CABRILLO Shadows of the Past

RESEARCH DESIGN
(continued)

II. THE INTER-SITE SETTLEMENT SYSTEMS RESEARCH QUESTION

The next question of importance is whether or not the discovered site is meaningful in a broader prehistoric land use pattern. In other words, is the site a placement idiosyncrasy or did the prehistoric people follow a pattern for selecting that location to perform activities?

To answer this question, the archaeologist needs to develop a comprehensive understanding of the status of research on the definition of Late Prehistoric settlement systems in the region. Review of the literature shows how local archaeologists believe early and later prehistoric groups had different strategies for creating sites. This requires understanding of the Archaic or Early Prehistoric which first occupied Point Loma over 9,000 years ago.

Point Loma in Regional Settlement System Theory

The basic theoretical premise for settlement system research on Point Loma is that large marine shell midden sites represent long periods of intense prehistoric occupation (Rogers 1929a, 1929b, 1938). It is the smaller sites with less complexity that force the issue of functional definition.

Interest in site function as a research topic developed with paleo-environmental chronological reconstruction investigations by the University of California at Los Angeles during the 1960s (Warren, True, and Eudey 1961:1-105; Warren 1966, 1967:168-185; 1968:1-14). Rather than try to define site function, research focused on chronological explanation of climatic change (Warren and True 1961:246-338; Wallace 1962:172-180; Crabtree, Warren and True 1963:319-349; Warren and Pavesic 1963:411-438; Bright 1965:363-375; Moriarty and others 1959:553-556).

The University of California at Los Angeles' approach to unlocking prehistoric settlement systems focused on holistic study of ancient geography. The role of human culture in this systemic process was interpreted as co-adaptation with other life forms (Aschmann, 1959:168-178; Arnold 1957:201-318). Clement Meighan and others introduced this approach in 1958 (Meighan, Pendergast, Swartz and Wissler 1958:1-23). Rainer Berger and other UCLA pioneers began correlating radiocarbon with prehistoric archaeology (Libby 1952:673-681; Suess 1954:467-473; Hubbs, Bien, and Suess 1960:197223; Hubbs, Bien and Suess 1962:204-238; Berger, Horney, and Libby 1964:999-1001). Coincident with the proliferation of marine shell middens, sea level changes hinted at climatic cycles (Shepard 1964:574-576).

Reconstruction of Paleogeography

Large and undisturbed prehistoric shell middens along the Baja California coast served as a testing ground for both UCLA and Scripps Institute of oceanography in pursuit of reconstruction of ancient geography (Aschmann 1959:1-23). Carl L. Hubbs focused on chemical studies of marine shell from midden sites to obtain oxygen-18 readings for temperature records (Hubbs 1958:10-22; 1959:43-47; 1961:201; 1964:143-186; 1965:30-36). The field sheet of November 30, 1951 notes 'Pleistocene clams' for possible dating by carbon-14 (Shor 1980:2-3), indicating Hubbs to rank among the pioneers in the use of radiocarbon dating. Three or four grueling days each month were devoted to driving from La Jolla to Punta Baja near El Rosario, Baja California, making 61 regular stops to record ocean temperatures by sturdy thermometers cast into the sea.

Archaeological data contributed to reconstruction of Paleogeography. Hubbs explored all other facets of natural history — birds, succulents, and stranded cetaceans, fossils — or noted sites for later detailed study. He systematically gathered charcoal, artifacts, and shells from many middens, and Laura Hubbs watched especially for fragments of Cryptochiton, a specific molluscan indicator of cool temperatures (Shor 1980:3).

Carl Hubbs expanded his research to include the UCLA team after a neighbor discovered a prehistoric human burial (Shumway, Hubbs and Moriarty 1961:1-32). Hubb's students coordinated with the UCLA teams working along the San Diego coastline in the early 1960s (Hubbs and Miller 1970:378-380).

Jacqueline Miller followed Hubb's research using marine shell from prehistoric sites to reconstruct paleo-climate (Miller 1966:378-380). This classic study influenced Claude Warren and others to investigate cycles of drought and rainfall and the associated affects to geography (Warren, True, and Eudey 1961:1-105; Warren 1968:1-14).

Scripps Institute of Oceanography investigations of coastal shell middens developed data to support the hypothesis that large shell middens of Baja California were created over long periods of time coincident with fluctuations in temperature and sea level. Hubbs' research at Punta Minitas revealed the following points:

1. Septifer bifurcatus is an indicator of warmer water than Mytilus californianus. The presence of Septifer bifurcatus could be an indicator of sea temperature change that might have implications for shellfish gathering pattern changes.

2. The giant owl limpet, Lottia giqantea, was a common species.

3. The gooseneck barnacle, Pollicipes polymerus, was common and a selected food species. The volume of broken specimens far exceeded Mytilus and could not have simply been broken to prepare other food species.

4. Tegula funebralis, were second in abundance to Mytilus, and a selected food source. It is an indicator of cool water.

5. Only the warm water Haliotis cracherodii species of abalone was present, but not in abundance throughout the midden.

6. No Cryptochiton stelleri were found in the midden; a cool water species.

7. Olivella biplicata is uncommon; ornamentation is suggested as the function of this shell.

8. The common littleneck clam, Protothaca staminea, represents 15% of the marine shell; it is a clam found near rocky reefs.

9. The drupe, Acanthina luaubris, and the pismo clam, Tivella stultorum, were found only in the historic mixed surface levels; the absence indicates a lack of prehistoric digging into the sand at low tides.

10. The presence of a few land snails, Micrarionta stearnsiana and Pupilla sterkiana indicate a moister climate in the 5000 to 7000 year time range.

11. Bones of mammals and fish were always less that 3% by weight of the total food remains except Mytilus and were comparatively absent in some levels. All fish otoliths were identified as white croaker, Genyonemus lineatus, a near shore fish.

Weather and Temperature Cycles

Scientists at UCLA and Scripps Institute of Oceanography began orienting Southern California archaeology research in additional directions besides chronology. To do this, they emphasized site correlation and structure to the cycles of moist and dry climates that emerged from the study of marine shell and radiocarbon dating.

Research at CA-SDI-49 (between Rosecrans Street, White Road and Sylvester Road at Naval Base Point Loma) revealed high volumes of butchered marine mammal in a deposit dated approximately 4000 years ago (Gallegos and Kyle 1988). This discovery hinted at El Niño sea temperature warming as a factor in this unusual volume of marine mammals. Recently, work on the Channel Islands has substantiated this hypothesis by correlating warmer El Niño effects with sudden appearances of marine mammal remains (Colten and Arnold 1998: 679-701). Correlation of marine shell species and marine mammal volumes could further advance knowledge on the effects of sea temperature warming and food procurement change.

An incorrect assumption by non-archaeologists holds that the shell middens of Baja California and San Diego were created at approximately the same time and for the same reasons. The cultural horizons named by Malcolm J. Rogers as Malpais and San Dieguito and La Jollan served as a framework against which the environmental changes could be understood (Rogers 1929a, 1929b: 454-467; 1938; 1945:157-198). The Paleogeography work of Carl Hubbs and Jacqueline Miller correlated with the radiocarbon dates demonstrated that the shell middens of San Diego began to develop at least 9,000 years ago, when the weather cycles and moisture regimes were quite different from today (Masters 1988; Gallegos 1985; 1987; 1991; Carrico, Cooley and Clevenger 1990).

Cultural Identity of the Earliest People

Research into the identity of the culture responsible for the coastal shell middens has focused on comparison of artifact and feature patterns with other regions of California. Although distinct dart points and metavolcanic flaked stone tools can be correlated to the San Dieguito Horizon at 9030±350 radiocarbon years ago at the C.W. Harris Site Archaeology District on the San Dieguito River, the majority of the early sites in the region date after 8500 radiocarbon years ago (Byrd and Serr 1993:9). This is consistent with Richard Norwood and Carol Walker's date of 8650±110 radiocarbon years ago and Roberta Greenwood's 8410 +/-190 radiocarbon year date at Diablo Canyon (1972:95; Norwood and Walker 1980:250).

Although several hundred prehistoric sites exhibit the fine grained metavolcanic scraper planes, crescentic and eccentric shaped bifaces, elongated bifacial knives, and intricate leaf-shaped dart points such as those dated to 9000 years ago on the San Dieguito River, Julian Hayden and others believe the San Dieguito had departed the area (Hayden 1966; Kaldenberg and Bull 1975; Ezell 1987; Gallegos 1987).

Clearly defined settlement systems developed in San Diego County and along the Baja California coast after 8500 years ago. The large shell middens that formed along the bluffs and shorelines remain rich in marine shell, splintered food bone, charred seeds and plant remains, crudely flaked cutting and chopping tools, and milling equipment (Rogers 1938; Warren; Davis 1976:2-4).

William J. Wallace proposed a Milling Stone Horizon in Southern California at 8500 years ago. He proposed that people of this horizon migrated from eastern deserts (Wallace 1955:214-230; 1978:28). Malcolm J. Rogers had earlier labeled the people who introduced milling equipment and crude flaked stone tools as La Jollan (Rogers 1938). Claude Warren described the Encinitas Tradition as a distinctive regional milling variant about ten miles north of La Jolla Shores (Warren 1968:1-14). Emma Lou Davis tended to agree with Wallace that a Milling Archaic from the eastern deserts migrated to the Pacific Coast to form these localized variants (Davis 1968:15-19).

There is a distinct possibility that milling tools recovered at the Harris Site (San Dieguito Type Site) might mark the introduction of milling equipment on the Pacific Coast between 9000 and 8500 years ago. The San Dieguito strata lack marine shell, but upper La Jolla strata are rich in both milling equipment and a dark gray shell midden. Greenwood reported finding milling equipment at the Diablo Canyon site, which she termed Diablo Canyon Focus of Early Milling Stone at 8400 years (Greenwood 1972:95).

The coastal shell middens do not exhibit evolution of the milling equipment. The basin metate associated with hand-sized mano stones appears to have been created by a culture with prior knowledge of milling equipment. Wallace suggested that this originated from peoples from drying and desiccated desert lakes (Wallace 1978:28). Emma Lou Davis had examined Milling Archaic sites in the Panamint Dunes and believed Altithermal climatic conditions adversely impacted desert habitats and drove desert people to the California coast and down into Baja California (Davis 1968:1519).

The UCLA archaeologists pursued the theme of desert cultures fanning west and southwest over the Peninsular Mountains and down the river drainages to the coast:

. . . [who] brought with them a way of life adapted to areas where large game was scarce and where a greater dependence was placed on gathering of vegetable foods and hunting and trapping of small game. Such an economy was not readily adaptable to the ocean resources; however, it appears to have been easily adapted to the lagoons which wrinkled the coast line and supported abundant supplies of easily gathered shellfish (Warren, True, and Eudey 1961:28).

Variation in local adaptation to each lagoon and associated terrace with nearby rivers should account for the technical distinctions reported as La Jollan and Encinitas (Rogers 1938; Warren 1968).

Melting Glaciers, Sea Level Changes, and Changing Geography

Point Loma prehistoric sites provide an important opportunity to study the effects of melting glaciers and the subsequent rising sea level on the Pacific Coast. Placed within the broader research context of oceanographic research, organic samples and faunal data can provide ecological sequence data linked to the sea level rise.

The rising sea level and development of settlement systems with specialty site functions may also account for variations in the assemblages observed today. The La Jollan sites were named for a site at the La Jolla Beach and Tennis Club, which coincided with littoral zone marine resources. Artifacts recovered off shore demonstrate that the site was occupied before 6,000 years ago when the sea level elevated to its current location (Shepard 1964:574-576).

Research into the paleo-geography of coastal California between 8500 and 6000 years ago should provide clues to the development of prehistoric settlement systems in the region. D.L. Inman has studied the effects of sea level change in response to valley cutting and sediment entrapment in bays (1983:1-49). J.R. Curray has plotted rapid sea level rise at 1-meter per century during the Flandrian transgression between 18,000 and 6,500 years ago, which has since slowed to 0.10 meter (1965:723-735). Patricia Masters has reported a fibrous root dated at 8270 +/500 years ago at the 10-fathom terrace which indicates the sea level has risen eighteen to twenty meters in the past 10,000 years (Masters 1988:4-8).

Masters has suggested that the sea level has risen from the 10 fathom terrace or Santa Monica Shelf between 5000 and 7000 years ago, which correlates with the Mortar Shoreline proposed by Inman for the La Jolla Shores beach (Masters 1988:4-8). Wave action cut terraces which can now be seen at a depth of four to five meters off shore. The Mortar Shoreline is the underwater component to the La Jolla Type-Site.

As the sea level rose during the Flandrian transgression, former channels were back-filled with fluvial sediments, which Masters has marked on a line drawing to demonstrate former coastlines (Masters 1988:4-14). San Diego Bay would have been a valley with marshy wetlands and Point Loma an inland mountain 10,000 years ago. The Point Loma River would have swept due south to a shore line about one mile distant. Between 8,000 and 10,000 years ago, the climate would have been cooler and wetter than today. Conifer forests would have been the dominant habitat, shifting to oak forests and scrub chaparral by 8,000 years ago. These changes coincided with eastern movements of populations from the deserts.

The sea level rose five meters to flood the Point Loma River Valley, creating the San Diego Bay (Inman 1974:2.17). The natural shoreline one hundred years ago would have been the same as 6,000 years ago. The Tijuana and Sweetwater Rivers created a flushing system that maintained the tidal range and extended the salt-water mix far back in the bay. This enabled abundant marine life to exist throughout the bay.

Settlement System Change Over Time

Few scientific investigations of prehistoric sites around San Diego Bay exist to synthesize the changes in settlement systems over the past 9,000 years. Paul Ezell reported a date of 7,130 radiocarbon years for a shell midden near the Fort Rosecrans National Cemetery (Personal Communication to Ronald V. May 1981). Dennis Gallegos and Carolyn Kyle obtained a 7830±80 radiocarbon date for CA-SDI-48 at Ballast Point. These early dates may represent the arrival of Milling Archaic cultures to San Diego Bay.

The distribution of prehistoric sites around San Diego Bay appears to have fluoresced over the next thousand years. Richard Carrico and Peter Ainsworth described a well-developed shell midden at CA-SDI-4360 at the south end of San Diego Bay, which dated to 6,095±415 radiocarbon years (Carrico and Ainsworth).

During this period of initial occupation around San Diego Bay, mud and sand levees were forming at the opening of the Point Loma River (Masters 1988:4-20). Holocene aquifers at North Island and Coronado Heights on the Silver Strand channeled fresh water through gravel beds of drowned river channels, providing two good water sources for prehistoric people.

Virtually nothing is known of the development of settlement systems around San Diego Bay between 7,000 and 4,500 years ago (Gallegos and Kyle 1988:4-21). Between 4,500 and 3,500 years ago, coastal erosion caused shoreline retreat. Coastal bluffs formed around Point Loma with avalanches and scouring of former river cobbles. Shoreline retreat included the disintegration of prehistoric archaeology sites along the former Point Loma River Valley, leaving only upland sites. The shell middens located around Point Loma may well have been considerably inland from the shoreline during occupation.

Prehistoric populations shifted settlements to the upland areas in response to the shoreline retreat and changing habitats. Eddy currents shaped the Zuniga Shoal off North Island. Ballast Point separated a marsh habitat on the inside bay from a sand mudflat to the south.

Although the Ballast Point shell midden dates as early as 7830 years ago, fourteen other radiocarbon dates indicate that the site was occupied primarily between 3510±90 and 1550±80 years ago (Gallegos & Kyle 1988:11-11). Exploitation at Ballast Point developed a diverse shark fishing industry quite distinct from other coastal sites in San Diego and Orange County to the north (Gallegos and Kyle: 8-8). Fish from Ballast Point were entirely rocky reef and kelp bed species. Although land mammals were present on Point Loma and North Island, the hunting emphasis shifted to adult sea mammals and sea birds (Gallegos and Kyle 1988:835). As stated earlier, this sea mammal hunting shift may correlate to El Niño sea temperature warming effects.

Point Loma exhibits both shallow and deep rocky reefs associated with kelp beds and shallow water feather boa kelp. Fishing equipment reported by Gallegos and Kyle included bone gorges and composite bone fishhooks, but no shell hooks (Gallegos and Kyle 1988:8-46).

Analysis of the Ballast Point shell midden at CA-SDI-48 demonstrates development of Milling Archaic marine exploitation of a wide spectrum of protein sources. Hunting of large marine mammals and rocky reef and shore species of fish and shell were concentrated in the post 3500 years ago stratum. Primary butchering in association with milled bone paste production reduced protein for soup and gruel meals. Very small bird and fish bones present in the midden indicate that the gruel included many species.

El Niño Effects to Faunal Resources and Hunting Strategies

Inman has proposed El Niño cycles of seawater temperature warming began around 1500 years ago) coincided with greater rainfall and intensification of river flooding (Inman et. al. 1986:50-52). El Niño cycles would have flushed San Diego Bay, destroying marine habitats and causing massive shellfish die off. Miller detected these cycles of die-off in four coastal lagoons (Miller 1966). Gallegos has proposed that Batiquitos Lagoon was so silted during those El Niño cycles that it did not provide support for prehistoric populations (Gallegos 1985). These cycles coincide with essential abandonment of CA-SDI-48 at Ballast Point.

Recent work in the Channel Islands confirmed this scenario of ecological catastrophe and hunting adaptive change (Arnold 1992; Colten and Arnold 1998). Seawater warming affected the entire food chain, thus driving marine mammals into the shallows in search of food. The coincidence with die-off of shellfish and the appearance of marine mammals near shore would account for increased marine mammal bones in coastal sites in the past 1500 years.

El Niño impacts to regional weather patterns probably stimulated population movements throughout the American Southwest, as well as the Pacific Coast. Hubbs and others from Scripps Institute of Oceanography studied weather pattern change through documented expansion of marine shell middens in Baja California south of Punta Minitas that span 1500 to 100 years ago (Moriarty 1980:4647). These sites include Arroyo Rosario, Colonio Guerrero, and North Coronado Island. To some extent, the rise of Baja California sites must have created opportunities for other marine species to thrive.

A distinctive typology of inter-site settlement functions has not been published, nor has a typology linking sites to a changing ecology. Malcolm J. Rogers described Upland La Jollan sites at Torrey Pines that included cemeteries, FAR and shell features, cobble flaking stations, and isolated milling artifacts associated with marine shell. However, prior to 1500 years ago, the satellite camps do not appear to be well developed.

As the marine resources declined coincident with the El Niño cycles, major population shifts inland marked diversification of site functions. The period of change between 1500 and 1000 years ago is poorly understood, as sites from that period are quite rare and few have been scientifically studied.

Eastern Desert Migrations to the Pacific Coast

East of the Peninsular Mountains, Hakataya or Patayan groups had developed settlement systems adapted to the Lower Colorado River and Lake Cahuilla (Schroeder 1957:176-178), which spread westward to San Diego Bay by the time Spanish explorers reached the area. A side tributary to the river filled a desert basin between 1000 and 500 years ago (Weide et. al. 1974). Populations around those habitats splintered off to explore and develop settlements up the canyons of the Peninsular Range (Rogers 1945:54; O'Connell 1971:180).

Colorado Desert Hakataya, Pottery, and New Religious Practices

Point Loma archaeology sites fall within a broader regional context associated with a westward movement of desert cultures during a long drought that spanned A.D. 1300 to A.D. 1600. People who intensively exploited western desert resources pressed west up mountain drainages toward the Pacific Coast. Cultural changes accompanied those population movements.

The earliest documented contact between coastal Milling Archaic populations and Colorado Desert Hakataya is recorded by the earliest documented Tizon Brown Ware ceramics at CA-SDI-777, in the Peninsular Mountains east of Point Loma (May 1976:103-107). Above an Archaic human flexed burial, a charcoal-rich level separated a gravel layer with the Tizon Brown Ware and a human cremation. The charcoal dated 960±80 radiocarbon years ago, which places the arrival of pottery approximately the same time. Both Tizon Brown Ware and cremation practices are Hakataya culture traits more common to the Lower Colorado River area.

The processes of Hakataya intrusion of Colorado Desert culture traits to the Peninsular Mountains and Point Loma coast is not clearly defined from current investigation of archaeological sites. Both pottery and human cremation practices appeared at different times between 1000 and 800 radiocarbon years ago. Yuman speaking ancestors of historic Ipay and Tipai people developed settlements along major drainages with specialized sites in upland geography over the past 1200 years (Kroeber 1925; Luomala 1978). Their earliest arrival on the coast remains unknown, but Tizon Brown Ware associated deposits radiocarbon dated at 660 years ago at CA-SDI-48 on Point Loma.

Late Milling Horizon Settlement System Change

Regional studies at Cuyamaca Rancho in the Peninsular Mountains documented a Late Milling Period settlement pattern with base camps surrounded by satellite stations (True 1970). A survey at Table Mountain, south of Cuyamaca Rancho, substantiated the pattern of base camps surrounded by satellites like spokes from the hub of a wheel (May 1975:1-25). The base camps included bedrock milling stations with complex mortar and basin features developed to process seeds and meats. Smaller satellite stations included small milling outcrops, flaked stone workshops, rock art, assaying and quarrying stations, trails, acorn granaries, hunting blinds, rock walled rooms, rock art, and rock walled alignments. The presence of Tizon Brown Ware and Lower Colorado River Buff Ware ceramics, small arrow points, and Obsidian Butte obsidian are distinct to these settlements. In all likelihood, Late Milling Period base camps with specialized satellites exist on Point Loma.

The Late Milling Period people who arrived at CA-SDI-48 on Ballast Point in San Diego Bay 660 years ago settled their base camps at a preexisting shell middens (Gallegos and Kyle 1988:1233). The most likely location of those first base camps are the historic 18th century Nipaguay rancherias at the mouth of the San Diego River, Cosoy at the foot of Presidio Hill, and Chollas rancheria at the mouth of the Sweetwater River. These Ipay-speaking people operated satellite hunting and plant gathering sites on Point Loma. The small encampment at Ballast Point (CA-SDI-48) might have been a satellite to Cosoy, perhaps a way station for harvesting marine resources (Eidsness et. al. 1979).

Since historic cities and public facilities development have obliterated most of the San Diego coastline prior to archaeological surveys, little opportunity remains for the study of coastal prehistoric settlement systems and identification of the range of types of sites. The Point Loma Peninsula provides one of the last opportunities to study large tracts of relatively undisturbed land. However, historic disturbance by Spanish, European, American whalers, Chinese fisherfolk, and 20th century military and civilian land development have damaged the site matrix integrity or eliminated many of those sites.