Marine geology and oceanography of Santa Cruz basin off southern California

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Frequently-anticipated questions:

What does this data set describe?

Title:
Marine geology and oceanography of Santa Cruz basin off southern California
Abstract:
"An intermediate basin between coastal and offshore depressions of the California Continental Borderland, Santa Cruz Basin, with a general depth of 1900 m, lies south of the Channel Islands. Steep walls, with a thin sediment cover, abut against the flat basin floor. Hummocky topography, related to slumping, marks the northwestern quadrant of the basin floor. Three major canyon systems provide paths for sediments from the northern and southern insular platforms, while buried channels mark the previous existence of a fourth system. The western wall is relatively straight and featureless when compared to the structural terraces, volcanic knolls, and other irregularities of the eastern slope. Hydrographic data indicate that the surface and near surface water circulation is affected by wind stress and the association of the Southern California eddy with the California current. Offshore transport of surface water by both the prevailing northwesterly and easterly ("Santa Ana") winds causes upward water movement, apparently at all depths, which is aided by low stability at and below the basin sill. Most subsurface water movement is toward the north and northwest with considerable variation in speed and direction. A tidal cycle is also shown by the data. Surficial mixing is caused by the combined effects of currents, upwelling, intrabasin seiches, and internal waves. Heatflow and sediment transport are suggested as possible factors in addition to seiches and upwelling to cause overturn of deep basin water. The complex pattern of sedimentation found in the basin is a reflection of oceanographic, physiographic and sedimentologic conditions and geologic history. Partial infilling comes from either end of the basin in the form of turbidite sedimentation. The resulting sedimentary structures reflect both a proximal and distal sedimentation regime. Turbidite and hemipelagic sedimentation is disrupted by bioturbation. This burrowing action of organisms is abundant but patchy, often disrupting structures to the extent of making them almost indiscernible. The hemipelagic sediments found in this basin are organically rich, olive gray clay-silts. The recent stratigraphic history of Santa Cruz Basin is marked by a decreased Holocene rate of "turbidite" sedimentation while the hemipelagic contribution has increased slightly. Carbonate production over the basin as reflected in foraminiferal abundances and total carbonate production has varied greatly, being greatest about 7,000 yr B.P. Correlation using carbonate abundance as a stratigraphic tool reflects a sedimentation trend controlled by topography. Rates of accumulation on the basin floor are greatest (30 mg/cm2/yr) in the deepest portions and become less (9 mg/cm2/yr) as the walls are approached. The changes in production are most probably reflecting changes in productivity of waters overlying the basin. Changes in the circulation pattern are due to the rise and fall of sea level and the resultant topographic effects on oceanography."
Supplemental_Information:
All stations were occupied with the University of Southern California's Research Vessel, Velero IV. Data digitized by the USGS for inclusion into usSEABED (<http://walrus.wr.usgs.gov/usseabed>)
  1. How should this data set be cited?

    Barnes, Peter W. , 1970, Marine geology and oceanography of Santa Cruz basin off southern California: USC-GEOL 70-3, University of Southern California, Los Angeles, CA.

    Other_Citation_Details:
    Partially funded through USGS Contract 14-08-0001-10862. Report was submitted to the Chief, Office of Marine Geology and Hydrology, U.S. Geological Survey, Menlo Park, CA, and duplicates Barnes' PhD. thesis.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -119.80000
    East_Bounding_Coordinate: -119.10556
    North_Bounding_Coordinate: 33.92778
    South_Bounding_Coordinate: 32.27500

  3. What does it look like?

    Barnes_PhD_1970 (.jpg)
    Sample distribution with coastline and bathymetry for reference.

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 1958
    Ending_Date: 1968
    Currentness_Reference: Publication date

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: Paper

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • Entity point (62)

    2. What coordinate system is used to represent geographic features?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.001. Longitudes are given to the nearest 0.001. Latitude and longitude values are specified in decimal degrees.

  7. How does the data set describe geographic features?

    Point
    SDTS point (Source: Source report)

    AHF Sta. #
    Station number (Source: Allan Hancock Foundation)

    Sequential alpha numeric code

    Water depth
    Water depth (Source: Source report)

    Range of values
    Minimum:200
    Maximum:1925
    Units:Meters
    Resolution:1.0

    Penetration
    Amount of core penetration (Source: Source report)

    Range of values
    Minimum:0.6
    Maximum:9.1
    Units:Meters
    Resolution:0.1

    Core length
    Length of core (Source: Source report)

    Range of values
    Minimum:0
    Maximum:5.7
    Units:Meters
    Resolution:0.1

    Remarks
    Additional information about station or sample (Source: Source report)

    Written text

    Description
    Photo descriptions (Source: Source report)

    Written text

    Lithologic description
    Core descriptions (Source: Source report)

    Written text

    Mean diam.
    Mean diameter of sample (Source: Source report)

    Range of values
    Minimum:3.2
    Maximum:95.4
    Units:Microns
    Resolution:0.01

    Sorting Std. Dev.
    Standard deviation of grainsize distribution (sorting) (Source: Trask, 1932)

    Range of values
    Minimum:0.76
    Maximum:2.82
    Units:Phi
    Resolution:0.01

    Skewness
    Skewness of grainsize distribution (Source: Trask, 1932)

    Range of values
    Minimum:-0.37
    Maximum:0.69
    Units:Unitless
    Resolution:0.01

    Kurtosis
    Kurtosis of grainsize distribution (Source: Trask, 1932)

    Range of values
    Minimum:-0.71
    Maximum:1.13
    Units:Unitless
    Resolution:0.01

    CaCO3
    CaCO3 in sample (Source: Kolpack and Bell, 1968)

    Range of values
    Minimum:0.5
    Maximum:26.42
    Units:Percent
    Resolution:0.01

    Organic
    Organic carbon in sample (Source: Kolpack and Bell, 1968)

    Range of values
    Minimum:0.45
    Maximum:6.32
    Units:Percent
    Resolution:0.01

    Nitrogen
    Nitrogen in sample (Source: Bradstreet, 1965)

    Range of values
    Minimum:0.1
    Maximum:0.51
    Units:Percent
    Resolution:0.01

    C/N
    Ratio of carbon to nitrogen in sample (Source: Source report)

    Range of values
    Minimum:0.9
    Maximum:17.6
    Units:Unitless
    Resolution:0.01

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    Peter W. Barnes at the University of Southern California for the collection and analysis of data. For inclusion into usSEABED: Digitization: Jane Reid (USGS); Formatting corrections: Jane Reid (USGS) and Chris Jenkins (University of Colorado).

  3. To whom should users address questions about the data?

    Peter W. Barnes
    Now at the U.S. Geological Survey (emeritus)
    345 Middlefield Road, MS999
    Menlo Park, CA 94025

    650-329-5265 (voice)
    pbarnes@usgs.gov

Why was the data set created?

" This study was initiated to extend the sedimentologic and stratigraphic knowledge of borderland history. Thus the objectives of this investigation were to define the basin's physiography, structure, oceanography, and sedimentology through geologic time. Being unique among borderland basins in many of these aspects, Santa Cruz basin offers an environment in which to seek answer to many geologic questions."

How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

    Date: Unknown (process 1 of 1)
    Core descriptions were made using wet cores. Grainsize analyses by sieve and pipette techniques (Rodolfo, 1967). Carbon and total carbon measured using a LEO carbon analyzer following Kolpack and Bell, 1968. Nitrogen content determined using the Kjeldahl technique as discussed by Bradstreet, 1965.

    Person who carried out this activity:

    Peter W. Barnes
    Now at U.S. Geological Survey (emeritus)
    345 Middlefield Road, MS999
    Menlo Park, CA 94025

    650-329-5265 (voice)
    pbarnes@usgs.gov

    Data sources used in this process:
    • Trask, 1932
    • Rodolfo, 1967
    • Kolpack and Bell, 1968
    • Bradstreet, 1965

    Data sources produced in this process:

    • Barnes_PhD_1970

  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

    No estimate made for the accuracy of the data in the original report. Data digitized by the USGS and partners were visually compared to the source data, and corrected. Where appropriate, data were tested for completeness using MS Excel. Locations checked using GIS.

  2. How accurate are the geographic locations?

    Navigation by radar fixes, LORAN, and dead reckoning. Estimated accuracy is 0.5 to 1.0 nm or 1-2 km.

  3. How accurate are the heights or depths?

    Depth determination by Times Facsimile precision depth recorder or Gifft GDR IC-19-T recorder; accuracy to 1 fathom.

  4. Where are the gaps in the data? What is missing?

    For usSEABED, appendices A and B were completely digitized. Some information from the report text is also included in usSEABED.

  5. How consistent are the relationships among the observations, including topology?

    Data fall within normal ranges for analytical results.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints:
None. Report is available at the USGS Library and other libraries.
Use_Constraints:
Cite Peter W. Barnes and the University of Southern California as originators of the data.

  1. Who distributes the data set? (Distributor 1 of 2)

    U.S. Geological Survey
    345 Middlefield Road
    Menlo Park, CA 95060

    650-329-5016 (voice)

  2. What's the catalog number I need to order this data set?

    203 (083) B2532m

  3. What legal disclaimers am I supposed to read?

    Although this dataset has been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data. Users of the data should be aware of limitations of the data due to possible imprecision due to navigational inaccuracies and limitations of the statistical data.

  4. How can I download or order the data?

  1. Who distributes the data set? (Distributor 2 of 2)

    University of Southern California
    Zumberge Hall
    Los Angeles, CA 90089

    213-740-6106 (voice)

  2. What's the catalog number I need to order this data set?

    Depends on library

  3. What legal disclaimers am I supposed to read?

    Although this dataset has been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data. Users of the data should be aware of limitations of the data due to possible imprecision due to navigational inaccuracies and limitations of the statistical data.

  4. How can I download or order the data?

  5. What hardware or software do I need in order to use the data set?

    None

Who wrote the metadata?

Dates:
Last modified: 2005
Metadata author:
U.S. Geological Survey
c/o Jane A. Reid
Geologist
400 Natural Bridges Drive
Santa Cruz, CA 95060

831-427-4727 (voice)
jareid@usgs.gov

Contact_Instructions: email preferred
Metadata standard:
CSDGM Version 2 (FGDC-STD-001-1998)

Generated by mp version 2.8.17 on Tue May 16 20:18:13 2006