Subject: Formations (Geology) - Yale University Library GeoBlacklight Search Results

21. Subsurface geology of Paleozoic, Mesozoic, and Cenozoic units in southeast Missouri

1988. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey ; For sale by Map Distribution. English. Public. Missouri. Paleozoic, Mesozoic, and Cenozoic.

22. The Maquoketa Formation (Upper Ordovician) in Iowa [cartographic material]

1971. 2018-04-20T18:43:31Z. 2021-05-04T22:29:48Z. Parker, Mary Combs. Iowa Geological Survey. English. cartographic image. Public. Iowa and Iowa. Ordovician and From 425 to 500 million years ago.

23. Thickness of upper Cretaceous rocks from the base of the Niobrara Formation to the top of the Frontier Formation, including the Carlile shale, Greenhorn Formation, and Sage Breaks shale, Powder River Basin, Wyoming and Montana [microform]

1987. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey. English. Public. Powder River Basin (Wyo. and Mont.). Cretaceous.