CABRILLO Shadows of the Past

Introduction

This synthesis of relevant published and unpublished literature addresses the potential scientific value of prehistoric archaeological sites located on Point Loma, California. The synthesis includes several broad anthropological research questions that have received considerable attention already and to which future recovery data from Point Loma sites could contribute. By discussing progress to date and future research goals, integration of information recovered from Point Loma sites into these broad questions can demonstrate their potential eligibility to the National Register of Historic Places. Conversely, ineligibility to the National Register for certain resources will be discussed as well. Historical archaeological resource sites are also judged in a similar way, as noted in following sections.

Laws and Regulations

Use of this overview will have utility in assessing the potential eligibility of historic and prehistoric archaeology sites. Natural erosion, impacts by wild and domestic animals, and man made improvements detract from the matrix integrity. The focus of a land manager should be to assess degrees of integrity loss against the potential of the resource to support scientific questions and thus meet Criteria D of the National Site Preservation Act of 1966 (Title 36 Code of Federal Regulations, Section 60.6). Criteria A of the Act which identifies a site as an example of a significant theme or pattern of history, architecture, archaeology, engineering or culture for a locality, state or nation may also apply.

Two other National Site Preservation Act criterion not likely to apply to prehistoric sites as evaluations are Criteria B which addresses associations with historically prominent persons and Criteria C which requires identification as work of a master, has high engineering distinction or possesses high artistic values. Some historical archaeological sites may also meet these criteria, however. Site integrity is also important to the automated archaeological database for the Park Service called the Archaeological Sites Management Inventory System (ASMIS).

Academic Research Schools

There have been several distinct academic 'schools' of research in San Diego that have focused on important research questions of their times. For example, early research by the San Diego Museum of Man attempted to develop cultural sequences that correlated to geologic chronology. Malcolm Rogers published, critiqued, and republished cultural sequences for the earliest to the most recent prehistoric people in Southern California. Rogers later adopted linguistic models to explain chronological tool and pottery sequence changes. In the 1950s and 1960s, the University of California at Los Angeles directed advanced students to the San Diego area to study potential environmental change during geological and cultural sequences. Carl Hubbs, Scripps Institute of Oceanography, contributed substantially to radioisotope and radiocarbon dating to study seawater temperature and marine species changes in those same chronological periods as ancient people occupied the region. San Diego State University, University of California at Riverside, and private contract archaeologists attempted to study cultural processes of change in the 1970s. Today, a wide variety of private, museum, and academic archaeologists are synthesizing these pioneering approaches to newly formed research questions.

Paleogeography of the San Diego Coast

Transformational effects such as rising sea levels, changing sea temperatures, world-wide sea and weather cycles and changes, and landform modification on populations of organisms are important to the understanding of the broader context of prehistory in the San Diego region. These transformational changes affected prehistoric people as they relocated occupation areas in response to changing shorelines and less reliable food sources. Population movements often brought groups of people together, where trade, exchange of ideas, marriage, and new political alliances further caused regional change. It is this broad context that provides the laboratory for scientific archaeological inquiry on Point Loma.

Since the peninsula is an exposed, prominent ridged landform separating San Diego Bay from the Pacific Ocean, this land has been steadily eroded by rising sea levels and landslides which have severely eroded the coastline over many thousands of years. The shoreline of today is not the same observed by the first prehistoric people, who arrived at least 9,000 years ago. Many of their original camping and occupation sites have fallen into the ocean. This dynamic environment is recorded in clues such as artifacts, pollen, marine shell, food bones, diatom, phytolith, and blood residue found on tools in the surviving prehistoric sites.

Archaeological Sites as Time Capsules

In essence, each archaeological site is like a time capsule, composed of materials and artifacts relevant to the time in which the objects were deposited. As noted, gradual or sudden changes in sea temperature, rising seawater, and coastal landslides affected creation of those time capsules. Orientation of scientific data recovery from Point Loma sites should be planned to recover evidence relevant to those issues. This orientation needs to incorporate lessons learned from previous researchers with new data to arrive at long-term cumulative solutions.

For example, since early radiocarbon dates were obtained on San Diego coastal sites, new radioisotope information has become available to indicate certain marine shellfish species populations substantially died-off during fluctuations in marine sea temperatures. Greater or lesser abundance of Chione clams, for example, would reflect such a change. If archaeologists only relied on Chione for radiocarbon dates they might misinterpret the occupation to fall within the time when the sea water temperature supported large populations of Chione. However, orienting a scientific investigation to obtain radiocarbon dates on Chione, Mytilus, animal bone, charcoal, and charred seeds would greatly improve the accuracy of dating the actual occupation of the site.