DESERT QUARTZITE SOLAR PROJECT FINAL PLAN AMENDMENT/ENVIRONMENTAL IMPACT STATEMENT/ENVIRONMENTAL IMPACT REPORT APPENDIX T PRELIMINARY PALEONTOLOGICAL RESOURCE ASSESSMENT TECHNICAL REPORT (see PDF files on enclosed CD) PRELIMINARY PALEONTOLOGICAL RESOURCE ASSESSMENT TECHNICAL REPORT prepared in support of DESERT QUARTZITE SOLAR PROJECT Southeastern Riverside County, California submitted to: Statistical Research, Inc. 21 West Stuart Avenue Post Office Box 390 Redlands, California 92373-0123 on behalf of: Desert Quartzite, LLC 135 Main Street, 6th Floor San Francisco, California 94105 Submitted by: Robert E. Reynolds & E. Bruce Lander, Ph.D. Paleo Environmental Associates, Inc. 2248 Winrock Avenue Altadena, California 91001-3205 626/797-9895 [email protected] March 2016 PALEO ENVIRONMENTAL ASSOCIATES MANAGEMENT SUMMARY Statistical Research, Inc., on behalf of Desert Quartzite, LLC, retained Paleo Environmental Associates, Inc., to conduct a paleontological resource literature review, archival search, and preliminary paleontological resource assessment for the Desert Quartzite Solar Project (Project). The approximately 5,010-acre Project site is situated on Federal land (4,850 acres) with a 160-acre private parcel. The Project is located 0.5 mile south of Interstate 10 and 7.0 miles west-southwest of Blythe in southeastern Riverside County, southeastern California. The Project includes development of a photovoltaic solar energy generating farm and a transmission line extending about 3 miles west of the northwestern corner of the Project site. The Project site is underlain by five continental sedimentary formations of Pliocene through late Pleistocene age. Five soil horizons (paleosols) have developed on these older formations, with two starting development in the late Pleistocene Epoch and three in the Holocene. The coarse sediments of the Bullhead Alluvium have produced a fossil horse bone. Soils developed on older Pleistocene terrace deposits have produced over 800 continental vertebrate specimens at newly recorded fossil localities 5 to 7 miles south of the Project site in the Rio Mesa Solar Electric Generating Facility (Rio Mesa) Project area. Eolian deposits in the latter project area have yielded reworked Pleistocene fossil remains. Thin Holocene deposits of fans, dunes and active washes cover less than 20 percent of the Project site. Those deposits cover fossiliferous soils and sediments and also might contain reworked fossils. Thus, Pliocene and Pleistocene deposits exposed at the surface, fan deposits and stabilized eolian deposits in the shallow subsurface, and surficial older soils in the Project site all have potential for containing scientifically important vertebrate fossil remains. Each stratigraphic unit in the Project area was evaluated using the United States Bureau of Land Management (BLM) Potential Fossil Yield Classification (PFYC) System. The privately owned parcel inholding was compared with the Riverside County paleontological impact sensitivity map where Riverside County has jurisdiction under California Environmental Quality Act (CEQA). Based on this evaluation, the mapped deposits within the Project site have the following potential: (1) The Pliocene Bullhead Alluvium (Tba) and Pleistocene terrace deposits (Qot) have a very high potential for producing scientifically important vertebrate fossil remains and are assignable to Class 3a and Class 5a. (2) Two late Pleistocene soils are developed over the mapped sediments (Item No. 1 above) and based on local fossil occurrences are assignable to Class 5b. (3) Shallow subsurface fan deposits of probable Pleistocene age have moderate to unknown (Class 3b) potential for containing vertebrate remains. (4) The stabilized portions of the eolian deposits have a moderate to unknown (Class 3b) potential for containing vertebrate remains. (5) Active, thin alluvial fan, dune, and wash deposits have a low potential for containing fossil remains (Class 2). Project-related earth-moving activities might result in the disturbance or loss of fossil remains and associated specimen and locality data at previously unrecorded fossil localities. Consequently, it is recommended that a preconstruction field survey of the entire Project site be conducted to verify the potential for fossil remains being encountered by Project construction. During the survey, fossils found exposed at the surface will be subject to a treatment plan developed in support of Project construction. Results of the survey will be used to develop a Project- specific paleontological resource impact mitigation plan/program (PRIMP) to be implemented during Project-related earth-moving activities. The Project PRIMP will be based on standard mitigation measures issued by the Society of Vertebrate Paleontology. This preliminary paleontological resource inventory and impact assessment recommends that: (1) a preconstruction field survey of the entire Project site be conducted, (2) fossils found during the survey be recovered and fully treated, and (3) a Project-specific PRIMP be developed and implemented during earth-moving activities associated with Project construction. The PRIMP, which will be based on the results of this inventory/assessment and the preconstruction field survey, will include: i PALEO ENVIRONMENTAL ASSOCIATES (1) a worker awareness training program that will provide information on fossil recognition and procedures to be implemented when fossil remains are discovered (e.g., temporary avoidance of fossil site by earth-moving equipment, notification of Project and PRIMP personnel); (2) activities to be conducted by qualified paleontologic monitors as part of paleontologic monitoring of earth- moving activities in portions of the Project area determined to have moderate or high sensitivity during the preconstruction field survey; (3) fossil recovery techniques to be used by the monitors or other PRIMP personnel; (4) methods for recording specimens, potentially fossiliferous sediment samples, and associated specimen, sample, and locality data; (5) procedures for collecting and processing sediment samples that might contain fossil remains too small to be seen by a monitor in the field; (6) a treatment plan for dealing with all remains recovered by monitoring and sample processing; and (7) preparation of a comprehensive final mitigation program report of results and finding for submission to the BLM and the designated museum repository. Implementation and completion of the PRIMP would reduce adverse Project-related impacts on the paleontological resources of the Project site to a less-than-significant level. ii PALEO ENVIRONMENTAL ASSOCIATES TABLE OF CONTENTS page Management Summary ............................................................................................................................................... i Table of Contents........................................................................................................................................................ iii Introduction ................................................................................................................................................................ 1 Project Location and Description ........................................................................................................................ 1 Purpose of Study ................................................................................................................................................. 1 Personnel ............................................................................................................................................................. 2 Methods ...................................................................................................................................................................... 3 Setting ......................................................................................................................................................................... 3 Geomorphology ................................................................................................................................................... 3 Geology ............................................................................................................................................................... 3 Paleontological Resources ................................................................................................................................... 6 Preliminary Paleontological Resource Assessment ...................................................................................................... 9 Introduction ........................................................................................................................................................... 9 PFYC System Evaluations of Stratigraphic Units ............................................................................................... 12 Bullhead Alluvium ....................................................................................................................................... 12 Old Terrace Deposits .................................................................................................................................... 12 Stabilized Alluvial Fan Deposits .................................................................................................................. 12 Stabilized and Active Eolian and Dune Deposits ........................................................................................