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HomeMy WebLinkAboutCT 80-25; LA COSTA MEADOWBROOK; ARCHAEOLOGICAL ASSESSMENT COMMENTS; 1981-01-23City of Carlsbad La Costa Meadowbrook page 2 Soils are a continually changing mixture. of mineral matter, organic matter, water, and air. The parent material produced by weathering of bedrock into unconsolidated mineral deposits. Plant growth occurs, animals, bacteria, and fungi feed upon the plants. Water enters the •soil by rain or run-off and, in varying proportions, excludes air trapped in the soil. As water is removed by evaporation, drainage, or plant growth, this pore space fills with air. Thus, in place soil development is not a static process but rather a combination of constantly interacting factors and components with input from the top as well. Soil properties are changed further when a human factor is introduced. Prehistoric peoples added both mineral and organic matter to soils when specific areas we term "sites" were used for various activities. This resulted in the buildup of midden deposits or an accumulation of in the soils of additional organic wastes, faunal remains from discarded food remains, and discarded artifacts. Not only did people deposit clean soil atop smelly old rotten garbage, but mud was used in the construction of wall insulation materials. People also excavated pits for sweat houses, roasting pits, and house pits. Wind deposited soil accumulated at these sites, just as dust accumulates atop'boxes stored under a modern house. Simply walking over sites functions to push the older debris into the forming soils. An example of a similar situation is the buried or partially buried debris seen in a modern day camp site. The latter case was tested some years back by Dr. David Weide of the Geoscience Department of the University of Nevada. Dr. Weide found that at the end of one season of camping he was able to find metal foil and paper trash as deep as four inches below the ground surface (Personal Communication 1975). Most archaeologists recognize that soil formation a metabolic process and that cultural deposits are subjected to constant, although usually very slow, counter- acting forces of soil addition and depletion such as those discussed above as well as erosional processes and gravity pull. Every single item in a site will not be the precise position as when the prehistoric population vacated the site, howev_er, the relationship between i terns has proven to be generally reliable. Even under the most radical conditions of complete loss, early Holocene sites in desert pavements have deposited artifacts in patterns which can be detected by carefull mapping and computer programming. The relative locations of those artifacts can be interpretted to mean specialized workshop activities, kitchens, house floors, plant processing, ceremonial shrines, and other features which are importnat to arhcaeologists and the general public. There are many studies on this subject and we will be happy to discuss them if you are interested. Most archaeologists are trained to observe site characteristics which would suggest otherwise and can recognize deposits with unreliable stratigraphic contexts. However, in California there is almost no such thing as an insigi::i.ificant site due to disturbance, City of Carlsbad La Costa Meadowbrook page 3 as has been proven by Dr. Joseph Winters in his analyses of back dirt from mechanical trenches excavated at the Holiday Inn Site in San Jose (Personal Communication 1975). Stratigraphy, as is classically discussed.in primary college text books, ,does-not occur in California. Rodent action is a basic process which is taught to all students working in sites i_n this region and not a newly discovered phenomenon. This is why we are taught to plot the precise location of atrifacts or to isolate them by arbitrary levels and then use mathematical models to discover patterns in the three dimensional context in which they were deposited. We are strongly opposed to the statement on page 12 that "there is no way to intro- duce a subsurface cultural component without it being introduced by the activities of a burrowing animal." This is a patently ridiculous statement, as most southwestern hunting and gathering societies excavated into the soil surface to partially bury: their houses for insulation and increase space. Refuse was buried, cooking ovens were excavated into the ground to ncrease heat conduction, storeage cists were exca- vated deep into the soils, and human burials were always excavated. Thus, even in the case where "in-situ" soils were forming there would be a buried site. In regard to site integrity in the presence of animal burrows, especially those of the California Ground Squirrel, the report states: "Furthermore if sites contain crotovinas or animal burrows, especailly those of California Gray Squirrrel, the site integrity should be 6tally·. suspect. (Apple and Olmo 1980:12)11 • We realize that the authors intended the quote ot mean California Ground Squirrels, as the gray squirrel is a mountain animal and does not burrow! The authors discuss the basis for their theory in the preceeding paragraph on page 12 and state that site soils will be completely mixed in 500 to 1000 years if sites are inhabited by squirrel communities. In the absence of supporting documentation in the report or tests demonstrating the degree of spatial movement of artifacts by burrowing animals, we must totally disagree with this statement. Please consider that the ancient peoples who inhabited the site would have been quick to harvest any unusual populations of squirrels, had there been an abundance after the sites were abandon. There were always people within the area and the populations would have been immediately thinned by the hunters. Meccas for squirrels in disturbed soils would have also been meccas for human hunters. \ Archaeologists do observe rodent activity in sites and recognize this is responsible for some soil mixing but there has been no indication that sites lack sceintific value due to this phenomenon. Squirrels probably are attracted to disturbed veg- etation lands and are known to thrive on-cultivated land or. grazing land. However, it has also been shown that squirrels can not persist in areas where t_he grass grows tall enough that they can·not see over it. Allowing grass to mature for three seasons will eliminate squirrels (Hall and Kelson 1959:354). Three years is quite a contrast to the 500 to 1000 years of squirrel community burrowing in the report. In fact, it seems that the authors have exceeded their knowledge level in the field of zoology. City of Carlsbad La Costa Meadowbrook page 4 Large populations of ground squirrels probably did not exist in prehistoric times, like one would see today. It is fairly common opinion among zoologists that the squirrel population flourished as a result of late 19th century clearing of Coastal Sage Scrub and Chaparral vegetation to provide fodder for cattle grazingl(John Rieger Personal Communication, 1981). In prehistoric times, disturbed vegetation suitable for supporting ground squirrels would be restricted to places like landslides and along the banks of water courses. Ancient people would have pressed the populations through hunting. Moreover, archaeological sites would have been separated by barrier areas of native vegetation. Surrounding the sites, domestic dogs and hunters would have kept the ground squirrels to very small numbers. If the prehistoric population of ground squirrels were as high as the report proposes, there would have been a high population of ground deaths in the burrows. Even if the soil were churned as suggested, one would anticipate high frequencies of intact ground squirrel faunal remains. On the contrary, data reported by Rieger (Ibid.) and Judy Berryman (Personal Communication 1981). --- Although the report states that SDM-W-915 was "riddled by animal burrows" the statement does not document nor, apparently, were measures employed to evaluate the degree of disturbance. We who have reviewed the report ask what part of the site was affected·~ ... were rodent burrows. encountered in the post holes .... S.(:)eci- fically where and how many .... were cultural materials associated with the burrows .... what were they .... how did soil profiles in the cultural deposit compare to the natural stratigraphy? The degree of disturbance can be studied by comparisons of soil profiles, frequencies of artifact types in arbitrary levels, radiocarbon dating, artifact seriation, pedology, and palynology. Pollen studies by Dr. Richard Hevly of the Museum of Northern Arizona on site material from the San Diego area has revealed significant pollen record data and evidence of micro-environmental • change over the past ~000 years. We want to know why these studies were not reported. This is standard practice by area archaeologists when "salvaging" sites doomed by land development. The report does not adequately present site specific information on the results of the investigation. The report indicates the site area was identified in Stratum 4 by a post hole series, but we were not afforded the data for our own evaluation. We need to know the depth of the post holes, the soil characteri- stics, the soil color, what artifacts were recovered in them and around them, and where were they in relation to the site area. I The results of the test units are so incomplete that the report only presents a catalogue of finds and no meaningful analysis. A simple table of type categories by arbitrary depths would provide us with artifact frequency data which could be exceedingly useful in addressing the question of rodent disturbance. We do not understand why there was such a problem in contrasting the fossil shell deposit from the cultural deposit, as fossils in this region are quite obvious in color and consistency. In the artifact groupings, there were 648 groups ... what typology was employed? From the artifact counts from units 4:and 5, Stratum 4 apparently has a high density of artifacts and is interpretted as the site area. Yet, this area has been rejected by Apple and Olmo as having no further scientific potential on the basis of squirrel activity in soils which are weathered in place. We do