Kilauea Iki, 1959— Macdonald and Katsura 
KILAUEA IKI LAVA 
The pool of lava in Kilauea Iki crater, a pit 
crater immediately adjacent to the east edge of 
Kilauea caldera, was accumulated during the 
eruption that lasted from November 14 to De- 
cember 20, ,1959. The eruption consisted of 16 
separate eruptive phases, from 2 to 167 hr. in 
length, separated by quiet periods of 8-101 hr. 
duration during which part of the lava flowed 
back into the vent from which It had issued 
(Macdonald, in press). Lava from fissures on 
the southwest wall of the crater about 300 ft. 
above the pre-emption floor poured down the 
crater wall and formed a pool that gradually 
deepened until its surface was above the level of 
the original vents. Temperature measurements 
up to nearly 1200° C. were obtained on the 
lava fountain at the vent (Richter and Eaton, 
I960). During eruptive phases lava was added 
to the crater fill partly by injection beneath the 
crust and partly by spreading over the previous 
crust. A new crust formed quickly on the molten 
lava as each successive outpouring covered the 
crater floor, but from time to time broke up 
and foundered during convective overturns in 
the liquid. The latter suggests that submerged 
crusts of previous eruptive phases had been 
largely destroyed (possibly accumulating as 
sunken fragments at the bottom ) , leaving a pool 
of melt that was essentially continuous from bot- 
tom to top. The final depth of the pool is ap- 
proximately 380 ft. 
In July, I960, 7 months after the end of the 
eruption, the drill hole already mentioned was 
sunk into the solid crust of the lava in Kilauea 
Iki crater. Continuous core samples were taken, 
and cutting samples were preserved from succes- 
sive drill runs to supplement the cores in inter- 
vals in which core recovery was poor. On July 
25 the drill bit encountered very viscous semi- 
solid material at a depth of 19.1 ft., and at 19.5 
ft. it entered underlying liquid lava and started 
to sink into it. The tools were immediately re- 
moved from the hole, and a sample of the liquid 
that had congealed in it was removed from the 
bit. Additional samples were taken the next day 
by thrusting the drill pipe, without a bit, down 
into the liquid and withdrawing it. By the morn- 
ing of July 28 liquid lava had risen in the hole 
to a level 18.7 ft. below the surface. 
361 
Eight samples from the drill hole, and one 
of the surface crust adjacent to it, have been 
analyzed chemically. They are listed in Table 1. 
Three analyses of lava extruded earlier in the 
eruption also are given. Of these, one is of Pele’s 
hair wafted from the crater during the first days 
of the eruption. The other two (S-l and S-2), 
by J. H. Scoon of Cambridge University, repre- 
sent lava poured into the crater and spatter 
thrown onto the crater rim during the first erup- 
tive period, between November 14 and 21 . 
Analyses 9 and 10 are of samples of the liquid 
lava that underlay the solidified crust. It will be 
noted that the two are not identical. Sample 10 
is decidedly richer in alkalies. Sample 9 contains 
many more phenocrysts of olivine than sample 
10, and is presumed to have come from a 
slightly lower level in the liquid. 
Column 1 of Table 1 is an analysis of Pele’s 
hair formed at the beginning of the eruption. 
Scattered phenocrysts of olivine were present in 
the Pele’s hair, but none were included in the 
sample analyzed. The sample consisted essen- 
tially wholly of glass, even microlites being al- 
most entirely absent. Therefore, the analysis 
represents magma that was completely liquid at 
the time of eruption. The norm indicates a 
notable degree of undersaturation of the liquid 
in respect to silica. It has generally been assumed 
that normative olivine in tholeiitic rocks is 
largely the result of addition to the magma of 
solid crystals of olivine that have sunk from 
higher levels. In the case of the Pele’s hair of 
analysis 1 the undersaturation is not, however, 
the result of inclusion of olivine crystals in the 
analyzed sample. The liquid phase of the magma 
was itself undersaturated. Yet its very low con- 
tent of alkalies and alumina mark it clearly as a 
member of the tholeiitic suite. It is close to the 
value suggested by Bowen (1928: 164) as the 
limit of undersaturation in completely liquid 
basaltic magmas, though less undersaturated than 
some rocks believed by Drever ( 1956) to have 
been derived from completely liquid magmas. 
In thin section the samples from the upper 17 
ft. of the drill hole differ from each other almost 
entirely in the abundance of olivine phenocrysts, 
which range from about 10 per cent in the 
sample from 16.5 ft. to 40 per cent in that from 
7.5 ft. The latter is a picrite-basalt of oceanite 
