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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 50 (1966)

Issue: 3. (March)

First Page: 631

Last Page: 631

Title: Eaglefordian (Cenomanian--Turonian) Stratigraphy in Mexico and Texas: ABSTRACT

Author(s): Emile A. Pessagno

Article Type: Meeting abstract

Abstract:

The biostratigraphy of the San Felipe Formation of Mexico and the correlative Eagle Ford Group of Texas has been studied extensively from well cores and measured sections. The San Felipe was examined in outcrop at Boca Canyon south of Monterrey whereas the Eagle Ford was studied at Chispa Summit in Jeff Davis County, at Lozier Canyon near Langtry, at Sycamore Canyon near Del Rio, on Bouldin Creek in Austin, at Atco near Waco, and at the type locality at Dallas.

Previously, Eaglefordian strata in Texas and Mexico were included in the Rotalipora cushmani-greenhornensis Subzone of the Rotalipora s.s. Assemblage Zone and the Marginotruncana sigali and Whiteinella archaeocretacea Subzones of the Marginotruncana helvetica Assemblage Zone. At Boca Canyon in Mexico all of these units are represented. Through most of Texas, however, sampling indicates that the Marginotruncana sigali Subzone is consistently absent, and the Whiteinella archaeocretacea Subzone rests unconformably on strata assignable to the Rotalipora cushmani-greenhornensis Subzone of the Rotalipora s.s. Assemblage Zone.

In view of these discoveries, the writer proposes to subdivide the Eaglefordian Stage of the standard Gulf Coast Upper Cretaceous section into three substages: (1) the Lozierian (late Cenomanian), (2) the Bocian (early Turonian), and (3) the Sycamorian (late Turonian).

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Copyright 1997 American Association of Petroleum Geologists