Swedish "Albatross” Cruise — Pettersson 
the rate of deposition in a certain core from 
the region considered. Arrhenius also drew in- 
ferences from his core analyses regarding the 
intensity and location of the equatorial cur- 
rent system during the Quaternary Age. Not 
all Arrhenius’ conclusions are accepted by 
other workers in the field, especially not the 
titanium-age calculations. Recent discoveries 
of an unexpectedly high titanium content in 
certain metamorphosed rocks on the Hawaiian 
Islands appear to make it more difiicult to 
accept any conclusion regarding a constant 
rate of accruement of this element to the 
bottom sediments. Nevertheless, the thesis 
published by Arrhenius is of outstanding 
value to future work on deep-sea geology. 
There are some aspects of our results which 
I consider to be of particular interest. One of 
these regards submarine volcanism. It is well 
known that the Pacific Ocean, both in its 
peripheral and in its central parts, has been 
an area of extensive volcanic activity and that 
its numerous islands have largely been built 
up from submarine volcanoes, the most mo- 
numental of which are these islands of Ha- 
waii. The "Albatross” cruise afforded ample 
evidence that submarine volcanic action has 
also worked in a horizontal direction, pro- 
ducing extensive lava beds on the ocean floor. 
For many years I have been of the opinion 
that submarine volcanic activity must also 
have had important geochemical effects by 
releasing magmatic volatiles like carbon di- 
oxide and mineral acids and that these have 
been active in dissolving away the lime from 
calcareous oozes and transforming them into 
Red clay and Radiolarian ooze. This would 
explain how these sediments can have been 
formed during the Tertiary Age when the 
temperature of the bottom water in great 
ocean depths must have been much higher 
than at present and when no Antarctic Bot- 
tom Current, generally held responsible for 
the dissolving away of the lime, swept over 
the ocean floor. That Red clay of Tertiary 
Age, formed under these conditions, actually 
exists in great depths was first proved by the 
361 
long cores raised by the "Albatross.” Some 
prominent geologists and oceanographers, 
such as W. Rubey and R. Revelle, have 
argued that the water filling the ocean basins 
has also been largely derived from magmatic 
volatiles released from the substratum be- 
neath the ocean floor. 
It seems to me that the central Pacific 
Ocean, especially the vicinity of the Hawaiian 
Islands, affords an ideal field for testing this 
hypothesis, a view I found strongly supported 
by the late master of volcanology, Professor 
T.Jaggar. 
A most important fact learned from the 
"Albatross” cruise, afterward confirmed from 
other expeditions, is the unexpectedly high 
geothermal gradient in the deep-sea deposits, 
quite as high as, if not even higher than, the 
average value for the continents. It seems 
reasonable to assume that the supply of geo- 
thermal energy below the ocean floor may be 
a sign of an extensive "latent” volcanism, 
whatever the ultimate source of this accu- 
mulated geothermal heat may be. 
Two more of our results appear to me 
worthy of being mentioned here. Thanks to 
co-operation with our great authority on ex- 
plosives, Professor W. Weibull of the Bofors 
Armament Works, we were able during the 
cruise to measure, for the first time, through 
a seismic method the thickness of the sedi- 
ment carpet spread over the ocean floor. 
Geochemical speculations by eminent author- 
ities had given 7,000 feet as a probable average 
value for the thickness of the Red clay, with 
higher values for other, more rapidly accu- 
mulating sediments. Weibull’s reflexion meas- 
urements gave comparable, in one case even 
higher, values for the central Atlantic Ocean 
between Madeira and the Mid-Atlantic Ridge. 
But to our great surprise the values found 
in the central Pacific and also in the Indian 
Ocean were only a small fraction of the theo- 
retical figures. This latter fact has been amply 
confirmed through later measurements by 
refraction shooting methods used both from 
the British research ship "Challenger” and 
