Trace Element Analysis of Obsidian Artifacts from the Andes

94 Pages·2010·5.89 MB·English

UC Berkeley
Archaeological X-ray Fluorescence Reports
Title
Trace Element Analysis of Obsidian Artifacts from the Andes: New Perspectives on Pre-
Hispanic Economic Interaction in Peru and Bolivia
Permalink
https://escholarship.org/uc/item/2kr0k9c1
Authors
Burger, Richard L.
Asaro, Frank
Publication Date
1977-06-01
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University of California
n
Trace Element Analysis Of Obsidian Artifacts
From The Andes: New Perspectives On Pre
Hispanic Economic Interaction In Peru
And Bolivia
Richard Burger and Frank Asaro
June 1977
it f Ie
U. S IEnergy Research and Development Administration under Contract No. W-7405-IENG-48
he tn 'Revista del Museo Peru
SIS
on
in
LE
I on
0
lysis 2
Neu Acti vat ion is 6
X-Ray Fluorescence (Rapid Scan XRF, U.C. Berkeley) 9
X-Ray Fluorescence (LBL) .. 10
Obsidian Use ..... 13
0' ••
Quispisisa Source 18
Ayacucho Type Obsidian 30
Acari e Obsidian 30
Type Obsidian. 31
as A Type i di an 32
Andahuaylas B Type Obsidian 33
CUlCO Type Obsidian 33
Titicaca Basin Type Obsidian. 37
Rare Unique Types of Obsidian 39
Models of Distribution Mechanisms 40
Discussion .... 43
edgments. 49
.........r '''''''''''
50
les 54
0 •
x
Bibl;
i
Li Fires
Fi 10 i si ic
in is
Fi 2. c on of at the Department
of Geol iversi of California, Berkel This initial
study usi on Sr, Rb and was unable distinguish
between of the principal types of obsidian. The graph
demonstrates the way in which the Pampas Type and Andahuaylas
B Type were lumped in cluster A ile the Quispisisa Source,
CUICO Type, the Andahuaylas A Type, and the rare Tum.Jku
were all incl in clu B. This confusion
made it necessary to seek the more isticated
techniques loyed at the Lawrence Ber ley Laboratory,
the res ts of ich are seen in Tables 1 and and in
2~
the Append i x.
L st les
le tions iations
neu ion at t
or
le it ions
neu ion t Lawrence L
rare
Table 2. Selected trace el ition of dean obs i dian:
x-ray uorescence anal is made Lawrence keley
(i n p i 11 i on) .
3. i dian ana 1 x fluorescence
iorL
le 4. excavations
ical P
Table 5. i di an excavat ions at site ka
i nce,
Table 6. i di an ions two sis in
in.
v
TRACE ELEMENT SIS ARTIFACTS FROM
New Perspectives on spanic Economic In ion
in Peru and Bolivia
Ric L. Burger Frank aro
INTRODUCTION
This article is an introduction to the study of the distribution
by trade of obsidian artifacts in ancient Peru and Bolivia. Obsidian
tools were used as early as Preceramic times and continued to be popular
through the Middle Horizon. The techniques of neutron activation
analysis (NAA) and x-ray fluorescence (XRF) were used to identify
eight main types of obsidian and to infer the locations of the natural
obsidian sources. These in conjunction with the findings of
data~
the archaeological research, have been used to make observations on
the changing patterns of regional and pan-regional economic interaction.
The data are discussed in context of the role of obsidian in ancient
Andean society and the social mechanisms by which this rare material
was distributed.
Obsidian, a natural glass, has a hardness of 5.5 on the Moh scale
(slightly harder than window glass) and is similar in chemical (but
not structural) composition to granite. It is formed during volcanic
activity by the cooling of viscuous lava rich in silica (over 65%)
at a rate slow enough to allow volatiles to escape, but rapid enough
to prevent crystallization. Because crystallization does not occur,
obsidian a vitreous luster and the abili to produce conchoidal
fractures struck. is fracturi characteristic is one its
most i ortant qualities, p s all
stone artifacts idian amen le to precision chi
idian sui le on of ifac mu come
ions usual iary or because
~
9
it is e tr fies over time~ los; qualities
is val ver, even some recent obsidian
f 1o ~"s suitable ippi ause tors s
as the presence phenocrysts, spherical or hydration
aggregates~
groundwater. although obsidian has great potential for
~
use in tools, it occurs rarely~ if at all, in most areas.1 In the
s, obs i dian de its exist in the highlands of Ecuador9
2
tra 1 sou Peru, 1i a.
SIS
re1 ive scarci obsidian suit le tools resul
in obsidian over long distances. Archaeologists interested
in anc i trade communication have ac ter is t 'i c s
idian useful in reconstructing these movements. Obsidian from
ical sites can matched th natural obsidian sources
use ical fi ; nt i methods.
visual qualities of obsidian are rarely of use
in distin d; idian sources. Bl , gray, c ear,
sidian can all occur in a single
is misl arc is
co ir idian collections
us; sua lities. 3
on can, h and ld ; dian
s at t most tive met d i in sh d
2
sources is ana el
el is one
1i c t on is
t idian comi one source
trace e 1 ition as
fingerpri le source
must be 'small in ison di
sources. These as ions been ri
Asaro and (1 a & b). Their i di an
9 9
sources can is is case ( as n
the single i dian source in lifornia)~ vari ion
is extraord nari removes icul
in ifi vari ion in source's el
composition. itional
ven i ence ana is less d
of or ceramics. ies
of quartzite statues n t i a 1 tional
variation in a s gle qu source izer et al.,
contra th i dian, on al
source i 1 as
sources.
sources. ience
q
s ld le measure d el tech-·
niques u wi some success. are activation
ana is x fluorescence ical 4
in arc ies sidian
ven ience s varied consi is has imes resulted
in mistaken identifications and inability to distingui between sources.
The accurate measurements published thus far have been made by
Perlman, Asaro, and others using NAA.
Ideally, provenience studies of obsidian should begin with analysis
of several samples taken from all possible sources which might have
been used in iqui unate ,in the Central Andes the st
little ion. sidian
use was n time ish is tor' i c
gives no clues for the location of idian sources.
Therefore~
ne geologists nor archaeologists have a useful to location
of obsidian sources. Because of is, it has been necessary work
in the os i te d i rec t ion.
is study, obsidian at 94 archaeol cal sites
in Bolivia was analyzed to determine its trace element com-
itions. These determinations were used to identi the di
i dian u i di an s a
di inctive geochemi intI! ich corresponds to an ivi al
source raw i dian. the exact source ions are ssi
in one case~ it t each i di an was
thin circumscri ical a~"ea . is 1y 3
ies Old ld ans s most i ve use
4