HomeMy WebLinkAboutCT 2018-0006; LAGUNA DRIVE SUBDIVISION; PALEONTOLOGICAL RESOURCES REVIEW; 2018-02-23
MEMORANDUM
To: Mr. Brett Farrow
From: Sarah Siren, M.S., GISP, Senior Paleontologist
Subject: Paleontological Resources Review – Laguna Drive Project
Date: February 23, 2018
cc: Callie Amoaku, Dudek
Attachment(s): Paleontological Records Search Results Letter
Dudek is providing this memorandum after completing a review of the potential for impacts to
paleontological resources during construction of Laguna Drive Project, located at 570 Laguna
Drive in the City of Carlsbad, San Diego County, California. The project site is relatively
undeveloped with the majority of the project site mapped as Quaternary old paralic deposits,
which are roughly correlative with the Bay Point Formation (early to middle Pleistocene,
approximately 750,000 to 11,000 years old; Qop6-7) (Deméré, 1981; Kennedy et al., 2007;
McComas, 2018).
The Bay Point formation was named for outcrops near Crown Point (formerly Bay Point), and
generally consist of poorly consolidated, pale brown fine- to medium-grained sandstones
(Valentine, 1959; Tan and Kennedy, 1996). The Bay Point Formation has produced important
invertebrate and vertebrate fossil localities along coastal San Diego (Stephens, 1929; Hertlein
and Grant, 1939; Valentine, 1959; Deméré, 1981).
According to the San Diego County guidelines for paleontology (County of San Diego, 2009;
Deméré and Walsh, 1993), and the records search results received from the San Diego Natural
History Museum (SDNHM) on February 1, 2018, the Bay Point Formation has a high potential
to yield paleontological resources (City of San Diego, 2011; County of San Diego, 2009;
McComas, 2018).
The museum records search results letter indicates that a single paleontological locality is
documented within a one-mile radius of the project boundaries (McComas, 2018; see attached
Paleontological Records Search Results Letter). The locality, SDNHM 4007, produced a
proboscidean (e.g., mastodons and mammoths) tusk. Pleistocene age localities elsewhere in San
Diego County have produced scientifically significant “Ice Age” mammals such as mammoths,
Memorandum
Subject: Paleontological Resources Review – Laguna Drive Project
10746
2 February 2018
mastodons, ground sloths, dire wolves, short-faced bears, sabre-toothed cats, horses, camels, and
bison (Deméré et al., 2013; Jefferson, 1991a, b; Rugh, 2009). The Bay Point Formaion, and
correlative old paralic deposits have the potential to yield scientifically significant vertebrate
fossils.
A paleontological resources mitigation program is recommended for excavation within
previously undisturbed, high sensitivity geological units (e.g., Bay Point Formation and age
equivalent Pleistocene age old paralic deposits) and should be implemented in accordance with
the mitigation measures included at the end of this report. Excavation within lower sensitivity
units (e.g, previously disturbed surficial deposits, if encountered) does not require mitigation.
If you have any questions regarding this memo, please feel free to contact me (760.846.9326 or
ssiren@dudek.com).
Sincerely,
______________________
Sarah A. Siren, M.S., GISP
Senior Paleontologist, Dudek
Enc. Paleontological Records Search Results Letter
Memorandum
Subject: Paleontological Resources Review – Laguna Drive Project
10746
3 February 2018
Mitigation Measures:
Prior to the issuance of grading permits, the Applicant shall provide written confirmation to the
City that a qualified paleontologist has been retained to carry out an appropriate mitigation
program. (A qualified paleontologist is defined as an individual with an M.S. or Ph.D. in
paleontology or geology who is familiar with paleontological procedures and techniques). A pre
grade meeting shall be held among the paleontologist and the grading and excavation
contractors.
A paleontological monitor shall be onsite at all times during the original cutting of previously
undisturbed sediments of highly sensitive geologic formations (i.e., Bay Point Formation, and
correlative old paralic deposits) to inspect cuts for contained fossils. (A paleontological monitor
is defined as an individual who has experience in the collection and salvage of fossil materials.)
The paleontological monitor shall work under the direction of a qualified paleontologist.
• The monitor shall be onsite during the original cutting of previously undisturbed
sediments of high sensitivity geologic formations (e.g., Bay Point Formation, and
correlative old paralic deposits) to inspect cuts for contained fossils. Monitoring is not
required during excavation into low and no resource sensitivity geologic formations (e.g.,
young alluvial flood-plain deposits and artificial fill, respectively).
• In the event that fossils are discovered in unknown, low, or moderately sensitive
formations, the Applicant shall increase the per-day field monitoring time. Conversely, if
fossils are not discovered, the monitoring, at the discretion of the City's Deputy City
Manager/Development Services Director or its designee, shall be reduced. A
paleontological monitor is not needed during grading of rocks with no resource
sensitivity.
When fossils are discovered, the paleontologist (or paleontological monitor) shall recover them.
In most cases, this fossil salvage can be completed in a short period of time. However, some
fossil specimens (such as a complete whale skeleton) may require an extended salvage time. In
these instances, the paleontologist (or paleontological monitor) shall be allowed to temporarily
direct, divert, or halt grading to allow recovery of fossil remains in a timely manner. Because of
the potential for the recovery of small fossil remains such as isolated mammal teeth, it may be
necessary in certain instances and at the discretion of the paleontological monitor to set up a
screen-washing operation on the site.
Prepared fossils along with copies of all pertinent field notes, photos, and maps shall be
deposited in a scientific institution with paleontological collections such as the San Diego
Memorandum
Subject: Paleontological Resources Review – Laguna Drive Project
10746
4 February 2018
Natural History Museum. A final summary report shall be completed. This report shall include
discussions of the methods used, stratigraphy exposed, fossils collected, and significance of
recovered fossils.
References Cited:
City of San Diego, 2011. California Environmental Quality Act, Significance Determination
Thresholds. Development Services Department, 84p.
County of San Diego, 2009. Guidelines for Determining Significance, Paleontological
Resources. Department of Planning and Land Use, Department of Public Works.
March 19, Modified January 15, 2009.
Deméré, T.A. 1981. A newly recognized late Pleistocene marine fauna from the City of San
Diego, San Diego County, California. In, P.L. Abbott and S. O'Dunn (eds.), Geologic
Investigations of the San Diego Coastal Plain. San Diego Association of Geologists,
fieldtrip guidebook, pp. 1-10.
Deméré, T.A., K.A. Randall, B.O. Riney, and S.A. Siren, 2013. Discovery of remains of an
extinct giant bison (Bison latifrons) in Pleistocene (Rancholabrean) fluvial strata in
the San Luis Rey River Valley, San Diego County, California, USA. San Diego
Association of Geologists Field Trip Guide, pp. 122-135.
Deméré, T.A. and S.L. Walsh, 1993. Paleontological Resources, County of San Diego.
Prepared for the San Diego Planning Commission, pp. 1-68.
Hertlein, L.G., and U.S. Grant, IV. 1939. Geology and oil possibilities of southwestern San
Diego County. California Journal of Mines and Geology 35:57-78.
Jefferson, G.T., 1991a. A Catalogue of late Quaternary vertebrates from California: Part One,
nonmarine lower vertebrate and avian taxa. Natural History Museum of Los Angeles
County, Technical Reports, No. 5.
Jefferson, G.T., 1991b. A Catalogue of late Quaternary vertebrates from California: Part
Two, Mammals. Natural History Museum of Los Angeles County, Technical Reports,
No. 7.
Kennedy, M.P., S.S. Tan, K.R. Bovard, R.M. Alvarez, M.J. Watson, and C.I. Gutierrez, 2007.
Geologic map of the Oceanside 30' x 60' quadrangle, California: California Geological
Survey, Regional Geologic Map No. 2, scale 1:100,000.
Memorandum
Subject: Paleontological Resources Review – Laguna Drive Project
10746
5 February 2018
McComas, K. 2018. Paleontological Record Search – Laguna Drive Project (Project No. 10746).
Unpublished letter report by the San Diego Natural History Museum. February 1, 2018.
Rugh, N.S., 2009. Fossil Discoveries in Downtown San Diego, Part II. Field Notes. Natural
History Magazine. Available at:
http://www.naturalhistorymag.com/partner/fossil-discoveries-in-downtown-san-diego
Stephens, F. 1929. Notes on the marine Pleistocene of San Diego County, California. San Diego
Society of Natural History, Transactions 5:245-256.
Tan, S.S., and Kennedy, M.P. 1996. Geologic maps of the northwestern part of San Diego,
California: California Division of Mines and Geology Open-File Report 96-02, 2 sheets
(scale 1:24,000).
Valentine, J.W. 1959. Pleistocene molluscan notes. I. The Bay Point Formation at its type
locality. Journal of Paleontology 33:685-688.
1 February 2018
Ms. Sarah Siren
Dudek
605 Third Street
Encinitas, CA 92024
RE: Paleontological Records Search – Laguna Drive Project (Project No. 10746)
Dear Ms. Siren:
This letter presents the results of a paleontological records search conducted for the Laguna
Drive project, located at 570 Laguna Drive in the northwestern portion of the City of Carlsbad, San Diego
County, CA. The project site is bounded to the south by Laguna Drive, to the north by undeveloped land,
and to the east and west by existing residential and commercial development.
A review of published geological maps covering the project site and surrounding area was
conducted to determine the specific geologic units underlying the project. Each geologic unit was
subsequently assigned a paleontological resource sensitivity following County of San Diego guidelines
(Deméré and Walsh, 1993; Stephenson et al., 2009). Published geological reports (e.g., Kennedy and
Tan, 2007) covering the project area indicate that the proposed project has the potential to impact the
Pleistocene-age Bay Point Formation. This geologic unit and its paleontological sensitivity are
summarized in detail in the following section.
In addition, a search of the paleontological collection records housed at the San Diego Natural
History Museum (SDNHM) was conducted in order to determine if any documented fossil collection
localities occur at the project site or within the immediate surrounding area (Figure 1). The SDNHM has
one recorded fossil locality, from the Bay Point Formation, within one mile of the project site. The
locality is described in greater detail below.
Geologic Rock Units Underlying the Project Area
Bay Point Formation – Nearshore marine deposits and associated fluvial terrace deposits of
the Pleistocene-age (approximately 750,000 to 11,000 years old) Bay Point Formation underlie the
entire project site. The SDNHM has one recorded fossil collection locality from the Bay Point Formation
within a 1-mile radius of the project site. The locality produced a fossilized partial tusk of a
proboscidean. The Bay Point Formation has been assigned a high paleontological sensitivity for the
diverse and well-preserved fossils of marine invertebrates and marine vertebrates that have been
recovered from these deposits.
Summary and Recommendations
The high paleontological sensitivity of the Bay Point Formation in San Diego County (Deméré
and Walsh, 1993; Stephenson et al., 2009) suggests the potential for construction of the proposed
project to result in impacts to paleontological resources. Any proposed excavation activities that extend
deep enough to encounter previously undisturbed deposits of this geologic unit have the potential to
impact the paleontological resources preserved therein. For these reasons, implementation of a
Laguna Drive Project - Paleontological Records Search 2
complete paleontological resource mitigation program during ground-disturbing activities is
recommended.
The fossil collection locality information contained within this paleontological record search
should be considered private and is the sole property of the San Diego Natural History Museum. Any use
or reprocessing of information contained within this document beyond the scope of the Laguna Drive
project is prohibited.
If you have any questions concerning these findings please feel free to contact me at 619-255-
0321 or kmccomas@sdnhm.org.
Sincerely,
Katie McComas
Paleontology Collections Assistant
San Diego Natural History Museum
Enc: Figure 1: Project map
Appendix: Localities in the vicinity of the project
Literature Cited
Deméré, T.A., and Walsh, S.L. 1993. Paleontological Resources, County of San Diego. Prepared for the
San Diego Planning Commission: 1–68.
Kennedy, M.P., and Tan, S.S. 2007. Geologic Map of the Oceanside 30' x 60' Quadrangle, California.
California Geological Survey, Regional Geologic Map Series 1:100,000 scale, map no. 2.
Stephenson, B., and seven others. 2009. County of San Diego Guidelines for determining significance,
paleontological resources. Land Use and Environment Group, Department of Planning and Land
Use, Department of Public Works, 46 p.
FIGURE1 Laguna Drive ProjectCity of Carlsbad, San Diego County, California
0 0.4
scale in miles
Project Map
San DiegoCo.Imperial Co.map extent
Sources: Bing Maps Hybrid Imagery, Microsoft et al., 2017
Project site
1 mile radius buffer
SDSNH localities
Project Site
Riverside Co.
Appendix: Locality List
San Diego Natural History Museum
Department of Paleontology
Locality Number Locality Name Location Elevation (feet)Geologic Unit Era Period Epoch
4007 I-5 and SR-78 City of Oceanside, San Diego County, CA 49 Bay Point Formation, unnamed nonmarine deposit Cenozoic Quaternary Pleistocene
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