HomeMy WebLinkAboutCT 99-13; Steiner Property; Tentative Map (CT) (32)f
San Diego
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28 May 1999 jy |j ,;;_.•; - 3 •-;.•: .;jj
Mr. Scot C. Sandstrom j
Western Pacific Housing L
2385 Camino Vida Roble, Suite 107
Carlsbad, CA 92009
RE: Paleontological Resources: Steiner Property, City of Carlsbad
Dear Scot:
This letter report presents my assessment of the paleontological resource potential
of the Steiner Property, City of Carlsbad. The report draws largely on an earlier field
walkover (28 August 1997) of the adjacent Lohf Property and on reviews of the Lohf
Property geotechnical report prepared by Pacific Soils Engineering, Inc. and on more
general published (Eisenberg and Abbott, 1985) and unpublished (Wilson, 1972)
geological reports for the coastal North County area.
According to the geotechnical and geological reports the bedrock unit exposed on
the project site is middle Eocene in age and referable to either the Santiago Formation.
Bedrock exposures of Eocene sedimentary rocks observed on the Lohf Property consist of
light gray and yellow-white, fine- and medium-grained, cross-bedded sandstones. Fossils
were observed in several outcrops and consisted of fragmentary remains and impressions
of plants, including leaves, stems, and seeds. Preservation ranged from very poor to
moderate. The cross-bedded sandstones containing these fossil remains have not been
precisely dated, but based on correlations with other areas in coastal San Diego County it
is suggested that the fossils are approximately 45-48 million years old. The discovery of
moderately preserved fossils in weathered bedrock exposures on the Lohf Property
indicates that grading operations will probably also encounter fossils during development
of the adjacent Steiner Property.
Mitigation of the predicted construction-related impacts can be accomplished
through implementation of a paleontological resource mitigation program. This program
should include the following elements:
[1] attend any pre-construction meetings;
[2] monitor grading operations and inspect cuts for unearthed fossil remains;
[3] salvage remains as they are uncovered;
[4] screenwash selected sites (if discovered) for recovery of small fossil remains;
[5] document the stratigraphic and geologic context of salvaged fossil remains;
[6] remove fossils from the project site;
[7] clean, repair, and sort salvaged fossils;
[8] catalogue prepared and sorted fossils for eventual donation to an institution
with professional curatorial staff and a long-term record of professional
collection conservation (e.g., SDNHM);
Post Office Box 121390 • San Diego, California 92112-1390 • Telephone: 619-232-3821 • Fax: 619-232-0248 • Website: http://www.sdnhm.org
O J»Y1^^ ^U' Accredited by the American Association of Museums
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[9] prepare a final report summarizing the results of the mitigation program. This
report will include a discussion of methods employed, fossils recovered,
geologic context of fossil remains, and significance of mitigation program.
If you have any questions concerning this report, please feel free to contact me at
(619)232-382l.ext. 232.
Sincerely,
Thomas A. Demere, Ph.D.
Curator, Department of Paleontology
Director, Department of Paleontological Services
References Cited:
Eisenberg, L.I., and P.L. Abbott. 1985. Eocene lithofacies and geologic history, northern
San Diego County. In, P.L. Abbott (ed.), On the Manner of Deposition of the
Eocene Strata in northern San Diego County. San Diego Association of
Geologists, fieldtrip guidebook, pp. 19-35.
Wilson, K.L. 1972. Eocene and related geology of a portion of the San Luis Rey and
Encinitas quadrangles, San Diego County, California. Unpublished M.A. thesis,
University of California, Riverside, 135 p.
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