Porvenir formation (new name)--and other revisions of nomenclature of Mississippian, Pennsylvanian, and lower Permian rocks, southeastern Sangre de Cristo Mountains, New Mexico Baltz, Elmer Harold 1927- creator author. Myers, Donald A. 1921- author. Geological Survey (U.S.) issuing body. text bibliography Terminology. vau 1984 monographic eng remote 1 online resource (iii, 39 pages) : illustrations, maps. by Elmer H. Baltz and Donald A. Myers. Title from title screen (viewed Aug. 4, 2014). Includes bibliographical references (pages 36-39). n-us-co n-us-nm From 230 to 570 million years ago fast Geology, Stratigraphic Paleozoic Geology, Stratigraphic Nomenclature Geology, Stratigraphic Paleozoic Geologic Period I 19.3:1537-B I 19.3:1537-B Porvenir formation (new name)--and other revisions of nomenclature of Mississippian, Pennsylvanian, and lower Permian rocks, southeastern Sangre de Cristo Mountains, New Mexico Baltz, Elmer Harold, 1927- (DLC) 82600110 (OCoLC)8347655 Contributions to stratigraphy Geological Survey bulletin ; 1537-B https://purl.fdlp.gov/GPO/gpo61671 COP 140812 20211120173436.0 in00003602521 eng