The observations made by the writer during the past four years confirm in all essentials the views set forth in the former article in the Quarterly, and while a volume might be written describing the phenomena exhibited by different mines and mining districts, the array of facts thus presented would be, for the most part, simply a re-enforcement of those already given.

The present article, which must necessarily be short, would hardly have a raison d’etre except that it affords an opportunity for an addition which should be made to the classes of mineral veins heretofore recognized in this country, and it seems called for by the recent publication of theories on the origin of ore deposits which are incompatible with those hitherto presented and now held by the writer, and which, if allowed to pass unquestioned, might seem to be unquestionable.

BEDDED VEINS.

Certain ore deposits which have recently come under my observation appear to correspond very closely with those that Von Cotta has taken as types of his class of “bedded veins,” and as no similar ones have been noticed by American writers on ore deposits they have seemed to me worthy of description.

These are zones or layers of a sedimentary rock, to the bedding of which they are conformable, impregnated with ore derived from a foreign source, and formed long subsequent to the deposition of the containing formation.  Such deposits are exemplified by the Walker and Webster, the Pinon, the Climax, etc., in Parley’s Park, and the Green-Eyed Monster, and the Deer Trail, at Marysvale, Utah.  These are all zones in quartzite which have been traversed by mineral solutions that have by substitution converted such layers into ore deposits of considerable magnitude and value.

The ore contained in these bedded veins exhibits some variety of composition, but where unaffected by atmospheric action consists of argentiferous galena, iron pyrites carrying gold, or the sulphides of zinc and copper containing silver or gold or both.  The ore of the Walker and Webster and the Pinon is chiefly lead-carbonate and galena, often stained with copper-carbonate.  That of the Green Eyed Monster—­now thoroughly oxidized as far as penetrated—­forms a sheet from twenty to forty feet in thickness, consisting of ferruginous, sandy, or talcose soft material carrying from twenty to thirty dollars to the ton in gold and silver.  The ore of the Deer Trail forms a thinner sheet containing considerable copper, and sometimes two hundred to three hundred dollars to the ton in silver.

The rocks which hold these ore deposits are of Silurian age, but they received their metalliferous impregnation much later, probably in the Tertiary, and subsequent to the period of disturbance in which they were elevated and metamorphosed.  This is proved by the fact that in places where the rock has been shattered, strings of ore are found running off from the main body, crossing the bedding and filling the interstices between the fragments, forming a coarse stock-work.