May 1, 1902 ] 
NATURE 3 
THE GEOGRAPHY AND GEOLOGY OF 
CELEBES. 
Materialen zur Naturgeschichte der Insel Celebes, Band 
iv.—Entwurf einer geographisch-geologischen Be- 
schreibung der Insel Celebes. By Dr. Paul Sarasin 
and Dr. Fritz Sarasin. Pp. xi + 344 + 28; 13 plates. 
(Wiesbaden : Kreidel, r901.) Price Mk. 50. 
HIS, the fourth volume of the series which the 
authors have devoted to the natural history of 
Celebes, is a welcome addition to our knowledge of the 
East Indian Archipelago. The recent geological history 
of the island, and the light thrown upon it by the distri- 
bution of the animals and plants of the region, has already 
formed the subject of a special memoir. Here we have 
a description of the surface features and configuration of 
Celebes so far as that has been explored, a record of many 
interesting observations, geographical and geological, 
made during several years spent in travel in nearly every 
quarter of the island, with petrographical notes on the 
rock specimens collected (including a special chapter 
by Prof. C. Schmidt), a sketch map on the scale of 
I in 2,000,000 and tables of the observed altitudes of 
many important stations. 
The outline of the island, sinuous and branching, is the 
external expression of its geological structure. A folded 
mountain chain, of which some peaks rise to 5000 or 
6000 feet above the sea, forms the axis or backbone of 
Celebes. It is not simple, but consists of several parallel 
ranges, more or less intermittent, with longitudinal valleys 
between them. These valleys appear to be synclinal or 
to be due in some cases to depression between parallel 
lines of fault which trend with the folds. Not much is 
known about the mountainous interior of the island, but 
from the specimens of rocks collected, which include 
granite, gneiss, mica schist, chlorite schist, epidote 
glaucophane schist, quartzite and crystalline limestones, 
it is certain that there is a large development of 
metamorphic rocks. No fossils have been obtained 
from this series, but the authors believe that some of the 
crystalline limestones may be of Jurassic age. 
This axis of metamorphic rocks is bent almost at a right- 
angle where it crosses the equator, and in the interior of 
the bend another less important series of folds runs 
roughly parallel to the main external ridge which forms 
the dominant structural feature of the island. A striking 
peculiarity of the surface configuration is the presence 
in each system of folds of a longitudinal depression 
flanked on each side by ridge-like elevations. This cen- 
tral valley runs from end to end of Celebes. It largely 
determines the direction of the drainage, as the principal 
interior streams run in it for long distances, parallel to the 
shores, till they take advantage sooner or later of one of 
the breaks in thé continuity of the hill ranges to pass 
outwards to the sea. 
The narrow and not very well defined coastal plain 
consists, for the most part, of Tertiary and later deposits 
very frequently intercalated with volcanic rocks. The 
Eocene is well represented by massive nummulitic and 
orbitoidal limestones, often coralline. Beneath these 
there are sometimes exposures of sandstone, and not un- 
commonly radiolarian clays and cherty beds which may 
be lower Eocene or possibly Cretaceous. Overlying the 
. NO. 1696, VOL. 66] 
Eocene are sandstones and conglomerates known as the 
“Celebes Taveyannaz beds” (from their similarity to the 
Taveyannaz group in the Alps) and an extensive 
“Celebes Molasse,” with fresh water, brackish water, 
marine and land fossils. Pliocene shell beds and Pleisto- 
cene strata are well developed in the lower grounds and 
along the shores. The Tertiary geological history of 
Celebes is outlined as follows :—The Eocene began with 
deep-water conditions (radiolarian clays) followed by 
shallow coral seas. In the Miocene the great upheaval 
took place and the mountain axis attained its complete 
development. This was an epoch of land conditions, 
and was accompanied by the deposit of the “‘ Celebes 
Molasse.” During the Pliocene the land area was much 
greater than at present, but in the Pleistocene depression 
ensued, and is regarded as having been at least 300 feet. 
Thereafter minor oscillations have taken place; a well- 
marked raised beach can be traced at heights of go feet 
above the sea-level indicating recent elevation, while in 
other places submerged forests point to slight and local 
depression. 
Over most of the island signs of volcanic activity 
abound. One crater named Una Una was in eruption 
in 1898, but there are few historic records of volcanic out- 
bursts, though many may be traced in the traditions of 
the natives. In the extreme south the great peak of 
Bantaeng (2970 m.), an Etna covered with parasitic cones, 
is a well-known object and has already been described 
by several travellers. The authors ascended it, and give 
a map of the higher parts of the mountain. This map 
shows a very large breached crater occupying the summit 
and accompanied by two enormous depressions (pre- 
sumably also craters) to the south of the principal one. 
Beds of ash and lava flows are very frequently inter- 
bedded with the Tertiary strata, and in the Minahassa 
region at the north-east termination of the island there 
is a cluster of volcanic mountains, some of which must 
have been very recently in eruption, while others are in 
various stages of denudation and decay. This is one of 
the most interesting parts of Celebes, and some of the 
best chapters of the book are those devoted to the de- 
scription of these volcanic cones and craters. For the 
excellent photographic illustrations which accompany 
them there can be nothing but praise. 
The volcanic activity appears to have first manifested 
itself in the Miocene, and to have followed the era of 
folding and upheaval. Many types of effusive rocks 
are found. The commonest are apparently andesites 
(propylites) and basalts. But leucite-tephrites, trachytes 
and phonolites were also emitted, and Prof. Schmidt has 
furnished descriptions of some very fine nepheline-bearing 
shonkinites which appear to be the plutonic representa- 
tives of this group. They are accompanied by bostonites 
and gauteites as dyke rocks. In the volcanic areas hot 
springs are numerous, and some of the quartz veins are 
auriferous. Some interesting notes are also given on the 
configuration of volcanic bombs. 
A special feature of the geography of Celebes which 
has attracted a good deal of attention is the existence of 
inland lakes of considerable size. These are found in 
the central valley depressions between the hill ranges, 
and they occur in well-defined chains in these valleys. 
The largest is the Towuti Lake, but Lake Posso and 
