Excerpt from Kaitlin M. Brown et al., “Sourcing Archaeological Asphaltum (Bitumen) from the California Channel Islands to Submarine Seeps.” Journal of Archaeological Science 43 (2014): 66–76.
…The hydrocarbon and carbon isotopic fingerprints of the archaeological asphaltum samples analyzed in this study correspond to San Nicolas Island tarball #1 (#2836) and bear a strong resemblance to several bitumen families issuing from submarine seeps in the general vicinity of Point Conception (Lorenson et al., 2009). The California current, guided by the prevailing northwesterlies and associated swells, flows southward along the coast; it passes Point Conception, flows west of San Miguel Island, and then passes the windward shore of San Nicolas Island [the northwest-facing beaches].
- Point Conception is along the California coast approximately 100 miles northwest of San Nicolas Island.
- Thomas D. Lorenson et al., Natural Offshore Oil Seepage and Related Tarball Accumulation on the California Coastline, Santa Barbara Channel and the Southern Santa Maria Basin; Source Identification and Inventory. Reston, VA: U.S. Geological Survey, 2009.