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PUMICE ARTIFACTS FROM THE MIAMI CIRCLE AT BRICKELL POINT (8DA12)

RYAN J. WHEELER

2026 Chuli Nene, Tallahassee, FL 32301
E-mail: rwheeler@nettally.com

 

Introduction

Review of materials recovered from excavations at the
Miami Circle (8DA12) revealed that a large number of pumice
artifacts (n=121) had been found. Pumice is a form of volcanic
glass, expelled from volcanoes during explosive eruptions
(Mottana et al. 1978:315). It consists of gas bubbles trapped in
a groundmass of fragile volcanic glass and minerals. The
numerous gas bubbles make pumice light-weight and buoyant
in water. It is not native to Florida, and represents a raw
material with an extra-local origin. The nearest sources include
volcanoes in the Lesser Antilles island arc and Mexico (Simkin
1981) (Figure 1). Pumice artifacts are occasionally found at
sites in Florida, especially in southern Florida, usually in small
numbers. The large amount of pumice from the Miami Circle
offered a good opportunity to study this rare and possibly
important artifact type. Questions addressed in this study
include the place of pumice artifacts in the toolkit of Florida
Indian peoples; a companion study uses several different
geochemical approaches to determine origins and relationships
of this material (see Kish 2006, this issue).

Previous Research

Archaeologist John Goggin (n.d.:615-616) speculated that
pumice in southern Florida sites was drift material carried by
the Gulf Stream from perhaps the Lesser Antilles. He cites an
early source (Guppy 1917:164) that suggests pumice found on
the eastern side of the Turks Islands may be from the eastern
Atlantic, perhaps the Azores. Goggin (n.d.:616) counters by
suggesting that some pumice could have originated in Peru,
carried from the mountains to the sea by the Amazon River.
Other authors have favored the Caribbean and Lesser Antilles
as the source for pumice in Florida sites (Griffin 1982:69,
1988:99; Willey 1949:37). Harley Means, of the Florida
Geological Survey (personal communication, 2002), notes that,
in recent years, pumice occasionally washes ashore along the
Florida coast. Dove (1745:318-319) provides a fascinating
account of an extensive raft of pumice encountered by shipping
traffic in 1724 in the southern Atlantic. Bryan (1972) analyzed
pumice that washed ashore in Palm Beach County in the late
1960s and concluded that the Lesser Antilles was a likely
source. These reports confirm that ocean currents and not
human activity areresponsible for transporting the pumice from
its source (or sources) to Florida. Donovan (1999:323)
indicates that pumice may survive on open beaches for as long
as 100 years, and that pumice clasts can float for up to a year
before becoming saturated and sinking.

Pumice artifacts are rarely found in Florida sites, and when
found are usually present in small quantities. A review of the
literature indicates that when found, pumice artifacts were
usually only mentioned in tables of artifacts, and not studied for
patterns of use wear or artifact form. Some authors have
described pumice artifacts as abraders, or noted perforated
examples. In some cases, pumice artifacts are misidentified as
fossils or limestone (see Steinen 1982:Figure 6.2h, Table 6.2),
while some objects identified as pumice turn out to be wood,
limestone, slag, or modern landscaping materials. A survey of
collections held by the Historical Museum of Southern Florida
(HMSF), the Florida Bureau of Archaeological Research
(FBAR), and Florida Museum of Natural History (FLMNH)
added additional specimens to our sample of pumice artifacts
(see Table 1 and Appendix A).

Geographically the pattern seems to indicate that pumice is
most frequently encountered at sites in southeastern Florida
Gncluding numerous Everglades tree island sites), with occa-
sional examples along the Atlantic coast and around Lake
Okeechobee, and rare examples on the southwestern Florida
coast (see Appendix A). Temporal patterns are more difficult
to discern, though many examples of pumice come from sites
dating to the Glades I period. There are clear examples of
pumice from Glades I] and Glades III contexts as well, includ-
ing several specimens from sites of the European contact period
(Glades IIc period). Paul Heinrich (personal communication,
2002), geologist with the Louisiana Geological Survey,
recovered pumice clasts from the Bayou Jasmine mound site in
Louisiana and reports that there are some occurrences of
pumice in Texas archaeological sites as well.

Study Sample

A total of 157 pumice artifacts were examined for this
study. The bulk of these are from the Miami Circle site
(8DA12). Samples from other sites held in museum collections
were studied as well for comparative purposes.

Pumice from the Miami Circle

Examples of pumice used in this study come from all three
phases of excavations at the Miami Circle site: the original
joint investigation by the Miami-Dade Office of Historic
Preservation and the Archaeological and Historical Conser-
vancy (1998-1999); the State of Florida investigation in late
1999; and the University of Houston field school in summer,
2000. A total of 173 pieces of pumice, representing 121
artifacts, were recovered from 91 proveniences across the site.

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VoL. 59(3-4)

THE FLORIDA ANTHROPOLOGIST

SEPTEMBER-DECEMBER 2006