428 
GEOLOGY OF THE FIRST DISTRICT. 
Figs. 4 and 5 of Plate 13, illustrate the position of the rocks in the Lebanon valley, between 
Canaan mountain on the west, and Hancock mountain on the east. 
Prof. Barnes described the geology of this region many years ago ;* and while many things 
are well described, he seems to have been led into a grave error in the position of the strata 
of Canaan mountain, which are represented as horizontal. He says, “ The lower stratum of 
limestone described in the section is at the same height on both sides of the Canaan mountain. 
It is associated with slate. This limestone, part of which is siliceous, is found with slate on 
the top of Hancock mountain. It was also observed on the top of a mountain in Lee, fifteen 
miles southeast of our section. These two strata, associated on the top of Hancock, and at 
the base of Canaan mountain, may perhaps without impropriety be considered as parts of the 
same original bed.”t “ That the strata have dropped in situ, and not bent downwards as Prof. 
Eaton supposes, appears from the horizontal position of the great masses of mountain strata 
in our section, and also from the fact that the slate is found at the same height on all the cir¬ 
cumambient hills, and the limestone at the same depth in all the circumjacent valleys, and the 
greywacke at the same elevation upon the neighboring mountains. This last rock is, more¬ 
over, laid hare to a great extent in that part of the mountain which lies south of the High 
knob. Here the whole formation is perfectly open to inspection. The upper'surface is hori¬ 
zontal. This surface is composed of the upper edges, termed in geology the outgoings of the 
strata ; for it must be carefully observed, that although the rocks are stratified, and the strata 
highly inclined, yet the great beds or mountain masses are disposed above each other horizon¬ 
tally, and these beds or masses are termed strata when in general we speak of geognostic 
relations.”!; The last sentence explains the cause of his error. The strata are all highly in¬ 
clined, dipping to the eastward, and are entirely distinct from laminations of slaty cleavage. 
Prof. Briggs, one of the assistants on the geological survey, describes the top of Canaan 
mountain as composed of a rock more than usually siliceous. He travelled in a zigzag direc¬ 
tion many times across the mountain, and found it as described by Prof, Barnes, composed of 
limestone, slate and siliceous rocks. The limestone flanks it on each side, and ranges along 
its base parallel to its length, and dips to the eastward at a high angle. 
The limestone in the Lebanon valley is frequently interrupted by faults. But few were 
traced out.^ Prof. Briggs examined the limestone near Lebanon springs with care; and 
speaking of that on the east side of the Lebanon valley, north of the springs, southeast of 
Mr. Locket’s, he says, “ It is thirty or forty rods in length, and appears to be a ledge of the 
sparry limerock imbedded in the slate, and conformable to its laminar divisions, which appear 
to dip S. 60° E. At the southwest part of the ledge, where it is about eighty-one paces 
wide, the limestone appears in some places to be interlaminated with the slate. On both sides 
• American Journal of Science, Vol. 5, p. 8 to 21, f Ibid. p. 16. t Ibid. p. 16. 
§ The reader undoubtedly already understands, that in consequence of the limited time for the geological survey, the 
great area to be examined, all of which must come under the eye of the geologists, and the time requiring sixteen square 
miles to be examined on an average during each working day by each of the geologists, little time could be spent in minute 
investigations. The outlines are marked out, and most of the filling up of the picture must be done by others. 
