1847.] DAWSON ON THE NEW RED SANDSTONE OF NOVA SCOTIA. 99 
APPENDIX. 
On the Lower Carboniferous Rocks of Windsor and Horton. 
The true age of these rocks was first determined by Mr. Lyell, 
and the facts now stated may be considered as supplementary to those 
contained in his paper on the coal formation of Nova Scotia. 
The lower carboniferous rocks of Horton and Windsor consist of 
two groups of beds, very distinct from each other in mineral charac- 
ter and fossils ; these are in descending order. 
1. A marine formation, composed of red and grey sandstones with 
red and purple marls, and large beds of gypsum and limestone, the 
latter with numerous fossil shells. 
2. A lacustrine or estuary deposit, consisting of dark shales and 
sandstones with some white and reddish sandstone, containing fossil 
plants and scales of fish. 
The first group is seen at the mouth of the Halfway River, and 
south of this place along both sides of the Avon. It occupies the 
greater part of the country between the estuaries of the Avon and the 
Shubenacadie, and eastward of the latter river. The lowest bed of 
gypsum in the group, as seen in the Aven estuary, is of great thick- 
ness and contains a large quantity of anhydrous gypsum. This bed 
is well-exposed near the mouth of Halfway River, and it is probably 
the same bed which forms the high cliff of gypsum extending for a 
considerable distance along the east side of the St. Croix River. 
Under this bed, at Halfway River, are coarse brownish and grey sand- 
stones which appear to rest on the upper beds of the second group. 
The second group is seen at Wolfville, and at several places on the 
road between that place and Windsor, at Horton Bluff, at Sneid’s 
Mills south of Windsor, on the St. Croix River near the road from 
Windsor to Halifax; and similar rocks, with some of the same 
fossils, are associated with the gypsiferous series on the upper part of 
Kennetcook River, at Five Mile River, on the Shubenacadie, and at 
Salmon Creek and Noel Bay. 
Near Horton Bluff is a bed containing numerous stumps of small 
trees, apparently in the place where they grew. The stumps are 
casts in clay and only a few inches high, and are marked only by 
transverse wrinkles, apparently caused by compression. The bed 
underlying them is filled with small branching roots, and that above 
contains numerous prostrate trunks of Lepidodendron, probably the 
upper portions of the stumps below. These fossil trees must have 
formed a thick grove as the stumps are very close together, and they 
had probably not attained their full growth when broken down and 
buried ; the largest which I saw being only eleven inches in diameter. 
This fossil forest is lower m the carboniferous system than any 
hitherto discovered in Nova Scotia. 
The dark shales of Horton and Windsor, though in some places 
containing small seams of coal, are not equivalents of the productive 
coal measures of Pictou and Cumberland, but rather correspond to 
some similar beds seen to underlie the gypsiferous series on the 
shores of the Gulf of St. Lawrence, noticed m the Geological Journal, 
vol. i. pp. 31 and 34. 
