Image from the Biodiversity Heritage Library.
Contributed by Yale Peabody Museum of Natural History.
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Transcription
July 14, Clam Cave.
About 1/8 of a mile from the shore then strikes out a direct line-
that makes a mile white
stone dipping steeply into the land. The strike of this ridge is only that of the
hill mountain and this limestone is full of joints and as Monocline and other
faults. Also there occur at about here an iftle for the immigration.
pools red are common it is concluded it like the Chagres bank of j & It is therefore
more fruitful for the mining in one of the ridges mountains.
In about 1/3 of a mile across the land then are two unrelated series of
strata - Devonian, Redmondian and [illegible] and they must be separated by a
fault. Evidently Long Point is due to faulting and the swell of St.
Lamere is cut down in a series of step faults.
Dunbars note regarding the strata seen to the south of
Clam Bank Cave, and in the Helderbergian is as follows:-
"The southern point of Clam Bank Cave is formed of greenish
gray sandy shale showing up fine development of sun cracks. These beds
are dipping steeply about S 20° E. In the next half mile there is a
shallow cave where the strata strikes out in an angle across the shore
or that succeeding down layers come in to the southward. About
200 feet of these red shales and their bedded black sandstone are
exposed in this second cave. At the south end of this cave is exposed
heavy beddened limestone and much cross-bedded deep red sandstone.
In the middle of the cave the dip has gradually decreased to 38° S,
20° E, for the conglomerate. At this point about 50 feet of the
cave is exposed. Two classes of pebbles are to be seen in the
conglomerate. Both of them are well rounded or subrounded and
foliated. Those are all of hard rocks, rein quartz, quartzite, as
dark specks are all. Some of these are as large as 4 inches across.