Unpacking the Bead: Exploring a Glass Bead Assemblage from Mission Santa Cruz, California, Using LA–ICP–MS

Abstract

This report focuses on the morphometric and elemental analysis of glass beads collected from an adobe structure (CA-SCR-217H-T) at Mission Santa Cruz, which operated between 1791 and the 1830s in the colonial province of Alta (upper) California. Previous chemical research established a chronological framework for opacified beads collected from sites in Canada, the Great Lakes region, and the southeastern United States. Testing the viability of this chronological framework for California, we analyzed 100 white glass beads using a conventional typology and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)—the first application of LA-ICP-MS to a California mission. We present the results of the LA-ICP-MS study and then briefly comment on the potential for LA-ICP-MS to refine chronologies associated with colonial missions and other postcontact sites.

The Elemental Analysis of Glass Beads

“…Of the beads from Mission Santa Clara, only the single bead from the pit feature that appears to have been filled around 1815 can be dated with any precision. Still, the lack of lead-arsenic beads at Mission Santa Clara corresponds well to the recent analysis of white glass beads from nearby Mission Santa Cruz, where only a single lead-arsenic bead was noted in a sample of 100 post-1820 beads (Dadiego et al 2021). In our study, all seven of the lead-arsenic beads were from Toms Point, sites CA-MRN-201 and CA-MRN-202, which date from the 1840s to about 1870 and are only 40 km southeast of Colony Ross.…”

“…His pessimism regarding glass beads was echoed by other prominent 20th-century archaeologists, including James Bennyhoff (1977:43), who himself helped create an enduring regional typology for Olivella shell beads (Bennyhoff and Hughes 1987). More recent work, however, suggests that a combination of documentary research and archaeometric analysis of archaeological beads may help illuminate the origins and temporal placement of many of the beads that passed through colonial and Indigenous hands in California and other areas of North America's Pacific Coast (Blair 2011(Blair , 2018Dadiego et al 2021;Ross et al 2016).…”

“…In California, beads-both glass and shell-have been at the center of recent approaches to understanding how Native Californian societies persisted despite the impacts of Spanish, Russian, Mexican, and American colonialism. In these contexts, beads play a number of interpretive roles, serving as evidence of postcontact occupation, indicators of the reach of various economic networks, and markers for the persistence of cultural traditions ranging from mortuary practices to personal adornment (Arkush 2011;Crull 1997;Dadiego et al 2021;Gamble and Zepeda 2002;Ross et al 2016). Nevertheless, the complexity of shell and glass bead assemblages from colonial-era sites in California poses various challenges.…”

“…Chemical compositional analysis offers an opportunity to expand the interpretive potential of glass beads from California and other North American contexts. Recent archaeometric research into the bead manufacturing process offers greater understanding of the chronological placement of particular glass bead types and, in some cases, the dispersal of glass beads from specific workshops in Europe or elsewhere Blair and Dussubieux, this volume;Dadiego et al 2021;Dalton-Carriger and Blair, this volume;Hawkins and Walder, this volume;see Annex B). This work has employed several analytical techniques including laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), instrumental neutron activation analysis (INAA), and x-ray fluorescence (XRF).…”

“…Nearly all of this research, however, has focused on sites in eastern North America (see Table 1 in Blair 2017), and some of the diagnostic shifts in opacifiers predate the onset of permanent European colonization of California in 1769. It is therefore unclear whether the presumed sequence of white glass bead opacifiers noted in previous studies is useful for the analysis of assemblages from California or other sites on the Pacific Coast of North America (but see Blair 2011;Dadiego et al 2021).…”