File - Olivella Shell Beads

Olivella Shell Beads At Cueva Santa Rita

Molly Sells 12/5/13 Environmental Archaeology

Introduction

This paper discusses shell beads found at the Cueva Santa Rita site in Baja California Sur, Mexico. The shell genus in topic is Olivella. The Olivella shell beads are important to the archaeological record because they show trade networks throughout the Americas. The shells have been collected for beads along the Pacific Coast since early Holocene times and were traded for hundreds of miles inland. Olivella shells can be found in the Pacific, Gulf of California, or Gulf of Mexico. Olivella, the common name of dwarf olives, is a genus of small predatory sea snails that are in the family of Olivellidea. Adults in the Olivella species are usually very small, hence the genus name of “dwarf olive”. There were two species of Olivella genus beads found at Cueva Santa Rita. They were Olivella biplicata and Olivella Dama. Olivella biplicata, also known as “purple olive”, has a purple coloration to it, even when worn. It prefers the colder waters of the pacific. They are found from the bottom of Alaska to the tip of Baja California Sur. They prefer bottoms of sandy lagoons and bays at about 50 meters depth. Olivella dama prefers warmer gulf waters of Baja California and lives in shallow waters and sandpits. Olivella biplicata has a bulging silhouette while Olivella dama has a torpedo silhouette. Olivella biplicata and Olivella dama are some of the most commonly found shells found in California and the Great Basin.

Study Site Cueva Santa Rita is a rock shelter located in Baja California Sur, Mexico. It is part of the Sierra de la Giganta, a mountain range that runs along the east coast of the peninsula. It was inhabited by the Guaycura peoples. Jesuit Missionaries recounted that they had larger social groups with considerable ingroup diversity. The shelter itself is wider than it is deep, with it being 50 meters in length. The shelter was excavated in three 2x2 meter units and three 1x1 meter units in a discontinuous trench pattern. Shell beads were recovered from bulk microbotanical samples that were processed in the lab (Henrickson, 2013).

Figure 1; Map of Baja California Sur. This shows the location of Cueva Santa Rita in relation to the Sierra de la Giganta. It also pictures the location of the Guaycura people (Henrickson, 2013).

Features of Olivella Presented here the terms pertaining to parts of the Olivella shell that were utilized in bead manufacture (Bennyhoff and Hughes, 1987).

Figure 3; landmarks and loci of Olivella Shell

Figure 2; landmarks and loci of Olivella Shell

Methods Bead types were identified using the metric and morphological criteria defined by Bennyhoff and Hughes. I oriented the beads according to their standard orientation. A standard orientation generally means that the beads are oriented spire up and the canal down. Shelves are normally at the top and, callus remnants are at the right side (Bennyhoff and Hughes, 1987). Measurements were taken of the diameter, length, and aperture length using a caliper in millimeters (mm). I also looked at the nature of the opening to determine if it was

horizontal or oblique and whether or not the beads had been fire treated. Fire treatment could have made the beads easier to work with when grinding of breaking. Various colors are the result of different stages of heating. Overheating results in a gray to black color, while no heat treatment resulted in a white or natural color. Many of the beads at Cueva Santa Rita were unbleached finished beads (Henrickson, 2013). Beads were then assigned to a type and class if they met the criteria listed in Bennyhoff and Hughes typology for size and overall morphological characteristics. If they did not match each of the of the measurements, another type was sought until a match was made (Hartzel,1991). Overall, this was a very straightforward process.

Id Number

Class

Diameter

Length

Aperture Length

Bleached

Nature Of Opening

CSR#2407

spire lopped bead(A1)

6.32

13.34

1.25

yes

horizontal

CSR#2408

end ground bead (B2)

8.54

17.7

1.92

yes

horizontal

CSR#2409

oblique spire lopped (A2)

4.82

8.09

2.81

yes

oblique

CRS#2410

spire lopped bead (A1)

5.06

10.62

1.34

yes

horizontal

CSR#2411

double oblique barrel bead

2.47

3.26

1.2

no

oblique

Table 1. This is a representation of the measurements taken of the 5 shells in my sample from CSR.

Description of Beads James Bennyhoff and Richard Hughes established a classification system of Olivella shell beads for California and the Western Great Basin. This work is, as the authors claim, a “more coherent and sensitive shell bead typology”. The Olivella beads are classified into 45 types and the work includes descriptions, measurements, and temporal significance of each type (Dahdul, 2002). Within my sample size, I found spire lopped beads, end ground beads, double oblique barrel beads, and oblique spire lopped beads. Spire lopped beads are defined as a nearly complete shell with on the spire removed perpendicular to the body axis (figure 4; Bennyhoff & Hughes, 1987). The spire can be broken off, ground off, or naturally worn. Some of the outer lip may be ground off to facilitate stringing. Oblique spire lopped beads are describes as having the spire ground off diagonally (figure 5; Bennyhoff & Hughes, 1987). End ground beads are describes as having the canal and spire end removed by grinding (figure 6; Bennyhoff & Hughes, 1987). The oblique spire lopped bead is a shell that has the spire removed at an angle. All of the Oblique Spire-lopped specimens are of the A2a class (Henrickson, 2013). The double oblique bead had the distal end ground parallel to the proximal end (figure 7; Bennyhoff & Hughes, 1987). Results There were only five beads that were analyzed and categorized in this research study. Olivella shells were found in all levels and units of Cueva Santa Rita that can indicate that and they were long-term trade networks. In a larger

study that Celeste Henrickson did, she found that there were more Olivella biplicata shells than Olivella dama shells. This can indicate that there was a preference in Olivella biplicata or an avoidance of the gulf coast (Henrickson, 2013). The way some beads were ground can also indicate different stringing methods and arrangements. If the opening of the shell has a notch or an oblique wear pattern, it can show that they beads were strung in a herringbone style or worn around the neck or ankle. Side grinding usually results in a herringbone pattern when strung. It shows the pattern of movement the bead had against a particular surface. All beads were identifiable despite the chips and other use ware. My findings did not change any of her data or findings (Bennyhoff and Hughes, 1987). Conclusion A review of the project documents provided a detailed description of the site, cultures, excavation methods, and bead manufacture. I was able to analyze five shell beads and categorize them into types and class according the criteria listed in the Bennyhoff and Hughes shell bead guide. The sample size I had was not sufficient enough to come to any new conclusions from Celeste Henrickson’s previous research on Olivella shells at Cueva Santa Rita.

Figure 4; Simple Spire Lopped beads (A1)

Figure 5; Oblique Spire Lopped beads (A2)

Figure 6; End-ground beads (B2)

Figure 7; Double-oblique barrel bead

Literature Cited Bennyhoff, James A., and Robert F. Heizer 1987 Shell Bead and Ornament Exchange Networks between California and the Western Great basin. American Museum of Natural History Anthropological Papers 64(2) Dahdul, Mariam 2002 Beads and Pendants from the Coachella Valley, Southern California. PCAS Quarterly, 38(2&3) Hartzel, Leslie L. 1991 Archaeological Evidence for Stages of Manufacture of Olivella Shell Beads in California, Journal of California and Great Basin Anthropology Henrickson, Celeste 2013. Olivella Shell Bead Production at Cueva Santa Rita in south-central Baja California Sur, Mexico: An Ethnohistoric and Archaeological study of manufacture and significance Unpublished Ph.D dissertation, University of California, Berkeley.