Origins and Problems of Cultral Stratigraphy and Chronology in Southern California, as Originally Defined at the Malaga Cove Archaeology Site in the Palos Verdes Hills

Mark L.Peterson
EcoSys Solutions, 4937 Seabreeze Way, Everett, WA. 98203

The archeology of the Malaga Cove site (CA-LAN-138) in the Palos Verdes Hills defines the original prehistoric cultural sequence for the known human occupation of southern California. The site, among the largest and most complex archaeological sites recorded in California, was located above Malaga Cove on the northwestern bluffs facing Santa Monica Bay. The cultural deposits of Malaga Cove have long been thought to comprise, uniquely in this single site, the four stratigraphic units that characterize the chronological sequence of prehistory from the early Holocene to European Contact. However, reported contradictions on the size, structure, and spatial configuration of the original prehistoric site deposits from over 80 years of investigation, has resulted in two major and conflicting stratigraphic interpretations. The first interpretation stems from early investigations by Richard Van Valkenburgh in 1931, who documented a series of sometimes over-lapping and irregular concentrations adjacent to prehistoric “campsites” surrounded by cultural debris. Later excavations conducted in 1936 by Edwin Walker describes a vertically-layered, and discrete sequence of contiguous cultural deposition recovered from a 12-m high mound that was buried by dune sands, with basal cultural strata that overlay sterile, nonmarine late Pleistocene terrace deposits. In 1955, William J. Wallace relied on a hand-drawn profile of the vertical schema proposed by Walker to organize regional-scale archaeological deposits into a broad, four-horizon, cultural sequence, to explain the chronology of human occupation for all of southern California. The study compared the data tabulations for each cultural stratum, along with the geological and paleontological work of W. P. Woodring et al. (1946), to calibrate the likely temporal ordering underlying the formation of similar deposits located elsewhere throughout the region. Wallace’s study represented a breakthrough in the use of geo-stratigraphy to establish cultural time, using non-mathematical seriation techniques and super-positioning. However, Wallace revealed 17 years later that Walker’s profiling data might have misrepresented the internal site morphology, and that vertical and contiguous site occupation never existed at Malaga Cove. After 1955, the site was lost to development and erosion, making efforts to resolve the issue through radiocarbon dating of in situ deposits impossible. Despite the reported inconsistencies, over 50 years of excavation has validated, not obviated the observed cultural sequence. Further complicating the issue, are recent studies that confirm that most cultural stratigraphy in southern California results from a stochastic process of spatial formation, where refuse materials are discarded laterally and adjacent to prehistoric activity areas and accrete on a series of overlapping surfaces through time. This normative pattern in the geoarchaeological record is consistent with all interpretations of LAN-138 stratigraphy, except for Walker’s scenario. The enigma of the Malaga Cove stratigraphy describes the evolution of spatial-temporal analyses in California archaeology. An historic overview suggests Walker devised the hypothetical time-ordering of cultural deposits depicted as vertical schema in an attempt to emulate geological study and more rapidly decouple complex, diachronic site formation processes in the absence of radiocarbon dates.

AAPG Search and Discovery Article #90076©2008 AAPG Pacific Section, Bakersfield, California