86 Reviews—The Geological Surrey of England. 
limestones. Judging from the fossils in this rock where it outcrops 
at the surface in other areas, the fauna is entirely invertebrate, and 
mainly consists of Crinoids, Trilobites, Brachiopods, Corals and 
Polyzoa. The volatile products of the decomposition are confined to 
the upper beds of the limestones by the presence of the massive 
overlying beds of the Utica shale. The animal origin of the petroleum 
in these limestones most probably accounts for the fact that the crude 
material contains a greater amount of sulphur, and is consequently 
more difficult to deodorize, so as to be suitable for burning, than the 
petroleum from the Pennsylvania wells, which in all probability is 
derived from the organic matter of bituminous shales, and is of 
vegetable origin. Prof. Orton is of opinion that in Ohio the petroleum 
has been produced at normal rock temperatures, and is not a product 
of destructive distillation of bituminous shales, and that the stock of 
petroleum in the rocks is already practically complete. This has 
been forcibly shown by the practical exhaustion of the supply in 
many areas which were at first productive, the place of the oil being 
taken by strongly saline water. 
In certain localities in the north-eastern part of Ohio, where 
Carboniferous and Devonian rocks occur, an important supply of 
petroleum and gas has been obtained in a sandstone rock of sub- 
Carboniferous age, known as the Berea grit. The petroleum is 
believed in this case to be derived from thick beds of bituminous 
shale underlying the grit, and it is probably of plant origin. Prof. 
Orton likewise discusses the value of the Ohio (Devonian) shales in 
Ohio as a source of oil and gas. Many particulars are likewise 
given of the amounts produced, the mode of drilling the oil-wells, 
and the transportation and methods of using the natural gas. 
G. J. H. 
TII.—Gerotocicat Survey or EnG@uanp anp WALES. 
1.—Tue Grotocy or Tue Curviot Hitts (Eneuisu sips). By 
C. T. Cuoven, M.A., F.G.S. 8vo. pp. 60. Price 1s. 6d. 
IYW\HE country described in this Memoir-belongs entirely to Northum- 
berland ; it is for the most part hilly, the highest point (Cheviot) 
being 2676 feet above sea-level. The oldest rocks, consisting of 
grey-green shales and greywackes, are grouped with the Wenlock 
Beds. They contain ‘‘ apparently very few distinct fossil remains.” 
These beds are overlaid unconformably by the Cheviot volcanic 
series—porphyrites, ashes, and ashy sandstones—grouped as Lower 
Old Red Sandstone. There is also a granitic core, probably of the 
same age. Higher still, there are representatives of Upper Old Red 
Sandstone, in certain conglomerates at Windy Gyle, etc.; these are 
not to be clearly separated from the conglomerates at the base of the 
Carboniferous system. The Lower Carboniferous beds are divided 
as follows :— 
Fell Sandstones = Bernician (in part). 
Cementstone Series 
Lower Freestone (flaggy sandstones) 
Basement Conglomerates. 
| = Tuedian. 
