HomeMy WebLinkAboutAppendix A Paleontological Analysis
CARLSBAD
FRESNO
IRVINE
LOS ANGELES
PALM SPRINGS
POINT RICHMOND
RIVERSIDE
ROSEVILLE
SAN LUIS OBISPO
20 Executive Park, Suite 200, Irvine, California 92614 949.553.0666 www.lsa.net
MEMORANDUM
DATE: September 7, 2018
TO: Kenny Nguyen, P.E., Senior Civil Engineer, City of Santa Ana
FROM: Sarah Rieboldt, Ph.D., Senior Paleontological Resources Manager, LSA
SUBJECT: Paleontological Analysis of the Fairview Street Improvements from 9th Street to
16th Street and Bridge Replacement Project, Santa Ana, Orange County, California
INTRODUCTION
The City of Santa Ana (City), in conjunction with the California Department of Transportation
(Caltrans) District 12, proposes to widen Fairview Street between 9th Street and 16th Street,
including replacing the Fairview Street bridge crossing over the Santa Ana River (proposed Project)
in Santa Ana, California. The purpose of the project is to reduce congestion and improve pedestrian
and bicyclist safety on Fairview Street between 9th Street and 16th Street, consistent with the
Orange County Master Plan of Arterial Highways and the City’s General Plan Circulation Element.
South of 9th Street, Fairview Street provides three lanes in each direction which are reduced to two
lanes in each direction north of 9th Street, across the existing four‐lane bridge, to 16th Street. The
Fairview Street segment between 9th Street and 16th Street is the only constraint for Fairview
Street to be built out to its planned width of six lanes. This condition causes a traffic “bottleneck”
during peak hours. In addition, there are no sidewalks, bikeways, or lighting on the existing bridge.
Pedestrians and bicyclists currently use the roadway shoulder to cross the bridge.
Within the project limits, Fairview Street is bordered by single‐family residences and a few
commercial properties.
This memorandum was prepared to ensure that the proposed Project is in compliance with all
applicable State and local regulations, requirements, and policies regarding paleontological
resources, as well as guidelines of the Society of Vertebrate Paleontology (SVP, 2010). The
applicable regulations, requirements, and policies include the California Environmental Quality Act
(CEQA), Public Resources Code (PRC) Division 13, Chapter 2.6; the State CEQA Guidelines, California
Code of Regulations (CCR), Title 14, Chapter 3, Appendix G; PRC 5097.5; and the Conservation
Element of the City of Santa Ana (City) General Plan (City of Santa Ana, 2010). This memorandum
addresses the potential for the proposed Project to impact paleontological resources and, if needed,
includes mitigation measures and other recommendations to minimize these impacts. The City is the
Lead Agency under CEQA.
PROJECT LOCATION
The Project site extends along Fairview Street from approximately 9th Street to 16th Street. The
Project site is depicted on the United States Geological Survey (USGS) Anaheim, California
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7.5‐minute topographic quadrangle map in unsectioned lands of the Los Angeles Land Grant (USGS,
1981; see Figure 1, provided in Attachment B).
PROJECT DESCRIPTION
The proposed Project includes widening Fairview Street between 9th Street and 16th Street,
including replacing the Fairview Street bridge crossing over the Santa Ana River. The proposed
Project would widen Fairview Street from two lanes in each direction to three lanes in each
direction. Fairview Street bridge would be replaced with a new six‐lane bridge (three lanes in each
direction), including a complete bridge deck with barrier rails, sidewalks, bicycle lanes, a raised
median, and lighting.
The proposed bridge would be expanded from approximately 52 feet (ft) to 100 ft in width, and
would have the same roadway profile as the existing bridge. The eight pier walls that support the
existing bridge would be removed, and four new pier walls would be constructed to support the
new bridge.
The proposed Project would acquire partial right‐of‐way take from three parcels (two commercial
parcels [Assessor’s Parcel Numbers (APNs) 405‐213‐02 and 405‐213‐01] and one single‐family
residence [APN 405‐213‐14]).
An existing 12‐inch water line and a bank of 12 phone conduits cross the Santa Ana River, suspended
under the deck of the existing bridge. These utilities would need to be temporarily relocated during
construction and then permanently relocated to the new bridge.
Water quality best management practices (BMPs) would be included to treat stormwater runoff
such as a vegetated swale adjacent to Fairview Street in the Fairview Triangle rest area.
Fairview Street would remain open during the construction period with two southbound lanes and
one northbound lane, with lanes shifted to one side of the bridge while the other side is replaced.
Therefore, no detours would be required for vehicles traveling along Fairview Street. Access to
properties would be maintained.
During construction, pedestrians and bikes would be detoured away from the Fairview Street bridge
to the 17th Street Bridge to cross the Santa Ana River by way of the Santa Ana River Trail (SART)
between the hours of 9:00 a.m. and 7:00 p.m., when the gates to the SART are open and unlocked.
After hours, pedestrians and bicyclists who wish to cross the Santa Ana River would be detoured to
adjacent City streets such as King Street.
Construction of the proposed Project would require temporary closure of a portion of the SART for
the demolition and placement of the bridge superstructure. The SART includes a Class I bike path on
the eastern side and a regional riding and hiking trail on the western side. The portion of the SART
affected by project construction would need to be temporarily closed four times for approximately 8
hours each time during two summer periods for the placement of precast concrete girders. During
these periods, SART users would be detoured and signage would be provided to display the dates of
the closures and to identify the detour routes. Work on the north and south sides of the bridge
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would be completed during separate periods so that SART users can be detoured to the trail on the
opposite side of the Santa Ana River at 5th Street. There are gates and ramps located on both sides
of the SART at 5th Street that provide access to bicyclists and pedestrians for these detours. Details
regarding the detours are being coordinated with Orange County Parks. Other short‐term closures
of up to 15 minutes would be allowed with flagmen.
A temporary detour within the river bed may be required as a contingency. This would involve
construction of dirt and gravel ramps with asphalt topping to and from the SART and the river bed.
Construction vehicles would access the Santa Ana River from the gate and ramp at the County of
Orange access road at the northwest corner of the bridge, and would use the existing concrete
access ramp into the river approximately 250 ft west of the proposed Project Area. All access roads
to the SART that are utilized by construction vehicles or for detour routes would be reconstructed
and restored to pre‐construction conditions or better prior to project completion.
Excavation associated with the various components of the proposed Project is expected to extend to
a depth of 2 ft for the roadway widening, 4 ft for the utility relocations, 6 ft for the river pier
footings, and 5 to 15 ft for the bridge abutments (personal communication, WKE, Inc., April, 2018).
METHODS
LSA examined geologic maps of the Project Area and reviewed relevant geological and
paleontological literature to determine which geologic units are present in the Project Area and
whether fossils have been recovered from those or similar geologic units elsewhere in the region.
A search for known fossil localities was also conducted through the Natural History Museum of
Los Angeles County (LACM) in order to determine the status and extent of previously recorded
paleontological resources within and surrounding the Project Area.
RESULTS
Literature Review
The proposed Project is located at the northern end of the Peninsular Ranges Geomorphic Province,
a 900‐mile‐long northwest‐southeast‐trending structural block that extends from the Transverse
Ranges in the north to the tip of Baja California in the south (California Geological Survey, 2002;
Norris and Webb, 1976). This province is characterized by mountains and valleys that trend in a
northwest‐southeast direction, roughly parallel to the San Andreas Fault. The total width of the
province is approximately 225 miles, extending from the Colorado Desert in the east, across the
continental shelf, to the southern Channel Islands (i.e., Santa Barbara, San Nicolas, Santa Catalina,
and San Clemente) (Sharp, 1976). It contains extensive pre‐Cenozoic (more than 66 million years ago
[Ma]) igneous and metamorphic rock covered by Cenozoic (less than 66 Ma) sedimentary deposits
(Norris and Webb, 1976).
Within this larger region, the proposed Project is located in the Los Angeles Basin, a broad alluvial
lowland bounded to the north and east by the San Gabriel and Santa Ana Mountains, respectively,
and by the Pacific Ocean to the southwest (Yerkes et al., 1965). The Basin is underlain by a structural
depression that has discontinuously accumulated thousands of feet of marine and terrestrial
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deposits since the Late Cretaceous (approximately 100.5 Ma) (Yerkes et al., 1965). Over millions of
years, the Basin has experienced episodes of subsidence, deposition, uplift, erosion, and faulting, all
of which have resulted in very complex geology and a very productive oil industry (Bilodeau et al.,
2007; Yerkes et al., 1965). The surface of the basin slopes gently southwestward toward the ocean,
interrupted in various places by low hills and traversed by several large rivers (Sharp, 1976; Yerkes et
al., 1965), including the Los Angeles River, the Rio Hondo, the San Gabriel River, and the Santa Ana
River.
Geologic mapping by Morton and Miller (2006) shows that the Project Area contains Very Young
Wash Deposits and Young Alluvial Fan Deposits (see Figure 2, Geologic Map, provided in Attachment
B). In addition, because the Project Area has been previously developed, some amount of Artificial
Fill is likely present at the surface above the geologic unit mapped by Morton and Miller (2006).
Ages for the geologic epochs and subdivisions are based on the International Chronostratigraphic
Chart prepared by the International Commission on Stratigraphy (ICS, 2017) and Walker et al.
(2012).
Artificial Fill
Artificial Fill consists of sediments that have been removed from one location and transported to
another location by human activity, rather than by natural means. The transportation distance can
vary from a few feet to many miles, and composition is dependent on the source and purpose.
While Artificial Fill may contain fossils, these fossils have been removed from their original location
and are thus out of stratigraphic context. Therefore, they are not considered important for scientific
study. As such, Artificial Fill has no paleontological sensitivity.
Very Young Wash Deposits
The Very Young Wash Deposits are late Holocene in age (less than 4,200 years ago; Walker et al.,
2012) and consist of unconsolidated sand and gravel in active washes, channels on active alluvial
fans, and ephemeral streams (Morton and Miller, 2006). These deposits accumulated along river
and stream channels as floods and debris flows carried sediment down from higher elevations. The
size, color, and types of clasts in these deposits are dependent on the local bedrock from which they
were derived, with boulder‐size clasts more common closer to the mountains and in areas prone to
flash floods (Morton and Miller, 2006). These deposits are mapped along the Santa Ana River
channel in the Project Area.
Although Holocene deposits can contain remains of plants and animals, only those from the middle
to early Holocene (4,200 to 11,700 years ago; Walker et al., 2012) are considered scientifically
important (SVP, 2010). Older deposits that may contain scientifically important fossils may be
encountered at undetermined depths below these late Holocene deposits. Therefore, the Very
Young Wash Deposits are considered to have low paleontological sensitivity.
Young Alluvial Fan Deposits
Young Alluvial Fan Deposits, which are Holocene to late Pleistocene in age (less than 126,000 years
ago; ICS, 2017), consist of unconsolidated gravel, sand, and silt with occasional cobbles and boulders
near mountain fronts (Morton and Miller, 2006). These sediments were deposited by flooding
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streams and debris flows coming down from higher elevations and generally form a fan or lobe
shape at the base of hills and mountains (Morton and Miller, 2006).
As noted above, only fossils from the middle to early Holocene (4,200 to 11,700 years ago; Walker et
al., 2012) are considered scientifically important (SVP, 2010). These Holocene deposits overlie older
Pleistocene deposits, which have produced scientifically important fossils elsewhere in the region
(Jefferson, 1991a, 1991b; Miller, 1971; Reynolds and Reynolds, 1991; Springer et al., 2009). These
older deposits span the end of the Rancholabrean North American Land Mammal Age (NALMA),
which dates from 11,000 to 240,000 years ago (Sanders et al., 2009) and was named for the Rancho
La Brea fossil site in central Los Angeles. The presence of Bison defines the beginning of the
Rancholabrean NALMA (Bell et al., 2004), but fossils from this time also include other large and
small mammals, reptiles, fish, invertebrates, and plants (Jefferson, 1991a, 1991b; Miller, 1971;
Reynolds and Reynolds, 1991; Springer et al., 2009). There is a potential to find these types of fossils
in the older sediments of this geologic unit, which may be encountered below a depth of
approximately 10 ft. Therefore, these deposits are assigned low paleontological sensitivity from the
surface to a depth of 10 ft and high sensitivity below that mark.
Fossil Locality Search
According to the locality search conducted by the LACM, there are no known fossil localities within
the boundaries of the proposed Project. The LACM reports that the Project Area is underlain by
deposits of younger Quaternary alluvium overlying older Quaternary alluvium (i.e., Young Alluvial
Fan Deposits). The museum notes that these deposits typically do not contain scientifically
significant fossils in the uppermost layers but, they may produce important fossils at depth.
The closest vertebrate locality in these older Quaternary deposits is LACM 1339, south‐southwest of
the Project Area near the top of the bluffs along Adams Avenue in Costa Mesa. This locality
produced a specimen of horse (Equus) at a depth of 43 ft below the street. The next closest locality
is LACM 2032, northeast of the Project Area near the intersection of Mission Road and Daly Street.
That locality yielded specimens of mammoth (Mammuthus) and camel (Camelidae) at a depth of 15
ft below the top of the bluff. Locality LACM 4943, which is located northeast of the Project Area near
the intersection of Glassell Street and Fletcher Avenue in Orange, produced a specimen of horse
(Equus) at a depth of 8 to 10 ft below the surface.
The LACM believes that shallow excavations in the Young Alluvial Fan Deposits in the Project Area
are unlikely to encounter any scientifically important vertebrate fossils. However, the museum notes
that deeper excavations into these deposits may encounter scientifically significant vertebrate
remains and should be monitored to recover those remains. A copy of the letter describing the
locality search results from the LACM is provided in Attachment C.
CONCLUSIONS AND RECOMMENDATIONS
Any Artificial Fill present within the Project Area has no paleontological sensitivity, the Very Young
Wash Deposits have low paleontological sensitivity, and the Young Alluvial Fan Deposits have low
paleontological sensitivity from the surface to a depth of 10 ft and high paleontological sensitivity
below a depth of 10 ft. The majority of project excavation is anticipated to be shallower than a
depth of 10 ft, with only the bridge abutments possibly extending to a depth of 15 ft. However,
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because much of the Project Area has been previously developed, excavation into any existing
native deposits for the abutments will have a limited impact area. Therefore, LSA recommends the
following mitigation measure:
PALEO‐1 If paleontological resources are encountered during the course of ground
disturbance, work in the immediate area of the find shall be redirected and a
paleontologist shall be contacted to assess the find for scientific significance. If
determined to be significant, the fossil shall be collected from the field. The
paleontologist may also make recommendations regarding additional mitigation
measures, such as paleontological monitoring. Scientifically significant resources
shall be prepared to the point of identification, identified to the lowest taxonomic
level possible, cataloged, and curated into the permanent collections of a museum
repository. If scientifically significant paleontological resources are collected, a
report of findings shall be prepared to document the collection.
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Implementation of this mitigation measure will ensure that project impacts to scientifically
significant paleontological resources will be mitigated to a level that is less than significant.
Attachments: A – References
B – Figure 1: Project Location
Figure 2: Geologic Map
C – Paleontological Locality Search Results from the Natural History Museum of
Los Angeles County
P ALEONTOLOGICAL A NALYSIS
S EPTEMBER 2018
F AIRVIEW S TREET I MPROVEMENTS FROM 9 TH S TREET TO 16TH S TREET
AND B RIDGE R EPLACEMENT P ROJECT
S ANTA A NA, O RANGE C OUNTY, C ALIFORNIA
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ATTACHMENT A
REFERENCES
Bell, Christopher J., Ernest L. Lundelius, Jr., Anthony D. Barnosky, Russell W. Graham, Everett H.
Lindsay, Dennis R. Ruez, Jr., Holmes A. Semken, Jr., S. David Webb, and Richard J. Zakrzewski
2004 The Blancan, Irvingtonian, and Rancholabrean Mammal Ages. Chapter 7 in
Michael O. Woodburne, ed., Late Cretaceous and Cenozoic Mammals of North America.
pp. 232–314.
Bilodeau, William L., Sally W. Bilodeau, Eldon M. Gath, Mark Osborne, and Richard J. Proctor
2007 Geology of Los Angeles, California, United States of America. Environmental & Engineering
Geoscience 13(2):99–160.
California Geological Survey
2002 California Geomorphic Provinces. California Geologic Survey Note 36. California
Department of Conservation.
City of Santa Ana
2010 Conservation Element, City of Santa Ana General Plan. Adopted September 20, 1982.
Reformatted January 2010. Website: http://www.santa‐ana.org/generalplan/documents/
Conservation.pdf (accessed April 2018).
International Commission on Stratigraphy (ICS)
2017 International Stratigraphic Chart. Published by the International Commission on
Stratigraphy. February 2017. Website: http://www.stratigraphy.org/index.php/ics‐chart‐
timescale (accessed April 2018).
Jefferson, George T.
1991a A Catalogue of Late Quaternary Vertebrates from California: Part One: Non‐marine Lower
Vertebrate and Avian Taxa. Natural History Museum of Los Angeles County Technical
Reports No. 5, Los Angeles.
1991b A Catalogue of Late Quaternary Vertebrates from California: Part Two: Mammals. Natural
History Museum of Los Angeles County Technical Reports No. 7, Los Angeles.
Miller, W.E.
1971 Pleistocene Vertebrates of the Los Angeles Basin and Vicinity (Exclusive of Rancho La Brea).
Los Angeles County Museum of Natural History Bulletin, Science: No. 10.
Morton, Douglas M., and Fred K. Miller
2006 Geologic Map of the San Bernardino and Santa Ana 30‐minute by 60‐minute quadrangles,
California. Digital preparation by Pamela M. Cosette and Kelly R. Bovard. Prepared by the
United States Geological Survey (USGS) in cooperation with the California Geological
Survey. USGS Open File Report 2006‐1217. Map Scale 1:100,000.
P ALEONTOLOGICAL A NALYSIS
S EPTEMBER 2018
F AIRVIEW S TREET I MPROVEMENTS FROM 9 TH S TREET TO 16TH S TREET
AND B RIDGE R EPLACEMENT P ROJECT
S ANTA A NA, O RANGE C OUNTY, C ALIFORNIA
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Norris, R.M., and R.W. Webb
1976 Geology of California. New York: John Wiley and Sons, Inc. 379 pp.
Reynolds, R.E., and R.L. Reynolds
1991 The Pleistocene Beneath our Feet: Near‐surface Pleistocene Fossils in Inland Southern
California Basins. In M.O. Woodburne, R.E. Reynolds, and D.P. Whistler, eds.,
Inland Southern California: The Last 70 Million Years, Redlands, San Bernardino County
Museum Special Publication 38(3 and 4):41–43.
Sanders, A.E., R.E. Weems, and L.B. Albright
2009 Formalization of the Middle Pleistocene “Ten Mile Beds” in South Carolina with Evidence
for Placement of the Irvingtonian‐Rancholabrean Boundary. Museum of Northern Arizona
Bulletin 64:369–375.
Sharp, R.P.
1976 Geology: Field Guide to Southern California. Kendall/Hunt Publishing Company,
Second Edition: 181.
Society of Vertebrate Paleontology (SVP)
2010 Standard Procedures for the Assessment and Mitigation of Adverse Impacts to
Paleontological Resources. Society of Vertebrate Paleontology. Impact Mitigation
Guidelines Revision Committee. 11 pp.
Springer, Kathleen, Eric Scott, J. Christopher Sagebiel, and Lyndon K. Murray
2009 The Diamond Valley Lake Local Fauna: Late Pleistocene Vertebrates from Inland
Southern California. In L.B. Albright, III, ed. Papers in Geology, Vertebrate Paleontology,
and Biostratigraphy in Honor of Michael O. Woodburne, Museum of Northern Arizona
Bulletin 65, pp. 217–236.
United States Geological Survey (USGS)
1981 Anaheim, California 7.5‐minute topographic quadrangle. Published 1965,
photorevised 1981. United States Geological Survey, Denver, Colorado.
Walker, M.J.C., M. Berkelhammer, S. Bjorck, L.C. Cwynar, D.A. Fisher, A.J. Long, J.J. Lowe,
R. Newnham, S.O. Rasmussen, and H. Weiss
2012 Formal Subdivision of the Holocene Series/Epoch: A Discussion Paper by a Working Group
of INTIMATE (Integration of Ice‐Core, Marine and Terrestrial Records) and the
Subcommission on Quaternary Stratigraphy (International Commission on Stratigraphy).
Journal of Quaternary Science 27:649–659.
Yerkes R.F., T.H. McCulloh, J.E. Schoellhamer, and J.G. Vedder
1965 Geology of the Los Angeles Basin, California – An Introduction. United States Geological
Survey Professional Paper 420‐A. 57 pp.
P ALEONTOLOGICAL A NALYSIS
S EPTEMBER 2018
F AIRVIEW S TREET I MPROVEMENTS FROM 9 TH S TREET TO 16TH S TREET
AND B RIDGE R EPLACEMENT P ROJECT
S ANTA A NA, O RANGE C OUNTY, C ALIFORNIA
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ATTACHMENT B
FIGURE 1: PROJECT LOCATION
FIGURE 2: GEOLOGIC MAP
SOURCE: USGS 7.5' Quad - Anaheim (1981) & Newport Beach (1981)
I:\WKE1702\GIS\HPSR_ProjLocUSGS.mxd (5/9/2018)
MAP 2LEGEND
Project Location
0 1000 2000
FEET Federal Project No.: BRLS 5063(184)
Fairview Street Improvementsfrom 9th Street to 16thStreet and Bridge Replacement ProjectProject Location
Se rvice L ayer Cre dits: Sou rce : Esri,DigitalGlob e, G eoEye, Earthsta r G eograp hics,CNES/Airbu s DS, USDA, U SG S, AeroGRID,IG N, and the GIS Use r Community
Santa Ana River
Qyf
Qw Qyf
KING
MARENGO
GLENARBOR 16TH14THWASHINGTON12THCASCADE
11THFAIR
JUDI
TH10THH U R O N
MAR LES
9THCIVIC CENTER17TH STFAIRVIEW S T
SOURCE: Bing (2015); WKE (2017); Morton and Miller (2006)
I:\WKE1702\GIS\Geology.mxd (5/9/2018)
FIG URE 2LEGEND
Project Boundar y
Geologic Units
Qw - Ver y Young Wash Deposits
Qyf - Young Alluvial Fan Deposits0100200
FEET Federal Project No.: BRLS 5063(184
Fairview Street Improvementsfrom 9 th Street to 16thStreet and Bridge Replacement ProjectGeologic M ap
P ALEONTOLOGICAL A NALYSIS
S EPTEMBER 2018
F AIRVIEW S TREET I MPROVEMENTS FROM 9 TH S TREET TO 16TH S TREET
AND B RIDGE R EPLACEMENT P ROJECT
S ANTA A NA, O RANGE C OUNTY, C ALIFORNIA
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ATTACHMENT C
PALEONTOLOGICAL LOCALITY SEARCH RESULTS FROM
THE NATURAL HISTORY MUSEUM OF LOS ANGELES COUNTY
Vertebrate Paleontology Section
Telephone: (213) 763-3325
e-mail: smcleod@nhm.org
23 February 2018
LSA Associates, Inc.
20 Executive Park, Suite 200
Irvine, California 92614
Attn: Sarah Rieboldt, Ph.D., Senior Paleontological Resources Manager
re: Paleontological Resources Records Check for the proposed Fairview Street Widening and
Bridge Replacement Project, LSA Project # WKE1702, in the City of Santa Ana, Orange
County, project area
Dear Sarah:
I have thoroughly searched our paleontology collection records for the locality and
specimen data for the proposed Fairview Street Widening and Bridge Replacement Project, LSA
Project # WKE1702, in the City of Santa Ana, Orange County, project area as outlined on the
portion of the Anaheim USGS topographic quadrangle map that you sent to me via e-mail on 9
February 2018. We do not have any vertebrate fossil localities that lie within the proposed
project area boundaries, but we do have localities nearby from the same sedimentary units that
may occur subsurface in the proposed project area.
The entire proposed project has surface deposits of younger Quaternary Alluvium,
derived as fluvial deposits from the Santa Ana River that flows through the northern portion of
the proposed project area. These deposits are unlikely to contain significant vertebrate fossils in
the uppermost layers, but older Quaternary deposits occurring at varying depths may well contain
significant fossil vertebrate remains. Our closest vertebrate fossil locality from older Quaternary
deposits is probably LACM 1339, south-southwest of the proposed project area in Costa Mesa
east of the Santa Ana River near the top of the mesa bluffs along Adams Avenue, that produced
fossil specimens of mammoth, Mammuthus, and camel, Camelidae, bones from sands
approximately 15 feet below the top of the mesa that is overlain by shell bearing silts and sands.
Our next closest vertebrate fossil locality in older Quaternary sediments is probably LACM 4943,
northeast of the proposed project area in the City of Orange between the Newport Freeway
(Highway 55) and the Santa Ana River near the intersection of Glassell Street and Fletcher
Avenue. Locality LACM 4943 produced a specimen of fossil horse, Equus, at a depth of 8-10
feet below the surface.
Surface grading or shallow excavations in the proposed project area probably will not
uncover significant vertebrate fossil remains. Excavations that extend down into the older
Quaternary deposits, however, may well encounter significant fossil vertebrate specimens. Any
substantial excavations below the uppermost layers in the proposed project area, therefore,
should be monitored closely to quickly and professionally recover any fossil remains discovered
while not impeding development. Also, sediment samples from these deposits should be
collected and processed to determine the small fossil potential in the proposed project area. Any
fossils recovered during mitigation should be deposited in an accredited and permanent scientific
institution for the benefit of current and future generations.
This records search covers only the vertebrate paleontology records of the Natural History
Museum of Los Angeles County. It is not intended to be a thorough paleontological survey of
the proposed project area covering other institutional records, a literature survey, or any potential
on-site survey.
Sincerely,
Samuel A. McLeod, Ph.D.
Vertebrate Paleontology
enclosure: invoice