T08 NEW YORK STATE MUSEUM 



that " until the contrary is proved, one must infer, that the 

 gneiss and schist massifs from central Celebes to the island of Roon, 

 are parts or horsts of an old massif which stretched formerly through- 

 out this whole extent. . . . Without being able to assert it dogmati- 

 cally, one may say that this old massif, folded in an east-west direc- 

 tion, is prolonged to the west, and that it reaches the middle of 

 Borneo, where Molengraaff and other explorers have also found 

 tectonic entities striking almost east and west." By tracing the 

 early Paleozoic rocks of Cambrian, Ordovician and Silurian age 

 to the north, south and southeast of the East Indian Archipelago 

 and noting that these rocks, as the Cambrian in the north lean 

 against and although often strongly folded, still retain their fossils, 

 but are as such entirely absent in the Archipelago; it is concluded 

 (ibid., p. 576) (1) that the gneiss, the mica schists, the phyllites, 

 and the real " old " schists (thus with the omission of the rocks 

 which do not make part of them) must be Archean and Precambrian 

 rocks; (2) that they once built up an old Paleozoic continent, which 

 extended at least over an area of 45 ° in latitude, between the tropics 

 from the southeast of Asia to the east of Australia, and from Sumatra 

 to the Philippine islands; (3) in the central part of this continent, 

 north and south of the equator, mountain ranges of an almost 

 east-west direction must have played an important part in this 

 very old continent. Later Cambrian, Silurian and Devonian trans- 

 gressions passed over the border areas, and folding occurred in these 

 border sediments; then in the Middle Carboniferous, denudation 

 and leveling took place and lastly, in Upper Carboniferous and Per- 

 mian time the continent itself was invaded. For this continent of 

 the old Paleozoic, Abendanon proposes the name Aequinoctia. 



Schuchert (1916, p. 98) has in a series of small charts of the 

 paleogeography of Australasia traced the history of this continent 

 and graphically brought out its relative constancy in early Paleozoic 

 time. 



The problem which above all interests us here concerning the Paleo- 

 zoic continent Aequinoctia and that is indicated by the presence of 

 the Precambrian rocks of the Archipelago and the absence of earlier 

 Paleozoic rocks and fossils, is whether the uniform east- west folding 

 of the Precambrian rocks that extends over such a large area, is 

 the primary folding of these rocks, or a superimposed early Paleozoic 

 folding. In the former case, the conclusion that we have here a 

 separate Precambrian entity located between that of Eurasia and 

 that of Afro- Australia is justified ; in the latter case this Precambrian 



