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HomeMy WebLinkAboutCT 05-12; Ocean Street Residences; Tentative Map (CT) (5)~~B~r~ia~n~F.~·~S~m~i-th~a~nd~A•s~s~o~c~ia~t~es~,~l~nc~.T-T-~T-~~~~~~~~~~~~ " Art:haeolo91 I Biolo59 I History I Faleontolo59 /Air Quality /TraFfic,' Acoustics 14 June 2013 Mr. Jim McMenamin Zephyr Partners 11750 Sorrento Valley Road, Suite 130 San Diego, California 92121 Subject: Paleontological Resource and Monitoring Assessment, 2303 Ocean Street Residence;, Carlsbad, San Diego County, California (CT 05-12, CP 05-11, COP 05-28) Dear Mr. McMenamin: A Paleontological Resource and Monitoring Assessment has been completed for the proposed Ocean Street Residences project site, located on the north side of Ocean Street and west of Mountain View Drive at 2303 Ocean Street, along the southwest shore of Buena Vista Lagoor in the City of Carlsbad, San Diego County, California (Attachments 1 and 2). The project site is located near the mouth of the lagoon in the southwest quarter of the northeast quarter of Secti<n 1, Township 12 South, Range 5 West, San Bernardino Base and Meridian, as shown on the USG; 7 .5-minute, 1:24,000 scale, San Luis Rey, Calif., topographic quadrangle (Attachment 2). Tht 3 .05-acre site is bounded on the south by Ocean Street, on the west-southwest by existing residential properties, and on the north by undeveloped land adjacent to the mouth of the lagocn. The proposed project calls for underground parking facilities, which will include approximate!/ 13,200 cubic yards of cut. Geologically, the basement rocks in the area are mapped as the middle Eocene (~ 40 to~ 50 million year old) Santiago Formation (Attachment 3, after S. S. Tan and M.P. Kennedy, 1996 Geologic maps of the n01thwestern part of San Diego County, California: California Division Jf Mines and Geology, DMG Open File Report 96-02, pl. 1). The Santiago F01mation contains a variety of lithologies, including ones derived from marine, estuarine, and terrestrial environmetts. Eocene sediments are mapped as being exposed along the water's edge on the shore of the lag< on. Much of the coastal area in this part of the county is also overlain by a thin veneer of Pleistoce,e marine terrace sediments that are not always mapped as such, but are evident based on the plru 1r terrace geomorphology. Some areas on the north side of the lagoon that are mapped as the Eo·~ne Santiago Formation have, for example, produced very rich Pleistocene fossil faunas from exposures of 300,000 to 400,000 year old interglacial estuarine sediments. Nearby areas have been mapped as Quaternary marine terrace materials (Qt, on Attachment 3, after Tan and 1-KliO Fbwa~ Road, Suite A, Powa~:h CA .91o6+1 Phone (8,_.) 67.9-8118 or (951) 681-.9.950; rax (858) 679-.98.96; vMw.bFsa-ca.com ~usin~ss office' 1+678 ibex Court, San Diego, CA .9212.9; Phone C85B) +M-0.91.5; f"ax (858) +il+-0.988 • Brhm F. Smith and A1·Juciales -Pagt! 2 Kennedy, 1996). The marine terrace (Qt,) here may correlate with the Bird Rock Terrace in San Diego (J.P. Kern and T. K. Rockwell, 1993, SEPM Special Publication no. 4S), and date to the latter phase of the last major interglacial period, whicl1 occurred about 80,000 years ago. Marine terraces of of the last interglacial period along the San Diego County coast are often abundantly fossiliferous, although sporadically distributed. Without a geotechnical report on the subject properties, we are not able to predetermine the thickness of the upper Pleistocene(-· 80,000 year old) 111arine terrace sediments that overlie the middle Eocene(~ 40 to~ 50 million year old) Santiago Formation. Paleontological collections and records of the Department of Paleontology at the San Diego Natural History Museum (SDNHM) in San Diego do not show any previously recorded fossil localities within the project boundaries. The museum's records and locality maps do show, however, a fossil mammoth locality (SDNHM Joe. 4007) about one mile to the north of the project site, and ten Pleistocene marine terrace localities with abundant marine invertebrate fossils a little farther to the north-northeast (SDNHM locs. 4024 through 4032). These Pleistocene localities date to an earlier interglacial period and are-330,000 years to-· 400,000 years old. Although there are no recorded Eocene fossil localities nearby, the Santiago Formation is often fossiliferous, and has yielded both important terrestrial vertebrate and marrine invertebrate faunas (T. A. Demen) and S. L. Walsh, 1993, Paleontological Resources-County of San Diego). Because of the "high paleontological resource sensitivity" of the underlying middle Eocene Santi<tgo Formation and of Pleistocene marine terrace sediments (Demere and Walsh, 1993), full time paleontological monitoring of mass grading and excavation activities, including utility trenching, etc., in areas so mapped should be required to mitigate any adverse impacts (loss or destruction) to potential nonrenewable paleontological resources (i.e., Pleistocene and/or Eocene fossils). A mitigation program consistent with the provisions of the California Environmental Quality Act (CEQA), regulations currently implemented by the City of Carlsbad, and proposed guidelines of the Society of Vertebrate Paleontology should be implemented. If you have any questions concerning this evaluation, please feel free to contact us at our Poway address. Thank you for the opportunity to provide paleontological services on this project. Sincerely, (~' C-"-SS< -· -ce: George L. Keunedy, Ph.D. Senior Paleontologist Attachments: Index maps, geologic map Attachment 1 General Location Map The Ocean Street Residences Project DeLorme World Base Map Service (I :250,000 series) .i ~~ ~~-~-~ ~~-'~-~ 1-------·-----_____ .Qg~!']}~!L....,, ' I 'l ....___ j ' ,.,.-- ... ~. # or·>-' i/ "' I ' ; i I I I ' ! I I! '' '' -!i· .,.,i '' Attachment 2 Project Location Map The Ocean Street Residences Project USGS San Lzti,,· RC:l' Quadrangle (7.5 minute series) rea, p., ~UtS rica ern nty, 6-8. 1nty, -15. icgo incs y of ivi~ 000. and rnia, - INDEX MAP Camo Pendleton Fallbrook Attachment 3 Geologic Map The Ocean Street Residences Project Geology after Tan and Kennedy (I 996) . M H ,---, o SOOm 0 1000 2000 ft