Correlation and taphonomy of late Cretaceous vertebrate localities in Fruitland and Kirtland formations, San Juan basin, New Mexico

Conference · Fri Sep 01 04:00:00 EDT 1989 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:5498980

Hunt, A P ^[1]

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1. Univ. of New Mexico, Albuquerque (USA)

Most fossil vertebrates in the Fruitland and Kirtland formations occur in two narrow stratigraphic intervals. The upper interval comprises the approximately 30 m-thick Naashoibito Member of the Kirtland formation. Fossiliferous localities within this interval are physically correlatable within the small and continuous outcrop belt of this unit. The lower fossiliferous interval comprises a 20 m-thick sequence between the stratigraphically highest, thick coal bed (1 m thick) in the Fruitland Formation and distinctive brown tabular sandstones in the lower Kirtland formation, which differ in color and geometry from adjacent sandstone bodies. Localities within this interval occur in physically discontinuous outcrops, principally between Hunter Wash in the northwest and Coal Creek in the southeast. These localities can be correlated utilizing the upper Fruitland coal, the lower Kirtland sandstones, and a series of volcanic ashes. Measurement of 38 stratigraphic sections and examination of more than 100 subsurface geophysical logs has allowed detailed correlation between the principal areas of vertebrate-fossil occurrences in Hunter Wash and the Fossil Forest. The occurrence of fossils in the Naashoibito is related to energy of depositional environment. Farther north, coarser deposits of the McDermott Member of the Animas Formation, which represent proximal facies of the Naashoibito, lack abundant fossil vertebrates. The geographic extent of vertebrate fossils in the upper Fruitland and lower Kirtland coincides with the extent of the tabular brown sandstones in the lower Kirtland and is related to Laramide downwarping of the central San Juan basin.

• OSTI ID: 5498980
• Report Number(s): CONF-8910195--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 73:9
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
COAL DEPOSITS
CRETACEOUS PERIOD
FEDERAL REGION VI
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC STRUCTURES
GEOLOGY
MESOZOIC ERA
MINERAL RESOURCES
NEW MEXICO
NORTH AMERICA
PALEONTOLOGY
RESOURCES
ROCKS
SANDSTONES
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
STRATIGRAPHY
USA