Archaeological Chemistry

6 Correlation between Terra Cotta Figurines and Pottery from the Valley of Mexico and Downloaded by UNIV OF CALIFORNIA SAN DIEGO on January 25, 2017 | http://pubs.acs.org Publication Date: June 1, 1974 | doi: 10.1021/ba-1974-0138.ch006

Source Clays by Activation Analysis R. ABASCAL-M. Instituto Nacional de Antropologia e Historia, Mexico D.F. G. HARBOTTLE

and Ε. V. SAYRE

Brookhaven National Laboratory, Upton, Ν. Y. 11973

Activation analysis of selected groups of sherds of typically Oaxacan and Teotihuacan ceramics has shed some light on the question of the Oaxacan presence at Teotihuacan and the related concept of long-distance trade between the two centers during early Classic times. Studies of Preclassic "Tlatilco" figurines reveal them to have been locally manufactured.

' T ' h e a p p l i c a t i o n o f n e u t r o n a c t i v a t i o n analysis t o t h e s t u d y of archaeo* ·• l o g i c a l ceramics is n o w w e l l e s t a b l i s h e d (1, 2, 3).

H e r e w e report

o u r present m e t h o d o f o p e r a t i o n , i n c l u d i n g t e c h n i q u e s o f d a t a p r o c e s s i n g and taxonomy

a n d some results o b t a i n e d

i n studying

archaeological

m a t e r i a l f r o m t h e P r e c o l u m b i a n V a l l e y o f M e x i c o a n d t h e O a x a c a n area. U n d e r the r u b r i c " V a l l e y of M e x i c o " w e discuss o u r w o r k o n t w o d i s t i n c t a r c h a e o l o g i c a l p r o b l e m s : first, a s t u d y of O a x a c a n - s t y l e p o t t e r y f o u n d i n the O a x a c a n b a r r i o o r s u b u r b o f T e o t i h u a c a n , a n d secondly, t h e p r o b a b l e o r i g i n o f the w e l l k n o w n preclassic t e r r a cotta figurines u n e a r t h e d i n t h e burial ground of Tlatilco. T h e first p r o b l e m w a s p o s e d to us b y E v e l y n C . R a t t r a y , w h o also s u p p l i e d t h e r e l e v a n t sherds a n d c l a y samples.

I n o n e section o f T e o t i

h u a c a n , so m a n y sherds of O a x a c a n - s t y l e p o t t e r y h a v e b e e n f o u n d that archaeologists h a v e c o m e to r e g a r d the s u b u r b o r b a r r i o as a p o s s i b l e site o f O a x a c a n o c c u p a t i o n (4).

I n a s m u c h as t h e h o m e o f O a x a c a n p o t

tery is l o c a t e d i n t h e M o n t e A l b a n r e g i o n some 400 k m s o u t h o f T e o t i 81 Beck; Archaeological Chemistry Advances in Chemistry; American Chemical Society: Washington, DC, 1974.

82

ARCHAEOLOGICAL CHEMISTRY

h u a c a n , across m o u n t a i n s a n d desert, i t is a q u e s t i o n of

considerable

interest to l e a r n w h e t h e r the O a x a c a n - s t y l e pieces f o u n d i n T e o t i h u a c a n w e r e m a n u f a c t u r e d i n O a x a c a a n d t r a n s p o r t e d b y h u m a n carriers over this great distance, or w h e t h e r t h e y w e r e s i m p l y p r o d u c e d i n T e o t i h u a c a n out of l o c a l clays b u t i n O a x a c a n style. C l e a r l y the a r c h a e o l o g i c a l i m p l i cations of t h e t w o p o s s i b i l i t i e s are q u i t e different, i n v o l v i n g questions of

Downloaded by UNIV OF CALIFORNIA SAN DIEGO on January 25, 2017 | http://pubs.acs.org Publication Date: June 1, 1974 | doi: 10.1021/ba-1974-0138.ch006

c u l t u r a l contact a n d l o n g - d i s t a n c e t r a d e .

Figure

1.

Teotihuacan

provenance:

typical

Teotihuacan

sherds

BNL No.

Rattray No.

Stratigraphy

Description

7-1 1-2 1-9 1-10 1-3 1-4 1-6 1-7 1-8 1-37

Teo. 5 4868 Ν 5045 Ρ 5045 R 4944 Τ 4946 Ν 4958 Q 4981 Μ 4990 S 5023 0

Surface layer 1 layer 3 layer 3 layer 3 layer 4 layer 5 layer 11 layer 11 layer 14

red on yellow basin (salt and pepper paste) olla rim comal red-orange olla body pol. hi. outcurving bowl San Martin orange amphora S MO crater, pocked base polished hi. br. outcurving red rim basin pol. br. bl. simple bowl

T h e actual provenance graphic pit (designated

of the O a x a c a n - s t y l e sherds was a s t r a t i -

N18W1)

excavated

by Rattray in a building

( S i t e 7 ) l o c a t e d i n g r i d square N 1 W 6 o n the M i l l o n m a p of T e o t i h u a c a n (5).

T h e p e r i o d is w i t h i n the classic T l a m i m i l o l p a n a n d X o l a l p a n phases,

r o u g h l y 350 to 600 A . D . T o p r o v i d e a reference g r o u p representative of T e o t i h u a c a n a set of t y p i c a l T e o t i h u a c a n - s t y l e sherds w e r e t a k e n f r o m t h e same p r o v e n a n c e .

A g r o u p of five sherds of a O a x a c a - T e o t i h u a c a n

h y b r i d style was also c o l l e c t e d b y R a t t r a y f r o m t h e same p i t , N 1 8 W 1 . T h e l o c a l c l a y chosen was that u s e d b y the p r e s e n t - d a y S a n S e b a s t i a n

Beck; Archaeological Chemistry Advances in Chemistry; American Chemical Society: Washington, DC, 1974.

6.

ABASCAL-M.

E T

Activation

AL.

Analysis

of Mexican

83

Ceramics

T e o t i h u a c a n potters, l o c a t e d i n t h e s o u t h e r n p a r t of the a n c i e n t c i t y o n g r i d s q u a r e S 2 E 1 of t h e M i l l o n m a p . T h e g e n u i n e O a x a c a n sherds t a k e n for c o m p a r i s o n w e r e surface collections f r o m t w o sites, C a b a l l i t o B l a n c o a n d D a i n Z u ( M a c u i l x o c h i t l ), l o c a t e d 40 a n d 22 k m ( r e s p e c t i v e l y ) s o u t h east of O a x a c a w h i l e the c l a y was f r o m t h e source b e i n g u s e d t o d a y b y the famous potter R o s a of C o y o t e p e c , a b o u t 12 k m south of O a x a c a . W e also r e p o r t o n another g r o u p of sherds, of fine orange paste f r o m


Lambityeco

(Oaxaca)

s u p p l i e d b y J o h n P a d d o c k of the I n s t i t u t o de

E s t u d i o s O a x a q u e n o s , a n d finally a s h e r d of postclassic M i x t e c a — P u e b l a p o l y c h r o m e , s u p p l i e d b y I g n a c i o B e r n a i of the I N A H ( M e x i c o ) , of p r o v e n a n c e Y a g u l , a site close to C a b a l l i t o B l a n c o i n O a x a c a ( β ) .

Photographs

of a l l the sherds a n a l y z e d are s h o w n i n F i g u r e s 1 t h r o u g h 5.

BNL No.

Figure 2.

Teotihuacan

Rattray No.

Stratigraphy

1-12 1-13 1-14 1-15 1-16 1-17

4944 4946 4949 4957 4950 4966

1-18 1-19 1-20

4974 F 4978 I 5042

Η Κ } Ε

layer hyer layer layer layer layer

3b 4 4b 4b 4c 6

hyer 9-10 layer 10 layer 11

provenance: Oaxacan-type

sherds

Description G 12, double line groove inside rim G 21, parallel incised lines inside bottom G 1, apaxtle G 1, apaxtle — perforated sieve or censer G 12, double line incising, inside rim, pol. gray — dense gray, pol. G 21, coarse incising, interior base G 21, wave-like incising, interior base

T h e second p r o b l e m concerns the analysis of six t e r r a cotta f r o m the site of T l a t i l c o .

figurines

T l a t i l c o , a s u b u r b of M e x i c o C i t y , has b e e n

d e s c r i b e d b y P i n a C h a n ( 7 ) i n these t e r m s : " D e todos los p u e b l o s p r e clâsicos d e l v a l l e de M e x i c o q u e h a s t a a h o r a se conocen, T l a t i l c o fué e l


84


mas c o s m o p o l i t a , e l mas n u m e r o s o

e l mas d e s a r r o l l a d o c r o n o l o g i c a

y

c u l t u r a l m e n t e . " A l t h o u g h its i m p o r t a n c e has l o n g b e e n e v i d e n t , B e r n a i (8)

r e m i n d s us t h a t " T l a t i l c o does not represent a c i t y " b u t was rather

" p r i m a r i l y a c e m e t e r y , " t h o u g h i n h a b i t e d . T h e r e is no e v i d e n c e of m o n u m e n t a l s c u l p t u r e or a r c h i t e c t u r e ; o n the c o n t r a r y its interest to a r c h a e ologists derives f r o m the great w e a l t h of s m a l l objects, c e r a m i c fragments, jade ornaments, " y u g u i t o s , " a n d a b o v e a l l ,

figurines.

These

figurines,


almost a l l r e p r e s e n t i n g w o m e n w i t h short a r m s , h e a v y legs, a n d b r o a d h i p s , are t r u l y r e m a r k a b l e i n t h e i r v a r i e t y a n d a n i m a t i o n . M a n y w e a r short skirts a n d some b e a r traces of r e d p i g m e n t , e s p e c i a l l y o n the h a i r .

Figure

3.

Teotihuacan

BNL No.

Rattray No.

1-22

4932 Ε

1-23 1-24 1-25 1-26

4945 4950 4958 4981

Bernai (6)

Β D C A

provenance:

Oaxaca-Teotihuacan

hybrids

Stratigraphy

Description

foyer 1 (N19W2) foyer 3c foyer 4c layer 5 layer 11

G 21, coarse incising on interior G 1, apaxtle brown sieve, matte finish — polished brown comal? G 21, gray-brown, incised base

has d e s c r i b e d t h e e x t r a o r d i n a r i l y close s t y l i s t i c r e l a t i o n

s h i p of some of these

figurines

to those of t h e O l m e c c u l t u r e i n the

m e t r o p o l i t a n O l m e c z o n e a l o n g the G u l f C o a s t : " c h a r a c t e r i s t i c O l m e c types are as fine a n d b e u t i f u l i n T l a t i l c o as are t h e i r c o u n t e r p a r t s i n L a V e n t a . A t times t h e y are so s i m i l a r t h a t i t w o u l d not be possible to t e l l t h e i r p r o v e n a n c e h a d t h e y not b e e n f o u n d d u r i n g e x p l o r a t i o n s . " T h e q u e s t i o n of these stylistic r e l a t i o n s h i p s a n d , m o r e g e n e r a l l y , of t r a d e d u r i n g O l m e c {i.e., 1300-400 B . C . ) times is one of c r u c i a l i m p o r tance to the correct

f o r m u l a t i o n of the w h o l e

c o n c e p t of a n

Olmec

presence, e m p i r e , or influence i n M e s o a m e r i c a . F o r e x a m p l e , T o l s t o y a n d P a r a d i s ( 9 ) , i n d e s c r i b i n g t h e i r most recent w o r k i n the V a l l e y of M e x i c o , state that "this ( O l m e c ) presence

has b e e n l i n k e d to trade b y

many

( C o e , F l a n n e r y , G r o v e , a n d J i m e n e z M o r e n o ) , t h o u g h the p r o d u c t s ex-



6.

ABASCAL-M.

E T

Activation

A L .

Figure 4. BNL No. 7-32 7-33 1-34 1-35 F-121 F-122 F-123 F-126 F-129

F-130 F-131 F-132 F-134 F-135

Rattray No.

Analysis of Mexican

Oaxacan provenance:

Stratigraphy

matching

Ceramics

85

group

Description

dense grey, polished grey slip brown matte basin, scraped exterior polished grey bowl, parallel G 12 Dain Zu incised lines matte grey, incised base G 21 Dain Zu barrel-shaped(P) vase, resist Lambityeco decor, Md. 195 Cut S-4 same, incised same, surface Β polished both sides, red-brown same, Ν-11 outside, buff inside Lambityeco S-8 Md. Cajete, brown rim on orange Rim> tecomate-like, incised line same, S-10 Md. on ext. rim, highly polished outside, near-black zone around rim Lambityeco rim, hemis. Cajete, type A-7 in Caso, Bernai, Acosta "La bag 6060 Cerarnica de Monte Alban" same, bag 6112 same Lambityeco flattened rim sherd, a fragment of object 6195(?) Lambityeco hemis. Cajete, incised-excised, traces of stucco obj. 7444 Lambityeco frag, bat claw vessel, A-7 object 5914

G 3 Caballitol Blanco Κ 17 Dain Zu

c h a n g e d b e t w e e n p a r t i c u l a r c o m m u n i t i e s c a n n o t a l w a y s be specified w i t h any confidence."

T h e y discuss not o n l y t h e possibilities of t r a d e

b e t w e e n the p e o p l e of the O l m e c presence i n the V a l l e y of M e x i c o a n d the G u l f C o a s t b u t of cross-tie i n t e r r e l a t i o n s h i p s a m o n g the different p r e c l a s s i c sites w i t h i n t h e V a l l e y of M e x i c o — i . e . , T l a t i l c o , T l a p a c o y a ,


86


Zacatenco,

E l A r b o l i l l o , as e v i d e n c e d

by

the m a t e r i a l f o u n d

i n the

s t r a t i g r a p h i c a l l y c o r r e s p o n d i n g layers i n these sites. It s e e m e d to us that the w h o l e p r o b l e m of O l m e c t r a d e a n d the i n t e r r e l a t i o n s h i p of the preclassic sites i n M e s o a m e r i c a offered

an u n

u s u a l l y f a v o r a b l e case for the m e t h o d of g r o u p i n g via p a s t e - c o m p o s i t i o n a l patterns b a s e d o n n e u t r o n a c t i v a t i o n analysis. A s a start o n this p r o g r a m w e i n c l u d e here the analysis of six p r e c l a s s i c T l a t i l c o figurines, a n d w e


c o m p a r e t h e i r analyses w i t h those of t w o m o d e r n specimens a n d t o u c h u p o n the a r c h a e o l o g i c a l conclusions possible. Experimental Analytical Procedures. T h e c e r a m i c b o d y is s a m p l e d as f o l l o w s . F i r s t a fresh surface is p r e p a r e d b y r e m o v i n g w i t h a t u n g s t e n - c a r b i d e b u r r a t h i n l a y e r of the e x i s t i n g surface a l o n g w i t h its d i r t , s l i p , a n d i n some cases w e a t h e r e d or e r o d e d m a t e r i a l . T h e n a t u n g s t e n - c a r b i d e d r i l l is u s e d to d r i l l i n t o the s h e r d a l o n g lines p a r a l l e l to the surfaces, a n d a s a m p l e of a b o u t 1 0 0 - 2 0 0 m g is r e m o v e d . W i t h sherds too t h i n to d r i l l , samples are r e m o v e d f r o m a fresh surface b y f u r t h e r a p p l i c a t i o n of the tungsten—carbide b u r r . C l a y specimens are not o n l y a n a l y z e d as r e c e i v e d b u t fine fractions are s e p a r a t e d f r o m t h e m for a d d i t i o n a l c o m p a r a t i v e analysis. S a m p l e s ( a n d s t a n d a r d s ) are o v e n - d r i e d at 6 5 ° - 7 0 ° C before use. S a m p l e s of 40 m g e a c h are sealed into u l t r a h i g h p u r i t y S u p r a s i l T - 2 0 f u s e d q u a r t z a m p o u l e s ( U . S . F u s e d Q u a r t z C o . , F a i r f i e l d , N . J.) for i r r a d i a t i o n i n the n u c l e a r reactor.

Figure

5. Non-matching sherds: descriptions given in Table Two modern sherds from San Sebastian Teotihuacan.

III.

I n a l l of o u r w o r k w e u s e d as standards the six U . S . G e o l o g i c a l S u r v e y s t a n d a r d rocks d e s i g n a t e d A G V - 1 , B C R - 1 , D T S - 1 , P C C - 1 , G S P - 1 , a n d G - 2 (10, 11). W e i g h e d samples of a l l six, p r e p a r e d a n d p a c k a g e d i n the



6.

ABASCAL-M.

E T

Activation

AL.

Analysis

of Mexican

Ceramics

87

same f a s h i o n as the c e r a m i c s , are i n c l u d e d w i t h e a c h set of 2 0 - 3 0 samples a n d share the t o t a l b o m b a r d m e n t h i s t o r y of t h a t set. T h e s e s t a n d a r d rocks w e r e a n a l y z e d b y m a n y laboratories for the m a n y elements present i n b o t h s u b s t a n t i a l a n d trace a m o u n t s , a n d the results are r e p o r t e d b y F l a n a g a n (10, 11). A l t h o u g h F l a n a g a n also tabulates the best values, w e p r e p a r e d o u r o w n t a b l e , e l i m i n a t i n g excessively d e v i a n t values b y a p p l y i n g C h a u v e n e t ' s c r i t e r i o n to F l a n a g a n ' s t a b u l a t i o n of o r i g i n a l d a t a . O u r s t a n d a r d t a b l e is p r e s e n t e d here as T a b l e I. M o s t of o u r n e u t r o n i r r a d i a t i o n s w e r e d o n e i n the B r o o k h a v e n H i g h F l u x B e a m reactor. B a s i c a l l y , t w o i r r a d i a t i o n s w e r e m a d e — a short one (0.5-3 m i n at 1 Χ 1 0 n e u t r o n s / c m sec) a n d a l o n g one ( t y p i c a l l y 3.5 h r at 5 Χ 1 0 n e u t r o n s / c m s e c ) . A f t e r t h e short b o m b a r d m e n t , w e c o u n t e d s h o r t - l i v e d radioisotopes of manganese, s o d i u m , p o t a s s i u m , a n d l a n t h a n u m w h i l e the l o n g b o m b a r d m e n t served for the r e m a i n d e r (see T a b l e s I I - I V ) . I n some instances the l o n g b o m b a r d m e n t w a s d o n e first. T h e n , after 8 - 1 1 days d e c a y , the same samples w e r e r e a c t i v a t e d b y a short b o m b a r d m e n t . T h e y w e r e t h e n i m m e d i a t e l y c o u n t e d for manganese alone ( c o u n t times of 200 s e c / s a m p l e suffice), a n d after it h a d d i e d , a longer c o u n t (4000 sec) for a l l r e m a i n i n g isotopes was t a k e n . Samples w e r e c o u n t e d w i t h a 7 % (ca. 3 5 - 4 0 m l ) l i t h i u m - d r i f t e d g e r m a n i u m c o u n t e r ( P r i n c e t o n G a m m a t e c h ) h a v i n g a r e s o l u t i o n of 1.82 k e V o n cobalt-60, c o u p l e d to a 4 0 9 6 - c h a n n e l N u c l e a r D a t a 2400 p u l s e h e i g h t a n a l y z e r . T h e use of six d i s t i n c t l y different r o c k standards i n each b o m b a r d m e n t a n d the statistical c o m p a r i s o n of the c a l i b r a t i o n constants d e r i v e d for t h e m constitute a rigorous test of the p r e c i s i o n of the e l e m e n t a l determinations. D a t a H a n d l i n g . I n p r e v i o u s studies w h e r e sufficient d a t a w e r e a v a i l 14

2

14

2

a b l e to p e r m i t a p r o p e r s t a t i s t i c a l analysis of t h e n a t u r e of the d i s t r i b u t i o n of the e l e m e n t a l concentrations i n r e l a t e d groups of specimens, w e h a v e f o u n d o u r d a t a to b e l o g a r i t h m i c a l l y d i s t r i b u t e d . T h a t is, plots of f r e quency

of o c c u r r e n c e

vs.

l o g of

concentrations

closely

approximated

n o r m a l d i s t r i b u t i o n curves. T h e use of l o g concentrations also a l l o w s one to g i v e e q u a l w e i g h t to a g i v e n f r a c t i o n a l change, i n d e p e n d e n t of the absolute v a l u e of the c o n c e n t r a t i o n r a n g e i n v o l v e d . I n m o r e extensive studies w e are n o w a p p l y i n g true m u l t i v a r i a t e statistical p r o c e d u r e s , s u c h as c l u s t e r i n g a n d g r o u p d i s c r i m i n a t i o n b a s e d o n g e n e r a l i z e d M a h a l a n o b i s distances

(12,

13).

S i n c e , i n the studies

r e p o r t e d here, w e h a d a n insufficient n u m b e r of specimens w i t h i n e a c h g r o u p to a p p l y these p r o c e d u r e s w i t h o u t s i g n i f i c a n t l y r e d u c i n g the n u m b e r of variâtes ( e l e m e n t s ) d e t e r m i n e d , w e h a d recourse to s i m p l e r p r o grams of d a t a c o m p a r i s o n a n d g r o u p testing. B e c a u s e the c o m p o s i t i o n a l groups

encountered

w e r e so c l e a r l y d i s t i n c t , these s i m p l e

procedures

s e r v e d w e l l for c l a s s i f y i n g specimens. O n e s u c h p r o g r a m w a s the p l o t t i n g of l o g c o n c e n t r a t i o n profiles f o r each sample through a computer program,

POTPLOT,

followed by simul

taneous v i s u a l c o m p a r i s o n of a l l elements i n different specimens b y s u p e r p o s i t i o n i n g t h e i r plots over a l i g h t box.

S u c h a p r o c e d u r e for s p e c i m e n


88

ARCHAEOLOGICAL

CHEMISTRY

Table I. Oxide Element Oxide

Factor

Na*0

1.3479 1.2045 1.0936 1.0602 1.1165 1.2912 1.2715 1.2726 1.5339 1.4297 1.1579 1.1510 1.1477 1.1372 1.4614 1.2284 1.1379 1.1793 1.4305 1.3285 1.2211 1.1728 1.197

Κ2Ο

Rb 0 Cs 0 BaO MnO CoO NiO SC2O3 Fe Os Eu 0i Tb 0a Dy 0 LusOs Cr 0s Ce0 Th0 Hf0 Nb 0s 2

2


2

2

2

2

8

2

2

2

2

2

Sb20

6

Ta 0 La Oj Sb 0 2

8

2

3

2

a

Master

U.S. Geological Survey Standard Rocks G-2 (97) 4.067 4.500 189.5 1.320 2108 354.1 6.01 9.26 6.12 2.696 1.73 0.60 2.35 0.20 13.01 204.5 28.77 8.84 21.4 0.080 1.11 114.7 0.072

(35) (41) (12) (6) ± (18) ± (54) (15) rb (16) rb rb (12) (41) dr rb (2) rb — (1) =fc — (1) ± — (1) rb 0.70 (22) 9.8 (4) =fc ± 0.31 (ID rb 0.98 (4) ± 2.10 (9) rb 0.004 (2) rb 0.11 (2) (13) db 5.2 0.004 (2) ±

rb =b rb =b

0.015 0.018 2.0 0.045 68 13.2 0.13 1.77 0.34 0.011 0.14

GSP-1 2.816 5.507 281.9 1.100 1515 408.6 8.60 14.63 12.19 4.309 3.18 1.5 6.50 0.19 19.14 553.8 125.6 14.56 39.20 3.61 1.34 297.2 3.25

(38)

=fc

0.017 dr 0.014 rb 5.2 ± 0.084 ±80 ± 11.2 rb 0.29 db 1.76 ± 0.94 ± 0.016 ± 0.87 rb db rb

— — —

±

1.2

±

3.0 1.43 1.09 0.77 0.39 27.3 0.69

dr 51.8 dr

± ±

rb dr db

AGV-1 (38) (41) (15) (5) (19) (51) (18) (21) (11) (40) (2) (1) (1) (1) (20) (5) (14) (4) (8) (4) (2) (16) (4)

4.255 2.909 76.2 1.334 1418 965.0 19.38 23.15 18.19 6.808 1.882 0.89 3.97 0.42 16.25 95.2 7.66 6.05 27.84 5.2 41.5 4.7

(64)

db db

0.019 0.082 2.1 0.041 59 14.6 0.71 1.58 0.49 0.022 0.087

rb — rb — zb — dr 0.79 db 14.0 dr 0.23 dr 0.72 rb 1.73 rb 0.84

(35) (48) (15) (6) (18) (54) (21) (21) (10) (43) (2) (1) (1) (1) (18) (4) (12) (4) (5) (4)

dr dr

4.8 .76

(5) (4)

dr

db db rb rb d= db

=fc

rb

Values in ppm of oxide unless noted as % . Number of items in parentheses.

m a t c h i n g is r o u g h l y e q u i v a l e n t t o t h e use o f m e a n c h a r a c t e r

difference

c l u s t e r i n g (14).

computer

program,

G r o u p s so f o r m e d w e r e tested b y another

POTSTAT,

w h i c h c a l c u l a t e d a n d p l o t t e d t h e geometric m e a n o f

t h e concentrations

w i t h l o g a r i t h m i c s t a n d a r d d e v i a t i o n ranges.

Speci

mens f o r w h i c h m o r e t h a n o n e e l e m e n t a l c o n c e n t r a t i o n w a s o u t s i d e o f 9 5 % confidence l i m i t s f o r t h e g r o u p w e r e e l i m i n a t e d . I n the earliest w o r k o n n e u t r o n a c t i v a t i o n analysis of a r c h a e o l o g i c a l m a t e r i a l a n d i n s o m e later studies o f other m a t e r i a l s ( 1 5 , 16, 17, 18, 19) it has b e e n n o t e d that t h e ratios o f t w o elements i n a g r o u p of samples c a n b e less v a r i a b l e t h a n t h e absolute amounts o f either element. I n another a r c h e o l o g i c a l s t u d y , one of t h e authors n o t i c e d that i n c e r t a i n G r e e k c e r a m i c s , n i c k e l a n d c h r o m i u m w e r e c o r r e l a t e d (20).

Quite re

c e n t l y B o w m a n et al. (21 ) r e p o r t e d analyses o f samples f r o m a n o b s i d i a n source i n w h i c h a n u m b e r o f elements are h i g h l y c o r r e l a t e d w i t h i r o n ( b o t h n e g a t i v e l y a n d p o s i t i v e l y ) ; these authors n o t e d that these o r d e r l y r e l a t i o n s h i p s c a n l e a d to p o s i t i v e i d e n t i f i c a t i o n o f o b s i d i a n f r o m source.

this

I n s u c h a case, t h e c o r r e l a t e d elements v a r y i n g over w i d e c o n

c e n t r a t i o n ranges, a n y a t t e m p t to c h a r a c t e r i z e this source

or identify

samples w i t h i t b a s e d o n p u r e c o m p o s i t i o n a l c l u s t e r i n g is b o u n d to f a i l . T h e u s e o f M a h a l a n o b i s distance o r c h a r a c t e r i s t i c vector analysis w o u l d be a p p r o p r i a t e

(13).

Results of Analysis T h e 29 p o t t e r y a n d t w o c l a y specimens f r o m T e o t i h u a c a n , s u p p l i e d b y R a t t r a y , w e r e s u b d i v i d e d b y h e r i n t o f o u r categories : ( a ) those w i t h


6.

ABASCAL-M.

E T A L .

List of Standards

Activation

Analysis

of Mexican

89

Ceramics

0

U.S. Geological Survey Standard Rocks


PCC-1 {16)

DTS-1

BCR-1

(47)

1172 136 3257 12.55 8.326

± 12 ± 5 ± 132 db 0.91 db 0.034

(40) (20) (23) (10) (41)

1227 167.6 3095 5.89 8.653

± 16 ± 6.2 dz 104 ± 0.58 ± 0.028

(47) (20) (25) (7) (38)

3909

db 140

(18)

5885

±

(21)

235

0.60

±

0.04

(3)

0.54

±

0.04

(3)

3.232 1.689 53.8 1.280 840 1816.2 45.57 16.87 49.93 13.472 2.461 1.2 7.17 0.68 21.39 56.9 7.07 5.13 34.92 0.84 1.07 33.0 0.76

{52)

± 0.015 db 0.009 ± 1.0 ± 0.124 ± 42 ± 16 ± 1.06 ± 1.53 ± 0.89 ± 0.039 ± 0.203 ± — ± — ± — ± 1.24 ± 4.7 ± 0.16 ± 0.53 ± 6.78 ± 0.23 ± 0.02 ± 2.0 ± 0.21

(33) (47) (13) (6) (20) (51) (22) (20) (10) (44) (2) (1) (1) (1) (18) (3) (10) (4) (7) (4) (2) (8) (4)

t y p i c a l T e o t i h u a c a n style; ( b ) those w i t h t y p i c a l O a x a c a n style; ( c ) those w i t h m i x e d T e o t i h u a c a n - O a x a c a n stylistic elements;

and (d)

modern

p o t t e r y k n o w n to h a v e b e e n m a d e of T e o t i h u a c a n c l a y together w i t h s a m ples o f t h e c l a y itself. A n a l y s i s s h o w e d t h a t 10 of t h e 12 specimens w i t h t y p i c a l T e o t i h u a c a n style w e r e v e r y s i m i l a r i n c o m p o s i t i o n , f o r m i n g a n acceptable

c o m p o s i t i o n a l g r o u p i n terms of a l l of t h e elements

deter

m i n e d . D a t a f o r these specimens are g i v e n i n T a b l e I I . T h e t w o e x c e p t i o n a l specimens w e r e q u i t e different f r o m the m a t c h i n g specimens n o t o n l y i n c o m p o s i t i o n b u t also i n m i c r o s t r u c t u r e ; one w a s a v e r y g r a n u l a r a m p h o r a , 1-5, a n d t h e other w a s a t h i n orange b o w l , 1-11, w i t h c h a r a c teristic s i z a b l e m i n e r a l i n c l u s i o n s . T h e authors c a r r i e d o u t a n extensive a n a l y t i c a l s t u d y of t h i n o r a n g e pottery. N o t s u r p r i s i n g l y , a l l of the T e o t i h u a c a n - O a x a c a n h y b r i d sherds h a d c o m p o s i t i o n s v e r y s i m i l a r to t h e p u r e T e o t i h u a c a n style m a t c h i n g g r o u p ( see T a b l e I I ). C o n s i d e r a b l y s u r p r i s i n g , h o w e v e r , w a s that n i n e of the 10 sherds w i t h t y p i c a l O a x a c a n style also m a t c h e d these t w o other in composition.

groups

D a t a f o r these specimens are also l i s t e d i n T a b l e I I , w i t h

those f o r the n o n - m a t c h i n g s h e r d , 1-21, w h i c h c a m e f r o m t h e lowest l e v e l , l a y e r 14. T h i s s h e r d h o w e v e r has a c o m p o s i t i o n s i m i l a r to most of those from Oaxaca

(Table

I I I ) . T h e analyses therefore

i n d i c a t e that most

of these three stylistic groups of sherds f o u n d i n t h e O a x a c a n

Barrio

at T e o t i h u a c a n w e r e d i s t i n c t l y s i m i l a r i n c o m p o s i t i o n f o r a l l elements d e t e r m i n e d a n d h e n c e m u s t h a v e b e e n m a d e f r o m v e r y s i m i l a r clays. M o s t p r o b a b l y this c l a y w o u l d b e t h e l o c a l c l a y of T e o t i h u a c a n .

This

p r o b a b i l i t y w a s c o n f i r m e d w h e n i t w a s o b s e r v e d that t h e t w o m o d e r n p o t t e r y specimens

a n d t h e t w o c l a y specimens

as t h e y w e r e


received

90


Table II.

Oxide Concentrations for Specimens Percent


Specimen

Fe^Oz

No.

NaiO

K2O

Typical Teotihuacan sherds

1-1 1-2 1-3 1-4 1-6 1-7 1-8 1-9 I-10 1-37

2.41 2.90 2.36 2.63 2.77 2.41 3.02 2.27 2.85 2.53

1.68 1.92 1.57 1.39 1.52 2.22 2.18 1.32 1.49 1.82

5.95 4.38 4.76 5.81 5.10 4.99 6.15 4.93 5.95 5.28

Oaxacan-style sherds

1-12 1-13 1-14 1-15 1-16 1-17 1-18 1-19 1-20

2.45 2.20 2.70 2.60 2.66 2.27 1.91 2.61 2.93

1.60 1.30 1.60 0.93 1.56 1.15 1.28 1.79 1.46

5.33 4.94 5.52 5.91 5.25 4.84 5.50 5.60 5.93

Oaxacan-Teotihuacan Hybrid sherds

1-22 1-23 1-24 1-25 1-26

2.96 2.69 2.33 2.63 3.34

1.30 1.72 2.10 1.63 1.31

6.07 4.62 5.82 5.23 4.85

Modern pottery

1-38 1-39

2.33 2.20

1.25 1.28

5.52 6.52

Clays (as received)

C37 C38

2.65 2.20

1.39 1.18

5.43 5.80

Fine fractions of above clays

C37F C38F

1.14 0.98

0.94 0.98

6.29 6.74

w h i c h are w i t h o u t q u e s t i o n f r o m T e o t i h u a c a n c o n f o r m e d

to the

same

c o m p o s i t i o n a l p a t t e r n ( see T a b l e I I ). F r o m the c o r r e l a t i o n b e t w e e n the a n c i e n t p o t t e r y a n d m o d e r n c l a y one c a n d r a w several significant conclusions i n a d d i t i o n to the most i m m e d i a t e l y o b v i o u s one that the m a t c h i n g a n c i e n t pots w e r e l o c a l l y m a d e . T h e a m o u n t of t e m p e r i n the ancient p o t t e r y , as e v i d e n c e d b y our c o m p a r i s o n w i t h the c l a y source, has not d i l u t e d or o t h e r w i s e s i g n i f i c a n t l y a l t e r e d the c o m p o s i t i o n a l p a t t e r n of the c e r a m i c .

A l s o the p o t t e r y m u s t

not h a v e s i g n i f i c a n t l y c h a n g e d i n c o m p o s i t i o n d u r i n g b u r i a l . I n a d d i t i o n w e o b s e r v e d a s m a l l b u t significant difference b e t w e e n the Table III.

composition

Oxide Concentrations for Rattray Specimens from the Matching Percent FeiOz

Specimen

No.

NazO

K2O

Granular amphora from Teotihuacan Thin orange incised bowl from Teotihuacan Polished grey incised bowl of Oaxacan style and composition from Layer 14 at Teotihuacan Red on pink, unslipped from Caballito Blanco Polished grey with incised rim from Caballito Blanco Coarse grey paste with cream and red-orange paint from Dain Zu Polished grey dense Caballito Blanco Apaxtle (thick) Caballito Blanco Apaxtle (thin) Caballito Blanco

1-5 1-11

1.65 0.22

2.27 4.31

7.30 5.07

1-21 1-27

1.42 0.65

2.85 3.00

5.17 5.52

1-28

1.87

2.93

3.70

1-36 1-29 1-30 1-31

4.27 1.53 1.64 2.31

2.14 2.72 2.97 2.43

2.31 4.99 5.02 5.62


6.

Activation

ABASCAL-M. E T A L .

Analysis

of Mexican

91

Ceramics

with Matching Compositions from Teotihuacan Parts per Million


RbîO

CstO

BaO

SCÎOZ

LaiOz CeOz EuiOz

LuiOi

HfOt

ThOi

Ta&h

CnOz

MnO

CoO 18.2 15.0 18.0 19.6 20.1 18.3 22.8 18.4 15.9 17.5

54.4 63.3 66.0 90.8 54.8 67.5 59.5 52.4 54.9 67.8

2.55 2.38 3.50 3.18 2.42 3.74 2.44 2.68 2.13 2.45

601 1280 1200 401 765 934 985 1100 1090 673

23.3 17.5 18.7 21.8 20.3 19.8 24.9 19.1 19.8 21.6

— — — — — — — — 30.5

50.7 44.7 50.2 55.6 66.4 68.2 64.8 50.2 41.4 60.7

1.80 1.61 1.52 1.69 1.68 1.50 1.96 1.79 1.46 1.91

— — — — — — — — 0.334

5.34 5.04 5.40 6.03 4.64 5.53 5.78 5.18 4.56 5.14

7.23 7.17 7.12 7.58 7.06 8.10 6.95 6.36 5.90 8.10

1.19 0.74 0.98 1.07 0.81 1.26 1.03 0.86 0.81 0.76

116 102 107 140 142 83 139 124 138 108

789 601 763 837 850 1030 892 839 675 802

59.4 66.0 54.3 71.8 63.5 80.0 71.0 45.0 58.3

3.63 3.71 2.52 3.29 2.78 4.40 5.12 2.28 3.19

613 651 919 350 861 680 714 629 585

20.3 18.4 19.3 20.5 19.0 18.6 20.3 22.3 21.4

32.9 33.5 30.0 28.3 26.4 36.5 35.8 24.3 27.0

62.7 79.8 52.3 52.8 49.2 72.2 68.9 46.4 45.6

2.02 1.81 1.69 1.76 1.60 1.99 1.86 1.66 1.73

0.550 0.562 0.483 0.505 0.438 0.682 0.693 0.374 0.291

6.11 5.58 4.79 6.08 5.17 6.51 5.79 4.68 4.91

7.20 9.11 7.31 7.22 7.44 9.77 8.55 5.68 6.00

1.06 1.17 0.94 1.16 1.31 1.53 1.36 1.30 1.19

85 69 114 125 140 72 72 162 132

1070 1050 686 737 779 1080 979 930 811

22.0 21.3 16.7 18.2 18.7 19.9 19.8 19.8 17.6

72.7 52.0 67.0 55.3 30.4

2.61 2.41 3.66 2.15 1.84

680 814 616 684 470

21.0 15.8 18.5 18.3 16.5

20.6 22.5 28.5 28.5 19.0

48.4 39.5 59.2 48.5 36.8

1.64 1.40 1.71 1.57 1.22

0.276 0.384 0.540 0.460 0.304

4.61 4.57 6.68 5.23 3.47

5.83 5.77 7.87 6.42 4.41

0.97 0.87 1.79 1.14 0.91

141 102 87 125 225

915 671 846 642 813

20.6 13.3 17.6 16.0 16.2

50.1 64.6

3.94 5.16

889

21.2 25.2

45.8 25.3

65.5 67.2

1.84 2.00

—

5.51 5.91

8.73 9.34

1.16 1.33

124 126

930 1290

19.3 21.9

64.8 86.8

4.16 4.11

597 619

21.7 22.8

—

62.9 65.9

1.94 1.86

—

5.51 5.74

8.73 9.05

1.24 1.12

135 145

1100 1040

19.4 19.6

104.0 91.9

4.29 4.48

604 587

26.5 28.9

46.9 48.3

86.7 91.5

2.40 2.26

0.548 0.556

6.28 6.91

10.90 11.50

1.00 1.01

93 104

1160 1190

20.2 19.3

of t h e c l a y as r e c e i v e d a n d t h e fine fractions e x t r a c t e d f r o m this clay. T h e p r i m a r y difference is that the s o d i u m concentrations i n the fine fractions w e r e i n each case a b o u t h a l f that i n t h e t o t a l c l a y (see T a b l e I I ) . S i n c e the a n c i e n t p o t t e r y coincides

w i t h t h e t o t a l c l a y r a t h e r t h a n t h e fine

fractions, i t suggests that these a n c i e n t potters d i d n o t fractionate t h e i r clay. A n a t t e m p t has b e e n m a d e w i t h F i g u r e 6 to present g r a p h i c a l l y t h e overall matching data from Teotihuacan.

T h e h o r i z o n t a l lines of t h e

crosses i n d i c a t e t h e m e a n oxide concentrations w i t h i n t h e ancient m a t c h i n g sherds w h i l e t h e extent of the v e r t i c a l lines indicates t h e s p r e a d of from Teotihuacan and Oaxaca with Compositions Different Groups of their Find Sites Parts per Million RbiO

CsiO

BaO

SaOz

96.7 196.0

6.28 14.5

1040 1060

37.6 27.4

102.0 88.4

8.66 7.15

1120 1590

24.7 29.7

23.8

1210

13.6

38.1

1.81 19.30 19.40 13.90

1840 1380 1550 1160

5.2 18.3 18.9 19.8

21.8 35.4 38.0 33.8

99.3 187 107.0 89.6 87.4

LatOz

—

37.6 52.7

CeOt

Eu-iOz

HfOt

ThOi

TatOf, CriOz

MnO

CoO

42.4 122.0

1.34 2.30

3.42 6.56

4.86 16.0

0.60 1.51

522 116

1030 673

37.1 19.2

61.9 114.0

1.75 2.47

4.74 5.79

8.06 8.93

0.85 1.00

117 110

607 554

17.4 17.6

63.8

1.43

6.25

9.62

1.00

57

660

13.3

55.0 76.9 78.2 73.3

2.91 1.62 1.63 1.70

1.71 6.12 7.01 5.33

0.75 11.30 11.90 9.58

0.23 1.18 1.19 1.09

17 87 91 109

353 859 895 929

10.4 18.7 19.1 19.5



92


*EXCEPT SODIUM, POTASSIUM AND IRON OXIDES WHICH ARE PLOTTED AS PERCENTS

Figure 6. Comparison of the concentrations of many oxides in ancient pottery and in mod ern pottery and clays from Teotihuacan. Aver age concentrations (—) and 95% confidence ranges (\) of 23 ancient sherds. Average con centrations (Φ) in two modern pottery plus two clay specimens. t w o s t a n d a r d d e v i a t i o n ranges—i.e., 9 5 % confidence l i m i t s for these d a t a . C o m p a r e d w i t h these means a n d ranges are points r e p r e s e n t i n g the m e a n concentrations o f the f o u r m o d e r n specimens.

Clearly the modern m a

t e r i a l is not s i g n i f i c a n t l y different i n c o m p o s i t i o n f r o m the ancient. F r o m O a x a c a , D r . R a t t r a y s u p p l i e d us w i t h sherds of t y p i c a l , l o c a l style p o t t e r y f r o m C a b a l l i t o B l a n c o a n d D a i n Z u , together w i t h a single clay specimen from Coyotepec.

W e w e r e also fortunate i n r e c e i v i n g f o r

analysis other p o t t e r y sherds e x c a v a t e d i n the O a x a c a n area, i n c l u d i n g a g r o u p o f 10 fine paste sherds f r o m L a m b i t y e c o f r o m J o h n P a d d o c k o f the Institute o f O a x a c a n S t u d i e s ; a m o r e Table IV.

extensive s t u d y i n v o l v i n g these

Oxide Concentrations for Specimens Percent

Specimen

No.

NaiO

K2O

Fe20z

Rattray sherd from Caballito Blanco

1-32

0.90

2.53

6.12

Rattray sherds from Dain Zu

1-33 1-34 1-35

2.01 1.43 1.68

2.91 2.75 2.93

5.64 6.08 5.72

Paddock fine paste sherds

F121 F122 F123 F126 F129 F130 F131 F132 F134 F135

1.34 1.12 1.15 1.14 1.34 0.89 1.04 0.93 1.04 0.88

2.86 2.75 2.33 2.61 3.30 2 42 3.17 2.58 2.13 2.72

6.38 5.65 5.96 5.79 7.49 5.61 5.50 5.58 5.27 5.40

Polychrome sherd

P C 19

1.05

3.34

6.52

Coyotepec clay (as received and fine fraction)

C39 C39F

1.02 0.64

2.83 2.52

5.81 6.36

Λ


6.

ABASCAL-M. E T

AL.

Activation

Analysis

sherds w i l l b e p u b l i s h e d separately.

of Mexican

93

Ceramics

Another specimen was a M i x t e c a

Postclassic p o l y c h r o m e s h e r d f r o m Y a g u l w h i c h w a s p r o v i d e d b y I g n a c i o B e r n a i of the M e x i c a n N a t i o n a l I n s t i t u t e of A n t h r o p o l o g y a n d H i s t o r y . A n a l y s i s s h o w e d that a n u m b e r of these sherds c a n be a r r a y e d i n a g r o u p of a p p r o x i m a t e l y m a t c h i n g c o m p o s i t i o n a n d that the single c l a y source also shows a reasonable c o m p o s i t i o n a l m a t c h to this g r o u p

(Table

I V ). T h i s s h o u l d not, of course, b e t a k e n to i n d i c a t e that w e b e l i e v e that


i n this c l a y source, C o y o t e p e c , w e have i d e n t i f i e d the p l a c e of m a n u f a c ture of the c o m p o s i t i o n a l l y m a t c h i n g g r o u p of O a x a c a n pottery.

To

do

this u n e q u i v o c a l l y i t w o u l d be necessary to s a m p l e a l l the p o t e n t i a l c l a y sources of t h e O a x a c a n p o t t e r y a n d to d e t e r m i n e that the v a r i a t i o n f r o m source to source w a s sufficiently great to e l i m i n a t e a m b i g u i t y . E v e n t h e n w e c o u l d not be c e r t a i n of i d e n t i f i c a t i o n since some c l a y sources in antiquity may have been

exhausted or o t h e r w i s e

disused.

used

I n this

c o n n e c t i o n w e p l a n to a n a l y z e the c l a y source r e p o r t e d b y P a d d o c k et al. ( 22 ) o n l y 400 m f r o m L a m b i t y e c o m o u n d 190 a n d t h o u g h t to h a v e b e e n w o r k e d i n a n t i q u i t y . W i t h this source t h e y c o u l d m a k e p o t t e r y d u p l i cating i n appearance

the M o n t e A l b a n I V style f o u n d i n t o m b 2 at

L a m b i t y e c o . C l e a r l y , m o r e w o r k needs to be d o n e i n s u r v e y i n g the c l a y sources of the V a l l e y of O a x a c a a n d i n a n a l y z i n g t h e m a n y types O a x a c a n ceramics.

T h e presence of a n u m b e r of n o n - m a t c h i n g

c o l l e c t e d i n the V a l l e y of O a x a c a a n d a n a l y z e d b y us ( T a b l e I I I ) to c o n f i r m o u r b e l i e f that there w e r e several c l a y sources confirms A n n a S h e p h a r d ' s o p i n i o n

of

sherds tends

i n use a n d

(23).

T h e p l a c e m e n t of the M i x t e c a p o l y c h r o m e s h e r d f r o m Y a g u l i n the m a t c h i n g g r o u p of T a b l e I V is of s p e c i a l interest.

T o the best of

our

k n o w l e d g e this is the first p i e c e of t e c h n i c a l e v i d e n c e that at least some of the famous M i x t e c a - P u e b l a p o l y c h r o m e was p r o d u c e d i n the V a l l e y of Oaxaca, confirming Bernais view

(24).

with Matching Compositions from Oaxaca Parts per Million RbtO

CstO

BaO

SCÎOZ

EutOz

HfOt

ThOi

TaiOi,

CnOz

MnO

CoO

99.3

8.75

981

30.3

39.6

82.2

1.84

4.72

10.70

1.34

129

520

17.6

77.6 113.0 97.8

8.19 11.20 9.86

1110 970 911

24.1 27.4 24.9

43.3 46.7 47.3

80.3 84.6 78.2

1.94 1.98 1.79

5.62 5.63 6.08

8.94 10.80 9.25

0.96 1.21 1.18

84 104 103

1130 798 856

17.1 22.1 20.9

96.2 113.0 99.9 99.5 140.0 116.0 113.0 103.0 102.0 135.0

7.56 6.93 6.12 6.11 8.77 7.11 6.97 7.45 5.65 6.30

777 751 709 833 819 856 709 — — —

28.9 26.9 24.1 23.6 32.1 27.8 27.4 28.9 24.0 26.6

37.0 39.0 47.0 40.0 50.0 36.0 46.0 40.0 39.0 37.0

— — — — — 74.5 88.0 68.8 66.4

1.60 1.48 1.64 1.75 1.94 1.62 1.76 1.71 1.72 1.67

5.72 5.76 6.15 5.66 5.42 5.16 4.86 5.12 5.28 5.14

7.76 11.10 10.60 10.20 11.20 10.20 9.32 10.90 10.50 10.40

1.10 1.49 1.50 1.40 1.46 1.21 0.98 1.11 1.31 0.89

114 114 117 110 131 104 98 113 113 104

1210 467 460 541 601 525 683 553 430 481

21.2 13.5 15.6 14.8 21.5 15.6 14.7 15.3 14.5 14.4

128.0

7.40

766

29.1

39.0

—

1.91

7.50

10.80

1.13

109

953

15.5

129.0 147.0

6.68 7.43

867 648

28.4 34.6

51.6

79.5 93.0

1.93 2.02

5.77 4.59

10.90 11.60

0.77 —

142 126

651 369

17.3 11.6

LaiOz

CeOi


94


F i g u r e 7 compares t h e concentrations of the v a r i o u s oxides present in the Oaxaca (Coyotepec)

c l a y a n d t h e average concentrations a n d

s p r e a d o f values o b s e r v e d i n the m a t c h i n g O a x a c a n pottery.

T h e con

centrations i n the c l a y l i e w i t h i n 9 5 % confidence l i m i t s f o r a l l elements b u t one.

F o r t h e n u m b e r o f elements d e t e r m i n e d i t is n o t s t a t i s t i c a l l y

i m p r o b a b l e t h a t a n i n d i v i d u a l s p e c i m e n b e l o n g i n g to a g r o u p I element w o u l d l i e o u t s i d e s u c h confidence l i m i t s , a n d w e consider the c o m p o s i


t i o n a l m a t c h b e t w e e n the c l a y a n d sherds to b e g o o d . T h i s m a y m e r e l y m e a n that the C o y o t e p e c c l a y is t y p i c a l i n c o m p o s i t i o n of a range o f c l a y sources t h r o u g h o u t t h e V a l l e y .

*

ο υ

0.5

* EXCEPT SODIUM, POTASSIUM AND IRON OXIDES WHICH ARE PLOTTED AS PERCENTS

Figure 7. Comparison of the concentrations of many oxides in ancient pottery and in mod ern pottery and clays from Oaxaca. See Figure 6 for legend. T h e O a x a c a n c o m p o s i t i o n differs f r o m the T e o t i h u a c a n c o m p o s i t i o n i n m a n y elements b u t p a r t i c u l a r l y i n t h e concentrations o f t h e a l k a l i metals. F i g u r e 8 compares the m e a n concentrations a n d s t a n d a r d d e v i a t i o n ranges o f t h e a l k a l i oxides of some groups of these specimens w i t h the average

c o n c e n t r a t i o n o f t h e T e o t i h u a c a n specimens

w h i c h have

e i t h e r p u r e o r h y b r i d T e o t i h u a c a n styles. P l o t t e d values a r e t h e ratios of the concentrations i n q u e s t i o n to the m e a n c o n c e n t r a t i o n of this refer ence g r o u p .

T h e centers of the d i a m o n d s y m b o l s , o r crosses, m a r k t h e

m e a n concentrations, a n d t h e i r v e r t i c a l spreads i n d i c a t e t h e s p r e a d of i n d i v i d u a l s t a n d a r d d e v i a t i o n ranges. T h e s o l i d b l a c k d i a m o n d s are t h e ranges of the c o m b i n e d p u r e a n d h y b r i d T e o t i h u a c a n sherds, a n d the o p e n d i a m o n d s are t h e same d a t a f o r t h e O a x a c a n style sherds of m a t c h i n g c o m p o s i t i o n . T h e i r c o m p o s i t i o n a l s i m i l a r i t y is apparent. T h e crosses a r e the c o m p o s i t i o n s o f t h e c o m p o s i t i o n a l l y consistent sherds f r o m O a x a c a . N o t e that t h e y a r e s i g n i f i c a n t l y different f r o m t h e T e o t i h u a c a n sherds.


ABASCAL-M.

Activation

E T A L .


SODIUM

Analysis

of Mexican

Ceramics

CESIUM

lo

A •

ONE STANDARD DEVIATION RANGE OF SPECIMENS WITH TEOTIHUACAN STYLE

Λ

ONE STANDARD DEVIATION RANGE OF SPECIMENS FROM

V LAYERS 3 THROUGH II AT TEOTIHUACAN WITH OAXACAN STYLE +

ONE STANDARD DEVIATION RANGE OF SHERDS FROM OAXACA

Ο

A OAXACAN STYLE SHERD FROM LAYER 14 AT TEOTIHUACAN

Figure 8. Ratios of concentrations in Teotihuacan and Oaxacan sherds to the average concentrations in sherds found at Teotihuacan with total or partial local stylistic characteristics

Figure 9. The figurines* descriptions and our laboratory numerical designations, reading from left to right, are as follows: figurine 3— height 7.7 cm, weight 21.9 grams, traces of red pigment on hair and generally over front of body; 2—height 8.0 cm, weight 23.8 grams, traces of red pigment; 5—height 11.4 cm, weight 42.8 grams, faint traces of red pigment overlying a cream-colored undercoat; 4—height 12.8 cm, weight 55.9 grams, red pigment on hair and skirt, underlayer of cream pigment over the entire body, face and skirt; 6—height 10.0 cm, weight 43.5 grams, red pigment overlying cream undercoat; 1—height 8.4 cm, weight 29.8 grams, trace of red pigment on headdress, fire-blackened in lower half. The clay is whitish gray.


96


Table V .

Oxide Concentrations Percent

Specimen Ancient

figurines

Clay from Tlatilco


Leg of modern

figurine

No.

ΝαιΟ

K2O

FeiOz

TF-1 TF-2 TF-3 TF-4 TF-5 TF-6

1.75 1.91 2.02 2.00 1.82 1.91

0.99 1.06 1.04 0.76 1.06 1.01

6.88 6.72 6.67 6.82 6.36 7.06

TF-7

1.84

0.94

7.27

TF-8

2.21

1.10

6.28

T h e o p e n circles s h o w the r e l a t i v e positions of one O a x a c a n style s h e r d f r o m T e o t i h u a c a n w h i c h d i d not c o n f o r m to t h e l o c a l T e o t i h u a c a n c o m p o s i t i o n — s p e c i m e n 1-21, a p o l i s h e d grey i n c i s e d b o w l f r o m l a y e r 14, t h e l o w e s t l a y e r s a m p l e d at the O a x a c a n B a r r i o . O u r d a t a are consistent w i t h the p o s s i b i l i t y that this s h e r d w a s i m p o r t e d f r o m O a x a c a . H o w e v e r , the p r e p o n d e r a n c e of o u r findings suggests that the t e n d e n c y was to i m p o r t potters r a t h e r t h a n pots f r o m there to T e o t i h u a c a n .

Table V I . Comparison of Mean Compositions of Six Ancient Tlatilco Figurines with a Modern Figurine and Clay from Tlatilco" Average Oxides

Determined

Iron (Fe 0 ), % Sodium (Na,0), % Potassium ( K 0 ) , % Manganese ( M n O ) , ppm Barium (BaO), ppm Chromium (Cr 0 ), ppm Cerium (CeO), p p m Rubidium (Rb 0), ppm Lanthanum (La 0 ), ppm Cobalt (CoO), ppm Scandium (Sc 0 ), ppm Thorium (Th0 ), ppm Hafnium (Hf0 ), ppm Cesium (Cs 0), ppm Europium (Eu 0 ), ppm Tantalum (Ta 0 ), ppm Terbium (Tb 0 ), ppm Antimony (Sb 0 ), ppm 2

3

2

2

3

2

2

2

3

3

2

2

2

2

2

2

3

5

3

2

3

Ancient 6.75 1.90 0.99 810 535 128 68.9 66.1 36.9 27.3 24.6 8.99 6.37 4.60 2.06 1.06 0.91 0.53

Specimens =b ± ± =b =fc =1= ±

0.23 0.10 0.11 190 26 6 5.4 db 4.0 ± 2.3 ± 1.8 =b 0.6 ± 0.34 ± 0.41 =fc 0.31 db 0.17 ± 0.07 ± 0.22 ± 0.14

Concentrations Modern 6.77 2.02 1.02 1040 515 158 67.6 55.3 35.1 27.1 24.8 8.42 6.83 4.12 2.14 1.04 0.94 0.45

Specimens db db

=b =b =b ± ± ± ± db

d= ± db db

± zb db

±

0.70 0.26 0.11 660 7 30 7.6 7.2 0.6 5.9 0.1 0.01 0.17 0.25 0.04 0.11 0.04 0.16

To simplify the presentation of means and standard deviations in Tables V I and V I I , the standard deviations are presented as if the data were linearly distributed. Actually we believe our data to be logarithmically distributed and treat it accordingly. What are presented in Tables V I and V I I are the geometric means of the groups of data with plus or minus one-half of the total standard deviation spread of the groups as calculated logarithmically. For reasonably closely matching groups the differences of notation are small and we felt that increased ease of reading justified the approximate notation. a


6.

ABASCAL-M. E T

AL.

Activation

Analysis

of Mexican

97

Ceramics

f o r T l a t i l c o Specimens Parts per Million RbiO

CsiO

BaO

HfOt

ThOi

MnO

CoO

SbiOi

67.3 59.8 66.2 63.4 69.8 70.2

4.77 4.66 4.17 4.35 4.65 5.05

507 500 550 510 530 550

24.3 25.3 25.2 24.6 23.8 24.9

38.0 37.2 38.6 38.1 37.1 32.4

72.8 71.7 71.3 72.8 65.4 59.4

2.01 2.13 2.23 2.23 1.94 1.80

6.30 6.76 6.81 5.66 6.36 6.31

8.51 9.28 9.19 9.10 9.24 8.60

1.01 1.16 1.05 0.97 1.03 1.11

129 126 137 127 118 133

626 725 699 751 1120 964

29.0 27.3 24.7 27.6 29.4 25.8

0.69 0.46 0.34 0.58 0.45 0.67

50.2

4.30

520

24.9

34.7

73.0

2.11

6.95

8.41

1.11

179

1513

31.2

0.56

136

575

22.9

0.34


60.4

3.94

510

SctOz LaiOz CeOi EuiOz

24.7

35.6

62.2

2.17

6.71

TazOb CnOz

0.96

8.43

A t this stage i t is not possible to estimate h o w extensive the c o m p o s i t i o n a l l y u n i f o r m c l a y deposits

at T e o t i h u a c a n a n d O a x a c a are; t h e y

m i g h t b e v e r y extensive, a n d i t is w e l l k n o w n that the B e c e r r a c l a y f o r m a t i o n u n d e r l i e s large portions of the V a l l e y of M e x i c o (25).

One might

e v e n t h i n k that the entire V a l l e y of M e x i c o contains o n l y c l a y so u n i f o r m i n c o m p o s i t i o n that i t w o u l d not be possible for one to differentiate p o t t e r y m a d e f r o m clays f r o m different sites t h r o u g h o u t it. T h i s is not the case,

however,

as i n d i c a t e d b y o u r second

the p r o b a b l e o r i g i n of the T l a t i l c o

investigation—a study

T h e six figurines, a l l of V a i l l a n t ' s class D - l (26) L u i s T l a t i l c o , w e r e s u p p l i e d b y the I N A H F i g u r e 9.

of

figurines. and provenance San

(Mexico)

a n d are s h o w n i n

T h e m o d e r n specimens i n c l u d e c l a y d u g at T l a t i l c o b y

one

of us ( R . A . - M . ) a n d the l e g of a f a k e figurine k n o w n to h a v e b e e n m a d e i n T l a t i l c o about 20 years ago (also s h o w n i n F i g u r e 9 ) .

The analytical

d a t a for these specimens are g i v e n i n T a b l e V , a n d the m e a n c o n c e n t r a tions a n d s t a n d a r d d e v i a t i o n ranges for the a n c i e n t figurines a n d m o d e r n specimens are c o m p a r e d i n T a b l e V I . T h e results i n T a b l e s V a n d V I s h o w that a l l six

figurines

have

essentially the same c o m p o s i t i o n a l patterns a n d that t h e p a t t e r n for the figurines

agrees e x c e e d i n g l y w e l l w i t h t h a t of the m o d e r n samples.

o b t a i n i n g these d a t a w e r e m o v e d o n l y s m a l l samples (50 m g )

In

to a v o i d

d i s f i g u r i n g the objects. W e f e e l that s o m e of the s p r e a d i n the m a n g a n e s e d a t a was p a r t l y the result of the samples' b e i n g too s m a l l to be t r u l y representative. M a n g a n e s e often tends to b e d i s t r i b u t e d i n a n o n u n i f o r m p a r t i c u l a t e m a n n e r i n p o t t e r y . N e v e r t h e l e s s , the i m p r e s s i v e o v e r a l l agree m e n t argues q u i t e s t r o n g l y that the figurines w e r e m a d e of the l o c a l c l a y . W e also a n a l y z e d s e v e r a l clays ( k i n d l y f u r n i s h e d b y M . D . C o e )

from

the O l m e c center at S a n L o r e n z o T e n o c h t i t l a n ; they w e r e q u i t e different f r o m the T l a t i l c o c l a y a n d figurines i n c o m p o s i t i o n . T o r e t u r n to o u r e a r l i e r p o i n t o n the v a r i a t i o n of c l a y w i t h i n the V a l l e y of M e x i c o , T a b l e V I I shows the m e a n

compositions concentrations

a n d s t a n d a r d d e v i a t i o n spreads of the T l a t i l c o , T e o t i h u a c a n , a n d O a x a c a n m a t c h i n g groups.

T h e s e d a t a s h o w that the T l a t i l c o a n d T e o t i h u a c a n


98


clays c a n b e as d e f i n i t e l y r e s o l v e d f r o m e a c h other as either c a n b e f r o m the O a x a c a n .

Conclusions W e h a v e s h o w n b y n e u t r o n a c t i v a t i o n analysis t h a t groups of sherds f r o m e a r l y classic layers at T e o t i h u a c a n , d e s i g n a t e d t y p i c a l T e o t i h u a c a n Downloaded by UNIV OF CALIFORNIA SAN DIEGO on January 25, 2017 | http://pubs.acs.org Publication Date: June 1, 1974 | doi: 10.1021/ba-1974-0138.ch006

style a n d h y b r i d , h a v e v e r y s i m i l a r c o m p o s i t i o n a l patterns a n d p r e s u m a b l y c a m e f r o m the same c l a y source.

A n a l y s e s of m o d e r n p o t t e r y a n d

c l a y f r o m T e o t i h u a c a n a g a i n r e v e a l a h i g h d e g r e e of c o m p o s i t i o n a l s i m i l a r i t y w i t h the o v e r a l l T e o t i h u a c a n s h e r d g r o u p , m a k i n g i t l i k e l y that the s h e r d g r o u p s a b o v e w e r e l o c a l l y m a d e .

C o m p a r i s o n of the T e o t i

h u a c a n p a t t e r n w i t h t y p i c a l a u t h e n t i c O a x a c a n sherds a n d c l a y shows significant differences w h i l e the O a x a c a n c l a y a n d sherds c o n f o r m to a consistent c o m p o s i t i o n a l p a t t e r n . O f 10 O a x a c a n style sherds f r o m T e o t i h u a c a n , n i n e h a d T e o t i h u a c a n c o m p o s i t i o n a l characteristics a n d h e n c e w e r e p r o b a b l y m a d e l o c a l l y b y potters u s i n g O a x a c a n s t y l i s t i c t r a d i t i o n s .

Table VII. Comparison of Concentration Means and Group Standard Deviations of Compositional Groups of Ancient Pottery Specimens Mean Oxides

Determined

Iron (Fe 0 ), % Sodium (Na 0), % Potassium ( K 0 ) , % Manganese ( M n O ) , p p m Barium (BaO), ppm Chromium (Cr 0 ), ppm Cerium (CeO), p p m Rubidium (Rb 0), ppm Lanthanum (La 0 ), ppm Cobalt (CoO), ppm Scandium (Sc 0 ), ppm Thorium (Th0 ), ppm Hafnium (Hf0 ), ppm Cesium (Cs 0), ppm Europium (Eu 0 ), ppm Tantalum (Ta 0 ), ppm 2

3

2

2

2

3

2

2

2

3

3

2

2

2

2

2

3

5

Tlatilco Figuri nes 6.8 1.9 1.0 800 530 128 69 66 37 27 25 9.0 6.4 4.6 2.1 1.06

zb zb

±

zb

zb zb zb zb zb zb zb zb zb zb zb zb

0.2 0.1 0.1 190 26 6 5 4 2 2 1 0.3 0.4 0.3 0.2 0.07

Concentrations

Teotihuacan Sherds 5.3 2.6 1.6 830 730 114 54 60 28 18 20 7.0 5.2 2.9 1.7 1.07

zb zb zb zb zb zfc zb zb zb zb zb zb zb zb zb zb

0.5 0.3 0.3 140 240 33 11 13 5 2 2 1.2 0.7 0.7 0.2 0.24

Oaxacan Sherds 5.7 1.2 2.7 680 930 107 77 105 41 17 25 10.2 5.6 8.7 1.7 1.19

H o w e v e r , one O a x a c a n style s h e r d f r o m T e o t i h u a c a n s h o w e d

zb zb zb zb zb zb zb zb zb zb zb zb zb zb zb zb

0.6 0.4 0.3 230 220 13 6 16 5 3 4 1.1 0.7 3.2 0.1 0.18

Oaxacan

c o m p o s i t i o n a n d thus was p r o b a b l y i m p o r t e d . F i n a l l y , the analysis of a g r o u p of six p r e c l a s s i c figurines a n d a c l a y f r o m T l a t i l c o i n the V a l l e y of M e x i c o v e r y s t r o n g l y suggests that the figurines w e r e also l o c a l l y m a d e .


6.

ABASCAL-M.

E T A L .

Activation

Analysis

of Mexican

Ceramics

99

Acknowledgments W e acknowledge the enthusiastic support shown b y our archaeologi c a l colleagues, J . P a d d o c k

(Institute of Oaxacan Studies), E . Rattray

( U n i v e r s i t y of Rochester), a n d I. Bernai

( I N A H , Mexico), the whole

h e a r t e d assistance of t h e B r o o k h a v e n R e a c t o r G r o u p , a n d o f o u r t e c h n i c a l assistants P . D o n n e l l y a n d R . G r a e s e r . W e also t h a n k G . S a n f o r d f o r h i s


work.

Literature Cited 1. Sayre, Ε. V., Chan, L.-H., Sabloff, J., in "Science and Archaeology," R. H . Brill, Ed., Chap. 12, M.I.T. Press, Cambridge, 1971. 2. Perlman, I., Asaro, F., Archaeometry (1969) 11, 21. 3. Al-Kital, R. Α., Chan, L.-H., Sayre, Ε. V., in "Hajar Bin Humeid: Investiga tion at a Pre-Islamic Site in South Arabia," Gus W. Van Beek et al., Eds., The Johns Hopkins Press, Baltimore, 1969. 4. Milon, R., "The Teotihuacan Map," Vol. I, Part 1, p. 41, University of Texas Press, Austin and London, 1974. 5. Teotihuacan Mapping Project, Science (1970) 170, 1077. 6. Bernal, I., in "Ancient Oaxaca," p. 345, J. Paddock, Ed., Stanford Univer sity Press, 1966. 7. Piña Chan, R., Anales del I.N.A.H. (SEP) Tomo IV 33-44 Mexico DF (1952). 8. Bernal, I., in "The Olmec World," Chap. 6, pp. 123-138, University of California Press, Berkeley and Los Angeles, 1969. 9. Tolstoy, P., Paradis, L., Science (1970) 167, 344. 10. Flanagan, F. J., Geochim. Cosmochim. Acta (1967) 31, 289. 11. Flanagan, F. J., Geochim. Cosmochim. Acta (1969) 33, 81. 12. Mahalanobis, P. C., Proc. Nat. Inst. Sci. India (1936) 2, 49. 13. Sneath, P. Η. Α., Sokal, R. R., "Numerical Taxonomy," Freeman and Co., San Francisco, 1973. 14. Sneath, P. Η. Α., Sokal, R. R., cit. op., pp. 121-128. 15. Sayre, Ε. V., Dodson, R. W., Amer.J.Archaeom. (1957) 61, 35. 16. Sayre, Ε. V., Murrenhoff, Α., Weick, C. F., Brookhaven Natl. Lab. Kept. BNL 508(T-122) (April 1, 1958). 17. Stenger, V., Anal. Chem. (1971) 43, 37A. 18. Rayudu, G. V. S., et al., Trans. Amer. Nucl. Soc. (1968) 11, 81. 19. Anders, Ο. U., Anal. Chem. (1972) 44, 1930. 20. Harbottle, G., Archaeometry (1970) 12, 23. 21. Bowman, H. R., Asaro, F., Perlman, I., Archaeometry (1973) 15, 123. 22. Paddock, J., Mogor, J. R., Lind, M. D., Bull. Oaxaca Studies (Dec. 1968) No. 25. 23. Shepard, Α., "Notas Sobre la ceramica de Monte Alban", In Caso, Bernal, and Acosta, "La Ceramica de Monte Alban" INAH-M 13. 24. Bernal, I., "Handbook of Middle American Indians," Vol. 3, Part 2, pp. 788 et seq. and 871 et seq., University of Texas Press, Austin, 1965. 25. Coe, M. D., "Mexico," p. 35, Ancient Peoples and Places Series No. 29, Thames and Hudson, London. 26. Vaillant, G. C., Excavations at Zacatenco, Anthropological Papers of the American Museum of Natural History XXXII-1 (1930); XXXV-2 (1935). RECEIVED July 9, 1973. Research done under the auspices of the U.S. Atomic Energy Commission.


Archaeological Chemistry

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