ART. 23 DURANGO MINERALOGY AND GEOLOGY FOSHAG 19 



width of 150 meters, with a thickness as near as can now be judged 

 not exceeding 60 meters. Its outcrops form prominent clifflike ex- 

 posures 30 to 40 meters high. Viewed from the south this ore body 

 appears to be a tabular mass with a general dip to the west. Its con- 

 tact with the country rock on the east is sharp, due to the well defined 

 fault that borders it. On the west the ore body passes abruptly into 

 numerous anastamosing veins so that its border has the general ap- 

 pearance of a breccia with a cement of ore. This ore body is prob- 

 ably made up of two segments; the main one including Picachos 

 Socavon 1, 2, and 4; and a down faulted segment that forms the ore 

 of the Penascos de la Industria. 



Socavon 1 which penetrates this ore body begins at its contact with 

 the latite at an elevation of 1,950 meters above sea level and passes 

 through 150 meters of solid iron ore and then enters a wide zone of 

 liighly altered latite for the rest of its length (225 meters). Another 

 adit, Socavon 2 begins at the contact of the ore at an elevation 1,975 

 and is driven east and north for a considerable distance and is en- 

 tirely in solid ore. 



The other ore bodies have not been explored but their size can 

 easily be judged from their prominent outcrops. Immediately east 

 of the ore body now being worked is a broad tilted tabular mass of 

 ore that caps Cordon Rangel. This body, roughly circular in outline 

 has a diameter of about 250 meters. Socavon 1 passes directly under 

 this ore capping but after leaving the western ore body is in altered 

 latite for the rest of its length. It can reasonably be concluded 

 that this ore body is tabular in form and probably does not exceed 

 40 meters in thickness. 



Further east and capping the central portion of the hill is the ore 

 body of Picachos Sur and Norte. Its southern outcrop is bold; to 

 the north it merges into the smoother slopes. Some old workings on 

 the north side of this body show that the rock has been considerably 

 brecciated and later cemented by the calcite, magnetite, and augite. 

 The southern part, however, is of firm iron ore of high grade. This 

 body is probably tabular in form with a slight dip to the north. 



The easternmost ore body is that of Picacho de la Cruz and Relices 

 Prieto where the iron ore forms bold castellated outcrops of pure 

 mineral. It is apparently faulted into several segments but lack of 

 any work on it precludes determination of its true form. 



Several minor bodies occur at the northern foot of Picacho Socavon 

 2 of which the most interesting is that of Socavon de la Cueva. This 

 ore body has been opened by several adits and shows fine flaky 

 hematite as bedlike schliers in a soft tuff. These schliers are con- 

 tinuous for considerable distances. 



Farther north, at the small knoll of iron ore called Picacho Rangel 

 the ore is similar to the ore of the main deposits but the country 

 rock is rhyolite instead of latite. 



