is identically the same as 

 that of the second horizon on the west side or centre of the mountain. 



These rocks have not been seen elsewhere except in Malone Mountain. If 

 they were continuous over the area of the Cretaceous rocks they would out- 

 crop between Quitman and Sierra Blanca mountains at the bases of Etholen 

 Knobs and follow the basin, passing on .the northeast side of Bluff Mesa and 

 down Devil's Ridge to Eagle Mountain. 



The occurrence of the overlying breccias and conglomeratic breccias that 

 pass from other areas near at hand over these gypsum horizons, points to the 

 fact that the shore of the gypsum-forming basin was not far away, and that 

 it had passed down over the sands and oyster breccias of Etholen Knobs be- 

 fore the beginning of the deposit of gypsum; for at Etholen Knobs the con- 

 glomeratic breccias rest on the sands, while in Malone Mountain, five miles 

 to the southwest, it has been thrown out directly on the gypsum. Three sec- 

 tions were made of the rocks of Malone Mountain, one at the south end, one 

 at the middle, and one at the north end. The middle section is the most 

 comprehensive. This section is given below, that the succession of the strata 

 and the connection of the Malone bed with the overlying rocks may be seen 

 at a view. 



MIDDLE SECTION OF MALONE MOUNTAIN, IN DESCENDING ORDER. 



1. Thinly bedded to flaggy, compact, finely crystalline limestone, blue to 



pale yellow in color, weathering pale yellow to yellow and brown. 

 Same in character as the flaggy beds at the base of Yucca and Bluff 

 mesas 100 feet. 



2. Limestone conglomerate 5 to 1 feet. 



3. Milky white calcite 1 to 2 feet. 



4. Slightly siliceous blue limestone, with small gasteropods and much finely 



comminuted oyster shell fragments 100 feet. 



5. Calcareous ferruginous sandy grit.. 5 feet. 



6. Siliceous limestone, with occasional chert and limestone pebbles 45 feet. 



7. Light blue compact limestone or marble, weathers pale yellow 4 feet. 



8. Black conglomeratic calcareous shale, weathers purple 10 feet. 



