i\>
Avatscha. The same rock is seen forming the foot of that part of the low range of
hills behind Petropaulski, where they border the lake on the eastern side. Veins of
variously-coloured quartz, assuming the character of jasper and chert, and of finely
waved talc-slate, lie between the strata.
The cliff, that first forms the sea-shore beyond the lake, in going to Avatscha, is
less distinctly stratified, but where it can be perceived to be so, tbe direction and dip
are nearly tbe same as in the isthmus already mentioned. Th e clay-slate is replaced
by talc-slate and basaltic porphyry, whilst the quartz rocks continue the same. A basaltic
tufa and green-stone, passing into serpentine, also prevail. Farth e r on, and close
to Avatscha, the cliffs are more generally formed of green-stone passing into serpentine.
From this part round the head of the bay to Paratunka the shore is low, and the
country plain for a considerable way to the foot of the snowy mountains, which form the
interior ot Kamschatka, and assuming the form of an amphitheatre, terminate the view.
Several small and shallow creeks are formed in this low ground near the sea, and
are remarkable by the raised banks, so similar to an artificial embankment as to have
suggested the idea to some of their having been constructed by art. To me these
mounds or dykes appeared the produce of the natural operation of the waters which
they contain.
Coming out of the bay, I observed a vein of several feel thick, composed of horizontal
basaltic columns, in the cliff forming the western side of the entrance.
No. 1. Clay-slate, forming the general rock of the coast from Petropaulski to the
entrance of Rakowena harbour.
No. 2. Greenish quartz and jasper, in No. 1.
No. 3. Horizontal strata of slate-clay hardened, under No. 4.
No. 4. Columnar porous basalt, forming the second promontory on the right side of the
harbour of Rakowena.
No. 5. Trap tufa, forming part of tbe cliffs in Rakowena harbour.
No. 6. Small-grained greenish trap tufa, forming part of the same cliffs as No. 5.
No. 7. Rolled basalt, forming part of the tufaceous cliff on the right side of the entrance
of Rakowena harbour.
No. 8. Quartz, serpentine and asbestos, imbedded in cliff No. 7.
No. 9. Chalcedony, in veins of cliffs, in Rakowena harbour.
No. 10. Chalcedony and crystals of greyish felspar in green-stone porphyry, in the
right hand cliffs of Rakowena harbour.
No. 11. Brownish jasper (altered by heat), from the cliffs of Rakowena harbour.
No. 12. Brownish felspar porphyry, with crystals of felspar, forming large beach stones
in Rakowena harbour.
No. 13. Reddish felspar porphyry, occurring with No. 12.
No. 14. Porphyritic green-stone, from the cliffs of Rakowena harbour.
No. 15. The same as No. 14, enclosing basaltic hornblende; locality of No. 14.
No. 16. The same as No. 15, lighter coloured; same locality.
GEOLOGY. 1 6 9
No. 17. Green-Stone porpbyry, imbedded in and forming one side of the lower part of
the cliff on which the north-eastern flagstaff is erected.
No. 18. Green-stone porphyry, with fewer imbedded crystals of felspar, traversed by
veins of milk-quartz.—C.
Ko t z e b u e ’s s o u n d .
The bounding shores of Kotzebue’s Sound for the most part rise by perpendicular
cliffs, either directly from the water or from a shelving beach. In some places the land
is remarkably low, aud only so much raised as to render the idea probable, that it is an
alluvial formation, the result of the accumulated mud and sand brought down by large
rivers and thrown up by the sea. The cliffs are in part abrupt aud rocky ; others are
made up of falling masses of mud, sand, and ice. The first or rocky cliffs, predominate
to the southward of a line drawn from the north-west side of Eschscholtz Bay to the
south-eastern part of the Bay of Good Hope. The second, or diluvial cliffs complete
the remaining north-east side of the sound, and take in part of the south-side of Eschscholtz
Bay. Low grounds chiefly border the Bay of Good Hope, and form the land of
and around Cape Espenberg. Th e history of these mud cliffs, and of the remarkable
organic remains contained in them, has been given in vol. 1. Appendix. ^
'fhree geognostic formations are exposed on the shores of Kotzebue’s sound.
The primary, (consisting of clay-slate. mica slate with beds of primitive lime-stone,
talc slate, alum slate, &c.) forms the whole of the rooky coast. The diluvial and alluvial
formations constitute the remaining part of the adjoining country.
In giving a more particular account of the primitive formations, I shall commence
where it first shows itself, in Choris Peninsula, between the Bay of Eschscholtz and
Kotzebue’s Sound (see pi. 1. Geology). This division is in the form of a narrow peninsula
variously indented, and lying longitudinally in a north and south direction. The
northern part of it is separated from the southern by a narrow low neck, and assumes
the shape of a round and somewhat conical eminence, surmounted by a flat hut-like
peak, the sides of which rise a few feet nearly perpendicular above the surrounding
surface. The whole height may be about 600 feet from the level of the sea. Both
sides of this peninsula terminate in rocky cliffs, which towards the west are 150 or 200
feet high, stratified, unbroken, and dipping to the west at an angle of 30". On the east
side towards Eschscholtz Bay, they are less high and more broken, presenting no evident
dip, and are composed of a greyish mica slate, with very few included minerals.
The cliffs expose a general rock of mica slate in loose aud falling fragments. The dip
is to the north-east in the first promontory looking to Eschscholtz Bay, at an angle of
60". The mica slate is here of a greenish hue, the mica considerably predominating,
with garnets, veins of felspar inclosing crystals of schorl, and fissures filled with quartz.
Nearly midway between this promontory and the low neck, a bed of milk quartz protrudes
at the top of the cliff, and marks its locality at a distance by the large white
blocks which have fallen down and remain unaltered by the seasons. Still nearer the
neck, a narrow bed of lime-stone above the mica schist, above ten yards high and five