• ccxlvii 
. ' p 2IJ. ” * 
ROCK SPECIMENS. 
>/Oi’ ■’ 'C 
The following Observations on the Rock Specimens, collected by the 
• Expedition, has been furnished by Charles Konig, Esq., F.R.S., &c. 
We may conclude, from the nature of the rock specimens collected on 
the former voyage for discovering the North-West Passage, that both the 
east and west coast of Davis’ Strait and Baffin’s Bay are composed of primi- 
tive formations, in connexion with others of a more recent date, which for 
the greatest part belong to several members of Werner's trap formation. It 
would appear, however, from the paucity of specimens decidedly referable 
to trap rocks among those brought from Baffin’s Bay by the late Expedition 
to the Arctic Seas, that the same formation is less prevalent on the western 
coast. While on the west coast of Greenland it exists in all its different 
gradations, but more particularly in the form of amygdaloidal transition trap, 
with many of those minerals which are usually found nidulating in it, such 
as calcedony, agate, jasper, green earth, &c., no traces of any of these sub- 
stances are seen among the specimens collected by the Expedition in its 
progress down the western coast of Baffin’s Bay, where the principal rocks 
are gneiss and micaceous quartz-rock, with some ambiguous granitic com- 
pound, in which hornblende seems to enter as a subordinate ingredient. 
In the latitude of the entrance into Sir James Lancaster’s Sound, the 
specimens, which I had an opportunity of seeing, begin to indicate the 
