170 
GEOLOGY. 
wide, forms a protrusion in the line of the cliff, traversing the general rock, and pro- 
jecting towards Kotzebue’s Sound. Here it forms the rock first exposed in the cliff to 
the south of the neck, producing four perpendicular and contiguous promontories, sepa- 
rated from each other by small receding bays, and presenting a white and blue striped 
stratification, with a dip of not more than 5°. The upper part of this lime-stone contains 
iron pyrites, and has cavities filled with chlorite. The lower strata are more abundantly 
intermixed with micaceous schistus, containing compact actynolite and flat prisms of 
glassy actynolite, crystals of tourmaline, and variously-formed crystals of iron pyrites. 
The quartz in some places assumes the colour of topaz. Garnets occur in the mica 
schist, and earthy chlorite is found in frequent small masses, chiefly investing quartz. 
The iron pyrites in one place becomes predominant, and composes a bed, which does 
not appear to be continued to any distance. 
In one of these promontories, a deep and capacious cavern would afford shelter, 
and may be a place of retreat for the natives, the foxes or the wolves. 
The western side of Choris Peninsula is mostly composed of mica-slate rock, and 
contains veins of quartz and felspar, with imbedded crystals of schorl, garnets, horn- 
blende, and calcareous spar. 
The Island of Chamisso, three or four miles in circumference, has rocky cliffs ex- 
posed on all sides except to the east, where a gradual ascent conducts from the low 
sandy point to the top. In its centre, a mound of bare rock constitutes the highest 
part ; and towards the southern side of it, there is an appearance as if a circular pave- 
ment of stones had been laid by the hand of man. 
The general rock of this island is mica slate passing into flinty slate, and on the 
north and south-west into gneiss. The strata rise at an angle of about 60° on the nor- 
thern side. The imbedded minerals are garnets, schorl, and chlorite ; in the veins are 
hornblende, quartz, felspar, and horn-stone. About seven miles east of Chamisso 
Island, the cliffs at Eschscholtz Bluff are formed of a chlorite slate containing iron 
pyrites. This rock constitutes an essential part of the formation for several miles south- 
westward along that coast ; it contains numerous small garnets, and passes into, and 
alternates with, mica slate and clay slate. The veins and imbedded minerals are 
quartz, calcareous spar, chlorite, earthy felspar, crystals of tourmaline, garnets, &c. 
Beds of blue and white primitive lime-stone, of slaty structure, cut the cliff a little, 
inside East-spot station ; they dip at a very great angle to the westward. 
Much of the coast of Kotzebue’s Sound, on the west of Cape Deceit, is composed 
of dark blue slate, and slaty lime-stone having its layers separated by mica slate. On 
the south coast of the Bay of Good Hope, the shore continues varied by cliffs of mode- 
rate height and sloping declivities, for the distance of eight miles to the north-west, 
apparently of the same formation, when it assumes a totally different aspect, being hol- 
lowed out by numerous small bays separated by projecting points. The whole is low, 
and the land rises up by gradual slopes covered with soil and vegetation. These low 
projecting points are thickly strewed with large masses, partly of vesicular, partly of 
compact lava containing olivine. Some of these blocks extend into the sea, others are 
