Stratigraphy and Depositional History of the Pantano Formation (Oligocene-Early Miocene), Pima County, Arizona
Author
Balcer, Richard AllenIssue Date
1984Keywords
absolute agealluvial fans
andesites
Arizona
Basin and Range Province
basins
Cenozoic
dates
environment
geochronology
igneous rocks
interpretation
lacustrine environment
Miocene
Neogene
North America
Paleogene
Pantano Formation
Pima County Arizona
provenance
rhyolites
sedimentary basins
sedimentary rocks
sedimentation
southern Arizona
terrestrial environment
Tertiary
United States
volcanic rocks
Geology, Stratigraphic -- Miocene
Geology, Stratigraphic -- Oligocene
Sedimentation and deposition -- Arizona -- Cienega Gap Region
Sedimentation and deposition -- Arizona -- Pima County
Advisor
Schreiber, J. F. Jr.Committee Chair
Schreiber, J. F. Jr.
Metadata
Show full item recordPublisher
The University of Arizona.Rights
Copyright © is held by the author. Digital access to this material is made possible by the Antevs Library, Department of Geosciences, and the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author or the department.Abstract
The Pantano Formation comprises 1,250 m of alluvial, fluvial, lacustrine, and volcanic rocks deposited in a basin formed in response to regional extension during mid- Tertiary time in southeastern Arizona. During deposition, the locations and composition of sediment source areas varied as contemporaneous uplift occurred adjacent to the basin. The lower half of the formation was deposited as alluvial fans that prograded northward, westward, and southward; the upper half was deposited during southwestward retreat of alluvial fan deposition and the onset of lacustrine deposition. An andesite flow separates the two depositional regimes. Radiometric dates of 24.4 ± 2.6 m.y. B.P. for the andesite and 36.7 ± 1.1 m.y. B.P. for a rhyolitic tuff disconformably underlying the formation indicate that deposition occurred during Oligocene to early Miocene time. Proper stratigraphic sequencing and description, paleocurrent analysis, and gravel provenance study aided in understanding the depositional history of the formation.Type
textThesis-Reproduction (electronic)
Degree Name
M.S.Degree Level
mastersDegree Program
Graduate CollegeGeosciences