Urantia During the Early Land-Life Era

60:4.1The great Cre­ta­ceous pe­riod was draw­ing to a close, and its ter­mi­na­tion marks the end of the great sea in­va­sions of the con­ti­nents. Par­tic­u­larly is this true of North Amer­ica, where there had been just twenty-four great in­un­da­tions. And though there were sub­se­quent mi­nor sub­mer­gences, none of these can be com­pared with the ex­ten­sive and lengthy ma­rine in­va­sions of this and pre­vi­ous ages. These al­ter­nate pe­ri­ods of land and sea dom­i­nance have oc­curred in mil­lion-year cy­cles. There has been an age­long rhythm as­so­ci­ated with this rise and fall of ocean floor and con­ti­nen­tal land lev­els. And these same rhyth­mi­cal crustal move­ments will con­tinue from this time on through­out the earth’s his­tory but with di­min­ish­ing fre­quency and ex­tent.

60:4.2This pe­riod also wit­nesses the end of the con­ti­nen­tal drift and the build­ing of the mod­ern moun­tains of Uran­tia. But the pres­sure of the con­ti­nen­tal masses and the thwarted mo­men­tum of their age­long drift are not the ex­clu­sive in­flu­ences in moun­tain build­ing. The chief and un­der­ly­ing fac­tor in de­ter­min­ing the lo­ca­tion of a moun­tain range is the pre-ex­is­tent low­land, or trough, which has be­come filled up with the com­par­a­tively lighter de­posits of the land ero­sion and ma­rine drifts of the pre­ced­ing ages. These lighter ar­eas of land are some­times 15,000 to 20,000 feet thick; there­fore, when the crust is sub­jected to pres­sure from any cause, these lighter ar­eas are the first to crum­ple up, fold, and rise up­ward to af­ford com­pen­satory ad­just­ment for the con­tend­ing and con­flict­ing forces and pres­sures at work in the earth’s crust or un­der­neath the crust. Some­times these up­thrusts of land oc­cur with­out fold­ing. But in con­nec­tion with the rise of the Rocky Moun­tains, great fold­ing and tilt­ing oc­curred, cou­pled with enor­mous over­thrusts of the var­i­ous lay­ers, both un­der­ground and at the sur­face.

60:4.3The old­est moun­tains of the world are lo­cated in Asia, Green­land, and north­ern Eu­rope among those of the older east-west sys­tems. The mid-age moun­tains are in the cir­cum­pa­cific group and in the sec­ond Eu­ro­pean east-west sys­tem, which was born at about the same time. This gi­gan­tic up­ris­ing is al­most ten thou­sand miles long, ex­tend­ing from Eu­rope over into the West In­dies land el­e­va­tions. The young­est moun­tains are in the Rocky Moun­tain sys­tem, where, for ages, land el­e­va­tions had oc­curred only to be suc­ces­sively cov­ered by the sea, though some of the higher lands re­mained as is­lands. Sub­se­quent to the for­ma­tion of the mid-age moun­tains, a real moun­tain high­land was el­e­vated which was des­tined, sub­se­quently, to be carved into the pres­ent Rocky Moun­tains by the com­bined artistry of na­ture’s el­e­ments.

60:4.4The pres­ent North Amer­i­can Rocky Moun­tain re­gion is not the orig­i­nal el­e­va­tion of land; that el­e­va­tion had been long since lev­eled by ero­sion and then re-el­e­vated. The pres­ent front range of moun­tains is what is left of the re­mains of the orig­i­nal range which was re-el­e­vated. Pikes Peak and Longs Peak are out­stand­ing ex­am­ples of this moun­tain ac­tiv­ity, ex­tend­ing over two or more gen­er­a­tions of moun­tain lives. These two peaks held their heads above wa­ter dur­ing sev­eral of the pre­ced­ing in­un­da­tions.

60:4.5Bi­o­log­i­cally as well as ge­o­log­i­cally this was an event­ful and ac­tive age on land and un­der wa­ter. Sea urchins in­creased while corals and crinoids de­creased. The am­monites, of pre­pon­der­ant in­flu­ence dur­ing a pre­vi­ous age, also rapidly de­clined. On land the fern forests were largely re­placed by pine and other mod­ern trees, in­clud­ing the gi­gan­tic red­woods. By the end of this pe­riod, while the pla­cen­tal mam­mal has not yet evolved, the bi­o­logic stage is fully set for the ap­pear­ance, in a sub­se­quent age, of the early an­ces­tors of the fu­ture mam­malian types.

60:4.6And thus ends a long era of world evo­lu­tion, ex­tend­ing from the early ap­pear­ance of land life down to the more re­cent times of the im­me­di­ate an­ces­tors of the hu­man species and its col­lat­eral branches. This, the Cre­ta­ceous age, cov­ers fifty mil­lion years and brings to a close the pre­mam­malian era of land life, which ex­tends over a pe­riod of one hun­dred mil­lion years and is known as the Meso­zoic.

60:4.7[Pre­sented by a Life Car­rier of Neb­a­don as­signed to Sa­ta­nia and now func­tion­ing on Uran­tia.]