Page:The Scientific Monthly vol. 3.djvu/170

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.
164
THE SCIENTIFIC MONTHLY

164 THE SCIENTIFIC MONTHLT

great amount of water that went into the formation of the ice any rate^ we know that all the continents were connected, a ^ bridge extended from Asia to North America across Bering the southeastern Asiatic region the shallow southern half of 1 sea, the Gulf of Siam and the shallow Javan sea were all di vast, fertile and well-watered plains teeming with life. Sun Java were connected with Borneo and the Malay peninsula and part of a broad eastward extension of land that reached to and Timor, the present eastern oiitpost of the spice islands. Theft still so shallow that ships can anchor in any part of thenL

The Menam Biver was lengthened a thousand miles an through the Gulf of Siam and sweeping around to the nortl charged into the China sea. A great Javan river with its head the vicinity of the straits of Malacca flowed eastward and so receiving many large and small tributaries from the uplands o and Sumatra. It flowed in a broad and densely forested valle; ing for a thousand miles along the bed of the Java sea and em{ the Flores Gulf. The mountain axis of Borneo continued n nearly or quite connected with Luzon by the enlarged Palawan \ doro islands. The Sulu archipelago was a part of western 1 and nearly or quite reached north Borneo. The Sangir islands i nected with the northern arm of the Celebes and nearly or quib Mindanao while a narrow strait separated Celebes from Bome< ing north of the former to form the Pleistocene Celebes sea. Tl man and Nicobar island festoon was connected with lower forming the large and almost land-locked Gulf of Burmah. Tl tain axis of Sumatra was continuous across Java and on to i ward, for the fault which formed the narrow Sunda Strait bet^ two islands was not yet in existence. The Pleistocene was al» of great volcanic activity in this whole region. Java has at volcanic centers many of which are great peaks, but only 13 of \ feebly active at the present time. During the Pleistocene vole tivity was at a maximum, as is shown by the fact that not onl cfent. of the present area of Java consists of these rocks, but mo remaining area is made up of sediments that are largely volcanii I have endeavored to picture the probable geography of the early cene in the southeastern Asiatic region in the accompanying ske (Fig. 2).

During the early Pleistocene broad and fertile river valleys e from the Pimjab eastward and southward. From the sharp turi Brahmaputra at Sadiya in Assam great valleys or verdant coasta flanked by salubrious uplands extended southeastward for a disi between two and three thousand miles and it was along these plains and valleys and the parallel mountain ridges that upla

�� �