350 CENTRAL MINERAL REGION OF TEXAS. 



nandan rocks, or of their thin edges only. The Magnetite Beds themselves 

 are not here so thick nor so prominent as in some other districts. 



B. THE LLANO BELT. 



There is an area about five miles in width between Packsaddle Mountain 

 and the Riley Mountains, in which the Fernandan rocks are well exposed 

 where they are not cut out by later uplifts. This belt extends northwest to 

 the Cambro- Silurian escarpment. The rocks are folded here as in the areas 

 on both sides, and several times the succession of the strata is repeated. In 

 all the exposures the typical Fernandan section is exhibited, and there is 

 usually some indication of the presence of iron ores in situations which corre- 

 spond to the horizon of the Iron Mountain Series. The marbles and graphitic 

 schists cross the Brady road between Pecan Creek and Valley Spring in two 

 places, and ores of value have been detected in a number of places among 

 these outcrops. Over much of the road between Lone Grove and Llano, and 

 between Llano and Valley Spring, there are beds of red hematite sand, which 

 may be the results of the alteration of underlying magnetites. A tract of 

 this kind, not very far from Lone Grove, very probably represents the Baby- 

 head Belt, either in place or as a transported product. Another passes west 

 of Wright Creek, and has been examined by me at several places in its 

 course. Near the mouth of Public Pen Creek, northeast of the Wolf Moun- 

 tains, between the two roads from Lone Grove leading to Valley Spring and 

 Llano respectively, I have seen good altered surface indications of the magne- 

 tite, and these also come out in Public Pen Creek not far northwestward, and 

 again in the upper valley of Willow Creek. In the same course, southwest- 

 ward, this belt crosses the Lone Grove and Llano road, where it exhibits 

 similar features. Still another line of outcrop crosses the Llano River near 

 the lower ford at Llano, and this is again repeated near the upper ford, one 

 mile above Llano, but in these cases the marbles prevail In all the outcrops 

 of these Llano belts, which are broken at intervals by faults and granitic 

 irruptions, the magnetite seems to lie at a considerable depth oelow the surface, 

 and its products appear at surface now as hematite or limonite. A marked 

 example of this is visible at the Chaney workings, near the southwest corner 

 of Packsaddle Mountain. Numerous observations have been made which 

 confirm my judgment that the magnetite horizon is a persistent one in the 

 Fernandan system. 



C. THE IKON MOUNTAIN BELT. 



There are two localities in which the development of the magnetite depos- 

 its has been undertaken with some degree of enterprise. In both places very 

 large and valuable masses of this mineral have been exposed. The belt is 



