Mary McGann
Research Geologist at the USGS Pacific Coastal and Marine Science Center
Science and Products
Filter Total Items: 13
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Filter Total Items: 67
Response of benthic foraminifers to sewage discharge and remediation in Santa Monica Bay, California
Examination of a time series of foraminiferal assemblage distributions on the continental shelf and slope of Santa Monica Bay from 1955 to 1997-1998 suggests that the benthic microfauna have been greatly affected by the quality and character of the municipal sludge and wastewater discharged into the bay over the last half-century by the Hyperion Treatment Plant serving the greater Los Angeles area
Authors
M. McGann, C. R. Alexander, S.M. Bay
Historical and modern distributions of benthic foraminifers on the continental shelf of Monterey Bay, California
Historical (early 1930s) and modern samples provide a detailed account of the spatial distribution of benthic foraminifers on the continental shelf of Monterey Bay, California. Ten species among a total of 110 present dominated the 110 samples investigated in the historical study. A cluster analysis of the foraminiferal abundances in the historical study identified five assemblages: Inner Shelf, M
Authors
M. McGann
Invasion by a Japanese marine microorganism in western North America
The earliest record in western North America of Trochammina hadai Uchio, a benthic foraminifer common in Japanese estuaries, is from sediment collected in Puget Sound in 1971. It was first found in San Francisco Bay in sediment samples taken in 1983, and since 1986 has been collected at 91% of the sampled sites in the Bay, constituting up to 93% of the foraminiferal assemblage at individual sites.
Authors
M. McGann, D. Sloan, A.N. Cohen
Recent introduction of the foraminifer Trochammina hadai Uchio into San Francisco Bay, California, USA
No abstract available.
Authors
Mary McGann, Doris Sloan
Ventilation changes in the northeast Pacific during the last deglaciation
Under present climate conditions, convection at high latitudes of the North Pacific is restricted to shallower depths than in the North Atlantic. To what extent this asymmetry between the two ocean basins was maintained over the past 20 kyr is poorly known because there are few unambiguous proxy records of ventilation from the North Pacific. We present new data for two sediment cores from the Cali
Authors
A. VanGeen, R.G. Fairbanks, P. Dartnell, M. McGann, J.V. Gardner, Michaele Kashgarian
Age and correlation of the Calera Limestone in the Permanente terrane of northern California
Planktonic foraminifers indicate that outcrops of Calera Limestone from the Permanente terrane in the Franciscan Complex of northern California range in age from possibly as old as Barremian to late Turonian. Underlying black limestone, which is devoid of planktonic foraminifers, presumably is Barremian in age or older. The top of the sequence exposed in major quarries is always faulted. Improved
Authors
William V. Sliter, Mary McGann
Paleoenvironmental analysis of latest Quaternary levee deposits of Monterey Fan, Central California Continental margin : foraminifers and pollen, Core S3-15G
No abstract available.
Authors
Mary McGann
Science and Products
Filter Total Items: 13
No Result Found
Filter Total Items: 67
Response of benthic foraminifers to sewage discharge and remediation in Santa Monica Bay, California
Examination of a time series of foraminiferal assemblage distributions on the continental shelf and slope of Santa Monica Bay from 1955 to 1997-1998 suggests that the benthic microfauna have been greatly affected by the quality and character of the municipal sludge and wastewater discharged into the bay over the last half-century by the Hyperion Treatment Plant serving the greater Los Angeles area
Authors
M. McGann, C. R. Alexander, S.M. Bay
Historical and modern distributions of benthic foraminifers on the continental shelf of Monterey Bay, California
Historical (early 1930s) and modern samples provide a detailed account of the spatial distribution of benthic foraminifers on the continental shelf of Monterey Bay, California. Ten species among a total of 110 present dominated the 110 samples investigated in the historical study. A cluster analysis of the foraminiferal abundances in the historical study identified five assemblages: Inner Shelf, M
Authors
M. McGann
Invasion by a Japanese marine microorganism in western North America
The earliest record in western North America of Trochammina hadai Uchio, a benthic foraminifer common in Japanese estuaries, is from sediment collected in Puget Sound in 1971. It was first found in San Francisco Bay in sediment samples taken in 1983, and since 1986 has been collected at 91% of the sampled sites in the Bay, constituting up to 93% of the foraminiferal assemblage at individual sites.
Authors
M. McGann, D. Sloan, A.N. Cohen
Recent introduction of the foraminifer Trochammina hadai Uchio into San Francisco Bay, California, USA
No abstract available.
Authors
Mary McGann, Doris Sloan
Ventilation changes in the northeast Pacific during the last deglaciation
Under present climate conditions, convection at high latitudes of the North Pacific is restricted to shallower depths than in the North Atlantic. To what extent this asymmetry between the two ocean basins was maintained over the past 20 kyr is poorly known because there are few unambiguous proxy records of ventilation from the North Pacific. We present new data for two sediment cores from the Cali
Authors
A. VanGeen, R.G. Fairbanks, P. Dartnell, M. McGann, J.V. Gardner, Michaele Kashgarian
Age and correlation of the Calera Limestone in the Permanente terrane of northern California
Planktonic foraminifers indicate that outcrops of Calera Limestone from the Permanente terrane in the Franciscan Complex of northern California range in age from possibly as old as Barremian to late Turonian. Underlying black limestone, which is devoid of planktonic foraminifers, presumably is Barremian in age or older. The top of the sequence exposed in major quarries is always faulted. Improved
Authors
William V. Sliter, Mary McGann
Paleoenvironmental analysis of latest Quaternary levee deposits of Monterey Fan, Central California Continental margin : foraminifers and pollen, Core S3-15G
No abstract available.
Authors
Mary McGann