Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/525

 the forests which have nourished these by no means insignificant coal-fields, whether we describe them by their horizontal or vertical extension. The small island of Takosima, which contains in a thickness of about 450 feet three beds of coal, averaging from 6 to 8 feet in thickness each, is an instance of the latter. The great length of the chain, some 50 degrees of latitude, is sufficient proof of the former.

The mechanical structure of the beds forces us to believe in the near proximity of a continent during their deposition. Sandstones, conglomerates, and coal itself may all be accepted as proofs of littoral conditions. Shut out from the west, we must therefore turn to the east as the probable source whence these beds derive their immediate origin. In this surmise we have, however, other grounds of probability to argue from. Darwin's theory of fringing coral-reefs marking a period of depression has long been accepted by many of the most able of geologists. Assuming it as proved, we are almost of necessity led to the belief in a great Pacific continent during comparatively recent geological time. If we assume that its depression was coincident with the elevation of the remarkable volcanic chain of the west Pacific islands, we may assume that these marked its western shores. Along these shores the greatest Tertiary coal-field in the world was deposited, while at a distance the finer sediment of its streams was thrown down over Eastern Asia in the form of Loess.

Geologists have been ready enough to accept great depressions during the Tertiary epoch, but have hitherto hesitated in pointing out the necessary counterbalance which must have existed between the areas occupied by land and water. I have therefore, at the risk even of being thought to a certain extent an innovator in the science, pointed out a few of the facts which have influenced me in placing the counterbalance within the limits now occupied by the Pacific Ocean.

Discussion.

Prof. Ramsay remarked that the author had not proved that the Loess he described was really stratified. He could not agree with his views of the inland escarpments he mentioned having been old coast lines. It was only accidentally that sea cliffs had any connexion with the line of strike of the strata, whereas inland cliffs always followed the strike. He thought the phenomena were rather in accordance with a long exposure of the land to subaerial influences than with the Loess having been of marine origin. Even in England, in those parts which had long been free from marine action, beds of brick-earth had been formed. He also instanced the plains of Picardy as exhibiting a vast extent of such subaerial beds.

Prof. T. Rupert Jones thought that the area treated of by Mr. Kingsmill was too large to have its geology explained merely by reference to rain-wash and valley deposits. Whatever his low-level Loess might be, the higher accumulations of loamy deposits, stated to be 1000 feet thick at an elevation of 3000 feet, and regarded by