PALEONTOLOGICAL RESOURCE
IMPACT MITIGATION PROGRAM
TENTATIVE TRACT MAP 36450
COLINAS DEL ORO SPECIFIC PLAN 364
PREPARED FOR:
Gregory P. Lansing
LANSING INDUSTRIES, INC.
12671 High Bluff Drive
Suite 150
San Diego, California 92130
(858) 523-0719
[email protected]
PRINCIPAL INVESTIGATOR AND REPORT PREPARER:
Paul A. Principe
PRINCIPE AND ASSOCIATES
29881 Los Nogales Road
Temecula, California 92591
(951) 699-3040
[email protected]
REPORT DATE:
November 5, 2013
PRINCIPE AND ASSOCIATES
CONSULTING PALEONTOLOGISTS
29881 Los Nogales Road
Temecula, California 92591
(951) 699-3040
[email protected]
November 5, 2013
David L. Jones,
Chief Engineering Geologist
COUNTY OF RIVERSIDE, TLMA
PLANNING DEPARTMENT
OFFICE OF THE COUNTY GEOLOGIST
Riverside County Administrative Center
4080 Lemon Street, 9th Floor
Riverside, California 92502-1629
Subject: Paleontological Resource Impact Mitigation Program
Tentative Tract map 36450
Colinas del Oro Specific Plan 364
APNs 345-190-016 and 345-200-013
Dear David,
Principe and Associates, Consulting Paleontologists, was hired by Gregory P. Lansing
to prepare a Paleontological Resource Impact Mitigation Program (PRIMP) on the
proposed Tentative Tract Map 36450 project (=Colinas Del Oro Specific Plan 364). The
approximately 126.4-acre proposed project site is located on the west side of State
Highway 74, between Ethanac Road (north) and Kimes Lane (south) in unincorporated
Riverside County, California. It is located about midway between the Cities of Lake
Elsinore and Perris in the Meadowbrook Community: a portion of the northwest 1/4 of
Section 15, Township 5 South and Range 4 West of the USGS Topographic Map, 7.5
Minute Series, Lake Elsinore, California Quadrangle (Site Vicinity and USGS Location
Maps).
This PRIMP is intended to satisfy Condition 05. Planning 005 (DRT – Paleo Study) (see
attached).
Based on the Update Geotechnical Evaluation and 100-Scale Grading
Plan Review, Tentative tract Map 36450, off of Highway 74, Perris Area of Riverside
County, California (GeoSoils, Inc., December 5, 2012), the geologic units encountered
within the site consist of undocumented artificial fill materials, topsoil/colluvium, younger
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alluvium, very old alluvial-channel deposits, and undifferentiated meta-sedimentary and
granitic bedrock.
As mapped by Morton and Weber Jr. (2003), the eastern portion of the site is locally
mantled by Pleistocene-age very old alluvial-channel deposits and undocumented
artificial fill materials, which are in-turn underlain by Mesozoic, meta-sedimentary and
Cretaceous-aged granitic bedrock units at depth (Regional Geologic Map). The metasedimentary bedrock onsite is generally assigned to the Jurassic-aged Bedford Canyon
Formation. The meta-sedimentary and granitic bedrock is locally exposed at the surface
throughout the central portion of the site and on the prominent foothill on the western
portion of the site. Localized granitic corestones or “Tors” are also exposed on the
prominent foothill on the western portion of the site.
The Riverside County TLMA Geographic Information System entry for Paleontological
Sensitivity shows the eastern approximately one-third of the site has been mapped with
Undetermined Potential for Paleontological Sensitivity:
•
“Areas underlain by sedimentary rocks for which literature and unpublished
studies are not available have undetermined potential for containing significant
paleontological resources. These areas must be inspected by a field survey
conducted by a qualified Vertebrate Paleontologist.”
Quaternary Very Old Alluvial-Channel Deposits have been mapped in the northeast
corner of the site.
These middle to early Pleistocene-aged sediments consist of
relatively dense, silty sands and sandy gravels with locally abundant rounded cobbles.
In 3 trenches excavated in the northeast corner of the site, 1-6 feet of Quaternary Very
Old Alluvial-Channel Deposits were encountered 1-2 feet below the surface.
A Paleontological Literature/Records Review was conducted by the Western Science
Center (WSC) for the proposed project site.
The WSC did not have any fossil
localities from the site and surrounding area (see letter attached).
The WSC however noted that alluvial units are considered to have the possibility of
high paleontological sensitivity. In general, Pleistocene-aged sediments provide an
important record of early Rancholabrean fossil vertebrate taxa dated at less than
700,000 years before present, which is rarely represented in California. At least 24
taxa have been previously identified in the greater Temecula Valley area. Cut-grading
activities occurring in the northeast corner of the site then has the potential to have a
direct adverse impact on the Quaternary Very Old Alluvial-Channel Deposits.
Relatively younger alluvial sediments (Quaternary Alluvium) were encountered
throughout localized areas of the site generally associated with incised drainage areas.
Low resource potential and low sensitivity are assigned to geologic units that, based on
their relatively young ages and/or high-energy depositional histories, are judged unlikely
to produce fossil remains of scientific significance. The Quaternary Alluvium is
considered to have a low potential to contain significant nonrenewable paleontological
resources based on its relatively young age. Therefore, the proposed cut-grading
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activities occurring in the Quaternary Alluvium geologic unit will not have a direct adverse
impact on significant nonrenewable paleontological resources pursuant to the California
Environmental Quality Act of 1970, as amended.
The Riverside County TLMA Geographic Information System entry for Paleontological
Sensitivity shows the western approximately two-thirds of the site as having Low
Potential for Paleontological Sensitivity:
•
“Following a literature search, records check and field survey, areas may be
determined by a qualified Vertebrate Paleontologist as having low potential for
containing significant paleontological resources subject to adverse impacts.”
It is the Jurassic-aged Bedford Canyon Formation (undifferentiated metasedimentary
bedrock) that has a Low Potential for Paleontological Sensitivity. The WSC and the San
Bernardino County Museum considers this local geologic unit to be a bedrock unit that
is not fossiliferous.
Scientific studies have revealed that the vast majority of Cretaceous and Jurassic
metasedimentary rocks from the Peninsular Ranges in Orange, Riverside and San
Diego Counties have not yet produced any fossil remains, and thus have no
paleontological resource sensitivity. They have been subjected to such intense heat
and pressure for tens of millions of years that any traces of plant or animal life they may
have contained have been compressed, overheated and otherwise destroyed. The
fossils that have been identified are poorly preserved shells and molds of marine
invertebrates (e.g., radiolarians, belemnites, ammonites, and clams) and permineralized
wood. It is possible that fossils will eventually be discovered in metasedimentary rocks,
but this will be done through exhaustive academic and scientific studies. It is out of the
scope of monitoring the cut-grading activities for a proposed mixed-use residential and
commercial project.
The proposed cut-grading activities occurring in the Bedford
Canyon Formation geologic unit will not have a direct adverse impact on significant
nonrenewable paleontological resources pursuant to the California Environmental Quality
Act of 1970, as amended.
As the proposed cut-grading activities that will occur in the Quaternary Very Old
Alluvial-Channel Deposits geologic unit has the potential to impact significant
nonrenewable paleontological resources, implementing a Paleontological Resource
Impact Mitigation Program is then required under the California Environmental Quality
Act. The Paleontological Resource Impact Mitigation Program follows:
1. Description of the project site and planned grading operations:
Project Site
The site is located in a relatively undeveloped portion of western Riverside County.
Adjacent land uses consist of rural residential development to the north, east, and south
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and undeveloped land to the west. Steele Peak lies northwest of the project site, and
Railroad Canyon and the San Jacinto River lie southeast of the project site.
The site was previously utilized for gold mining. Mining was conducted periodically on
the site from around 1870 through the mid 1960's. It is now frequently disturbed with
evidence of mowing and disking as well as off-road vehicle use and illegal refuse
dumping. Several dirt roads dissect the property. There is evidence of a fire including
burned vegetation and recently created firebreaks. The USGS topographic quadrangle
map shows a mine located in the eastern portion of the site, which is no longer
operational.
Topography is steep in the western portion of the site, sloping down to areas of low
relief in the eastern half. Elevations on the project site range from approximately 2,000
feet above mean sea level (msl) in the west to approximately 1,640 feet above msl in
the east. The majority of the relatively flat-lying topography in the eastern half of the
site is situated around 1700 feet in elevation above msl.
There are no blueline streams depicted within the site on the Elsinore USGS
topographic quadrangle map.
A drainage system is present in the southwestern
portion of the site, while isolated drainage features are present in the northern portion.
The drainage features within the project site are described as upland swales. The
upland swales are topographic features within gently rolling hills associated with the
foothills located southeast of Steele Peak. The upland swales appear to receive
seasonal storm flows and runoff from the adjacent 36-acre watershed to the northwest
of the project site. They transport natural runoff from adjacent undeveloped areas north
and west of the project site downslope to culverts placed beneath SH 74. There is a
single artificially created ponded area previously used as a stock pond for cattle in the
central portion of the project site just west of the main dirt access road. Cattle grazing
no longer occurs on the site.
The project has no direct relationship to existing wetland regulations. Other kinds of
seasonal aquatic features that could be classified as freshwater wetlands are not
present on the site (i.e., open waters, perennial streams, marshes, vernal pools or
swales, vernal pool-like ephemeral ponds, stock ponds or other human-modified
depressions, etc.).
A variety of soil types were previously mapped at the site, including Bosanko clay,
Cajalco fine sandy loam, Cajalco rocky fine sandy loam, Honcut sandy loam, and Lodo
rocky loam.
The vegetation associations growing on the site include Riversidian sage scrub,
Riversidian sage scrub/Non-native grassland ecotone, Non-native grassland, willow
stand, tamarisk stand, and ruderal.
The site was providing habitat for a medium
abundance and diversity of common wildlife species.
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As stated above, the geologic units encountered within the project site consist of
undocumented artificial fill materials, topsoil/colluvium, younger alluvium, very old
alluvial-channel deposits, and undifferentiated meta-sedimentary and granitic bedrock
(Site-Specific Geologic Map). These units are described by GeoSoils, Inc. (2012) as
follows, from youngest to oldest:
Artificial Fill - Undocumented (Map Symbol - Afu)
Significant amounts of undocumented artificial fill, associated with past mining activities
and road building efforts onsite, have been geologically mapped onsite. GeoSoils, Inc.
recent and previous subsurface investigations encountered these materials in
stockpiles, as well as spread over localized areas of the site, up to ±14 feet in thickness,
or greater. These materials generally consist of end-dumped granular soils and rock
debris. [Note: GeoSoils, Inc. has prepared 8 geotechnical documents on the site since
1990.]
Quaternary Alluvium - Younger (Map Symbol - Qal)
Relatively younger alluvial sediments were encountered throughout localized areas of
the site generally associated with incised drainage areas. These sediments were
generally observed to be predominantly grayish brown, silty to clayey sands. The
alluvial sediments varied from dry to damp, and were generally loose. Where
encountered, these sediments are generally ±2 to ±4 feet, or greater, in thickness, and
have a potentially compressible and collapsible nature.
Topsoil/Colluvium (Unmapped)
In general, the site is discontinuously mantled by a relatively thin layer of
topsoil/colluvium. The colluvium/topsoil was generally observed to be dark brown to
reddish brown, dry to damp, soft/loose, sandy/clayey silts to silty/clayey sands. The
topsoil/colluvium was generally encountered up to ±3 feet in thickness. In general,
these materials typically have a very low to low, and sometimes medium expansion
potential, and a potentially compressible nature.
Quaternary Very Old Alluvial-Channel Deposits (Map Symbol - Qvoa)
As mapped by Morton and Weber Jr. (2003), the eastern portion of the site is locally
mantled by Pleistocene-age very old alluvial-channel deposits. As encountered, these
deposits consisted of relatively dense, silty sands and sandy gravels with locally
abundant rounded cobbles. These materials are dry to damp and generally medium
dense to dense with depth. These sediments typically have a very low to low expansion
potential; however, medium expansive soils may not be precluded from occurring. The
near surface (upper ±2 to ±3 feet) channel deposits are weathered.
Undifferentiated Bedrock (Map Symbol - Kgr/Jbc)
Stratigraphically underlying the surficial deposits onsite, and locally exposed in the
central and western portion of site, is undifferentiated bedrock, primarily Mesozoic metasedimentary rocks generally assigned to the Jurassic-aged Bedford Canyon Formation,
in-turn intruded/uplifted by Cretaceous-aged crystalline granitic rocks. Prior and current
studies by GeoSoils, Inc. encountered primarily hornsfelsic metamorphic rocks that
were generally dense, locally weathered, jointed, and fractured; and Cretaceous-aged
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crystalline granitic rocks previously mapped as biotite-hornblende tonalite composition
(Morton and Weber Jr., 2003), that were medium dense to very dense, jointed,
fractured, and locally weathered. The metamorphic rocks occur as re-crystallized roof
pendants (a remnant of a rock that is intruded by crystalline, plutonic rock). Localized
granitic and metamorphic boulder outcrops were noted onsite. The near surface (upper
1 to ±2 feet) of the bedrock is weathered.
Planned Grading Operations
Prior to grading, the site will be cleared of any vegetation and tree stumps (including
roots), which will be hauled off the site. Any existing surface/subsurface structures, and
any miscellaneous trash and construction debris will be removed from all areas
proposed to be graded and hauled off the site.
Raw earthwork quantities have been estimated as 50,000 cubic yards of cut. The total
disturbed area will be approximately 6.0 acres.
The channel deposits are anticipated to excavate with moderate ease utilizing
conventional grading equipment in proper working condition (i.e., excavator, bulldozer,
scrapers, grader, and tractor/loader/backhoe).
All undocumented artificial fill, colluvium/topsoil, younger alluvial deposits, and
weathered near surface channel deposits and/or bedrock will be removed to competent
channel deposits and/or bedrock (i.e., greater than or equal to 85 percent saturation,
and/or greater than or equal to 105 pounds per cubic foot [pcf] dry density for in-place
native materials), if not removed by proposed excavation within areas proposed for
settlement-sensitive improvements.
On a preliminary basis, remedial grading is
estimated to consist of the removal of the upper ±2 to ±20 feet, or greater, of
undocumented artificial fill, potentially compressible native soils and/or weathered
bedrock materials, below existing grades. Actual depths of removals will be evaluated
in the field during grading by the geotechnical consultant.
Existing artificial fill, colluvium/topsoil, alluvium, and weathered channel deposits and
bedrock, etc., may be reused as compacted fill provided that all trash, organic materials,
and miscellaneous debris are removed prior to or during fill placement.
Localized deeper removal may be necessary due to buried drainage channel meanders
or dry porous materials. The project geotechnical consultant/geologist should observe
all removal areas during the grading.
2. Description of the level of monitoring required for all earth-moving activities in
the project area:
It will take an estimated 40 hours to complete all cut-grading activities in the northeast
corner of the site, or the equivalent of 5 regular 8-hour work days. As the northeast
corner of the site is underlain by Quaternary Very Old Alluvial-Channel Deposits with an
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Undetermined Potential for Paleontological Sensitivity, a Paleontologic Monitor will be
present during 100% of the earth-moving activities.
The WSC did not have any fossil locality records from the site and surrounding area,
but noted that alluvial units in general are considered to have the possibility of high
paleontological sensitivity.
As information on the Quaternary Very Old AlluvialChannel Deposits in the Meadowbrook area does not now exist, monitoring the
excavation of this geologic unit may result in new paleontological discoveries.
3 and 4. Identification and qualifications of the qualified paleontological monitor
to be employed for grading operations monitoring. Identification of personnel
with authority and responsibility to temporarily halt or divert grading equipment
to allow for recovery of large specimens:
For this project, Paul A. Principe will act as Paleontological Monitor.
Since 1977, Paleontological Consulting services have included preparing Paleontological
Assessments, Paleontological Impact Reports, Paleontological Resource Impact
Mitigation Programs, and Paleontological Reports of Findings. Compliance services
include onsite grading monitoring, excavation/recovery of fossils, specimen preparation
and identification, itemized accessioning, and regional site locality inventorying. Projects
included monitoring tens of millions of cubic yards of Quaternary Old Alluvium, Pauba
Formation and Unnamed Sandstone sediments throughout the Temecula Valley.
Thousands of specimens representing at least 15 known fossil vertebrate taxa and one
unknown taxon have been recovered. All recovered specimens are now the property of
the Western Science Center. Before working as a Consulting Paleontologist in Southern
California, Principe was a Paleontology Field Assistant for a National Geographic Society
expedition in Nebraska, a Scientific Technician (Paleontology) at the Pratt Museum of
Natural History at Amherst College, Massachusetts, a Research Associate (Paleontology)
for the Wyoming Field Institute at Fossil Butte National Monument, in Kemmerer, and
Visiting Faculty (Paleontologic Research) at the Thomas Burke Memorial Washington
State Museum at the University of Washington in Seattle where he named a new species
of fossil fish from the Late Pliocene Ringold Formation in South-Central Washington.
5. Direction for any fossil discoveries to be immediately reported to the property
owner who in turn will immediately notify the County Geologist of the discovery:
Paul A. Principe will be responsible for notifying the property owner, Gregory P.
Lansing, and the County Geologist of any discoveries.
As Mr. Lansing’s office is
located in San Diego, Mike Naggar, Mr. Lansing’s development consultant, will also be
notified of any fossil discoveries. His office is located in Perris, California, which is
located only a few miles north of the project site.
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6. Means and methods to be employed by the paleontological monitor to quickly
salvage fossils as they are unearthed to avoid construction delays:
The Paleontological Monitor will be properly equipped with tools and supplies to allow
rapid removal of specimens, including hammers and chisels, picks and shovels,
brushes, foil and rags, and buckets and boxes. Plaster of Paris and burlap strips will
also be available to secure large specimens in plaster casts (jackets). Provisions will be
made for additional assistants to help remove large specimens or an abundant amount
of fossils.
7. Sampling of sediments that are likely to contain the remains of small
invertebrates and vertebrates:
Many significant fossils (i.e., small mammals, birds, retiles, amphibians, etc.) are too
small to be readily visible within the sedimentary matrix, and are referred to as
“microvertebrates”. Small fossils can also include non-vertebrate paleoenvironmental
indicators (i.e., foraminifers, gastropods, plant seeds, etc.). Fine-grained sedimentary
rocks most often contain such fossils, which are typically recovered through a process
of bulk matrix sampling followed by screen washing.
The Logs of Exploratory Test Pits encountered Quaternary Very Old Alluvial-Channel
Deposits consisting of gray to grayish brown, dry, relatively dense, silty sands and
sandy gravels with locally abundant rounded cobbles (GeoSoils, Inc., 2012). An
adequate amount of bulk matrix samples will be collected and taken from the site. If
indicators of potential microvertebrate fossils are found in a hand sample, then
screening of a “test sample” may produce significant returns and indicate whether or not
a larger sample needs to be screen washed. Samples of the matrix will be removed
from the site and processed elsewhere.
8. Procedures and protocol for collecting and processing of samples and
specimens:
Many specimens recovered from excavations are readily visible to the eye and large
enough to be easily recognized.
Upon discovery of such macrofossils, the
Paleontological Monitor will flag the area for avoidance by grading equipment until the
specimens are removed. Because Quaternary Very Old Alluvial-Channel Deposits are
relatively recent geologic units, fossils discovered in the greater Temecula Valley area are
usually poorly preserved.
They have barely been converted into fossils through
petrification (minerals replacing bone structure) or permineralization (water-borne
minerals replacing bone structures). The sub-fossilized bone retains a fair amount of
organic material (collagen) as well as the original mineralized bone material
(hydroxyapatite). These fossils may require stabilization with archival quality media (i.e.,
Paleobond, Acryloid, Butvar, etc.) before moving. Others may require protection by
encasing them within a plaster jacket before removal to a laboratory for later preparation
and conservation. Occasionally complete skeletons will require moving either as a whole
or in multiple blocks for preparation at a later time. Such specimens require a lot of time
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to excavate and strengthen before removal. It is important for both the grading contractor
and project proponent to be fully aware of how fragile the fossils are, and the length of
time it may take to properly recover the specimens.
9. Fossil identification and curation procedures to be employed:
The Western Science Center (WSC) will be responsible for the preservation and
conservation, identification and curation, recordation, and storage of the recovered
fossil collection. The WSC Paleontology Repository Project/Site Review form has been
signed by Gregory P. Lansing and the WSC Curator, Darla Abigt (see attached).
10. Identification of the permanent repository to receive any recovered fossil
material.
Western Science Center.
11. All pertinent exhibits, maps and references:
See maps on pages 2, 3, 5, and 9.
References:
GeoSoils, Inc., December 5, 2012. Update Geotechnical Evaluation and 100-Scale
Grading Plan Review, Tentative tract Map 36450, off of Highway 74, Perris Area of
Riverside County, California.
Mann, John F., Jr., 1951. Cenozoic Geology of the Temecula Region, Riverside County,
California: in Geology of Southern California, Bulletin 170, Chapter II, California Division
of Mines; 1954.
Mann, John F., Jr., October 1955. Geology of a Portion of the Elsinore Fault Zone,
California. California Division of Mines, Special Report 43.
Morton, Douglas M .and F. Harold Weber, Jr., 2003, Preliminary geologic map of the
Elsinore 7.5' quadrangle, Riverside County, California: U.S. Geological Survey OpenFile Report 03-281, U.S. Geological Survey, Menlo Park, California.
Reynolds, R. E., and Reynolds, R. L., 1990a. A new late Blancan faunal assemblage
from Murrieta, Riverside County, California: San Bernardino County Museum
Association Quarterly, v. XXXVII, p. 34.
Reynolds, R. E., and Reynolds, R. L., 1990b. Irvingtonian? Faunas from the Pauba
Formation, Temecula, Riverside County, California: San Bernardino County Museum
Association Quarterly, v. XXXVII, p. 37.
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12. Procedures for reporting of findings:
At the completion of the cut grading operations, Principe and Associates will prepare
and submit a Paleontological Report of Findings if no specimens have been recovered.
If specimens have been recovered, the Western Science Center will prepare and submit
the report.
13. Identification and acknowledgement of the developer for the content of the
PRIMP as well as acceptance of the financial responsibility for monitoring,
reporting and curation fees:
The Cost Proposal for the preparation of the PRIMP and the Onsite Monitoring and
Fossil Recovery by Principe and Associates has been signed by Gregory P. Lansing
(see attached).
Also attached is the list of Repository Fees for Paleontological Material from the
Western Science Center signed by Gregory P. Lansing accepting the financial
responsibility for the preservation and conservation, identification and curation,
recordation, and storage of the recovered fossil collection.
Thank you for your attention to the above-mentioned matters. If you have any
questions or comments, then please call me at (951) 699-3040 or Email me at
[email protected].
I hereby certify that the statements furnished herein and in the attached exhibits present
the data and information required for this Paleontological Resource Impact Mitigation
Program to the best of my ability, and that the facts, statements and information presented
are true and correct to the best of my knowledge and belief.
Sincerely,
PRINCIPE AND ASSOCIATES
_________________________
Paul A. Principe
Principal
Attachments:
Condition 05.PLANNING 005
Western Science Center Paleontological Literature/Records Review
Wet-Signed Western Science Center Paleontology Repository Project/Site
Review Form
Wet-Signed Principe and Associates Cost Proposal
Wet-Signed Western Science Center Repository Fees for Paleontological Material
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