The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1894-01-13

still where they fell, is found in Tele
graph Hill.
Diamond Head is beautiful spe-
cimen of q tufa cone, pure and sim
pie: Punchbowl of a tufs cone winch
ended in election Of molten leVa' Ia
sufficient to form any stream, al
though several miniature nssureS
opened in its sides, leaving bea1IlIui
examples of eruptive dykes Ian-
talus. Sugar-loaf and Round-toP' as
we'll as gravel beds, to leeward OF
them. illustrate the results OF expo
sive eruptions-
The ridges separating Pauoa ana
Nnnanu. Nuuanu and kallhl, or
Nanoa and PaIolo. illustrate the
extreme effects of erosion IN dlssec1
inc q volcanic mountain, while IN
contrast, the ridges between fauoa
and Manoa show their angular out.
lines softened by the covering. OF
volcanic sand that has been slfted |
over them from Tantalus.
The filling up of the upper parts
of Makiki and Pauoa has gwen US
also in these valleys picturesque
waterfalls and gorges-
Streams diverted from their course
by obstructing lava flows are seen IN
those issuing respectively from Ma
noa and Palolo, crowded close to-
gether by encroaching lava from
Rocky Hill on one side and Tele.
graph Hill on the other. MaKlkl
stream, after having been damned
ND by volcanic gravel, has had 10
form for itself a new channel, giving
us thus a pretty illustration OF the
action of water on comparatively
level ground consisting of loose ma
terial. The example of the Moanalua
stream in cutting through obstruct-
ing tufe is most interesting OF all.
Effects of hot springs, charged
with calcareous matter, are seen on
Diamond Head and in connection
with other tufa cones, as also IN Ma
kiki valley.
The prolonged action of heat from
the molten lava of Punchbowl has
resulted in giving the tufa OF that
cone a remarkable semi crystalline
character from crystallization of car
Donate of calcium.
Wind drifted sand has accumu.
lated at the base of Diamond
Head. The action of the sea has
formed also at the base of that cone
blnffs. now removed a short distance
from shore by elevation OF the land:
Other evidence of change OF level
| in the land Tor of the sea), IS seen In
the reef formations which crop out
in Honolulu, On Prison island aud
throughout the Moiliili region.
| OF course the coast is fringed ev-
erywhere with living reefs, the en-
trance to Honolulu harbor illustrat.
ing the effect on living coral polyps OF
water from mountain stream.
Sandstone, formed from shell and
coral sand, and conglomerate, or
breccia. from tufa fragments or from
tufa, lava and coral fragments mixed.
are among the interesting formations
at the base of Diamond Head. where
also may be seen illustrations OF the
formation of pot holes and parallel
orooyines. and other exceptional!
effects of the action OF sea waves
The capricious behavior of tidal cur
rents has been recently illustrated to
the cost of property owners along the
Waikiki beach.
Deposits of oxide of manganese
forming a crust on rocks that nave
been submerged. are not rare, especi
aliy about the base of Telegraph Hill
A crust of the same material covering
the surface of some of the tufa on the
northeast slope of Diamond Head
seems rather to have been deposited
from flowing water, although the re
zion NAV once have been submerged
the lava of the Moiliili quarry, which
seems to have flowed over coral, ant
. probably at recent period, Is dis
tinctly amygdaloidal, the result
think, of submergence.
I have drawn roughly a geo
. logical map of Honolulu, recog
nizing the following superhcla
. formations: 1. The original Law
+ of the dissected mountain
:. mass, in the ridges separating tn
great valleys. 2. Low land with
). soil consisting of ancient decompose
, lava 1.-THE Palama region). 3. AIlu
vial deposits from Nuuanu and hf
a Iihi streams. 4. Tufa of PunchboW
+ 5. Volcanic sand in stu from the Nj
q kiki group of craters. 3. GravelI
r soil consisting mainly Of decompose
volcanic sand of No. 5, covering niue
4 OF the plain and extending into Nut
3 anu Valley. Z. Scoria and lava froi
q Rocky Hill, which seems to extend
! far as the Moiliili quarry. 8. Law
8 from Telegraph Hill. 9. Out -crol
q ping reef rock in Honolulu; Moilll
f aud makai of Palama. 10. Sand an
q other coast formations OF kakaal
\ and Waikiki. / have not yet accu
= ately determined the limits Of thei
several areas; the map shows rattle
+ work laid out to be done than wh'
v has been actually accomplished.
n shall try to get help in carrying
is out from my next geology class.
t, The Pacific Cable.
LONDON. Dec. 25.-Mr. Sandfol