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Geology. — G. A. F. MoLENGRAAFF : “On recent crustal movements 
in the island of Timor and their bearing on the geological 
history of the East-Indian archipelago.” 
The occurrence of elevated coralreefs on the islands of the eastern 
portion of the East-Indian archipelago, amongst others on the island 
of Timor, has attracted the attention of many scientists, because it 
proves that in a geological sense not long ago, these islands have 
been considerably raised above the level of the sea. 
The Timor-expedition ') particularly studied these elevated reefs 
and their results may throw some light on the question of the 
character and correlations of the recent crustal movements in the 
East-Indian archipelago. 
The following brief remarks, therefore, are intended as introduction 
to the history of these reefs. 
The strata of the island of Timor were greatly folded at a time, 
which is known to be post-eocene and pre-pliocene, but which cannot 
at present be more precisely defined. Among these strata besides schists 
of unknown age various formations ranging from the Permian to the 
Eocene are represented, the whole of which will be here indicated by 
the name of the Perm-Eocene-series or simply as the older formations. 
This period of folding and tilting was most probably followed by 
a period of prolonged and considerable denudation, because it is 
observed that a later-tertiary formation of neogene age is found 
resting unconformably on the much denuded (peneplainized) older 
formations. The oldest strata of these neogene deposits consist of pure 
Globigerina-limestone, a pelagic sediment devoid of the elements of 
terrigenous origin, which must have been formed in an open sea 
far distant from the land.’) 
From the time of deposition of the Globigerina-limestone important 
crustal movements had set in, which resulted in the forming of basins 
(graben), in which the soil was deposited slowly but continuously 
and thus filled up these true depressions *). 
1, Messrs. H. A. Brouwer, F. A H. WeECKHERLIN DE MAREZ OYENS and the 
author as leader, formed the Timor-expedition, during which geological explora- 
tions were made in the eastern half of the Netherlands-Timor in the years 1910—1912. 
2) [ am not inclined to regard this formation as a deep sea deposit, although 
it must have been formed in the open sea far from the land, but believe, that it 
may have deposited under similar conditions as the white chalk of Europe, to 
which this late-tertiary Globigerina deposit bears petrologically a remarkable resem- 
blance. 
3) Only the most important of those graben or depressions, which have been 
of such vital importance in the development of the later-tertiary deposits, are 
mentioned in this paper. 
As the German terms “graben” and “horsten” are frequently used in this paper, 
