304 W. M. DAVIS 
I should rather suppose that on that spot in the Ceram Sea . . . . a drowned 
coral island rises to about 1,300 m. below sea-level. Such a supposition seems 
justified if it is borne in mind that the Ceram Sea is one of the most remark- 
able trough-shaped deep basins in the eastern part of the Indian archipelago, 
the origin of which is probably connected with crust movements in Pleistocene 
and post-Pleistocene times. They were formed by downward movements, 
simultaneous with, and more or less compensated by, elevations of about ° 
equal amount of other parts.? 
The crustal instability inferred for the Ceram Sea is not excep- 
tional. Recent studies in other parts of the great archipelago attest 
a wide extension of diverse movements in late geological times. 
Thus the Sarasin brothers infer various movements of Celebes in 
modern geological periods,? and more detailed studies of the same 
island by Ahlburg and Abendanon reach similar conclusions. The 
first of these two investigators has published a monograph in which 
various changes of island level are described. The second has: 
given an abstract of his report on a geological and geographical 
traverse of middle Celebes in the Journal of the Dutch Geographical 
Society; itis there stated that a region of crystalline rocks which was 
reduced to a peneplain in Oligocene time has suffered great dis- 
placements in later periods, including plio-Pleistocene upheavals of 
1,000 meters, and subsidences of similar measure; the deepening of 
the adjoining seas is explicitly stated to have accompanied the 
elevation of land areas, thus indicating strong differential move- 
ments.* Many other articles might be cited to the same conclusion. 
Thus Becker’ and Smith® both testify to diverse movements in the 
1G. A. F. Molengraaff, “The Coral-Reef Problem and Isostasy,” Proc. k. Akad. 
Wet. Amsterdam, XIX (1916), 610-27; see p. 624. Fine charts of the Australasian 
mediterraneans are given by G. F. Tyddeman, Hydrographic Results of the Siboga 
Expedition, Leiden, 1903. 
2P. and F. Sarasin, Ueber die geologische Geschischte ... . der Insel Celebes, 
Wiesbaden, root. 
3 J. Ahlburg, ‘Versuch einer geol. Darstellung der Insel Celebes,”’ Geol. and 
Pal. Abh., XII (1913), heft r. 
4E. C. Abendanon, “‘ Historische Geologie van Midden-Celebes,”’ Tydschr. k. ned. 
Aardr. Gen., XXIV (1917), ?-456, 548-64. 
5G. F. Becker, ‘“‘Report on the Geology of the Philippine Islands,” U.S. Geol. 
Surd., 21st Ann. Rept., 1901, Part III, pp. 1-139; see pp. 19, 69. 
6W. D. Smith, “Contributions to the Physiography of the Philippine Islands. 
I, Cebé Island,” Phil. Jour. Sci., 1 (1906), .1043-57. 
