Table 2. Selective Petrographic Modes of Florida Pumice Artifacts.

Sample Location Void Glass Mt. Plag. Qtz. Bt. Cpx. Glom. Other Count’ Density’

Southern Florida

MDC 1.567.6b Miami Circle 68.4 25.0 0.5 1.4 0.0 1.4 0.0 2.4 0.5 212 0.75

MDC 1.166.4 Miami Circle 71.1 20.1 Tr. 0.5 2.5 0.5 0.0 5.4 0.0 204 0.68
MDC 1.222.11a Miami Circle 77.8 74 Tr. 7.4 2.0 1.0 0.0 0.0 2.0 203 0.55
MDC 1.472.4 Miami Circle 74.5 20.2 Tr. 0.5 0.0 0.5 0.0 3.8 0.0 208 0.60
MDC 1.893.1 Miami Circle 70.8 274 Tr. 1.4 0.0 0.5 0.0 0.0 0.0 219 0.69
HMSF 896 Brickell Point 75.1 166 Tr. - 0.6 1.1 0.0 0.0 6.1 0.0 181 0.59
FBAR 75.62.10.1 Higgs Site 66.4 29.9 Tr. 1.4 0.0 0.0 0.0 2.4 0.0 ait 0.80
FBAR 72.20.534.1 Indian Key 45.0 24.5 Tr. 0.0 0.0 0.0 0.0 0.0 0.0 216 0.59
HMSF 427.5 Custom House 45.5 16.5 Tr. 6.5 0.0 0.0 1.5 0.0 0.0 711 0.68

Northwestern Florida

EGLIN 056 Wynnhaven Beach 58.6 144 Tr. Tr. 0.0 0.0 0.0 0.0 . 0.0 309 1.15

Explanation for table labeling. Mt. = magnetite; Plag. = plagioclase; Qtz. = quartz; Amp. = amphibole; Bt. = biotite; Cpx. =clinopyroxene; Glom. = glomerocrysts; Tr. = trace amounts, observed
but not counted. Modes are reported in volume percent.

1. Total number of points used to calculate petrographic modes.

2. ~ Calculated density based upon the ration of void space to glass and minerals using the following density information from Daley et al. (1966): rhyolitic glass (2.37), andesitic glass
(2.47), basaltic glass (2.77). Compositional information for each sample was obtained from Figure 5.

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