1

Characterizing the micromorphology and chemistry of sediments associated with Chinchorro mortuary

materials using SEM, EDS, and XRD

John G. Van Hoesen and Bernardo Arriaza

Green Mountain CollegeInstituto de Alta Investigación

• Background

• Methods

• Results

• Discussion

• Future Work

Outline

Arriaza, 2008

2

N

Background 1.0

1. Quebrada Jaquay

2. Ring Site

3. Quebrada Tachuay

4. Los Burros

5. Acha and Chinchorro

6. Camarones

7. Punta Pichalo

8. Tiliviche and Aragón

9. Patillo

10. Los Conchas

Santoro et al. 2005

3

N

Background 2.0

QUESTIONS• Do cavity sediments & face masks have a unique geochemical

signature?

• Where did the Chinchorro source mortuary materials?

• How mobile were Chinchorro relative to their coastal occupation sites?

Methodology

• XRD, SEM, EDS• Cavity sediment (7 samples)• Clay face mask (5 samples)• Field sediment (7 samples)

Arriaza, 2008

4

Cancha de Tiro

Vitor Perfil Melus

5

Results 1.0

Equidimensional, well-rounded quartz grains lacking visible cement

Abraded quartz grains coated with pedogenic argillans

SEM & EDS – cavity sedimentsIndicates sediment is primarily composed of quartz, halite, gypsum, clay and muscovite.

Results 2.0

SEM & EDS – cavity sediments

Subhedral halite crystal exhibitingevidence of dissolution surrounded

by clay minerals

Anhedral, amorphous gypsum exhibiting evidence of dissolution

H

C

C

H

6

Results 3.0

SEM & EDS – cavity sediments

Anhedral, amorphous gypsum with relict cleavage

EDS spectra indicating presence of Na, Cl, and Au

H

Results 4.0

SEM & EDS – cavity sediments

Euhedral, lenticular gypsum crystal Euhedral, tabular gypsum crystalssurrounded by clay.

C

C G

G

G

C

C C

C

7

Results 5.0

SEM & EDS – cavity sediments

Organic fibers from reeds used in mortuary preparation

Honeycomb texture associated with reeds

XRD – cavity sedimentsIndicates sediment is primarily composed of quartz (30%), albite (26%), sanidine (15%) muscovite (12%) and a variety of accessory minerals (17%).

Results 6.0

Average values for minerals identified using XRD

Otros4%

Heulandita1%

Moscovita12%

Sanidina15%

Albita26%

Cuarzo30%

Moscovita5%

Beidellita4%

Halita2%Mordenita

1%

CuarzoAlbitaSanidinaMoscovitaMoscovitaBeidellitaMordenitaHalitaHeulanditaOtros

8

---0,03---Dolomita [CaMg(CO3)2]

0,74------Calcita (CaCO3)

0,64-1----Caolinita (arcilla, grupo Caolinita) [Al2Si2O5(OH)4]

1,813,793,5----Heulandita (zeolita) [Ca(Si7Al2)O18x6H2O]

1,79-1,590,43-6,45-Halita (NaCl)

0,83--0,440,770,5-Hematita (Fe2O3)

-1,41--0,921,53-Nitratina (NaNO3)

0,53---0,96--Yeso (CaSO4x2H2O)

----5,3--Montmorillonita (arcilla, grupo Smectita) [Na0,3(Al,Mg)2Si4O10(OH)2x6H2O]

----7,5--Montmorillonita (arcilla, grupo Smectita) [Na0,3(Al,Mg)2Si4O10(OH)2x8H2O]

---3,6---Vermiculita (arcilla) [Mg3Si4O10(OH)2]

0,44------Actinolita [Ca2(Mg,Fe)5Si8O22(OH)]

------0,13Actinolita [Na0,08Ca1,76Mn0,16Mg1,88Fe2,72Fe0,32Al0,32Si7,68O22(OH)2]

-----1,39-Clorita [(Mg5Al)(Si,Al)4O10(OH)8]

------1,54Clorita [(Mg,Fe)6(Si,Al)4O10(OH)8]

---3,87--5,19Mordenita (zeolita) [Ca 0,40Al0,98Si5,03O12(H2O)3]

2,41,11,76,36,63,810,1Beidellita (arcilla, grupo Smectita) [Na0,3Al2(Si,Al)4O10(OH)2x2H2O]

16,4---19,69--Moscovita [(K,Na)Al2(Si,Al)4O10(OH,F)2]

-16,0320,9218,21-8,9911,07Moscovita [KAl2Si3AlO10(OH)2]

10,8822,6514,3716,0315,4113,6614,59Sanidina (Na0,56K3,44Al4Si12O32)

28,9727,4226,0419,0220,2329,8727,06Albita[NaSi3AlO8]

34,5627,630,8832,0722,6233,8130,32Cuarzo (SiO2)

PLM8Cr01

Maestranza Chinchorro

C4

Maestranza Chinchorro

C2

Maderas Enco C2

Maderas Enco C1

M1T1C7M1T1C6Especies Minerales (% en peso)

Results 7.0

Cross section along edge of clay mask

SEM & EDS – clay face masksIndicates mask is primarily composed of manganese coating a thin layer of clay.

9

Results 7.0

Cross section along edge of clay mask (internal side facing)

SEM & EDS – clay face masksIndicates mask is primarily composed of manganese coating a thin layer of clay.

50.0814.77O

FeO8.926.736.93Fe K

MnO39.9130.5230.91Mn K

CaO1.561.511.11Ca K

K2O3.524.052.92K K

0.001.140.75Cl K

SiO23.993.601.86Si K

Al2O30.860.910.45Al K

Na2O0.831.450.61Na K

FormulaCompd%Atomic%Weight%Element

Results 7.0

XRD – clay face masksIndicates sub-equal amounts of psilomelane and pyrolusite, and possibly rhodochrosite.

Psilomelane(Ba,H2O) 2Mn5O10

PyrolusiteMnO2

RhodochrositeMnCO2

BrauniteMn2+Mn3+6SiO12

PiedmontiteCa2Al1.8Mn2+0.9Fe2+0.3(SiO4)3(OH)

? ?

?

10

Discussion 1.0

XRD – cavity sedimentsSignificance of biedelite, montmorillionite, mordenite, heulandite

• Smectites associated with local bentonites• Expansive clays aids plasticity of clay• Geochemical signature different from identified clay sources

• Zeolites = “La Roca Magica”(Bascuñan et al. 2007; Utada, 2001; Mumpton, 1999; Levy et al. 1989)

• Desiccant properties (Virta, 1997; PAHO, 2004)• Pet litter and odor control • Embalming techniques for body fragments

Discussion 2.0

SEM & EDS – clay face masksSignificance of high Mn content

• High graded material = large source• Significance in mortuary process?• Geochemical signature for sourcing

• Currently indicative of greater travel distances

• ~ 40km inland travel (Núñez, 1983; Núñez and Zlatar, 1980)• No local source for Mn

11

Discussion 3.0

XRD – clay face maskSignificance of manganese minerals

• Geochemistry of Mn minerals should help isolate source• Soil nodules (Sanz et al. 1996)• Marine nodules (Achurra et al. 2009; Somayajulu, 2000)• Ore deposits

• Local Candidates?

• Huaylas Formation ~80-140km east of Arica (Garcia et al. 1996; Ossa, 1970)• Psiliomelane ~90km from Arica (Hewitt and Olivares, 1962)• Fluvial transport by Rio Lluta & Rio San José? (Zeilinger et al. 2005)• Los Pumas Manganese Project ~ 170km from Arica?

• Oxygen isotopes (Mandernack et al. 1995)?

}

Geologic Map of Arica (SERNGEOMIN, 2002)

40km bufferfrom coastal

sites

Potential Mn~80-90km

12

Zeilinger et al. 2005

Future Work

• Collect and analyze clay and Mn deposits

• Least-cost-path analysis?

• Link with Arsenic?

• Oxygen isotopes (Mandernack et al. 1995)?

13

Acknowledgements

This project was supported by a Fondecyt International Grant (7080013). XRD analyses were performed by Nelson Guerra at the Universidad Católica del Norte and Peter Ryan at Middlebury College.

Achurra, L.E., Lacassie, J.P., Le Roux, J.P., Marquardt, C., Belmar, M., Ruiz-del-Solar, J., and Ishman, S.E., 2009, Manganesenodules in the Miocene Bahía Inglesa Formation, north-central Chile: Petrography, geochemistry, genesis andpalaeoceanographic significance. Sedimentary Geology, 217 (1-4): 128-139.

Assa, A.C., 1970, Genesis of manganese deposits in Northern Chile. Economic Geology, 65: 681-689.

Bascuñan, S., Kelm, U., Sanhueza, V., and Alfaro, G., 2007, Zeolitization of tuffs at Quinamavida, Central Southern Chile. Claysand Clay Minerals, 55(5): 524-533.

Garcia, M., Herail, G., and Charrier, R., 1996, The Cenozoic forearc evolution in northern Chile: The western border of thealtiplano of Belen (Chile). Third ISAG, St Mala, France, 17-19.

Hewett, D.F. And Olivares, R.S., 1962, High-potassium cryptomelane from Tarapaca Province, Chile. The American Mineralogist, 53: 1551-1557.

Levy, B., Aguirre, L, Nystrom, J.O., Padilla, H., and Vergara, M., 1989, Low-grade metamorphism in the Mesozoic volcanicsequiences of the Central Andes. Journal of Metamorphic Geology, 7: 487-495.

Mumpton, F.A., 1999, La roca magica: Uses of natural zeolite in agriculture and industry. Proceedings of the National Academy of Science, 96: 3463-3470.

Núñez, L., 1983, Paleoindian and Archaic cultural periods in the arid and semiarid regions of Northern Chile. Advances in World Archaeology, 2: 161-222.

Núñez, L. and Zlatar, V., 1980, Coexistencia de comunidades recolectoras-cazadoras. Actas del V Congreso Nacional de Arqueología Argéntica Tomo 1: 79-92.

Pan American Health Organization, 2004, Management of dead bodies in disaster situations. (PAHO disaster manuals and guidelines on disaster series, no. 5.) Washington, 190p. Retrieved July 18, 2009, from:http://www.paho.org/English/dd/ped/DeadBodiesBook.pdf

References

14

Santoro, C.M., Arriaza, B.T., Standen, V.G., and Marquet, P.A., 2005, People Of The Coastal Atacama Desert Living BetweenSand Dunes and Waves of the Pacific Ocean, in, Veth, P., Smith, M., and Hiscock, P., (eds), Desert Peoples: ArchaeologicalPerspectives, John Wiley and Sons, 243-260p.

Sanz,A., Garcia-Gonzalez, M.T., Vizcayno, C., and Rodriguez, R., 1996, Iron-manganese nodules in a semi-arid environment. Australian Journal of Soil Science, 34: 623-634.

SERNGEOMIN, (2002), Mapa Geológico de Chile. Servicio Nacional de Geología y Mineria, Chile. Carta Geológica de Chile, Serie Geología Básica (75), 1 mapa, 1:1.000.000. Santiago, Chile.

Somayajulu, B.L.K., 2000, Growth rates of oceanic manganese nodules: Implications to their genesis, paleo-earth environment and resource potential. Current Science, 78(3): 300-308.

Utada, M, 2001, Zeolites in burial diagenesis and low-grade metamorphic rocks, in, Bish, D.L., and Ming, D.W., (eds), Natural Zeolites: Occurrence, Properties, Application. Reviews in Mineralogy and Geochemistry, V45, p.277-304.

Virta, R.L., Zeolites. U.S Geological Survey, Minerals Information. Retrieved July 18, 2009, from:http://minerals.usgs.gov/minerals/pubs/commodity/zeolites/zeomyb97.pdf

Zeilinger, G., Schlunegger, F., and Simpson, G., 2005, The Oxaya anticline (northern Chile): a buckle enhanced by river incision? Terra Nova, 17: 368-375.

References

15

Hewitt and Olivares, 1962