GILPIN CARBONIFEROUS DISTRICT OF ST. GEORGE's BAY. 363 



cave is about thirty yards long, very low in places, and terminating 

 in a similar vault. 



Close to the cave a large deposit of barytes is exposed on the 

 beach. The vein is several feet wide, running north and south ; 

 its quality is excellent, being compact and free from impurity. 

 The whole of this district is crossed by small veins of crystallised 

 calc spar, sometimes containing galena ; they are of workable size 

 only at one place, in East Bay, where a mine has been opened and 

 vigorous operations pushed forward. The vein is exposed in a 

 land locked cove, worn out by the action of the sea on the soft bed 

 rock. The foot wall of the richest portion of the vein, yielding 

 about fifteen per cent of lead, has been defined. The total width 

 of the plumbiferous rock is over twenty feet. The ore is the com- 

 mon sulphuret of lead, with copper pyrites, calc and fluorspar. 

 I was informed that the per centage of silver present was incon- 

 siderable. The limestones on the east side of the cove contain a 

 beautiful shell bed, affording the characteristic Lower Carboniferous 

 fossils, and near this is an argillaceous sandstone filled with indis- 

 tinct fragments of broken plants. 



On the point of land separating East and West Bays are found 

 abundant indications of petroleum ; it oozes from crevices in the 

 rock, and can be secured in considerable quantities. No attempt 

 has yet been made to trace it to its source. 



In this connection, a notice of the position of the Pennsylvania 

 Petroleum may be interesting. Beneath the conglomerate are a 

 series of thin bedded sandstones and shales, the latter often an olive 

 green color. These may be readily recognized as belonging to the 

 Chemung and Portage groups of the New York Geologists, and 

 known in Ohio as the Waverley series. Under this is a bed of 

 bituminous shale from two hundred to three hucdred feet thick, 

 called in New York the Hamilton shale, and known in Ohio as the 

 black slate. Much oil is found in this bed. Dr. J. S. Newberry 

 considers that the indications of oil in higher measures are derived 

 from this reservoir by percolation through the more porous strata. 



I have glanced over the more prominent geological features (f 

 the Bay, they are of unusual interest both to the geologist and 

 miner. Almost the whole series of the carboniferous measures are 



