U.S. Army
Coastal Engineering Research Center
John Cherry
1965
Sand movement along a portion of the northern California coast
Paper
Monterey, CA
United States Naval Postgraduate School
"The long-term beach and offshore sand movement along the portion of the northern California coast between Drakes Bay and the Russian River has been studied. Analysis of hindcast swell data, availability of sand for transport, refraction diagrams and knowledge of stable shapes of sedimentary coastlines suggested that under present conditions little net longshore movement of sand occurs in the area and that the beaches are generally in equilibrium with negligible supply or loss of sand. Surface sediment samples were collected from beaches and offshore zones. Twelve sedimentary petrologic provinces were outlined on the basis of the patterns of heavy mineral distribution. Sands of the provinces nearest the dioritic cliffs of the headlands, Point Reyes, Tomales Point and Bodega Head, have been derived from these cliffs by erosion during the present sedimentation period. The dioritic debris have been supplied from the cliffs at an imperceptibly slow, yet geologically significant, rate. The heavy mineral compositions of the headland are distinctly different from the dioritic sands near the headlands. The mineralogical evidence confirms the results of initial analysis, and shows that negligible quantities of sand move southward around the headlands. In effect the headlands Point Reyes and Bodega Head are barriers to longshore transport. West of Point Reyes Beach the grain size and heavy mineral patterns of distribution indicate that the sands beyond 90 feet are relatively inactive. These sands are probably relic deposits of an ancient period of sand transportation and deposition. The sands of several of the active nearshore provinces apparently were derived and originally made available for coastal transport during ancient sedimentation periods. These active sands now exist in a relatively stable distribution. The dilution rate as a result of present supply is negligible."
"The primary objective of this investigation was to determine the patterns of net or long-term littoral and offshore sand movement along the portion of the northern California coast indicated in Figure 1" (just north of the Russian River to an point between Pt. Reyes and Bolinas Bay)
Data digitized for inclusion into usSEABED. (http://walrus.wr.usgs.gov/usseabed)
1963
Publication date
None
-121.193
-122.78451
38.4634
37.9565
None
U.S. Army Corps of Engineers
Coastal Engineering Research Center
CERC
ISO 19115 Topic Category
Oceans and Estuaries
Location
GeoscientificInformation
NASA/Global Change Master Directory (GCMD) Earth Science Keyword. Version 5.3.3
Marine Sediments
Sediment Composition
Sedimentary Textures
Terrigenous Sediments
Geographic Names Information System (GNIS)
California
Drakes Bay
Point Reyes
Tomales Point
Bodega Head
None
Cite John Cherry and the U.S. Army Coastal Engineering Research Center as the originators of the data.
U.S. Army Coastal Engineering Research Center
Physical
5201 Little Falls Road NW
Washington
DC
20016
Unknown
CERC_TM14
Screen grab of GIS-produced sample distribution, with bathymetry and land for reference.
.jpg
USACE CERC and J. Cherry for collection and analysis of data. usSEABED digitization (data): Jennifer Mendonca (USGS); locations: Nadine Golden (USGS). Formatting corrections: Jane Reid (USGS) and Chris Jenkins (University of Colorado).
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.
Data fall within normal ranges for the given parameters.
For inclusion into usSEABED digitized data include Appendix A (Grain size distribution in each of the beach and offshore samples) and Appendix B (Heavy minerals composition of each of the beach and offshore samples).
Navigational technique not noted in report. Digitization report: Data locations determined by georeferencing location figure, using digital coastline in ArcGIS 8.3 (2004) and are given to 0.0001 decimal degrees. Poor reproduction quality of the report did not allow for precise digitization of the locations of samples 1-167; 221a-c; and 394-579; while these samples are included in usSEABED, the locations should be used with caution.
No water depths are given in the report.
Beach samples collected with a 3-inch diameter steel tube at approximately Bascom's 1951 mid-tide level of reference. The tube was inserted into the sand to a depth of about 7 inches. Two of these samples, about 2 feet apart comprise the total sample for each location. Nearly all the offshore samples were collected by means of 4.5-inch diameter steel tubes, which were dragged 10 to 50 yards. Only the upper one or two inches generally is sampled by this method. In the laboratory the sediment samples were mixed, washed, and subjected to grain size analysis for sieving in the standard manner (Krumbein and Pettijohn, 1938). The heavy minerals from a split of the 53 to 247-micron size fraction were then separated in bromoform (density 2.89) and the strongly magnetic grains removed by a hand magnet. Petrographic counts were done using a line-count method.
Krumbein and Pettijohn, 1938
Bascom, 1951
Unknown
CERC_TM14
U.S. Army Coastal Engineering Research Center
Physical
5201 Little Falls Road, NW
Washington
DC
20016
Unknown
Vector
Point
588
0.0001
0.0001
Decimal degrees
Point
SDTS point
Source report
Sample penetration
Penetration of sampler
CERC Technical Memo 14
0.05
0.18
Meter
0.01
Q50
Median diameter of grainsize
CERC Technical Memo 14
1.49
3.74
Phi
0.01
Q10
Tenth percentile of grainsize distribution
CERC Technical Memo 14
-0.77
4.32
Phi
0.01
Q25
First quartile of grain size distribution
CERC Technical Memo 14
-1.14
4.16
Phi
0.01
Q75
Third quartile of grain size distribution
CERC Technical Memo 14
-2.17
3.25
Phi
0.01
Q90
Ninetieth percentile of grain size distribution
CERC Technical Memo 14
-1.63
2.83
Percent
0.0001
So
Sorting (Standard deviation of grainsize)
Trask, 1932
1.04
3.21
Percent
0.01
Heavy mineral analysis
Heavy mineral analysis
CERC Technical Memo 14
Percents, in the sand fraction, of apatite, sphene, dark green hornblende, total hornblende, other hornblende, augite, glaucophane, actinolite and tremolite, garnet, hypersthene, ankerite, lawsonite, zircon, epidote, other minerals. Grain counts of biotites and opaques; grain counts of biotite.
U.S. Army Coastal Engineering Research Center
Physical
5201 Little Falls Road NW
Washington
DC
20016
Need
CERC Technical Memomorandum 14; P(200) W124tm2 no. 14
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, digitization errors, and limitations of the statistical data.
Report is available at some libraries and through the U.S. Army Coastal Engineering Research Center.
Unknown
U.S. Geological Survey
Mail and physical
345 Middlefield Road
Menlo Park
CA
94025
650.329.5026
men_lib@usgs.gov
P(200) W124tm2 no. 14
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 the limitations of the data due to possible imprecision due to navigational inaccuracies, statistical limitations, and digitizing errors.
Report is available for viewing or checkout at the USGS library, Menlo Park, and at other libraries.
None
1965
2005
U.S. Geological Survey
Jane A. Reid
Geologist
Physical and mail
400 Natural Bridges Drive
Santa Cruz
CA
95060
831-427-4727
jareid@usgs.gov
Email preferred
CSDGM Version 2
FGDC-STD-001-1998
None
Metadata was written by a user of the data. Any information contained in the physical report is authoritative and supercedes any information given here.