Voi/. 6, 1920 
GEOLOGY: R. A. DALY 
249 
A second test naturally inheres in the expectation that the deleveling 
should be synchronous in all parts of the ocean. Observers dwell on the 
recency of the sea-level shifts registered in all of the cases compiled. 
Fossils from the St. Lawrence, Scottish, Irish, Cuban, Patagonian, New 
Zealand, Australian, Funafuti, Murray Island, New Jersey, Maryland, 
Georgia, and Florida beaches, reefs, or coastal plains belong to species now 
living in the adjoining seas, or, exceptionally, to species now living in 
slightly warmer water. Great recency is also shown by the relatively 
small damage done by erosion to the strand-marks, except in the case of 
those exposed to powerful surf. The beaches of the higher latitudes are 
clearly post-Glacial and also of later dates than the post-Glacial uplifts 
following the melting of the ice-caps. Brogger puts the completion of the 
last 4-meter to 8-meter emergence of the Christiania region at about the 
year 500 B.C. The development of the corresponding sea-cliffs, benches, 
and other strand-marks is referred by him to the late Tapes (Neolithic) 
period, between 1400 B.C. and 2400 B.C. During late Tapes time the 
Christiania sea was about 2° C. warmer than now."^ The fossils in the 
Patagonian beaches also betoken water warmer than the adjacent sea. 
Simultaneous emergence of the many separate regions is the more credible 
because of the similarity in the histories of their respective coasts before 
emergence. Repeatedly one encounters the description of terrace, bench 
or beach near the 20-foot level as the best developed, the most conspicuous, 
of the most persistent in areas characterized by "raised" strand-marks. 
One may conclude that the different regions must have had sea-level 
nearly constant for a considerable time, during which the strand-marks 
were well incised or built up. Such widespread accordance itself must 
deepen suspicion that local deformations of the earth's crust have not been 
responsible for the recent emergence of so many continental and island 
coasts. 
In conclusion, the facts at hand seem to permit belief in the synchrony 
of the different strand-markings and emergences here considered, but this 
second test of the hypothesis clearly demands further investigation. 
Before the fact is established, it would be idle to dwell overmuch on the 
explanation of a 20 -foot drop in the level of the ocean. The most promis- 
ing idea appears to be that a few thousand years ago there was an increase 
in the volume of the existing, non-floating glaciers. If the Antarctic ice- 
cap were then thickened to the average amount of about 700 feet, an 
average sinking of sea-level to the extent of nearly 20 feet would be inevit- 
able. In favor of this suggestion would-be evidence of a world-wide os- 
cillation of climate like that which seems to have affected the Christiania 
region in Recent time. If the whole earth was, in the Tapes period, a 
little warmer than now, less water may have been taken from the ocean to 
constitute the ice-caps ; sea-level was a little higher than at present. The 
