GEOLOGY — COAL OF COOSE BAY. 63 



the public, and it was confidently believed that there had at last been found beds of bitu- 

 minous coal equal in quality to that imported from the eastern States. 



I had an opportunity of examining several cargoes of Coose bay coal at Portland, Oregon, 

 and San Francisco; and from Mr. Northrup, of Portland, Messrs. Flint, Peabody & Co., of 

 San Francisco, and from others, I have received full descriptions of the mines, and much inter- 

 esting information in reference to the character and extent of the coal deposits. Subsequently, 

 through the kindness of Lieutenant W. P. Trowbridge, U. S. A., I received a map of the bay 

 and of the locality where the mines are situated, and a section across from Point Arago to the 

 bay, including the strata of coal which are worked ; also drawings of a large number of the 

 fossils taken from the associated strata, very beautifully executed by Mr. Bridgens, of San 

 Francisco. I was able to bring home a suite of specimens of the coal, of which I have since made 

 chemical analyses. From this material I am able to make the following report: 



COOSE BAY COAL. 



Geological position. — This coal is interstratified with sandstones and shales, which form a 

 series several hundred feet in thickness, the strata being very much disturbed by intrusion of 

 trap rock, some of them being inclined at an angle of 45°. The beds of coal are found in the 

 upper part of the series, being most fully developed on the shores of the bay, where the strata 

 are much less disturbed than nearer Cape Arago. From the description and section given by 

 Mr. Higgins, I infer that a line of upheaval, with a northwesterly trend, passes between Coose 

 bay and the ocean, giving character to the headland of which Cape Arago is the extremity, 

 and tilting up the stratified rocks on either side. Several of the strata associated with the coal 

 are highly fossiliferous, most of the fossils being marine mollusca. Impressions of plants are 

 also found, but none are represented in the drawings of Mr. Bridgens. Among the fossil shells 

 which he has figured, I recognize Nautilus, Area, Cardium, Tellina, Nucula, Natica, Fusus, 

 Cerithium, &c , with bones of fishes. It is impossible to be certain with reference to the species 

 of these fossils, but they have all a general resemblance to those obtained from the sandstones 

 and shales of the Columbia, and some of the species are probably the same. Those portions of 

 the series from which the fossils come are evidently tertiary, and there is little doubt that the 

 series, as a whole, is identical with that of the Columbia, which has been pronounced by Mr. 

 Conrad to be Miocene. 



The coal occurs in several distinct strata, three of which are represented in Mr. Higgins' 

 section. They are apparently confined to the upper portions of the series which I have men- 

 tioned. The most important stratum varies considerably in thickness in different localities, its 

 maximum being about 9 feet. These beds of coal are said to extend over a large area in the 

 vicinity, and have been traced many miles inland. 



Physical and chemical character. — The coal is bright, black, and handsome, and when first 

 mined has much the appearance of some of the bituminous coals of the Mississippi valley ; most 

 resembling those from the coal fields of Illinois and Iowa. Upon a closer examination, however, 

 it is readily seen to be a tertiary lignite, most of it exhibiting very distinctly the structure of 

 the wood from which it has been formed. I have seen masses of several hundred pounds weight, 

 which were evidently portions of the carbonized trunks of trees of large size. In these, the 

 rings of annual growth, knots, and branches, were almost as plainly perceptible as in recent 

 wood. Like most of the lignites of the west, though firm when first mined, having a conchoidal 



