20 PROCEEDINFS OF THE CANADIAN INSTITUTE. 
Prof. T. S. Hunt, of Montreal, is disposed on chemical and lithological 
grounds to assign both this and the following to the Huronian. The next is a 
Siliceous Argillyte (F) passing into an impure Serpentine, with, however, 
some seams of Tale and Precious Serpentine. The relative age of this and 
the preceding series is difficult to make out. However, together with frag- 
ments of A, C, and E, it seems to have constituted an island some four miles 
in diameter in the midst of the Carboniferous marsh or estuary. All the 
rocks described above are presumably of Pre-Carboniferous age, and upon the 
different members of this series, for they do not seem to have been uniformly 
deposited, the Carboniferous rocks were laid down. The lowest bed of Car- 
boniferous age is a conglomerate of fine Quartz pebbles with some argillaceous 
matter, metamorphosed into a dark, compact, siliceous rock, containing here 
and there a layer of black slate with Annularia longifolia (G). This probably’ 
helengs to the ‘‘ Millstone Grit.” The overlying bed is a Sideritic Argillyte 
(H)—a finely laminated slate generally with minute nodules of carbonate of 
iron with a crystalline structure. Then a thick bed of coarse conglomerate 
(1), the pebbles and boulders of which consist of a micaceous Quartzite, and 
contain in some localities Lingule. Minute crystals of Magnetite abound in 
the cement of this conglomerate. The pebbles are often coated with scales of 
Mica, and the shells of the Lingule are sometimes plumbaginous. Lastly, 
we have the Coal-measures proper consisting of alternating conglomerates, 
sandstones, clay slates and Mica-schists, together with several seams of 
plumbaginous Anthracite (J). About sixty species of coal plants occur in the 
slates of this series—mainly of the genera: Annularia, Calamites, Lepido- 
dendron, Neuropteris, Odontopteris, Pecopteris and Sphenophyllum, The 
impressions are sometimes coated with Talc or Pyrite. The latest analysis of 
this coal* afforded the following extremes in nine analyses: Carbon 67—79 
%, Ash 11—17 %, Volatile combustible 44—74 7%, Water 24—10}4 {%. The 
Ash contains from 50—75 % of Silica. This coal, as stated by Dr. Emmons, 
possesses the property, after being dried at 115° Centigrade, of absorbing, 
when exposed to a N.W. wind, over 13 % its own weight of water, and, when 
placed over water, 224 7%. Veins of Quartz and of Asbestus traverse the coal 
seams. 
The Pre-Carboniferous beds measure at least from 4,000 to 7,700 feet, the 
Carboniferous from 4,000 to 5,500, and in other parts of the basin perhaps 
8,000 feet. All the beds have been folded parallel to the Appalachian chain, 
and the last flexure probably took place at the close of the Carboniferous 
Period, The beds were also flexed, though on a much smaller scale, in the 
opposite direction, indicating a pressure operating N.N.E.—S.S8.W., as well 
as one W.N.W.—E.S.E.] 
In the western part of the basin, along the West Passage of 
Narraganset Bay, the strata of the Coal-measures are much disturbed, 
being in places vertical or folded over upon themselves. In accord- 
* Arthur B. Emmons, Notes on the Rhode Island and Massachusetts Coals. Transactions of 
the American Institute of Mining Engineers, Sept., 1884. 
