S T R A T A . gigantic ftatues o f Eafter Ifland are formed, and therefore they cannot
be o f very remote antiquity, as the done is.of an extremely perUhahle
nature. On the-South, fide o f the i£Le, the whole cliff towards .the
fea for more than a quarter o f a mile confifts: of folid ponderous rock
o f a honeycombed flag or lava* which may be expected to yield' fome
portions, o f iron. Befides thefe, we faw feveral black glaffy ftones,
which to mineralogifts are known by the name o f .black agate :(pUr-
mexvitreus Linn.) found in Iceland, linear the'Vefuyiofin. Italy,
§ the Mongibello in Sicily, and ,on the file o f Afcenfionj: Hin-fhort
in all. the neighbourhoods .-of volcanos.- - W e obferved likewife a
ftony, light, fpungy kind o f lava, o f a whit-ifh grey colour.
T he M a rque sa s have a rocky foore,-!cpnfifting o f ipdurated
clay; a ponderous, folid flate, o f a blueifh grey colour, containing
fome iron particles; and laftly, a ftony lava, which is either grey,
fpungy with lamellated,, vitreous, pentagonal or hexagonal fherl, p f
a brownifhand in fome. o f a gr-eenifh, or o f a blackifh colour, with
brownifh and fometimes white ftarlike or radiated fherl. Th e fur-
face o f the foil is a clay mixed with mould, which the natiyes manure
with fhells. Under this mould, is. an earthy argillaceous fob.
ftance, mixed with tarras and puzzplana, As we ftaid but a, few
days here, we had not much time to examine the higher parts o f
the i f le , . - O-Taheitee
t Fcritr's travels, p ,. J5.8. Mi. Rafpt’s note, § •Fcrltr's tra-jih, p, 1.57, ,
i| Cronfted's mineralogy, fe£t. 295. p,, 269..
0-2kiirifeAandjall the &>ciety Ijks. are no dou,bt. o f the fame: nature.'.
Their fhores are coral: rock extending: from the. reef encircling,
thefe ifles to the very high-water.mark.. There begins the land,
formed hrfcime places from' final! fhellsc and rubbed pieces o f coral-
rock ; hut mothers:the fhores are covered by a.hlackifli kind of fand,
confifting o f the former fort mixed with black, fometimes fhining
and glitterihg particles o f coaffe'daze or gliVc (Mica) and here, and
there fome particles o f refractory iron .ores .called in England.ShiW
(ferrim miaaceumi Einn^iandRALL (molybdtenumfpumalupi, Linn.)
Th e plains from the fhores to the foot o f the hills, are covered with
a very fine thick ftratum:of black mould,. mixed with the.above-m.en'-
tianed kind.of-fand, and:when the natives .cadtivate fome, fpots; for
raifi-ngthe inebriating pepper plant f'piper niethyflicumj: or: the cloth
plant •/marus papyrifera) they . often, ufo- fheHs' as a kind of manure.
T h e firft and lower rang®; o f hills are commonly formedof a
red ochreous earth ( bchra mart is I .inn;) .fometimes fo intenfely. red;,
that the natives ufe it to paint their canoes and cloth :, and. in'this
earth I found here and there pieces, as I believe of the ofteocolla
(tophus q/itoct>Ila -Lin n .) T h e higher .hills confiftof a hard, compact,
and ftiff clayey fubftance;. which in the ft’rata that, are out. o f the
reach: of fun, air. and r-ain,. ace hardened intola ftone.- - There.are.
at the top, of the valleys, along the, hanks of the rivers, large.maflek
e f Goarfe granite f t o n e s o f Vatiousmixtures,; and. at a place
STRATA.
off