Evening star., 1952-09-12
Two Of Least Known
Pacific Spots Explored
AtoIIs Of Toonei and Bikur
Studied by U. S. Biologists
By Thomos R. Henry

Two Of the Pacific's least known spots
are being explored by U. S. Geological
Survey scientists.
They are the atolls of Taongi and
Bikar, northernmost and dryest of the
Marshall Islands, which never have been
inhabited and the only scientific OBJ
Servations of which have been made at
a distance from aboard ship. They are
Of particular interest because the hand
Of man never has interfered with the
course OF nature. Army and Geological
Survey observers have studied more than
so islands in other Marshall atolls.
The Geological Survey scientists are
interested especially in the light which
may be thrown on the life history Of
atolls. The islands visited thus far range
In size from tiny sand bars to Islands
nearly three miles long. Nearly every
where, however. there have been the
complications due to the presence of
man at some time during the past few
centuries.
The geology of these atolls will be
studied by DR.. Charles q. johnson. while
DIR. F. Raymond Fosberg will make ex-
tensive botanical studies.
IranSltOry In Geography.
Actually. it has been determined, atoll
islands are quite transitory geographical
features, although they may endure a
long time compared with the generations
of men. The real stable features are the
reefs on which the islands rest.
The birth and death of an island, It
has been determined. is likely to be an
extremely complex process. Such an
island is the child Of storms, and the ex-
tent to which it grows and the length
OF time 1t survives depends on storms.
Typhoons. particularly, are responsible
Tor the greatest accumulations of debris
sand and rockS-and also for the
greatest destruction. The effects at any
particular time. however, are unpre-
dictable. Almost everything depends on
the location Of the center of the storm
with respect to the atolls. the Geological
Survey scientists say.
Existing reef flats are believed to be
due to the planning off of the tops Of
reefs that extended higher during the
period Of high sea level Just after the
last glacial period-probably about
5000 years ago. Coarse rubble is thrown
on reef by storms during all geological
level. however. these rubble deposits
gradually are worn away. During pc
riods of rising sea level they are built
up and keep the reef level close to the
existing level Of the sea.
Platforms Of Bubble Rock.
Many islands in the Marshall atolls
are built on platforms of rubble rock
which stand one to three feet above the
present high tide level. The upper sur
face Of such q raised platform appears
to be q plain surface, similar to the
present reef fiat. Such surfaces are at
tributed to cutting down by waves dur
ing minor pauses in the steady drop in
sea level all over the world which has
gone on since the last glaciation. There
has been drop Of about six feet in the
past 5000 years.
Examination Of the soils shows that
there has been little alteration Of the
original sediments-sand and fragments
OF coral. Various amounts of humus
have been added to the surface layers,
producing darkening in color There
are areas Of buried soils"-layers in
which a noticeable amount of humus
has accumulated and which then have
been buried under sand deposited by
winds or waves
The vegetation on most Of the atoll
islands Is relatively simple BY far the
greater part of the cultivable area
has been cleared and planted to COCO
nuts, obliterating all evidence of the
original vegetation. Before the coming
Of man, it is probable forests of great
trees were the dominant vegetation. On
newer areas the vegetation is scrubby,
dense, tangled and difficult to pene-
trate.