Author: Jeffrey Todd PietrasPublisher:
ISBN:
Category : Eocene-Oligocene boundary
Languages : en
Pages : 436
Book Description
Sequence Stratigraphic and Facies Analysis of the Eocene to Oligocene in the Santa Ynez Mountains, California
Author: Jeffrey Todd PietrasPublisher:
ISBN:
Category : Eocene-Oligocene boundary
Languages : en
Pages : 436
Book Description
Geological Survey Professional Paper
Author: Stratigraphy and Sedimentology of the Eocene Tejon Formation, Western Tehachapi and San Emigdio Mountains, California
Author: Tor Helge NilsenPublisher:
ISBN:
Category : Geology, Stratigraphic
Languages : en
Pages : 122
Book Description
U.S. Geological Survey Professional Paper
Author: Sedimentology and Paleontology of Eocene Rocks in the Sespe Creek Area, Ventura County, California
Author: A. Eugene FritschePublisher:
ISBN:
Category : Science
Languages : en
Pages : 112
Book Description
Conglomerates of the Upper Middle Eocene to Lower Miocene Sespe Formation Along the Santa Ynez Fault
Author: Jeffrey L. HowardPublisher:
ISBN:
Category : Argillite
Languages : en
Pages : 64
Book Description
Geological Survey Professional Paper
Author: Geological Survey (U.S.)Publisher:
ISBN:
Category :
Languages : en
Pages : 494
Book Description
Sedimentation and Tectonics in the Early Tertiary Continental Borderland of Central California
Author: Tor Helge NilsenPublisher:
ISBN:
Category : Geology
Languages : en
Pages : 72
Book Description
U.S. Geological Survey Bulletin
Author: Colin F. WilliamsPublisher:
ISBN:
Category : Argillite
Languages : en
Pages : 214
Book Description
Phosphatic concretions occur within diatomite in the upper part of the Miocene Monterey Formation near Lompoc, Calif. Absence of disruption of fine laminar bedding in the associated sediment by the concretions shows that they formed after complete compaction of the enclosing sediment.The concretions exhibit a strongly concentric color, chemical, and mineralogic zonation. Many of them are composed of a nucleus in which vivianite is the dominant mineral. Amorphous ferric phosphate, mitridatite, and francolite are the dominant phosphatic phases in successive layers toward the surface of the concretions. Cd and As contents increase tenfold from the nucleus outward, reaching a maximum of 2,000 ppm, whereas Ni content, with a maximum of 720 ppm, and Co content show the opposite trend. This mineralogy and elemental composition favor accretion under conditions of continuously increasing Eh and pH, during uplift into the fresh-ground-water zone of the terrestrial environment. Shale-normalized rare-earth-element patterns, however, suggest a marine source for the elements biogenic debris consisting of opal-A, organic matter, and carbonates of the enclosing sediment.
Author: