Mississippi River

• Mississippi River

59:3.9280,000,000 years ago the con­ti­nents had largely emerged from the sec­ond Sil­urian in­un­da­tion. The rock de­posits of this sub­mer­gence are known in North Amer­ica as Ni­a­gara lime­stone be­cause this is the stra­tum of rock over which Ni­a­gara Falls now flows. This layer of rock ex­tends from the east­ern moun­tains to the Mis­sis­sippi val­ley re­gion but not far­ther west ex­cept to the south. Sev­eral lay­ers ex­tend over Canada, por­tions of South Amer­ica, Aus­tralia, and most of Eu­rope, the av­er­age thick­ness of this Ni­a­gara se­ries be­ing about six hun­dred feet. Im­me­di­ately over­ly­ing the Ni­a­gara de­posit, in many re­gions may be found a col­lec­tion of con­glom­er­ate, shale, and rock salt. This is the ac­cu­mu­la­tion of sec­ondary sub­si­dences. This salt set­tled in great la­goons which were al­ter­nately opened up to the sea and then cut off so that evap­o­ra­tion oc­curred with de­po­si­tion of salt along with other mat­ter held in so­lu­tion. In some re­gions these rock salt beds are sev­enty feet thick.

• Mississippi River

59:5.20180,000,000 years ago brought the close of the Car­bonif­er­ous pe­riod, dur­ing which coal had been formed all over the world—in Eu­rope, In­dia, China, North Africa, and the Amer­i­cas. At the close of the coal-for­ma­tion pe­riod North Amer­ica east of the Mis­sis­sippi val­ley rose, and most of this sec­tion has ever since re­mained above the sea. This land-el­e­va­tion pe­riod marks the be­gin­ning of the mod­ern moun­tains of North Amer­ica, both in the Ap­palachian re­gions and in the west. Vol­ca­noes were ac­tive in Alaska and Cal­i­for­nia and in the moun­tain-form­ing re­gions of Eu­rope and Asia. East­ern Amer­ica and west­ern Eu­rope were con­nected by the con­ti­nent of Green­land.

• Mississippi River

61:7.2750,000 years ago the fourth ice sheet, a union of the North Amer­i­can cen­tral and east­ern ice fields, was well on its way south; at its height it reached to south­ern Illi­nois, dis­plac­ing the Mis­sis­sippi River fifty miles to the west, and in the east it ex­tended as far south as the Ohio River and cen­tral Penn­syl­va­nia.

61:7.10This is the glacier that sent forth the many tongues, or ice lobes, which carved out the pres­ent-day lakes, great and small. Dur­ing its re­treat the North Amer­i­can sys­tem of Great Lakes was pro­duced. And Uran­tian ge­ol­o­gists have very ac­cu­rately de­duced the var­i­ous stages of this de­vel­op­ment and have cor­rectly sur­mised that these bod­ies of wa­ter did, at dif­fer­ent times, empty first into the Mis­sis­sippi val­ley, then east­ward into the Hud­son val­ley, and fi­nally by a north­ern route into the St. Lawrence. It is thirty-seven thou­sand years since the con­nected Great Lakes sys­tem be­gan to empty out over the pres­ent Ni­a­gara route.