Antarctica

• Antarctica

61:2.335,000,000 years ago marks the be­gin­ning of the age of pla­cen­tal-mam­malian world dom­i­na­tion. The south­ern land bridge was ex­ten­sive, re­con­nect­ing the then enor­mous Antarc­tic con­ti­nent with South Amer­ica, South Africa, and Aus­tralia. In spite of the mass­ing of land in high lat­i­tudes, the world cli­mate re­mained rel­a­tively mild be­cause of the enor­mous in­crease in the size of the tropic seas, nor was the land el­e­vated suf­fi­ciently to pro­duce glaciers. Ex­ten­sive lava flows oc­curred in Green­land and Ice­land, some coal be­ing de­posited be­tween these lay­ers.

• Antarctica

61:5.3The great ice sheets of this pe­riod were all lo­cated on el­e­vated high­lands, not in moun­tain­ous re­gions where they are found to­day. One half of the glacial ice was in North Amer­ica, one fourth in Eura­sia, and one fourth else­where, chiefly in Antarc­tica. Africa was lit­tle af­fected by the ice, but Aus­tralia was al­most cov­ered with the antarc­tic ice blan­ket.

58:4.3500,000,000 years ago prim­i­tive ma­rine veg­etable life was well es­tab­lished on Uran­tia. Green­land and the arc­tic land mass, to­gether with North and South Amer­ica, were be­gin­ning their long and slow west­ward drift. Africa moved slightly south, cre­at­ing an east and west trough, the Med­i­ter­ra­nean basin, be­tween it­self and the mother body. Antarc­tica, Aus­tralia, and the land in­di­cated by the is­lands of the Pa­cific broke away on the south and east and have drifted far away since that day.

57:8.21The in­creas­ing down­thrust of the Pa­cific Ocean op­er­ated fur­ther to up­thrust the con­ti­nen­tal land mass. Eu­rope and Africa be­gan to rise out of the Pa­cific depths along with those masses now called Aus­tralia, North and South Amer­ica, and the con­ti­nent of Antarc­tica, while the bed of the Pa­cific Ocean en­gaged in a fur­ther com­pen­satory sink­ing ad­just­ment. By the end of this pe­riod al­most one third of the earth’s sur­face con­sisted of land, all in one con­ti­nen­tal body.

61:7.11100,000 years ago, dur­ing the re­treat of the last glacier, the vast po­lar ice sheets be­gan to form, and the cen­ter of ice ac­cu­mu­la­tion moved con­sid­er­ably north­ward. And as long as the po­lar re­gions con­tinue to be cov­ered with ice, it is hardly pos­si­ble for an­other glacial age to oc­cur, re­gard­less of fu­ture land el­e­va­tions or mod­i­fi­ca­tion of ocean cur­rents.