110 
FOURTEENTH REPORT. 
have I been referred to the Oriskany as marking the division between the 
two. It has interested me very greatly to note that the fossil-bed 
characteristic- of the Anderdon limestone beds lies between these two 
sandstone deposits at the No. IT location, at 52 ft. to 5G ft. in the core, 
—below the recognized Oriskany horizon at 45'G" and above the lower 
deposit of the same sand grains at 59'6". The drill penetrated a 
heavily silicated rock at about the same lower horizon in nearly every 
hole put down through the Anderdon at Sibley. 
Without knowledge of this additional evidence on the part of the re- 
viewer. there appears in the November, 1911, number of the American 
Journal of Science (and over the initials “ C . S.”) this review of the 
paper in which the former evidence was presented: — “This paper pre- 
sents conclusive evidence that the Anderdon limestones are not Silurian 
in age and cannot be included in the Monroe series, but ‘are of Devonian 
age/ The Anderdon limestone lies in a trough of Monroe strata, and 
is to be grouped with the Onondaga formation of Middle Devonian 
time.” 
In one core (No. 20), and in this one only, the characteristic Ander- 
don fossil bed begins at once at the top of the Anderdon; and in this 
core only was the material of the fossil-bed found to be heavily silicated. 
The location is at the south side of the limestone deposit. Across the 
limestone field from this, on the northward side, both the top of the 
Anderdon is heavily silicated and the base of the Dundee. 
Ox the occurrence of the Anderdon limestones, it may be noted 
in passing that rock of the same quality and varied appearance out- 
crops along the Maitland river at Goderich, Ontario; in the neighbor- 
hood of Kincardine and Southampton, along Lake Huron north of 
Goderich; at Cargill and at St. Marys, following along the north side 
of an arm of the old Devonian sea; and in the Thames valley between 
Ingersoll and Woodstock, Ontario. It has been identified to the west- 
ward of the Columbus (Comiferous) outcrop on Marble Head, Ohio, also. 
The smaller Canadian islands in the west end of Lake Erie were also 
examined, but these show only dolomites and no trace of Anderdon. If 
the Anderdon beds outcrop in Lake Erie it will be along a line west of 
Pelee and Kellys islands and east of Put-in Bay, the Bass islands and 
Old Hen island. 
A cross section of the Detroit river area from the Amlierstburg 
quarry to the Sibley quarry, and including both of these, shows Ander- 
don and overlying Corniferous at each end of the section, with only the 
underlying dolomites over the middle distance. The direction of the 
cross section is NW. x 12 ? W. ; the distance 35,700 feet; eastern end 
of the section 10,200 ft. east of east channel bank of Detroit river, and 
the western end G.000 ft. west of west channel bank. The Silurian 
dolomite surface is anticlinal from the middle of the Anderdon field at 
either end, and over the whole Detroit river distance between. This 
anticline is succeeded at each end of the section by a minor syncline, 
1 he combined distance of which is less than half the total distance of the 
intervening anticline. In these synclinal basins the material of the 
Anderdon beds lies, — in immediate contact with the dolomitic limestone 
base of the Gorniferous above it, and separated from the dolomites 
below by another dolomitic limestone that is richer in CaCO., than is 
Ihe limestone at the base of the Corniferous. 
