North Dakota Gravel Deposits

Our gravel deposits or glacial moraines are a deposit of the different glaciers that invaded this state, probably millions of years ago. The gravel now being mined for use on the Air Base, one mile north of Emerado, North Dakota, is partly the result of huge waves which pounded the glacial moraines, probably thousands of years, when Lake Agassiz covered what is now the Red River Valley, forming deep beach heads of gravel. No doubt some moraines were already ground to different consistencies by glacial movement. As the lake retreated, new beach heads were formed. The large fresh water lake could not flow south being dammed by glacial deposits, and it could not flow north being dammed by ice. The glacial receding periods were not always of the same duration, which accounts for the amount of deposit and variation in distance from one beach head to another. It also accounts for the present level farm land between each beach head. We must also consider that there were four glacial invasions into North Dakota. The quality of gravel now mined, therefore, depends on the type deposited by the different glaciers and also upon the number of years it could have been subject to wave action. Some of the gravel requires very little or no washing. Other pits are mixed gravel, sand, quicksand clay and rock. Just exactly what took place we will probably never know.

July 23, 1960