Shorter Contributions to General Geology, 1936 (open access)

Shorter Contributions to General Geology, 1936

From abstract: This report describes four species of Ostreidae from the Upper Cretaceous of the Gulf region. The zones that the species characterize lie either in the upper part of the Austin chalk or in beds of upper Austin age.
Date: 1940
Creator: Loughlin, G. F.
System: The UNT Digital Library
Some Middle Cenomanian (Upper Cretaceous) Acanthoceratid Ammonites from the Western Interior of the United States (open access)

Some Middle Cenomanian (Upper Cretaceous) Acanthoceratid Ammonites from the Western Interior of the United States

Abstract: The ammonite family Acanthoceratidae de Grossouvre is represented in the Western Interior region by many genera. Species and subspecies of Calycoceras, Acanthoceras, Cunningtoniceras, Plesiacanthoceras, and Protacanthoceras are important guide fossils to narrow zones of middle Cenomanian age in southeastern Montana, northeastern Wyoming, western South Dakota, and central Kansas. In this region, the ammonite zonation through most of the middle Cenomanian seems to be, from oldest to youngest, a zone of Acanthoceras muldoonense Cobban and Scott, a zone of Acanthoceras bellense Adkins and Calycoceras leonense (Adkins), a zone of Cunningtoniceras amphibolum (Morrow) with subzones of C. amphibolum amphibolum and C. amphibolum fallense (n. subsp.), and a zone of Plesiacanthoceras wyomingense (Reagan). In this report, Acanthoceras muldoonense, A. bellense, and Calycoceras leonense are described from the northern part of the Western Interior for the first time. Cunningtoniceras amphibolum, originally assigned to Acanthoceras, is described in more detail and divided into the nominate subspecies and the new subspecies C. amphibolum fallense. The earliest whorls of Plesiacanthoceras wyomingense, previously unknown, are described as well as all the later growth stages. The small genus, Protacanthoceras, is represented by several new species and one new subspecies. Protacanthoceras fisheri is found in the zone of Acanthoceras …
Date: 1987
Creator: Cobban, William Aubrey
System: The UNT Digital Library
Geology of the southern Guadalupe Mountains, Texas (open access)

Geology of the southern Guadalupe Mountains, Texas

From Abstract: "This report deals with an area of 425 square miles in the western part of Texas, immediately south of the New Mexico line. The report describes the geology of the area, that is, the nature of its rocks, tectonics, and surface features, and the evidence that they give as to the evolution of the area through geologic time. Incidental reference is made to the geology of surrounding regions in order to place the area in its environment."
Date: 1948
Creator: King, Philip B.
System: The UNT Digital Library