144
Illinois Archaeology Vol. 19, 2007
Trace Element Analysis of Obsidian Artifacts
from Six Archaeological Sites in Illinois
Richard E. Hughes and Andrew C. Fortier
Ten obsidian artifacts from six archaeological sites in Illinois were analyzed to determine
their geologic source(s) of origin using nondestructive energy-dispersive X-ray fluorescence
analysis. Results indicate that the majority of samples, representing Middle and perhaps Early
Woodland period times, were manufactured from volcanic glass of the Obsidian Cliff chemical
type, located in Yellowstone National Park, Wyoming, with one specimen derived from a more
distant western North American obsidian source (Bear Gulch, Idaho).
Introduction
Ten years ago (Hughes and Fortier 1997), we presented the initial results of a long-term,
collaborative project to determine the sources of various obsidian artifacts from prehistoric
contexts in Illinois. The first-order objective of this project is to determine the sources of
obsidian used to manufacture artifacts recovered from sites in Illinois, but we are concerned
more generally with determining contextual patterns for obsidian at archaeological sites,
investigating technological aspects of obsidian manufacture (i.e., are they lamellar blades,
cores, or flakes), identifying potential regional variations in source use, and identifying any
patterns that may be cross-correlated among the aforementioned components of our study.
This article contributes further to these goals by presenting recent results derived from our
ongoing research.
Earlier Obsidian Studies in Illinois
For this project, 10 obsidian artifacts from six Illinois sites were analyzed to determine
their geologic source(s) of origin. Of these, six are formed tools and four are unutilized
flakes. Although flakes occur at many sites in Illinois (Griffin 1965), obsidian tools are
comparatively rare and few reports containing baseline elemental analysis data have been
published (but see Griffin et al. 1969; Hughes and Fortier 1997). Obsidian has typically
been recovered from surface contexts in Illinois, and more rarely from specific features.
Richard E. Hughes, Geochemical Research Laboratory, 20 Portola Green Circle, Portola Valley, CA 94028, [email protected]
Andrew C. Fortier, Illinois Transportation Archaeological Research Program, University of Illinois at Urbana-Champaign,
209 Nuclear Physics Lab, 23 East Stadium Drive, Champaign, IL 61820, [email protected]
© 2007 Illinois Archaeological Survey, Inc., Illinois Archaeology, vol . 19, pp. 144–157
144
Hughes and Fortier
145
However, 119 pieces of obsidian were reported from the Napoleon Hollow site in the
lower Illinois River valley (Wiant and McGimsey 1986:333), and many of these were recovered from fills directly above features, including a circular post structure. Four of the
10 artifacts in this study are from pit feature contexts. The remaining six artifacts are from
surface contexts.
Obsidian has also been identified in multiple mound contexts in Illinois (Griffin 1965;
Perino 2006; see also Farnsworth 2006). In some cases, obsidian is definitely associated
with specific tomb contexts; in others, contexts are mound fills or adjacent fills. Some better-known examples from excavated tomb or fill contexts from the Kaskaskia River region
in Illinois include the North site, Mound 2, Tomb B (Perino 2006:341), and the Kraske site,
Mound 8, Burial 2 (Perino 2006:329). From western Illinois contexts, examples include the
Lawrence Gay Mound 5, Burial 1; Bedford Mound 12 (Perino 2006:267); Montezuma Mound
8, Burial 2 (Perino 2006:286); the Gibson Mound 2 site (Perino 2006:346); and the Frederick
site, Mound 4 (Perkins 1965:Figure 47). There are at least twice as many other occurrences
(K. Farnsworth 2007, personal communication), but they are too numerous to list here. Although it is beyond the scope of this article to correlate all of the known obsidian-bearing
contexts with specific artifact types (documenting, for example, where blades or bifaces
come from within specific sites), doing so could reveal some previously unrecognized patterns and relationships.
Virtually all of the obsidian documented in Illinois has come from Middle Woodland
contexts, and it occurs mostly during a relatively restricted horizon that is commonly referred
to as Hopewell. The dates for Hopewell vary somewhat by region but in Illinois probably
range between cal. A.D. 50–200 (Fortier et al. 2006:173). One piece in the present sample (from
Barnhill’s Farmstead), however, may date to the Black Sand horizon (the Ringering phase
in the American Bottom) of the Early Woodland period (circa cal. 700–800 B.C.). If ongoing
analysis confirms its Early Woodland age, this specimen would be temporally coeval with
obsidian reported from Early Woodland (Marion/Red Ochre) contexts in Wisconsin and
Michigan (Pleger 1998, 2000; Stoltman and Hughes 2004).
The Obsidian Artifacts and Their Contexts
Ten obsidian artifacts were available for sourcing. Four of these represent nonutilized flake
debitage. The remaining six artifacts are either bifacially (N = 4) or unifacially worked (N
= 2) tools, including one effigy biface, three biface fragments, a worked blade core fragment, and one unifacial knife. Six of the samples are lamellar blades, three of which are
the tools.
The 10 prehistoric obsidian artifacts analyzed and reported here come from a variety of
archaeological contexts in Illinois and include samples from the American Bottom, western
Illinois, and the lower Kaskaskia River regions (Figure 1). A number of the samples from
surface or midden contexts are included because they occur at single-component sites (based
on other surface diagnostics). All but one of the 10 samples appear to date to the Middle
Woodland period or Hopewell horizon. The other artifact may date to the Early Woodland
period. Brief descriptions of each artifact and its context follow.
Illinois Archaeology Vol. 19, 2007
146
11PK1
Pool
11PK2
Irving
pi
sip
sis
Riv
er
0
10
20
30
River
11MG179
Spoon Toe
is
Illinois
M
km
40
11MS637
Barnhill s Farmstead
‘
11S41
Kraske
Ka
a
ski
ska
r
Rive
11R231
Simpson
Floodplain #1
Figure 1. Illinois site locations yielding obsidian artifacts analyzed in this study.
American Bottom
Two obsidian samples come from sites in the American Bottom, one each from the Simpson
Floodplain #1 (11R231) and Barnhill’s Farmstead (11MS637) sites.
Simpson Floodplain #1
This sample (Marge Erb collection, Inloan 2006.012; Figure 2a) is a 3.45 cm long bifacially
retouched lamellar blade, weighing 2.5 g and having a thickness of .38 cm. The blade is 1.64
cm wide at its widest point and there are three arrises or dorsal ridges. Approximately 80
percent of the dorsal edge is retouched, and about 60 percent of the ventral edge is retouched.
147
Hughes and Fortier
a
b
c
d
0
5 cm
Figure 2. Obsidian tools from the American Bottom and Kaskaskia River.
The artifact appears to represent some kind of effigy, possibly a bird (raptor). Two opposing
notches, essentially accentuating what appear to be folded wings, demarcate the base from
the upper torso. The head is notched on one side, giving the appearance of a beak turned
sideways. There is also bilateral notching at the top of the artifact that may represent a top
head tuft. This artifact is a surface find. The site has yielded a variety of Middle Woodland
artifacts, dating probably to the Holding phase or Hopewell horizon. A portion of this site
was identified during the 1970s Historic Sites Survey directed by James Porter (Porter and
Linder 1974), but at that time, no diagnostics were recovered or component assignments
made. This is the first obsidian artifact that we are aware of that was ever recovered or
sourced from Randolph County.
Barnhill’s Farmstead
A fragment of a retouched obsidian blade core, weighing 5.4 g, was recovered as a midden
piece plot from the Barnhill’s Farmstead site (11MS637), located at the north end of the
American Bottom in Madison County on a colluvial slope (piece plot 1573; Figure 2b). Although this site was excavated by ITARP in 1992 and the material is curated by ITARP, the
site has not yet been fully analyzed. The artifact was located on the colluvial slope located
along the Mississippi floodplain/bluff edge. No Middle Woodland materials were recovered from the site; the midden yielded primarily Early Woodland Black Sand (Ringering
phase) materials, although no datable features were identified. Because of this, a precise
148
Illinois Archaeology Vol. 19, 2007
chronological assignment cannot be made with confidence, but an Early Woodland association for this piece of obsidian certainly is possible. This artifact is approximately .86 cm
thick, but because it is irregular in shape, no other measurements were taken. The piece
appears to represent a fragment of a blade core: there are three parallel linear flake scars on
one dorsal surface. Utilization scars occur on one dorsal edge. The striking platform is still
intact and exhibits a crushed surface. There is a large white mineral inclusion (probably a
phenocryst or spherulite) evident on the platform, which is often characteristic of geological
(and archaeological) examples of Obsidian Cliff obsidian (see Iddings 1888).
Lower Kaskaskia River
Two obsidian artifacts were analyzed from the Kraske site (11S41), both surface finds from
the Middle Woodland village portion of this site. There are also Middle Woodland mounds
in the vicinity of the village, some excavated by Perino (2006).
Kraske
Knife Fragment. The first piece (11S41; ITARP Inloan 2006.011; Figure 2c) is a bifacially
retouched knife fragment, weighing 2.4 g and measuring .64 cm in thickness. It is pressure
flaked around the entire lateral edge as well as on both ventral and dorsal surfaces. It is
made on a flake, not a blade.
Tool Fragment. The second piece (11S41; ITARP Inloan 2003.011; Figure 2d) is also bifacially retouched and represents a tool fragment made on a lamellar blade. It weighs 2.4
g and is 3.27 cm long, 1.50 cm wide, and .54 cm thick. It is pressure flaked, but only along
the lateral edges.
Western Illinois
Six obsidian artifacts were analyzed from three sites in western Illinois: one from the Pool site
(11PK1), one from the Irving site (11PK2), and four from the Spoon Toe site (11MG179).
Irving
A single obsidian artifact (11PK2; #1998.19.4000; Figure 3) was recovered from Feature 47, a
Hopewell pit in Area S at the north end of the site. This artifact was excavated by McGregor
and illustrated in the Pool/Irving report (McGregor 1958:120, Figure 40). This artifact is
an unbroken unifacially worked outrepasse’ (over-shot flake) lamellar blade knife. It is 7.35
cm long, 1.72 cm wide with two arrises, and is .37 cm thick. It weighs 8.3 g. It is one of the
longest utilized obsidian blades known from Illinois.
Pool
This specimen (11PK1; A6877; Figure 4a) is made on a nonutilized lamellar blade. It is unintentionally nicked along its edges, but not retouched. It was recovered during McGregor’s
excavations of the Pool village, a large Hopewell habitation site in Pike County in the Illinois
149
Hughes and Fortier
a
c
0
5 cm
Figure 3. Obsidian knife from the Irving site (11PK2).
0
b
d
e
5 cm
Figure 4. Obsidian debitage from the
Pool (11PK1) (a, b), and Spoon Toe
(11MG179) (c, d, e) sites in western
Illinois.
River valley of western Illinois. It was described as a “broad flake knife” in the site report
(McGregor 1958:122), but within-site provenience was not given. It is presently being curated
by ITARP. The artifact is .47 cm long, 1.80 cm wide, and .45 cm thick. It weighs 2.3 g.
Spoon Toe
Lamellar Blade. This artifact (11MG179; Feature 20-9/piece plot 2; Figure 4b) was recovered from a pit feature (Feature 20) at the Spoon Toe site, a Hopewell camp located in
the uplands of western Illinois, east of the Illinois River. It is a lamellar blade, but is not
utilized. It is 5.84 cm long, 2.50 cm wide, and .39 cm thick. It weighs 5.9 g. It has a single
dorsal ridge and is snapped horizontally at the distal end.
Lamellar Blade. This artifact (11MG179; Feature 20-10/piece plot 3; Figure 4c) also comes
from pit Feature 20 and is also a nonutilized lamellar blade. It weighs 14.1 g and is 5.50
cm long, 3.05 cm wide, and .73 cm thick. It has a snapped base and two prominent dorsal
ridges (arrises).
150
Illinois Archaeology Vol. 19, 2007
Shatter Flake. This is a smaller shatter flake (11MG179; Feature 37-11/piece plot 1; Figure
4d) recovered from pit Feature 37. It is not utilized and weighs .7g and is .29 cm thick.
Shatter Flake. This artifact (11MG179; 900-8/backdirt; Figure 4e) was recovered from the
backdirt located near several excavated features. It is a nonutilized shatter flake weighing
only .2 g and having a thickness of .20 cm.
All of the Spoon Toe materials are derived from recent excavations carried out by ITARP
where the materials are curated. Analysis of this site is ongoing (D. Nolan, 2007 personal
communication).
X-Ray Fluorescence Laboratory Analysis and Results
Obsidian samples from the Spoon Toe (11MG179) and Barnhill’s Farmstead (11MS637) sites
(Table 1) were analyzed by the senior author using the same energy-dispersive X-ray fluorescence (EDXRF) spectrometer and analytical conditions reported in Hughes and Fortier
(1997). Laboratory analyses on specimens from the Kraske (11S41), Pool (11PK1), Irving
(11PK2) and Simpson Floodplain #1 (11R231) sites were conducted by the senior author
using a QuanX-EC™ (Thermo Electron Corporation) EDXRF spectrometer equipped with
a silver (Ag) X-ray tube, a 50 kV X-ray generator, digital pulse processor with automated
energy calibration, and a Peltier cooled solid state detector with 145 eV resolution (FWHM)
at 5.9 keV. The X-ray tube was operated at differing voltage and current settings to optimize
excitation of the elements selected for analysis. Analyses were conducted on all specimens
for the elements rubidium (Rb Kα), strontium (Sr Kα), yttrium (Y Kα), zirconium (Zr Kα),
and niobium (Nb Kα), and certain artifacts were analyzed to determine concentrations of
barium (Ba Kα), titanium (Ti Kα), manganese (Mn Kα), and total iron (Fe2O3T). Iron vs. manganese (Fe Kα/Mn Kα) ratios also were computed for some samples. In all cases, X-ray tube
current was scaled to the physical size of each specimen. Other details involving calibration
procedures, element-specific measurement resolution, and comparative literature references
appear elsewhere (Hughes 1988:257-258, 1994:265-267; Hughes and Pavesic 2005:221-222).
The analyses were completely nondestructive; sample pretreatment was limited to a simple
cleaning with distilled water to remove any possible surface contaminants.
Tables 1 and 2 present trace element data showing that nine of the 10 specimens analyzed were manufactured from volcanic glass of the Obsidian Cliff, Wyoming, geochemical
type. A single specimen, from 11R231, was fashioned from Bear Gulch, Idaho, obsidian (see
Figure 5). The artifact-to-source (chemical type) correspondences between these Illinois
artifacts and geologic obsidian parent materials are illustrated graphically by contrasts in
Y vs. Zr composition (see Figure 6). As noted elsewhere (Hughes 2007:note 2) Y/Zr ppm
measurements separate Obsidian Cliff glass from all other obsidian sources (chemical types)
identified in middle western archaeological sites, but they overlap slightly with values for
obsidians erupted in the Jemez Mountains of northern New Mexico (i.e., Obsidian Ridge
[a.k.a. Cerro Toledo Rhyolite] and Cerro del Medio [a.k.a. Valles Rhyolite]; Shackley 2005:
Tables A.4 and A.5). However, because Nb values for Obsidian Ridge material are typically
90–100 ppm and those for Obsidian Cliff range from ca. 40–45 ppm, the two are readily
distinguished from one another. Likewise, because Obsidian Cliff contains ca. 100 ppm
more Rb than does Cerro del Medio (cf. Macdonald et al. 1992:Appendix I, 148–149), these
two obsidians also are easily distinguished on the basis of mid-Z trace element contrasts
(as well as by differing Fe/Mn ratios).
78
±6
69
±6
79
±6
67
±5
11MG179,
F37-1
11MG179,
F20-10
11MG179,
F20-9
11MS637,
pp1573
19
±3
22
±3
18
±3
20
±3
21
±4
Ga
238
±4
249
±4
230
±4
246
±4
250
±5
Rb
6
±3
7
±3
6
±3
7
±3
4
±4
Sr
80
±3
78
±3
73
±3
79
±3
80
±4
Y
165
±4
168
±4
160
±4
166
±4
164
±4
Zr
36
±3
43
±3
36
±3
42
±3
44
±3
Nb
nm
nm
nm
nm
nm
Ba
471
±16
502
±17
531
±17
503
±18
514
±19
Ti
255
±11
256
±11
255
±11
244
±11
237
±11
Mn
Trace and Selected Minor Element Concentrations
1.36
±.10
1.38
±.10
1.34
±.10
1.30
±.10
1.27
±.10
Fe2O3T
All trace element values in parts per million (ppm) except total iron (expressed in weight percent composition; ± = pooled
expression (in ppm) of x-ray counting uncertainty and regression fitting error at 300 seconds livetime. nm= not measured.
83
±7
Zn
11MG179,
900-8
Cat.
Number
Obsidian Cliff, WY
Obsidian Cliff, WY
Obsidian Cliff, WY
Obsidian Cliff, WY
Obsidian Cliff, WY
Obsidian Source
(Chemical Type)
Table 1. X-ray Fluorescence Data for Obsidian Artifacts from the Spoon Toe (11MG179) and Barnhill’s Farmstead (11MS637)
Archaeological Sites in Illinois.
Hughes and Fortier
151
nm
15
nm
nm
nm
nm
11PK1,
2003.011
11PK2,
2006.013
11R231,
2006.012
RGM-1
(measured)
RGM-1
32
(recommended)
149
151
±4
171
±4
238
±4
237
±4
235
±4
239
±4
Rb
45
±3
80
±3
78
±3
78
±3
80
±3
Y
307
±4
173
±4
170
±4
168
±4
168
±4
Zr
56
±3
43
±3
43
±3
44
±3
42
±3
Nb
701
±10
0
±10
8
±10
17
±10
20
±10
Ba
nm
nm
nm
nm
nm
Ti
nm
nm
nm
nm
nm
Mn
108
104
±3
25
25
±3
219
224
±4
9
8
±3
807
803
±10
1600
nm
279
nm
U.S. Geological Survey Comparative Reference Standard
49
±3
6
±3
5
±3
5
±3
6
±3
Sr
Trace Element Concentrations
1.86
nm
nm
nm
nm
nm
nm
Fe2O3T
nr
61
52
66
62
60
67
Fe/Mn
Ratio
Glass Mtn., CA
Glass Mtn., CA
Bear Gulch, ID
Obsidian Cliff, WY
Obsidian Cliff, WY
Obsidian Cliff, WY
Obsidian Cliff, WY
Obsidian Source
(Chemical Type)
Values are given in parts per million (ppm) except total iron (which is express in weight percentage composition and Fe/Mn intensity ratios; ± = X-ray counting
uncertainty and regression fitting error at 120–360 seconds livetime. nm = not measured. nr = not reported.
nm
nm
nm
nm
nm
11S41,
2006.011
nm
Ga
nm
Zn
11S41,
2003.011
Cat.
Number
Table 2. X-ray Fluorescence Data for Obsidian Artifacts from the Kraske (11S41), Pool (11PK1), Irving (11PK2) and Simpson #1
(11-R-231) Archaeological Sites in Illinois.
152
Illinois Archaeology Vol. 19, 2007
Hughes and Fortier
153
Big Southern
Butte
Figure 5. General location of obsidian sources in the Rocky Mountains
and vicinity.
Summary and Concluding Comments
Just as volcanic glass from Obsidian Cliff is the preponderant chemical type identified
archaeologically in adjacent areas of the middle and upper Midwest (Anderson et al. 1986;
Griffin et al. 1969; Hughes 2006, 2007), results of this research provide additional support
for the results of our earlier study at sites in the American Bottom (Hughes and Fortier
1997) wherein Obsidian Cliff volcanic glass was the most frequent obsidian encountered.
Although the number of artifacts analyzed in that pilot study was quite small, the sourcespecific results are remarkably similar to those generated here. In the present case, nine of
Illinois Archaeology Vol. 19, 2007
154
300
Big Southern Butte
250
Y (ppm)
200
150
100
Bear Gulch
Malad
50
Obsidian Cliff
Teton Pass
0
0
50
100
150
200
250
300
350
Zr (ppm)
Figure 6. Y vs. Zr composition of obsidian artifacts from Illinois archaeological sites.
Data from Tables 1 and 2 herein. Open triangles represent values for artifacts, while dashed lined demarcate
the range of variation measured in geological obsidian reference samples (from Hughes 1984: Table 3; 1995;
Hughes and Nelson 1987: Table 1; Nelson 1984: Table 5, source # 38; Macdonald et al. 1992: Appendix I, p.
142). The numbers of plots do not correspond exactly to the numbers in the tables because of convergence in
data points at this scale.
the 10 samples analyzed were manufactured from Obsidian Cliff material, with a single
artifact (sample 2006.012 from 11R231) made from Bear Gulch, Idaho, obsidian. At the risk
of imbuing this latter specimen with too much significance, it is worth noting that regardless of whether one subscribes to the notion that it is an effigy, it is clearly a formed tool. As
such, its presence conforms to findings in the American Bottom and several Middle Woodland Hopewellian sites (Hughes 2006) that, to date, Bear Gulch obsidian debitage is rare
or altogether absent. The sample analyzed from the Simpson Floodplain #1 site represents
only the second documented occurrence of Bear Gulch obsidian in the American Bottom
(Hughes and Fortier 1997:88). Furthermore, if sustained by ongoing analysis of the overall
site assemblage, the Early Woodland age assignment for the specimen from Barnhill’s Farmstead (11MS637) would provide the first evidence for the use of Obsidian Cliff obsidian in
the American Bottom during this time period. Because all obsidian samples analyzed from
stratified, C14-dated Early Woodland contexts at the Tillmont (47CR460) site in Wisconsin
were made from Obsidian Cliff volcanic glass (Stoltman and Hughes 2004), the presence
of this obsidian in both Early Woodland and Middle Woodland contexts indicates a more
complex pattern of acquisition and conveyance in the Midwest than previously proposed.
The obsidian from the Tillmont site in Wisconsin is associated with the Indian Isle component, a variant of the Early Woodland Marion culture. The Barnhill’s Farmstead artifact was
recovered from a sealed midden with only Black Sand pottery and contracting-stemmed
Hughes and Fortier
155
projectile points, suggesting that two otherwise distinct Early Woodland groups apparently
had access to the same obsidian. In addition, this complex pattern of acquisition during the
Early Woodland period is further supported by a block of Obsidian Cliff obsidian found
with a burial at the Riverside site in Michigan that is associated with the Early Woodland
Red Ochre culture, a third distinct group within this period (Pleger 1998, 2000; Stoltman
and Hughes 2004). Taken together, these data provide additional support for the view that,
contra Griffin (1965:146), the initial arrival of obsidian in the Midwest predates Hopewell
by several centuries.
Acknowledgments
We would like to thank Dr. Thomas E. Emerson, program director of the Illinois Transportation Archaeological Research Program (ITARP), for funding this obsidian-sourcing project
and, as editor of this journal, for promoting timely publication of the results. Thanks are
also due to the Spurlock Museum at the University of Illinois at Urbana-Champaign for
the loan of one of the obsidian specimens from the Irving site, and to Laura Kozuch, curator at ITARP, for expediting the loan arrangement and tracking down various artifacts in
ITARP’s curation facility in Champaign. Brad Koldehoff was very helpful in providing
additional obsidian artifacts from the Kraske and Simpson Floodplain #1 sites that were in
private collections in southern Illinois. The Simpson Floodplain #1 artifact belongs to the
local landowner, Ms. Margie Erb, and was brought to our attention by Brad Koldehoff, who
acquired the artifact on loan to ITARP so that we could obtain metric attributes as well as
an illustration and photograph. The two Kraske items analyzed here were collected by Mr.
Dean Burke, who made them known to Brad Koldehoff. ITARP received both pieces on loan
and took measurements and illustrations before submitting the samples for analyses. We
would like to thank Ms. Margie Erb and Mr. Dean Burke for entrusting the authors with
these artifacts. Dave Nolan provided additional, as yet unanalyzed, specimens from the
Spoon Toe site in western Illinois. We also thank Linda Alexander of ITARP for illustrations
of the individual artifacts and Mike Farkas of ITARP for the production of Figure 1. Maps
and illustrations created by ITARP are used with that organization’s permission. Finally, we
thank Anne Rogers for editing the manuscript and very much appreciate the substantive
comments and suggestions from Kenneth Farnsworth and Thomas Emerson.
References Cited
Anderson, Duane C., Joseph A. Tiffany, and Fred W. Nelson
1986 Recent Research on Obsidian from Iowa Archaeological Sites. American Antiquity
51:837–852.
Farnsworth, Kenneth B.
2006 Introduction. Gregory Perino’s Archaeological Career and Illinois Site Excavations. In Illinois Hopewell and Late Woodland Mounds: The Excavations of Gregory
Perino 1950–1975, edited by Kenneth B. Farnsworth and Michael D. Wiant, pp.
1–98. Studies in Archaeology No. 4. Illinois Transportation Archaeological Research Program, University of Illinois at Urbana-Champaign.
156
Illinois Archaeology Vol. 19, 2007
Fortier, Andrew C., Thomas E. Emerson, and Dale L. McElrath
2006 Calibrating and Reassessing American Bottom Culture History. Southeastern
Archaeology 25:170–211.
Griffin, James B.
1965 Hopewell and the Dark Black Glass. In Papers in Honor of Emerson E. Greenman, edited by James A. Fitting, pp. 115–155. Michigan Archaeologist 11(3-4).
Griffin, James B., Adon A. Gordus, and Gary A. Wright
1969 Identification of the Sources of Hopewellian Obsidian in the Middle West. American Antiquity 34:1–14.
Hughes, Richard E.
1988 The Coso Volcanic Field Reexamined: Implications for Obsidian Sourcing and
Hydration Dating Research. Geoarchaeology 3:253–265.
1994 Intrasource Chemical Variability of Artefact-Quality Obsidians from the Casa
Diablo Area, California. Journal of Archaeological Science 21:263–271.
1995 X-Ray Fluorescence Analysis of Geologic Obsidian Samples from Yellowstone and Grand
Teton National Parks, Wyoming. Geochemical Research Laboratory Letter Report
95-8. Geochemical Research Laboratory, Portola Valley, CA.
2006 The Sources of Hopewell Obsidian: Forty Years After Griffin. In Recreating
Hopewell, edited by Douglas K. Charles and Jane E. Buikstra, pp. 361–375. University Press of Florida, Gainesville.
2007 The Geologic Sources for Obsidian Artifacts from Minnesota Archaeological Sites.
Minnesota Archaeologist 66:53-68.
Hughes, Richard E., and Andrew C. Fortier
1997 Identification of the Geologic Sources of Obsidian Artifacts from Three Middle
Woodland Sites in the American Bottom, Illinois. Illinois Archaeology 9:79–92.
Hughes, Richard E., and Fred W. Nelson
1987 New Findings on Obsidian Source Utilization in Iowa. Plains Anthropologist 32:
313–316.
Hughes, Richard E., and Max G. Pavesic
2005 Proximity and Provenance: A Lesson from the Sterling Cache, Idaho. Journal of
California and Great Basin Anthropology 25:221–225.
Iddings, Joseph P.
1888 Obsidian Cliff, Yellowstone National Park. In Seventh Annual Report of the U.S.
Geological Survey for 1885–1886, pp. 249–295. Government Printing Office. Washington, D.C.
Macdonald, Ray, Robert L. Smith, and John E. Thomas
1992 Chemistry of the Subalkaline Silicic Obsidians. U.S. Geological Survey Professional
Paper 1523. Government Printing Office, Washington D.C.
McGregor, John C.
1958 The Pool and Irving Villages: A Study of Hopewell Occupation in the Illinois River
Valley. University of Illinois Press, Urbana.
Nelson Fred W., Jr.
1984 X-ray Fluorescence Analysis of Some Western North American Obsidians. In
Obsidian Studies in the Great Basin, edited by Richard E. Hughes, pp. 27–62. Contributions of the University of California Archaeological Research Facility No.
45.
Hughes and Fortier
157
Perino, Gregory
2006 Illinois Hopewell and Late Woodland Mounds: The Excavations of Gregory Perino
1950–1975. Studies in Archaeology No. 4. Illinois Transportation Archaeological
Research Program, University of Illinois at Urbana-Champaign.
Perkins, Raymond W.
1965 The Frederick Site. In Middle Woodland Sites in Illinois, edited by Elaine Bluhm
Herold, pp. 68–95. Illinois Archaeological Survey Bulletin No. 5. University of
Illinois at Urbana-Champaign.
Pleger, Thomas C.
1998 Social Complexity, Trade, and Subsistence during the Archaic/Woodland Transition in the Western Great Lakes (4000–400 B.C.): A Diachronic Study of Copper
Using Cultures at the Oconto and Riverside Cemeteries. Ph.D. dissertation,
Department of Anthropology, University of Wisconsin–Madison. University
Microfilms, Ann Arbor, Michigan.
2000 Old Copper and Red Ochre Social Complexity. Midcontinental Journal of Archaeology 25:169–190.
Porter, James W., and Jean R. Linder
1974 An Archaeological Survey of the Mississippi Valley in St. Clair, Monroe, and
Randolph Counties. In Preliminary Report of 1973 Historic Sites Survey Archaeological Reconnaissance of Selected Areas in the State of Illinois, Part I, Summary Section A,
pp. 28–32. Illinois Archaeological Survey, Urbana.
Shackley, M. Steven
2005 Obsidian: Geology and Archaeology in the North American Southwest. University of
Arizona Press, Tucson.
Stoltman, James B., and Richard E. Hughes
2004 Obsidian in Early Woodland Contexts in the Upper Mississippi Valley. American
Antiquity 69:751–759.
Wiant, Michael D., and Charles R. McGimsey
1986 The Middle Woodland Lithic Assemblage: Summary and Interpretation. In
Woodland Period Occupations of the Napoleon Hollow Site in the Lower Illinois Valley,
edited by Michael D. Wiant and Charles R. McGimsey, pp. 330–363. Kampsville
Archeological Center Research Series Vol. 6. Center for American Archeology,
Kampsville, Illinois.