Our major purpose in continuing field work at the Tank Site was to establish with greater certainty the relationships between the diverse artifact types and classes, and other manifestations, already recognized. In the hope that the general region in which burials had been located in 1947 would continue to be productive in this respect, we expanded from there in all directions, especially toward the center of the mound. Digging in the deeper northwestern part of the site was furthered with the intent of verifying the suggested stratigraphy and acquiring, possibly, a deep undisturbed burial in better condition than those from the upper soil horizons.

The procedure of excavation and notation was essentially unaltered from that previously employed. A grid of coÖrdinates had already been established with reference to permanent data. Burials and features were again entered on standard University of California archaeological forms. A slight change, however, was made in the method of recording and cataloguing field data.

Originally a data sheet had been completed for each 6-inch interval of a 5-foot grid section, on which artifacts were plotted in exact horizontal location. In working up the material it became clear that the specific spatial distribution of isolated implements lacked patterning. It was therefore considered adequate, when returning to the field, to designate provenience by excavation unit and level only. In addition, the method of cataloguing was simplified and so organized that 90 per cent of the tabulation of data could be completed in the field. This was possible because the specimens derived from the 1947 field work had already been classified and constituted a sample on which expectations could reasonably be based.

The procedure followed was to strip each 5-foot section in 6-inch levels, and to sack together all the artifacts from one such test unit. At the end of the day the level bags were taken to camp where the artifacts were washed, labeled, and tabulated. All items were marked in India ink according to section number and level interval, e.g., 15R10-1, a specimen from the 0- to 6-inch level of the pit; 15R10-2 would indicate the 6- to 12-inch level, etc. A tabulation sheet was kept for each excavation unit. This sheet listed the most frequently occuring types or categories, allowing for the notation of rare forms, and was ruled vertically to indicate depth intervals. Artifacts were entered according to type, or category, and level, and then packed for transport. Atypical specimens or those to be used for illustration were set aside for separate shipment and more intensive examination.

This system had many advantages. Records were readily kept up to date, problems that suggested themselves as excavation progressed could be more closely defined and investigated, and artifacts could be expeditiously and finally cleared from the work area. The data sheets served as a field catalogue and covered the groundwork of the final statistical compilation. The number assigned each specimen referred not only to its catalogue entry but also its provenience.

In 1947 we could not anticipate what might be found, nor could we establish immediately the significance of what we did encounter. Thus it has been our policy to save all worked stone and ship it back to the Museum of Anthropology at Berkeley for study. During the second season, however, we felt a little more discrimination was warranted in order to save the museum valuable storage space. Therefore, the bulk of the hammerstones and a number of complete, and all fragmentary, manos, metates, and scrapers were tabulated and piled into pit 21R4 before backfilling.

Map 2. Tank Site LAn-1