The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1856-1888, 1883-03-31

ct the summit, Immediately sealed up, being
tapped, l presume, by the outbreaks which oe-
CURED at a considerable lower level.
Tie lavas of both KIiauca and Mauna Loa
seem 70 ne 10 be of an abnormal type. The anal
Uses are not yet made and | can, therefore, give
only their superficial character. They have the
appearance of being extremely basic, decidedly
more 80 than n3ruial basalts. | cannot help think
ing that they may be Eirly ~relegated to what
Judd describes us ultra basalis. Most of the
lavas Of Mauna LOa contain excessive quantities
of divine, many specimens being at least half
composed of that mineral. The laYas of KIlauea,
on the other hand, whether IN the pit itself or 10
the country round about, seldom show much
Divine. But the eruption of 1910, which be-
longs physically to the KIlauea group, is highly
ollylntic, while the last eruption of Mauna LOa
shows little or no Divine. | am led to suspect
that the ultimate analyses of the two lavas,
whether oliyintc or not, will show but little diff
ference. In other words, | suspect that in some
cases the Divine was crystallized in the lava be-
fore eruption, while in others il was not, the
magma being very nearly identical In both cases.
| spent a great deal of time in the study of
Mauna kea. This volcano contrasts strongly IN
its aspect with Mauna Loa. Its laVas are APP
parently more nearly normal basalts and show a
somewhat wider range of variety. The most
striking difference in the two mountains is the
absence Of fragmeutal products upon Mauna Loa
and their great abundance on Mauna Kea. The
latter mountain is covered all over with magnif-
cent cinder cones of large size and beautiful pro-
portions, which are, by far, the most striking
features of its mass. Many superb cinder cones
are scattered thickly around its base and over
it's great TANKS, and a large cluster of them forms
it's summit. The activity of Mauna kea has
probably been extinct for a very considerable
period of time. When we first look upon its
ciuder cones in a perfect state of preservation.
the first impressions Is in favor Of great regency in
Its activity, but a more careful study OF the sur
roundIngs leads to Il modification Of this view.
UPON the windward side Of the mountain the
Tavages OF time are very apparent and quite ex-
teusive. Upon the lceward side they are far less
extensive, but are by no means wanting. During
the past few years my attention has frequently
been called to the very great inequalities of effects
produced upon the same mass by varying degrees
of energy in the agenciesoi degradation. Nowhere
does it come out 2ore clearly than on these is
lands. The windward sides in most cases have
been devastated to an astonishing degree, so
much so that | sometimes shrink from the task Of
trying to convince anybody of the reality which
| am sure Of. But on the leeward sides, which
have undoubtedly been exposed for an equal
period of time, the degradation is but a small
fraction Of what appears upon the windward
sides.
The cause of the difference in the FIRMS of
Muana Loa and Mauna Kea is very apparent
the former being built up entirely OF fluent lavas,
with fragmental products and the lava strea ms
being of great magnitude, the elected material
has diffused itself over a very wide extent of
country and flowed many miles away from the
principal focus of eruption. The mountain, there
fore, is abnormally fiat in its profile. In Mauna
Kea, on the other hand, 50 large n proportion of
the ejecta being in a fragmental form, they are
piled up around the places where they were
thrown out. The mass of Mauna Kea is many
times smaller than that of Mauna Loa but the
top of its summit platform is only six or seven
hundred feet lower than that of Mauna Loa,
while the cinder cones upon the summit carry its
apex about two hundred feet higher than the
summit of Mauna Loa.
On all the slopes Of Mauna Loa there is no.
where to be found anything like a ravine. Nor
is there a single living stream however small.
And vet on all sides the precipitation is very
great, but the water sinks as rapidly as it falls.
The lava is highly vascular ard much broken,
never compact except in bands here and there,
at the bases of the larger flows. Every lava
stream gives rise to long pipes or tunnels and
there are literally thousands of them, some of
which are several miles in length. In truth, these
long caverns must form an appreciable portion
of the entire volume Of the mountain. Remem-
bering also the very vascular character of the
lava, it seems plain that while the absolute dem
sity Of the materials is very high, the specific
gravity of the mass as a whole is by no means so.
1t appears to be a general fact throughout the
islands that erosion does not take hold of these
volcanic piles to any appreciable extent during
their activity, and after they become extinct II
long period must Stlll cllpSe before surface erosion
other than chemical weathering can begin. The
cutting of ravines is impossible without running
water, and the water cannot collect in streams
until the cracks and pores oG the lava are silted
up. Of course, this takes place more quickly
~upousthe windward than upon the leeward sides.
These facts are abundantly illustrated on every
island on the group.
| also visited H|ualalai. which has an altitude
Of about 5000 feet. 1t seems to be inter
mediate as regards the charact + Of it's lavas
and many Of its %eruptions between Mauna kea
and Mauna LOa being more basic than the
former, less so than than the latter. 1t has
many cinder cones upon it, especially at the
summit, some OF which resemble those of Mauna
Kea. while others have the abortivc, abnormal
and dwarfcd character OF the very few which
occur upon Mauna Loa. This volcano is well
known, has been active in the early part Of the
present century. From 1901 to 1911 there were
three distinct cruptions, separated by intervals of
a very few years. but all of them were small.
One Of them. as nearly as can be made out. must
have occurred about the year 1901, the second in
1905, and the last in 1910 or 1911.
Kohala Mountain, at the north end Of the ISL
and, is about 5400 feet in height, and its activity,
no doubt, ceased at an earlier period than that of
Alauna Kea. Its lavas are largely normal basalts
much Of il approaching andesite in character. lt
appears to be notably less basic on the whole
than the lavas of Marna Kea 1t has many Gin
der cones, some of them perfectly we'll pre-
served. others showing Conspicuous traces Oh ue-
cay.
My visit to Maui, though brieier than to
Hawaii, was very interesting. The great vol
cano of Haleakala is about lU,40O feet high. The
great 'crater, - sO-called. at the summit possesses
a grandeur and impressiveness which have not
been overratcd by travellers who have heretofore
described it. The form of this summit depression
is certainly most extraordinary and not easy to
account for. 1t is impossible. however, TO des-
cribe this mountain briefly. and | shall not here
attempt to do so. 1t is wholly basaltic and in its
general characteristics a pretty close imitation Of
Mauna LOa. The mountain piles which make
up west Maui are much older. They are very
much degraded by erosion and literally sawed to
pieces by corges and ravines two thousand to
three thousand feet in depth, with precipItous
walls. Some of the scenery in these gorges pos
sesses a beauty and grandeur seldom equalled.
1t is highly peculiar, and so far as | know has
its counterpart only in other islands of the
Pacific. | found here some lavas which appear
to be true andesItes, though in the main the