Author: Robert Minssen KleinpellPublisher:
ISBN:
Category : Science
Languages : en
Pages : 372
Book Description
The Miocene Stratigraphy of California Revisited
Author: Robert Minssen KleinpellPublisher:
ISBN:
Category : Science
Languages : en
Pages : 372
Book Description
U.S. Geological Survey Professional Paper
Author: Microdistribution of Foraminifera in a Single Bed of the Monterey Formation, Monterey County, California
Author: Roberta K. SmithPublisher:
ISBN:
Category : Science
Languages : en
Pages : 42
Book Description
While several papers exist on the small scale spatial distribution of living foraminifera, almost no work exists on the small scale spatial distribution of fossils. The present study took 24 (5 ml) replicates 10 cm apart along one bed of the Monterey Formation in California.The mean density for all replicates is 6084.96 with a standard deviation of 8776.95. Both inspection and a cluster analysis of the data indicate replicates 20-24 have a much higher density and different rank order of abundance than replicates 1-19. The mean density for the total of all species in replicates 1-19 is 2387.47 with a standard deviation of 1175.58. For replicates 20-24 the mean density is 20135.40 with a standard deviation of 11181.40. The spatial variability is so great that four replicates (more than commonly taken) would only allow us to be 95% confident that we are within 50% of the true mean. Because age determination is based on presence of particular taxa rather than on densities, stratigraphic assignment would still be possible.The three species dominating the 1-19 group make up from 86% to 99% of the fauna. The three species dominating the 20-24 group make up from 77% to 85% of the fauna. Two of these are also dominant in the 1-19 group, but the most dominant species in the 20-24 group constitutes only
U.S. Geological Survey Bulletin
Author: Sedimentology of the Conglomeratic Lower Member of the Lospe Formation (Lower Miocene), Santa Maria Basin, California
Author: Samuel Y. JohnsonPublisher:
ISBN:
Category : Geology, Stratigraphic
Languages : en
Pages : 40
Book Description
Classic Cordilleran Concepts
Author: Eldridge M. MooresPublisher: Geological Society of America
ISBN: 0813723388
Category : Science
Languages : en
Pages : 507
Book Description
Cenozoic Giant Pectinids from California and the Tertiary Caribbean Province
Author: Judith Terry SmithPublisher:
ISBN:
Category : Paleontology
Languages : en
Pages : 244
Book Description
Thirty-nine taxa, many of them index species, are described and illustrated; their biostratigraphic and chronostratigraphic significance are related to tectnostratigraphic settings.
Geological Survey Professional Paper
Author: Geological Survey (U.S.)Publisher:
ISBN:
Category :
Languages : en
Pages : 260
Book Description
MMS.
Author: 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.