APPENDIX D. Paleontological Resources Report

Transcription

1 APPENDIX D Paleontological Resources Report

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3 MEMORANDUM To: From: Joanne M. Dramko, AICP, GISP, Senior Environmental Manager, PBS&J/ΛTKINS George J. Burwasser, California Registered Geologist 7151, PBS&J/ΛTKINS Date: Thursday 28 October 2010 Project: - PBS&J/ΛTKINS Project Number Re: Palaeontological Resources: Vallecitos Water District, San Diego County, California Introduction Palaeontological resources, usually referred to collectively as fossils, are the remains or traces of prehistoric animals and plants. Palaeontology is the study of the evolution of life on earth, for the most part over the past 600 million years, based on fossil plants and animals. Fossils are important scientific and educational resources because of their use in documenting the presence and evolutionary history of particular groups of now-extinct organisms, reconstructing the environments in which those organisms lived, and determining the relative ages and geologic processes of the strata (sediment or rock layers) in which they occur. With few exceptions, fossils that are useful for these determinations are preserved in sedimentary rocks. Occasionally, rocks that have been metamorphosed (changed by heat or pressure), such as marble metamorphosed from limestone, retain fossil remnants which are identifiable, but not necessarily valuable for sedimentary age or process research. There are three major categories of fossils: vertebrate animals, invertebrate animals, and plants. Each category represents a somewhat different set of conditions for preservation, although they often overlap. Marine invertebrate animals with hard parts (usually shells) tend to be preserved as fossils in relatively large numbers because they typically were numerous and lived in environments of high sediment-deposition rates. In general, vertebrate fossils (bones, teeth, etc.) are rarer than fossils of plants or invertebrates. The types and vertical or horizontal extent of fossils in an area are related to the ages of the rock and sediment and what geologic conditions existed at the time those rocks formed. Documentation Key Sources Consulted References Kennedy, Michael P. and Siang S. Tan, Geologic Map of the Oceanside 30 x 60 Quadrangle, California, California Geological Survey, 2007 Jennings, Charles W., Carlos Gutierrez, William Bryant, George Saucedo, and Chris Wills, Geologic Data Map GDM 2, State Geologic Map of California, California Geological Survey, 2010

4 Page 2 of 7 County of San Diego, Land Use and Environment Group, Department of Planning and Land Use, Department of Public Works, Guidelines for Determining Significance, Paleontological Resources, 2009 Society of Vertebrate Paleontology Committee for Conformable Impact Mitigation Guidelines, Robert T. Reynolds, Chair, Assessment and Mitigation of Adverse Impacts to Nonrenewable Paleontologic Resources Standard Guidelines, January 1995 Society of Vertebrate Paleontology News Bulletin, volume 163, pages 22 through 27 Databases University of California Museum of Paleontology, available at online locality and specimen search through UCMP Locality Search, October 24, 2010 by G. J. Burwasser, PG 7151 Area Description San Diego Natural History Museum -Paleontology Collection, available at online formation, locality, and specimen search October 24, 2010 by G. J. Burwasser, PG 7151 The Vallecitos Water District is in the Oceanside 30 x 60 minute topographic quadrangle approximately 45 miles north of San Diego. The District service area is in northern San Diego County and covers approximately 45 square miles including portions of San Marcos, parts of the Carlsbad, Escondido, Vista, and unincorporated areas in the County. The District service area is mostly rolling hills and ridges reaching elevations of about 1630 feet above sea level. Regulatory Framework American Antiquities Act [16 USC Sections 431 to 433] The American Antiquities Act prohibits appropriation, excavation, injury, or destruction of any historic or prehistoric ruin or monument, or any object of antiquity located on lands owned controlled, or funded by the federal government. The act establishes penalties for such actions and sets forth a permit requirement for collection of antiquities on federally owned lands. Objects of antiquity are considered by a number of federal agencies to include fossils. The Act has been amended specifically to allow funding for palaeontological mitigation. There is no federal law that specifically protects natural or palaeontological resources on privately owned land. Paleontological Resources Conservation Act [S. 546, 108th Congress, 1st Session (2003)] This act protects palaeontological resources on federally owned lands and limits collecting vertebrate fossils and other rare and scientifically significant fossils on those lands to qualified researchers with a permit from the appropriate state or federal agency. Paleontological Resources Preservation Act [16 USC Sections 6301] This act aims to manage and protect palaeontological resources on federally owned lands and promotes the use of scientific principles and expertise and the development of plans for inventorying, monitoring, and deriving the scientific and educational use of such resources.

5 Page 3 of 7 CEQA Under California law, palaeontological resources are included in the California Environmental Quality Act (CEQA), California Administrative Code, Title 14, Section 4306 et seq., and Public Resources Code Section , and are required to be examined as part of the CEQA process. Section V(c) of Appendix G of the CEQA Guidelines refers to unique palaeontological resources or sites and unique geological features, but does not address species diversity or quantity of information recoverable from those sites or features. In the context of CEQA, fossils of land-dwelling vertebrates and their environment are considered important (i.e., significant) palaeontological resources. Such fossils typically are found in river, lake, and bog deposits or rocks formed from such deposits, although they may occur in nearly any type of sedimentary sequence. County of San Diego General Plan Policy COS-9.1: Preservation This policy requires the salvage and preservation of unique palaeontological resources when exposed to the elements during excavation or grading activities or other development processes on unincorporated County lands. Anticipated Permits No specific permits related to palaeontological resources would be required for implementation of the master plan. If palaeontological resources were discovered during excavation for construction of elements of the plan, such as pipelines, the County could request the preparation of a palaeontological resources study. Agency Coordination The amount of agency coordination would be dependent upon the actual footprint master plan elements and the depth of excavated for their construction. The San Diego Natural History Museum and the County should be consulted if palaeontological resources are discovered during excavation. Categories of Palaeontological Sensitivity Palaeontological sensitivity refers to the likelihood of finding significant fossils in a specific geologic formation. 1 The Conformable Impact Mitigation Guidelines Committee of the Society of Vertebrate Paleontology (SVP) published Standard Guidelines in response to a recognized need to establish procedures for the investigation, collection, preservation, and cataloguing of palaeontologically sensitive (i.e., vertebrate fossil bearing) sites. The Standard Guidelines are widely accepted among paleontologists, followed by most investigators, and identify the two key phases of paleontological resource protection as (1) assessment and (2) implementation. Assessment involves identifying the potential for a project site or area to contain significant nonrenewable paleontological resources that could be damaged or destroyed by project excavation or construction. Implementation involves formulating and applying measures to reduce such adverse effects. The SVP established three sensitivity categories for sedimentary rocks: High, Moderate, and Low, as listed below. High Sensitivity: assigned to geologic formations known to contain paleontological localities with rare, well-preserved, and/or critical fossil materials for stratigraphic or paleoenvironmental interpretation, and fossils providing important information about the 1 Geologic formation refers to the types of rock or sediment present in a given area.

6 Page 4 of 7 paleobiology and evolutionary history (phylogeny) of animal and plant groups. Generally speaking, highly sensitive formations are known to produce vertebrate fossil remains or are considered to have the potential to produce such remains. Moderate Sensitivity: assigned to geologic formations known to contain paleontological localities with moderately preserved, common elsewhere, or stratigraphically long-ranging fossil material. The moderate-sensitivity category also is applied to geologic formations that are judged to have a strong but unproven potential for producing important fossil remains (e.g., Pre-Holocene sedimentary rock units representing low to moderate energy, of marine to non-marine depositional settings). Low Sensitivity: assigned to geologic formations that, based on their relative youthful age and/or high energy depositional history, are judged unlikely to produce important fossil remains. Typically, low sensitivity formations may produce invertebrate fossil remains in low abundance. Two additional categories have been established by San Diego County (2007). Marginal Sensitivity: assigned to geologic formations that are composed either of volcanoclastic (derived from volcanic sources) or metasedimentary rocks, but that nevertheless have a limited probability for producing fossils from certain formations at localized outcrops. Volcanoclastic rock can contain organisms that were fossilized by being covered by ash, dust, mud, or other debris from volcanoes. Sedimentary rocks that have been metamorphosed by heat and/or pressure caused by volcanoes or plutons are called metasedimentary. If the sedimentary rocks had palaeontological resources in them, those resources may have survived the metamorphism and still be identifiable in the metasedimentary rock, but because the probability of this occurring is so limited, these formations are considered marginally sensitive. No Potential: assigned to geologic formations that are composed entirely of volcanic or plutonic igneous rock, such as basalt or granite, and therefore do not have any potential for producing fossil remains. These formations have no palaeontological resource potential, i.e. they are not sensitive. The relative importance of a particular fossil-bearing site (i.e., a palaeontological resource) depends on a number of factors that may be weighted differently, depending on the type of research being conducted. Based on established professional standards and opinion, areas known or expected to yield vertebrate fossils generally are assigned greater significance (i.e., importance) than areas where only invertebrate or plant fossils occur. Many specimens from restricted localities may be needed to describe or identify any species adequately. Consequently, vertebrate fossil-bearing sites and geologic units likely to yield vertebrate fossils generally are characterized by palaeontologists as having higher sensitivity than those containing only invertebrate fossils. The sediments and rocks containing only marine invertebrate fossils are considered by palaeontologist to be of relatively lower sensitivity. Research based on fossils may emphasize their use as indicators of geologic time, records of anatomical details of extinct organisms, evidence of the course of evolution, or samples of former ecosystems. Palaeontologists usually consider three general attributes when deciding

7 Page 5 of 7 whether a site is a significant locality: uniqueness, species diversity, and quantity of information about past life. For the purposes of this memo, the paleontological sensitivity rank of a geologic unit in the study area is based on the presence or absence of known vertebrate fossil-bearing sites in the geologic unit, although not necessarily in the District s service area. Geologic Units Numerous geologic studies have been conducted by the California and United States Geological Surveys of all or part of the Oceanside quadrangle. Sufficiently detailed descriptions of the sediment and rock types in the Vallecitos Water District are available online in Kennedy and Tan (2007). According to their map and report, which are part of the basis for the current version of the geologic map of California (Jennings et al. 2010), the District service area contains one geologic unit of high palaeontological sensitivity; the Santiago formation. The other units, provided in the attached map and description extracted from Kennedy and Tan (2007) consist of unconsolidated Quaternary deposits (low sensitivity) in the valleys and on the lower hillsides and the more ancient hill and ridge rocks of igneous (no potential) or meta-volcanic (marginal sensitivity) origin which are not expected to contain recoverable palaeontological resources. Research Results As indicated in the list of sensitivity levels, the types of geologic units have a strong influence on the potential for a site to contain paleontological resources. The geologic sediments at the District s service area date from the Pleistocene and Holocene epochs, the youngest portion of the Quaternary period, and consist of unconsolidated, poorly sorted, gravel, sand, silt, and clay deposited by rivers in alluvial flood-plain environments. Based on their youthful age and relatively high-energy depositional histories, these units were considered unlikely to contain important paleontological resources (vertebrate fossils) and were assigned to the Low Sensitivity category. The Santiago formation of the middle Eocene epoch, not to be confused with the Santiago Peak Volcanics (Mesozoic), is sandstone and conglomerate throughout most of its exposed area: it is finergrained and muddier in the southern part of the County. Petrified wood of avocado and other types of trees and terrestrial mammals (e.g. horses, rodents, insectivores, etc.) indicate a coastal lowland palaeo-environment. Searches of the palaeontological databases listed at the beginning of this memo confirmed that thousands of vertebrate specimens have been recovered and catalogued from this formation by the University of California and the San Diego Natural History Museum, attesting to the significance of this geologic unit. It was assigned to the High Sensitivity category. This formation has produced so much palaeo-environmental information that the County assigned it to the special category of Very High Sensitivity. The granitic rocks of Cretaceous age crystallized from hydrothermal fluids at temperatures that would preclude fossil preservation. Consequently, they were assigned to the No Potential category. The metamorphic rocks of Mesozoic have been subjected to heat and pressure for tens of millions of years, compressing and cooking any traces of plant or animal life they may have contained. Therefore, they were assigned to the Marginal Sensitivity category.

8 Page 6 of 7 Potential Impacts Implementation of the Vallecitos Water District Master Plan, as such, would have no effect on palaeontological resources in the District s service area. When specific excavation projects are proposed under the Master Plan, those that cross the Santiago formation, along the southern portion of the District s western boundary have the potential to disturb or destroy palaeontological resources. Palaeontological Resource Mitigation Measures Conduct project-level palaeontological resources investigations in cooperation with the County and the San Diego Natural History Museum during environmental review of projects proposed under the Master Plan that would impinge on the Santiago formation. For the purposes on the review, the District shall retain a professional who meets the qualifications standards for a principal palaeontologist, as described below. The study shall include: a review of the records search prepared for this program EIR and, if necessary, an updated records search; project-level pedestrian surveys of portions of the project site where palaeontological resources could be encountered; formal evaluation of any potentially affected palaeontological resources to determine if they qualify as unique palaeontological resources; and recommended measures to avoid, where feasible, impacts on unique palaeontological resources, including preservation in place, planning construction to avoid palaeontological sites, deeding palaeontological sites into permanent conservation easements, or planning parks, green space, or other open space to incorporate palaeontological sites. Where avoidance or preservation in place is not feasible, excavation and curation may be recommended as mitigation. The results of the study shall be compiled into a technical report or memorandum which shall be submitted to the District for further coordination with the County and the San Diego Natural History Museum, as necessary. Should the project include federal funding or oversight or otherwise qualify as a federal undertaking, the palaeontological study shall be prepared in accordance with Section 106 of the National Historic Preservation Act. The palaeontological study and inclusive mitigation measures shall form the basis for the palaeontological resources component of the project-level environmental documentation prepared for the project. There are no State of California statutes establishing qualifications for an investigating paleontologist, but Caltrans, which deals with projects extending thousands of miles throughout the state, defines a qualified principal palaeontologist as an individual with the following qualifications (Caltrans, 2007). A graduate degree in palaeontology, geology, or related field, with demonstrated experience in the vertebrate, invertebrate, or botanical palaeontology of California or related topical or geographic areas; and

9 Page 7 of 7 At least one year full-time professional experience, or equivalent specialised training in palaeontological research (i.e., the identification of fossil deposits, application of palaeontological field and laboratory procedures and techniques, and curation of fossil specimens), administration, or management; and At least four months of supervised field research and analytic experience in general North American palaeontology; and Demonstrated ability to carry research to completion. An advanced degree is less important than demonstrated competence in fieldwork, reporting, and curation. Conclusion The potential exists for palaeontological resources to be disrupted or destroyed by excavation projects along the southwest boundary of the District s service area. Recommendation Conduct project-level palaeontological resources investigations in cooperation with the County and the San Diego Natural History Museum during environmental review of projects proposed under the Master Plan that would impinge on the Santiago formation. For the purposes on the review, the District should retain a professional who meets the qualifications standards for a principal palaeontologist., \\SDOFS01\Data\Environmental\Projects - Current\ Vallecitos Master Plan EIR\Technical Reports\D Paleo Report\ docx

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