Congressional Serial Set Volume 3386 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1895 Excerpt: ...rule prevails throughout, and among the many veins which I have seen no exceptions are found. This regularity is the more remarkable inasmuch as the fissures were produced in a region which had already acquired pronounced schistosity during some earlier era of disturbance. The cleavage of the gneissoid schists is much less regular than at most points in the Southern States. In the region surrounding the South Mountain district the usual strike is that of the Appalachain chain, and the dip is easterly. On the flanks of the South Mountain the schistose cleavages strike on the average N. 20 W., dipping at various angles to the northeast, and there appears to be some local cause of confusion. In the western portion of the district the strike is more nearly northeast, with a southeasterly dip, but the dip of the surfaces varies greatly and is often nearly flat. Thus the forces which opened the fissures now filled with ore acted upon a highly eolotropic mass. In this connection the reader may be reminded of the conglomerates which have been sliced up by joints; for example, the Carboniferous pudding stones of Newport Island. As most of the veins are exposed only iu the saprolite, it is impossible to study the faulting on them satisfactorily. One small vein on the Mills property was noticed, with a normal fault of an inch, and two of the small veins at the Marion Bullion are faulted, one 3 inches and one one-half inch, both normal. Since the veins manifestly form a system, and since on any system of parallel fissures the direction of faulting is uniform, these three cases may be taken as indicative of the movement of the entire district. Faults such as these would be produced by a force acting in a vertical plane which strikes N. 20 W. and directed southward at an...