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Journal of Archaeological Science 37 (2010) 2984e2994

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Journal of Archaeological Science

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Late Holocene Neotropical agricultural landscapes: phytolith and stable carbonisotope analysis of raised fields from French Guianan coastal savannahs

José Iriarte a,*, Bruno Glaser b,1, Jennifer Watling a, Adam Wainwright a, Jago Jonathan Birk b,Delphine Renard c, Stéphen Rostain d, Doyle McKey c

aDepartment of Archaeology, School of Humanities and Social Sciences, University of Exeter, Laver Building, North Park Rd., Exeter EX4 4QE, United KingdombDepartment of Soil Physics, University of Bayreuth, Universitätsstr. 30, Bayreuth D-95447, GermanycUniversité Montpellier II, Centre d’Ecologie Fonctionnelle et Evolutive, UMR 5175 CNRS, 1919 route de Mende, F-34293 Montpellier Cedex 5, FrancedArchéologie des Amériques, UMR 8096 CNRS, Maison René Ginouvès, 21 Allée de l’Université, F-92323 Nanterre, France

a r t i c l e i n f o

Article history:Received 22 March 2010Received in revised form25 May 2010Accepted 18 June 2010

Keywords:Raised-field agricultureZea maysGreater AmazoniaFrench GuianaLate HolocenePhytolith analysisCarbon isotopes

* Corresponding author. Tel.: þ44 (0) 1392 264513E-mail address: j.iriarte@exeter.ac.uk (J. Iriarte).

1 Current address: Terrestrial Biogeochemistry, MaWittenberg, von-Seckendorff-Platz 3, 06120 Halle, Ge

0305-4403/$ e see front matter � 2010 Elsevier Ltd.doi:10.1016/j.jas.2010.06.016

a b s t r a c t

This paper summarizes phytolith analyses from four pre-Columbian agricultural raised-field sites of thecoastal savannahs of French GuianadSavane Grand Macoua, Piliwa, Bois Diable and K-VIIIdand carbonisotope analyses from the first-named site. The combined phytolith and 13C isotope analyses evidence thetransformation of the landscape from a relatively homogeneous wetland vegetation comprised ofa mixture of C4 and C3 plants (the latter including Cyperaceae and other herbaceous monocots such asMarantaceae and Heliconia, Oryzoideae grasses, and other plants typical of frequently flooded areas) tothe construction of raised fields that were dominated by C4 plants (maize and other Panicoideae grasses).Our analysis proves the utility of phytoliths for tracing the agricultural history of landscapes, showingthat, as in other parts of the Central and South American lowlands, maize (Zea mays) was one importantcrop cultivated in raised fields. We also estimated the productivity of raised-field agriculture, showingthat in combination with other subsistence activities, it certainly had the capacity to sustain sizeablepopulations.

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1. Introduction

The Late Holocene was a time when lowland Native Americansocieties in South America began to transform the landscape ata scale not seen before (Denevan, 2001; Iriarte, 2007). Manyseasonally flooded tropical savannahs of South and Central Americasuch as the Beni in the Bolivian Amazon (Erickson and Walker,2009), the Mompos depression in Colombia (Plazas and Falchetti,1990) and the coastal belt of the Guianas (Rostain, 2008a) werereclaimed into vast agricultural landscapes through the construc-tion of raised fields by pre-Columbian farmers. Early Europeanaccounts describe the practise of raised-field agriculture by theOtomac in Venezuela (Gumilla, 1963 [1791]) and by the Tainos inHispaniola (De Las Casas, 1986 [1560]), who constructed smallmoundsusingwooden tools similar to theArauquinoid shovel foundin Suriname and dating to 790� 30 14C yr BP (693e733 cal yr BP)(Versteeg, 2003). Raised-field agriculture provided pre-Columbian

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farmers with better drainage, soil aeration and moisture retention(important for these environments subjected to a long rainy seasonand a severe dry season), increased fertility, and possibly easierweeding and harvesting. In addition, channels between raised fieldscan be used for fish and turtle farming, and their muck and aquaticvegetation can provide a renewable source of nutrients for the soil(Denevan, 2001).Modern raised-field experiments show that raisedfields can be very productive, reaching between 2 and 5.8 t ha�1 ofmaize (Zeamays L.) and up to 21 t ha�1 ofmanioc (Manihot esculentaCrantz) (see summaries in Denevan, 2001; Whitmore and Turner,2001; Barba et al., 2003; Saavedra, 2009).

Building upon the previous work of Rostain (1991, 2008a), ourinternational cross-disciplinary study combined archaeology,archaeobotany, paleoecology, soil science, ecology, and aerialimagery to examine the scale of landscape modification by pre-Columbian people during the Late Holocene. The archaeobotanicalcomponent of the project focused on tracing the history of theseagricultural landscapes, detecting what plants were grown in theraised fields, and estimating their potential agricultural produc-tivity. To address these questions we designed a research strategythat combined (i) phytolith and carbon isotope analyses fromraised-field soil profiles, (ii) the analysis of starch grains from

J. Iriarte et al. / Journal of Archaeological Science 37 (2010) 2984e2994 2985

artefact residues from archaeological habitation sites, and(iii) combined pollen, phytolith, and charcoal analyses from sedi-ment cores retrieved from nearby wetlands to reconstruct the LateHolocene vegetation history of the region and detect natural andhuman-induced environmental changes. In this article we presentthe results of phytolith analysis from four raised-field sites: SavaneGrand Macoua, Piliwa, K-VIII, and Bois Diable, and stable carbonisotope analysis from the first of these sites. This study expandsupon our previously published summary paper (McKey et al., 2010)to show detailed phytolith stratigraphic diagrams, estimate agri-cultural productivity of these systems and discuss the broaderimplications of our results.

2. Regional setting and brief archaeological background

Coastal landscapes of French Guiana are characterized bywaterfront mangrove vegetation along the Atlantic seashore mudflats, followed by freshwater marshes, seasonally flooded savan-nahs with scattered forest patches and inland tropical forest. Theclimate has a highly seasonal annual rainfall between 2.5 and 4 m,most of it during a December to July rainy season (Barret, 2001).The coastal savannahs are bounded by a series of elongate sandyridges (cheniers), representing Late Quaternarymarine terraces thatrun parallel to the seashore (Plaziat and Augustinus, 2004; Prost,1989). The agricultural raised fields occur in the savannahs, whichare characterized by marine clay substrata belonging to the LateQuaternary Demerara Formation (Granville, 1986; Prost, 1989).Freshwater marshes in the savannahs are dominated by Cyperaceae(Cyperus giganteus Vahl, Eleocharis mutata (L.) Roem. & Schult.,Lagenocarpus guianensis Nees, Scleria eggersiana Boeckeler),Typhaceae (Typha angustifolia L.) and Marantaceae (Thalia genicu-lata L.), in addition to Montrichardia arborescens (L.) Schott (Ara-ceae) and Blechnum serrulatum Rich. ferns (Blechnaceae), amongothers. In marshes, the family Poaceae is mainly represented byLeersia hexandra Sw. and Echinochloa polystachya (Kunth) Hitchc.The relatively higher savannahs are predominantly covered byCyperaceae (Bulbostylis spp., Rhynchospora spp., Carex spp.), Poa-ceae (Andropogon spp., Axonopus spp., Leptocoryphium lanatum

Fig. 1. Map of the Guianas showing distribution of raised fields and

(Kunth) Nees, Panicum spp., Paspalum spp.), Heliconia psittacorum L.f. (Musaceae) and Mauritia flexuosa L. f. (Arecaceae). In moreelevated parts of the savannahs (ancient mud banks) and in thehigher platforms created by the raised fields grow some woodytaxa, including Dilleniaceae (Curatella americana L., Davilla aspera(Aubl.) Benoist, Tetracera asperula Miq.) and Malpighiaceae(Byrsonima verbascifolia (L.) DC.). The forest on the well-drainedupper marine terraces includes Arecaceae (Astrocaryum vulgareMart., A. muru-muru Mart., Oenocarpus bacaba Mart.), Burseraceae(Protium heptaphyllum (Aubl.) Marchand), Fabaceae (Hymenaeacourbaril L., Inga spp.), Chrysobalanaceae (Licania spp.) and Myr-taceae (Eugenia sp.), among others. Detailed descriptions of thevegetation of the coastal savannahs of the Guianas can be found inLindeman (1953), Hoock (1971) and Granville (1986).

Pre-Columbian agricultural landscapes along the Guianan coastare characterized by raised fields, canals, and ponds, which spreadover ca. 600 km, from the Berbice River in Guyana to near Cayenne(Fig. 1) (Rostain, 2008a). French Guiana shows considerable diver-sity of raised-field types including (i) small round fields (ca.1e1.5 mdiameter), known in Spanish as “montones”, which are found inlarge numbers covering entire patches of seasonally floodedsavannahs such as Savane Grand Macoua (Fig. 2c), (ii) larger, roundor squaremedium-sized fields (up to 5 m diameter), which occur inlesser numbers mainly along the slopes of sandy ridges, such as inthe Bois Diable and K-VIII sites (Fig. 2a,d), and (iii) elongate fields(1 m high, 1e5 mwide, and 30e50 m long), known as ridged fields(Denevan, 2001) or “camellones” in Spanish, which are usuallylocated in the deepest wetland areas such as in the lower ManaRiver (Fig. 2b) (Rostain, 2008a). We obtained the first direct datesfor raised-field construction in the region. Organic matter of theuppermost sector of buried A horizons beneath raised fields at theBois Diable and K-VIII sites, marking the beginning of theirconstruction, dates to 750� 40 14C yr BP (670e700 cal yr BP) and1010� 40 14C yr BP (920e950 cal yr BP) respectively (Figs. 6aand 7a) (McKey et al., 2010).

These new dates from raised fields are broadly contempora-neous with the Barbakoeba culture dating between 800 and 120014C yr BP, which is associated with the Arauquinoid Tradition. The

sites discussed in the text (modified from McKey et al., 2010).

Fig. 2. Plate with aerial photos of raised fields. A) K-VIII (Photo: Institut Géographique National, Paris, 1987, scale 1:8000). B) Piliwa (Photo: S. Rostain). C) Savane Grand Macoua,Rectangular Patch (Photo: B. Roux of the company L’Avion Jaune, and D. Renard). D) Bois Diable (Photo: S. Rostain).

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latter originated in the Middle Orinoco around 1500 yr BP(Roosevelt, 1980), reached western coastal Suriname around1300 yr BP, and then spread eastward to near present-day Cayenne(Rostain, 1994, 2008b; Rostain and Versteeg, 2004). In FrenchGuiana, the Barbakoeba and Thémire cultures, which are charac-terized by ceramic bowls, jars, and griddles exhibiting diagnosticdecoration including zoomorphic and anthropomorphic adornos,flourished between ca. 1000e800 yr BP and 800e500 yr BP,respectively (Rostain, 1994, 2008b). Habitation sites of thesecultures are located in the higher marine terraces parallel to thecoast. The newly excavated domestic sector of the Sable Blanc sitedates between 825 and 990 14C yr BP (708e938 cal yr BP) (McKeyet al., 2010; Rostain, 2010; Van den Bel, 2009). In addition, thestratigraphy and stylistic analysis of ceramics of Bois Diable(another new residential site excavated during this project locatedabout 200 m NNE of the Bois Diable raised fields) shows the pres-ence of a Barbakoeba occupation layer beneath a layer of the laterThémire culture (Rostain, 2008b).

3. Raised-field sites investigated

Here we present the most significant and informative phytolithdiagrams from a total of 90 samples analysed representing fourraised-field sites: Piliwa, Savane Grand Macoua, K-VIII and Bois Dia-ble. Piliwa (5� 430 5500 N, 53� 530 5400 W) contains 5 ha of cultivablesurface of large rectangular ridged fields located in a depression onthe lowerMana River inwestern FrenchGuiana. Belowwe present indetail the results of theanalysis of a soil coreprofile of one rectangular

raised field (ca. 60 m long� 5 mwide) called Ridged Field 2 (Figs. 2band 4). SavaneGrandMacoua (5� 320 2100 N, 53� 240 3800 W) is a 238 hapatchof coastal savannah located1 kmNWofFlèchevillage. Fromthissite, we present the results from the phytolith analysis of soil coresfrom distinctive raised-field group patterns informally called Rect-angularPatch, TriangularPatch, andProfiles 3 (mound) and4 (matrix)(Figs. 2c, 5 and 8) (Table 1). Stable carbon isotope analyses fromSavane Grand Macoua represent average and standard deviationvalues of three pairs of soil core profiles comprising mound andmatrix called Profiles 1, 3, 5 (mounds) and Profiles 2, 4, and 6 (matrixsites). The K-VIII site is a group of raised fields located ca. 5 kmNWofKourou (5� 110 4800 N,52� 410 6600 W) (Rostain,1991). TheK-VIII localitycontains different types of raised fields, including large round raisedfields (up to 5 m diameter) and elongate ridges (1e4 m wide andusually 20e30m long). Below we report in detail the phytolithdiagram from a medium-sized round mound about 5 m in diameterand 0.6 m tall calledMound 1.1 (Figs. 2a, 6). Bois Diable (5� 100 3100 N,52� 390 4800 W) is a group ofmedium-sized roundmounds located ca.200 mSSWof theBoisDiablehabitationsite in thewestern suburbsofthe city of Kourou (Rostain, 1991). At this site, we carried out analysisof a medium-sized round mound called Mound 1 described below(Figs. 2d, 7).

4. Methods

Phytoliths offer important advantages for studying agriculturallandscapes because (i) being made of silica, they are preserved inthe hot-humid conditions of the tropics where other types of plant

Fig. 3. Scale photomicrographs of phytolith morphotypes defined in the analysis. a) Panicoideae cross-shaped phytolith (BD M1, 10e20 cm). b) Oryzoideae scooped bilobate(P. Ridged Field 2, 0e10 cm). c) Aristida sp. bilobate (GM RP, 0e15 cm) d) Z. mays cob wavy-top rondel (K-VIII M. 1.1, 0e10 cm). e) Z. mays cob half-decorated rondel (P Ridged Field 2,0e10 cm). f) Pooideae oblong phytolith (BD M1, 40e50 cm). g) Olyreae phytoliths with irregular concavities and pointed edges (K-VIII M 1.1. 0e10 cm). h) Phragmites large ridgedsaddle (P Ridged Field 2, 10e20 cm). i) Cyperaceae hat-shaped phytolith with satellites (BD M1, 20e30 cm). j) Cyperus/Kyllinga achene body (BD M1, 10e20 cm). k) Scirpus-typeachene body (BD M1, 0e10 cm). l) Cucurbita scalloped sphere (P Ridged Field 2, 10e20 cm). m) Globular psilate phytolith (GM RP, 20e30 cm). n) Globular granulate phytolith (GMProfile 4, 60e70 cm). o) Marantaceae sphere (BD M1, 20e30 cm). p) Decorated Heliconia body with troughs (K-VIII M 3.1, 0e10 cm). q) Marantaceae seed phytoliths (P Ridged Field 2,10e20 cm). r) Dilleniaceae-type hair base phytoliths (GM RP, 0e15 cm). s) Asteraceae opaque perforated platelets (GM Profile 4 0e10 cm). t) Indeterminable phytolith. P¼ Piliwa;GM RP¼ Savane Grand Macoua, Rectangular Patch; BD: Bois Diable.

J. Iriarte et al. / Journal of Archaeological Science 37 (2010) 2984e2994 2987

Fig. 4. Percentage phytolith diagram from Piliwa Ridged Field 2.

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remains are not (Pearsall, 1995), (ii) they are deposited from plantmaterials that decay in place, a particularly useful trait for detectingwhat plants were grown on agricultural fields (Pearsall, 2000), and(iii) some plant species, such as maize, produce different phytolithsin separate parts of the plant, which allows for the identification of

Fig. 5. Percentage phytolith diagram from Sa

activity areas related to the processing of crops (Piperno, 2006).Because many root and tuber crops of major economic importance,such as manioc, do not produce diagnostic phytoliths, we carriedout preliminary starch grain analysis from plant-processing andcooking artefacts such as ceramic sherds (McKey et al., 2010).

vane Grand Macoua, Rectangular Patch.

Fig. 6. K-VIII site. a) Soil profile of Mound 1.1. b) Percentage phytolith diagram.

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Soil samples were processed, identified, and counted at theUniversity of Exeter Archaeobotany Laboratory following standardprocedures (Piperno, 2006). A minimum of 200 phytoliths werecounted per slide. In order to maximize the recovery of importantphytoliths of different size classes, such as those that derive fromthe rinds of Cucurbita fruits (Bozarth,1987; Piperno et al., 2000) andfrom leaves and cobs of maize (Iriarte, 2003; Pearsall et al., 2003;Piperno and Pearsall, 1993), raised-field sediments were sepa-rated by wet‑sieving into silt (2e50 mm) and sand (50e2000 mm)fractions. Phytoliths were identified and counted under a ZeissAxioscope 40 light microscope at 500� magnification. Fig. 3 showsthe main phytolith morphotypes identified by comparisonwith ourphytolith reference collection (150 plant taxa) collected at theHerbier de Guyane (CAY, Cayenne, French Guiana) and the RoyalBotanic Garden (K, London) (J. Watling and J. Iriarte, unpublisheddata), in addition to the phytolith reference collection curated atthe Archaeobotany Laboratory at the Department of Archaeology,University of Exeter. When possible, we followed the criteria of theICPN group for naming phytolith types (Madella et al., 2005).Identification of Poaceae phytoliths was based on a morphologicalclassification first proposed by Twiss et al. (1969), and later modi-fied or refined by various researchers by taking into account criteriabased on three-dimensional morphology and other micro-morphological features (e.g., Brown, 1984; Fredlund and Tieszen,1994; Iriarte and Alonso, 2009; Pearsall et al., 1995; Piperno andPearsall, 1998; Zucol, 2000). Cyperaceae achene bodies and

Dilleniaceae hair bases were identified following Piperno (1989,2006). A minimum of 25 cross-shaped phytoliths were identified,rotated andmeasured to the nearest 0.01 mmusing Pearsall’s (1978)and Piperno’s (1984: 368e371) cross-shaped and three-dimen-sional variant definitions, respectively. Phytolith diagrams weremade using C2 software (Juggins, 2003). Horizontal bars representpercentages; circles correspond to presence/absence of plant taxalower than 1% in abundance. Carbon stable isotopic ratios (d13C)were analysed by means of elemental analysis e isotope ratio massspectrometry following standard procedures (Craig, 1953).

5. Results

5.1. Phytolith analysis

5.1.1. PiliwaThe Piliwa phytolith assemblage is dominated by Poaceae (grass

family), whose short-cells are predominantly composed of those ofthe subfamily Panicoideae from 50 to 60 cm below surface (here-after b.s.) to the ground level (65e36%) (Fig. 4). At 60e70 cm b.s.,Panicoid grasses sharply increase from ca. 6% at lower levels to 65%above this level. The abrupt increase in Panicoid grasses is paral-leled by a sharp decrease in the abundance of globular psilatephytoliths. The latter reach 53% at the base of the sequence anddrop abruptly from ca. 53% to 5% at 50e60 cm. Later (higher) in thesequence, between 0 and 60 cm b.s. they fluctuate between 5 and

Fig. 7. Bois Diable a) Soil profile of Mound 1. b) Percentage phytolith diagram from Bois Diable Mound 1.

Fig. 8. Phytolith assemblages from Profiles 3 and 4 and average d13C values as a function of depth in profiles 1, 3 and 5 (mounds) and profiles 2, 4, and 6 (matrixes) in Savane GrandMacoua (from McKey et al., 2010).

Table 1Discriminant function analysis for data on cross-shaped phytoliths from the Grand Macoua, Piliwa, Bois Diable and K-VIII sites (from McKey et al., 2010).

Site Provenience N Mean Var 1 Mean Var 5/6 % Var 1 Canonical scores Presence ofZea mays

Maize prediction Wild prediction

Grand MacouaRectangular patch 0e10 cm 45 14.21 10.44 82.2 0.846 0.154 Maize

10e20 cm 43 13.68 12.57 84.0 0.749 0.251 Maize20e30 cm 34 12.94 12.56 85.0 0.639 0.361 Maize

Trinangular patchProfile 3

0e10 cm 38 13.67 11.09 73.5 0.680 0.320 Maize0e10 cm 37 14.35 11.05 75.7 0.807 0.193 Maize10e20 cm 32 13.20 14.05 90.0 0.703 0.297 Maize

PiliwaRidged field 1 0e10 cm 30 13.61 16.64 93.0 0.760 0.240 Maize

10e20 cm 27 13.43 11.77 85.0 0.728 0.272 Maize

Ridged field 2 0e10 cm 29 13.80 11.38 86.0 0.800 0.200 Maize10e20 cm 25 13.30 12.74 84.0 0.686 0.314 Maize

Bois DiableMound 1 0e10 cm 27 14.15 10.36 92.0 0.918 0.082 Maize

10e20 cm 16 14.80 14.93 93.0 0.972 0.028 Maize

K-VIIIMound 1.1 0e10 cm 40 12.30 11.90 82.0 0.521 0.479 Maize

10e20 cm 30 12.75 11.68 80.0 0.579 0.421 Maize

Mound 2.1 0e10 cm 40 13.10 13.10 75.0 0.576 0.424 Maize10e20 cm 37 12.98 11.55 83.0 0.642 0.358 Maize

Mound 3.1 0e10 cm 30 12.61 11.38 80.0 0.560 0.440 Maize10e20 cm 29 13.94 13.56 86.0 0.795 0.205 Maize

Var¼Variant of three-dimensional structure of cross-shaped phytoliths.Maize prediction: �1.96660þ 0.1597589 (mean width for Variant 1)� 0.0126672 (mean width of Variant 6)þ 8.20956� 3 (% Variant 1).Wild grass prediction: 2.96669� 0.1597589 (mean width for Variant 1)þ 0.0126672 (mean width of Variant 6)� 8.20956� 3 (% Variant 1).(Piperno, 2006: 54).

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25%. Following the Panicoid grasses, the most abundant Poaceaephytoliths are those of wild rices (Oryzoideae) (Fig. 3b), followed bylesser amounts of Chloridoideae and Pooideae phytoliths. ThesePoaceae subfamilies are not represented below 60 cm deep.Phragmites saddles are present in very small percentages (1.2%) inlevel 10e20 cm b.s. (Fig. 3h). Olyreae phytoliths are mainly presentin level 50e60 cm b.s. (Fig. 3g). They possibly represent Pariana sp.or Olyra sp., which are reported to grow mainly in shaded, wet,lowland forest, but are also often found in periodically floodedvárzea (Judziewicz et al., 1999: 279). Hoock (1971: 41) alsodescribes Pariana sp. and Olyra sp. growing in forest edges, as wellas in open savannahs in the vicinity of Kourou. Cyperaceae achenebodies and hat-shaped bodies are also present throughout thesequence, totalling between 4 and 10%. They are not present below60 cm deep. Marantaceae seed and sphere phytoliths are presentbetween 30 and 60 cm deep (Fig. 3o and q). They are absentbetween 0 and 30 cm b.s. and only present in trace amounts in thebasal 60e70 cm level. Arecaceae globular echinate phytoliths andAsteraceae opaque perforated platelets (Fig. 3s) are both onlypresent in the two uppermost levels. All samples contain largeamounts of sponge spicules and diatoms. In the upper 0e20 cm b.s.levels we detected the presence of maize wavy-top and half-decorated rondels and a maize leaf signature (Table 1) (Fig. 3a, d, e),in addition to squash (Cucurbita sp.) scalloped spheres (Fig. 3l). Thelarge size of the latter confirmed they were produced by domes-ticated Cucurbita sp. (McKey et al., 2010).

5.1.2. Savane Grand MacouaThe phytolith assemblages of the Rectangular Patch are domi-

nated by the Poaceae, whose short-cells are predominantlycomposed of those produced by the subfamily Panicoideae,followed by trace amounts of Pooid and Chloridoid short-cells, as

well as Oryzoid and Aristida bilobates (Fredlund and Tieszen, 1994;Mulholland, 1989; Piperno and Pearsall, 1998) (Figs. 3c, 5). Panicoidgrasses exhibit an increasing trend from the lower level of thisprofile (50 cm b.s.) to the ground surface. This is correlated witha decreasing trend in globular granulate and psilate phytoliths,which are abundantly produced in the Cyperaceae that are thepredominant vegetation in freshwater marshes. Psilate globularphytoliths are produced by woody and herbaceous dicotyledons aswell as by herbaceous monocotyledons. Within the latter, they areabundantly produced by the Cyperaceae (Iriarte and Alonso, 2009;Watling and Iriarte, unpublished data). The presence of globularpsilate phytoliths in the upper part of the profiles is interpreted asmainly produced by the Cyperaceae due to their association withother Cyperaceae genus-specific phytoliths produced by Carex,Cyperus/Kyllinga, and Scirpus, as well as other phytoliths from planttaxa adapted to freshwater wetlands such as Oryzoid grasses andherbaceous monocots (Heliconia, Marantaceae), all indicating thepresence of freshwater wetlands. Below 60 cm b.s., at the very baseof the profile, the phtyolith assemblage is absolutely dominated byglobular granular and psilate spheres. This trend is also observed inthe mound Profile 3 (Fig. 8) and this is a recurrent pattern in all theraised-field profiles analysed. Heliconia bodies with troughs,Cyperaceae achene bodies, and Asteraceae phytoliths are onlypresent in the upper levels. Heliconia bodies are assigned to thespecies H. psittacorum, which is the only Heliconia species thatgrows in the savannahs today (Fig. 3p). Small percentages (0.5e3%)of hair bases of Dilleniaceae are also present in the first 0e15 cmb.s. Today, these woody plants, mainly comprising C. americana,T. asperula and D. aspera, only grow in the drier, better-drainedpatches of savannah (Hoock, 1971) and on the tops of abandonedraised fields. The assemblage of non-domesticated plants appearsto represent background vegetation that grew during the fallows

J. Iriarte et al. / Journal of Archaeological Science 37 (2010) 2984e29942992

when the fields were active and vegetation that grew since theywere abandoned. In the upper 0e30 cm levels b.s. we detected thepresence of maize wavy-top rondels and a maize leaf signature,which are also present in the Triangular Patch and in Profiles 3 and4, indicating that maize was an important food crop planted inSavane Grand Macoua (Table 1).

5.1.3. K-VIIIAs in the other raised-field profiles, the upper levels of K-VIII

Mound 1.1. are dominated by Poaceae phytoliths. Panicoid short-cells sharply increase at 60 cm b.s. at the expense of globular psilatephytoliths, which plummet from 91 to 23% at 60e70 cm b.s. (Fig. 6).Panicoid short-cells fluctuate between 17 and 28% from 60 to 10 cmb.s. and reach 75% in the top level (0e10 cm b.s.). Comparable to theother raised-field profiles, below 60 cm deep, where sedimentsrepresent marine clays, the assemblages are completely dominatedby globular psilate spheres. The reason for the absolute predomi-nance of globular psilate spheres in the basal marine clays isunknown. Other Poaceae phytoliths are less well represented.Chloridoid short-cells are present in small amounts (0.3e3.5%) onlyabove 60 cm b. s. Pooid short-cells are only present in traceamounts (0.4%) between 30 and 40 cm deep and Oryzoid short-cells are present in minor proportions (0.4e1.7%) above 50 cmdeep. Heliconia is absent below 50 cm b.s., and ranges between 1.3and 4.8% from 50 cm b.s. to the ground surface. The profile containsCyperaceae phytoliths only in trace amounts, represented by Scir-pus-type and Cyperus/Kyllinga achene bodies (Fig. 3k and j,respectively), as well as Cyperaceae hat-shaped bodies (Fig. 3i).Asteraceae is only present in trace amounts at 60e70 cm b.s.Marantaceae spheres appear in 50e60 cm b.s. (1%) and graduallyincrease up to 10e20 cmwhere they reach 7%. They are not presentin the uppermost level. Globular granulate phytoliths are repre-sented throughout the profile, ranging from 3.5 to 14.5%. As atPiliwa, the profile of Mound 1.1 at K-VIII has abundant spongespicules and diatoms. As in all the other raised fields analysed, wedetected a maize leaf signature and wavy-top rondels in theupper 20 cm b.s of Mound 1.1 and in two other long rectangularmounds called Mound 2.1 (ca. 20� 4� 0.25 m) and Mound 3.1(ca. 50� 5.5� .25 m) (Fig. 2a) (Table 1).

5.1.4. Bois DiablePoaceae phytoliths dominate assemblages of the upper levels of

Bois Diable Mound 1 (Fig. 7). Panicoid short-cells are the mostabundant: theyshowasharp increase from1.5% in the lowest levels to14% at 60e70 cm b.s. and reach 43% in the uppermost level. Oryzoidshort-cells are well represented throughout the sequence (2.5e13%),except for the bottom level. Chloridoid phytoliths are scantily repre-sented (1e2.5%) in levels 0e10, 40e50, and 50e60 cm, and Pooidshort-cells are only present in level 40e50 cm. Cyperaceae phytolithsare represented throughout the sequence by distinctive Carex, Cype-rus, and Scirpus achenebodies, in addition to thehat-shapedbodies (afamily-level trait), which in total range from 1 to 10%. Marantaceaespheres are present in all the sequence except the lower level. Theyincrease from 7 to 17% from 60e70 cm to 40e50 cm and then starta decreasing trend reaching 2% at ground level. Heliconia appears forthe first time at 30e40 cm and fluctuates from 1.3 to 22%. There isa general decreasing trend of globular psilate phytoliths from thebottom to the top, except for level 60e70 cm,where their percentagefalls abruptly from 86 to 9%. Maize cob phytoliths and a maize leafsignature were detected in the upper 20 cm b.s.

5.2. Carbon isotope analysis

Data from analyses of both phytolith assemblages from Profiles3 and 4 and average carbon stable isotope composition in Profiles 1,

3 and 5 representing mounds and Profiles 2, 4, and 6 representingmatrix areas at Grand Macoua also document the transformation ofthe landscape (Fig. 8) (McKey et al., 2010). Below 70 cm b.s. theprofile shows a mixed C3/C4 signal. Between 70 and 40 cm, theprofiles evidence establishment of freshwater wetlands showingless 13C depleted mixed C3/C4 value. The upper part of the profilesshows the transition from a relatively homogeneous vegetationcomprised of a mixture of C4 and C3 plants, the latter includingsedges (Cyperaceae), herbs (Marantaceae and Heliconia), Oryzoidgrasses and other plants typical of frequently flooded areas, todivergence between raised fields and adjacent floodedmatrix, withraised fields being dominated by C4 plants (mostly Panicoidgrasses) and thematrix continuing to show a higher contribution ofC3 plants. This transition corresponds to the construction of raisedfields in a previously more homogeneous freshwater wetland, andthe beginning of maize cultivation. In contemporary vegetation ofthis site, C4 species continue to be more frequent on abandonedraised fields and C3 species more frequent in the matrix (McKeyet al., 2010, SI Table 2).

5.3. Construction of raised fields

The buried A horizon observed in large raised fields in the K-VIIIand Bois Diable siteswas at about the same level as the surroundingmatrix (Figs. 6a and 7a). Study of these buried soil surfaces in pre-Columbian raised fields gave insight into their construction. Figs. 6aand 7a show the following sequence from top to bottom. Beneaththe mound’s thick A horizon, rich in organic matter, is a transitionalhorizon (A/Bgv), with the part corresponding to the B horizonlighter in colour and less rich in organic matter. Grey clayey subsoilinclusions are concentrated at the bottom of this horizon. Beneaththe transitional horizon is the organic matter-rich buried A horizon(Agvb). Raised-field construction apparently began with theupside-down placement of slices of topsoil plus subsoil from thesurrounding area. The material above was apparently mainlytransported from elsewhere. This is apparent in the K-VIII sample50e60 cm b.s., where we see a sharp decrease of globular psilatephytoliths showing the inversion of stratigraphy. All horizons fromA/Bgv downwards show characteristics of stagnic conditions(denoted by “g”) and the occurrence of plinthite (denoted by “v”).Transport of soil to create raised fields is also suggested by theobservation in the K-VIII raised-field complex of nearby largepatches bare of topsoil, with clay-rich subsoil exposed at thesurface and bearing sparse vegetation (McKey et al., 2010, SI Fig. 2).

5.4. Raised-field agricultural productivity

Raised-field agriculture certainly had the capacity to supportlarge and concentrated populations in the Guiana coast. A conser-vative estimate using the lowest maize productivity figure(2 t ha�1) obtained from raised-field experiments (Arce, 1993), fora single annual crop, and assuming 25% of fields (allowing for fallowperiods), shows that maize agricultural production would havebeen able to support 234 persons in Grand Macoua (75 ha ofcultivable surface) assuming a maize equivalent of 160 kgconsumption per person per year, the rest being supplied by otherfoods (Sanders et al., 1979). A moderate estimate, assuming 75% offields in use and 3.725 t ha�1 (Sanders et al., 1979), indicates the sitewould have been able to support 1310 people. The maximumamount of people that the system might have been able to supportwith a maize productivity of 5.78 t ha�1 (Muse and Quinteros,1987), 100% of fields in use, and 2 crops/year, would have been5400 people. The moderate estimate seems reasonable to assume.These estimates of carrying capacity are similar to those previouslyproposed by Rostain (2008a).

J. Iriarte et al. / Journal of Archaeological Science 37 (2010) 2984e2994 2993

6. Summary and conclusions

This analysis reinforces the utility of phytoliths and stablecarbon isotopes for studying agricultural landscapes (e.g., Denhamet al., 2003; Fernández et al., 2005; Mulholland, 1993). Despite thebioturbation caused in soil profiles by ecosystem engineers (McKeyet al., 2010), the analyses show significant patterns. In generalterms, from bottom to top we observe the following stratigraphicunits. The phytolith content of the clayey marine sediments locatedbelow 50e70 cm b.s. (depending on the height of raised fields) isalmost completely composed of psilate globular spheres. Levelsbetween 60 and 40 cm are co-dominated mainly by Panicoid short-cells and psilate globular phytoliths representing the establishmentof freshwater marshes. This level represents a peat layer that isclearly visible in K-VIII and Bois Diable raised fields (Figs. 6 and 7),where we were able to dig stratigraphic trenches.

The upper levels of the profiles represent the establishment ofraised fields, and the associated phytolith assemblages contain thecrops and vegetation that grew during the fallows and were adaptedto the relatively drier environments created by the elevated plat-forms. In addition, the phytolith assemblages from the various typesof raised fields occurring in different savannah environments reflectthe local background vegetation. For example, the phytolith assem-blages from Piliwa, which is located in the lower Mana River andaffected by the Atlantic Ocean tides, contained large ridged saddlesof Phragmites, a plant that is adapted to brackish water conditions.Similarly, Oryzoid phytoliths are more abundant in the raised fieldssurrounded by permanent standingwater such as Piliwa. Conversely,the phytolith assemblages from the raised fields of Savane GrandMacoua, which is seasonally flooded, were more dominated byplants adapted to drier conditions, such as Panicoid grasses, Aster-aceae, Dilleniaceae, and H. psittacorum.

The combined phytolith and carbon isotope analyses evidencethe reclamation of these seasonally flooded savannahs into agri-cultural landscapes. From above around 70 cm b.s., they show thetransformation of relatively homogeneous wetland vegetationcomprised of a mixture of C4 and C3 plants mainly includingCyperaceae, Marantaceae and Heliconia herbs, Panicoid and Ory-zoideae grasses, into agricultural raised fields being dominated byC4 plants, including maize and other Panicoid grasses.

Both the diagnostic wavy-top rondels produced in the glumes ofmaize cobs and cross-shaped leaf phytolith assemblages weredetected in all types of raised fields analysed (Table 1). Phytoliths ofsquash (Cucurbita) were also found in Piliwa and preliminary starchgrain residue analysis from the Sable Blanc site documented theconsumptionofmaize andmanioc (McKeyet al., 2010). These resultsindicate that, as in other raised-field systems in the Neotropicallowlands, such as Central Veracruz, Mexico (Siemens et al., 1988),Cob Web Swamp (Pohl et al., 1996) and Pulltrouser Swamp(Wiseman, 1983), Belize, and the Guayas Basin, Ecuador (Pearsall,1987), maize represented a major cultivated crop. Pre-Columbianraised-field constructionwas labour intensive (Bandy, 2005), but asmodern experiments indicate, raised fields can also be extremelyproductive (e.g., Barba et al., 2003; Muse and Quinteros, 1987;Saavedra, 2009). It is thus reasonable that maize, arguably one ofthe most productive crops in the Americas, was a major crop culti-vated in raised fields by pre-Columbian farmers. Combined withslash-and-burn agriculture in terra firme forest, hunting, gathering,and fishing in the bountiful estuaries, the French Guiana coast musthave been able to support large and dense human populations.

Acknowledgements

This research was funded by the “Amazonie” interdisciplinaryprogrammeof INEE (National Instituteof EcologyandEnvironment),

CNRS, France.We thank the Centre Spatial Guyanais for providing usaccess to the K-VIII site. The EcoFoG laboratory in Kourou and CNRSGuyane provided us with logistical support. Stable isotopes weremeasured at Bayreuth Center of Ecology and EnvironmentalResearch (BayCEER) in the Laboratory of Isotope Biogeochemistry.We are grateful to anthropologist Fernando Santos Granero whoprovided us with references on descriptions of Native Americanhistoric raised-field agriculture. The following persons helpedduring fieldwork: Lydie Clerc, Alexander Hänel, Martin Hitziger,Verena Pfahler, Bruno Roux, Matthias Schnier, Susanne Stark andTimothy Thrippleton. Mike Rouillard and Seán Goddard fromUniversity of Exeter drafted the figures.

References

Arce, J., 1993. Evaluación y comparación de rendimientos de cuatro cultivos en tresanchuras de camellones (campos elevados) en la Estación Biológica del Beni(Prov. Ballivián, Dpto. Beni). PhD thesis, Department of Agronomy, UniversidadTécnica del Beni, Trinidad.

Bandy, M.S., 2005. Energetic efficiency and political expediency in Titicaca Basinraised field agriculture. J. Anthropol. Archaeol. 4, 271e296.

Barba, J., Canal, E., García, E., Jordà, E., Miró, M., Pastó, E., Playà, R., Romero, I., Via, M.,Woynarovich, E., 2003. Moxos: Una Limnocultura. Cultura y Medio Natural en laAmazonia Boliviana. CEAM, Barcelona.

Barret, J., 2001. Atlas Illustré de la Guyane. IRD Editions, Cayenne.Bozarth, S.R., 1987. Diagnostic opal phytoliths from rinds of selected Cucurbita

species. Am. Ant. 52, 607e615.Brown, D.A., 1984. Prospects and limits of a phytolith key for grasses in the Central

United States. J. Archaeol. Sci. 11, 345e368.Craig, H., 1953. The geochemistry of stable carbon isotopes. Geochem. Cosmochem.

Acta 3 (2e3), 53e92.De Las Casas, B., 1986 [1560]. Historia de las Indias. Biblioteca Ayacucho, Caracas.Denevan, W., 2001. Cultivated Landscapes of Native Amazonia and the Andes.

Oxford University Press, Oxford.Denham, T.P., Haberle, S.G., Lentfer, C., Fullagar, R., Field, J., Therin, M., Porch, N.,

Winsborough, B., 2003. Origins of agriculture at Kuk Swamp in the Highlands ofNew Guinea. Science 301, 189e193.

Erickson, C., Walker, J., 2009. Precolumbian causeways and canals as landesquecapital. In: Snead, J.E., Erickson, C.L., Darling, J.A. (Eds.), Landscape of Move-ment. Trails, Paths, and Roads in Anthropological Perspective. University ofPennsylvania Museum of Archaeology and Anthropology, Philadelphia, pp.232e252.

Fernández, F.G., Johnson, K.D., Terry, R.E., Nelson, S., Webster, D., 2005. Soilresources of the ancient Maya at Piedras Negras, Guatemala. Soil Sci. Soc. Am. J.69, 2020e2032.

Fredlund, G.G., Tieszen, L.T., 1994. Modern phytolith assemblages from the NorthAmerican Great Plains. J. Biogeogr. 21, 321e335.

Granville, J.-J. de, 1986. Les formations végétales de la bande cotière de GuyaneFrançaise. In: Le Littoral Guyanais. Fragilité de l’Environnement. 1er Congre

sre�cgional de la SEPANGUY, Xe Colloque SEPANRIT. SEPANRIT, Cayenne, pp.47e63.

Gumilla, J., 1963 [1791]. The Orinoco Illustrated and Defended. Biblioteca de laAcademia Nacional de la Historia, Caracas (translated from Spanish).

Hoock, J., 1971. Les Savanes Guyanaises: Kourou. Memoire 44. ORSTOM, Paris.Iriarte, J., 2003. Assessing the feasibility of identifying maize through the analysis of

cross-shaped size and tridimensional morphology of phytoliths in the grass-lands of southeastern South America. J. Archaeol. Sci. 30, 1085e1094.

Iriarte, J., 2007. New perspectives on early plant domestication and the develop-ment of agriculture in the New World. In: Denham, T., Iriarte, J., Vyrdaghs, L.(Eds.), Rethinking Agriculture: Archaeological and EthnoarchaeologicalPerspectives. Left Coast Press, Walnut, California, pp. 165e186.

Iriarte, J., Alonso, E., 2009. Phytolith analysis of selected native plants and modernsoils from southeastern Uruguay and its implications for paleoenvironmentaland archaeological reconstruction. Quat. Int. 193, 99e123.

Judziewicz, E.J., Clark, L.G., Londoño, X., Stern, M.J., 1999. American Bamboos.Smithsonian Institution Press, Washington, D.C.

Juggins, S., 2003. C2 User Guide. Software for Ecological and Palaeoecological DataAnalysis and Visualization. University of Newcastle, Newcastle upon Tyne.

Lindeman, J.C., 1953. The Vegetation of the Coastal Region of Suriname. Kemink enzoon N.V., Utrecht.

Madella, M., Alexandre, A., Ball, T., 2005. International code for phytolith nomen-clature 1.0. Ann. Bot. 96, 253e260.

McKey, D., Rostain, S., Iriarte, J., Glaser, B., Birk, J.J., Holst, I., Renard, D., 2010. Pre-Columbian agricultural landscapes, ecosystem engineers and self-organizedpatchiness in Amazonia. Proc. Natl. Acad. Sci. U. S. A. 107, 7823e7828.

Mulholland, S.C., 1989. Phytolith shape frequencies in North Dakota grasses:a comparison to general patterns. J. Archaeol. Sci. 16, 489e511.

Mulholland, S.C., 1993. A test of phytolith analysis at Big Hidatsa, North Dakota.In: Pearsall, D.M., Piperno, D.R. (Eds.), Current Research in PhytolithAnalysis: Applications in Archaeology and Paleoecology. MASCA Research

J. Iriarte et al. / Journal of Archaeological Science 37 (2010) 2984e29942994

Papers in Science and Archaeology, vol. 10. MASCA, Philadelphia, pp.131e145.

Muse, M., Quinteros, F., 1987. Experimentos de reactivación de campos elevados,Peñón del Río, Guayas, Ecuador. In: Denevan, W.M., Mathewson, D.,Knapp, G. (Eds.), Pre-Hispanic Agricultural Fields in the Andean Region, PartI. British Archaeological Reports. International Series 359(i), pp. 249e266.Oxford, UK.

Pearsall, D.M., 1978. Phytolith analysis of archaeological soils: evidence for maizecultivation in formative Ecuador. Science 199, 177e178.

Pearsall, D.M., 1987. Evidence for prehispanic maize cultivation on raised fields atPeñón del Rio, Guayas, Ecuador. In: Denevan, W.M., Mathewson, K., Knapp, G.(Eds.), Pre-Hispanic Agricultural Fields in the Andean Region. Part ii. BARInternational Series 359 (ii), pp. 279e295.

Pearsall, D.M., 1995. “Doing” paleoethnobotany in the tropical lowlands:adaptation and innovation in methodology. In: Stahl, P.W. (Ed.), Archaeologyin the Lowland American Tropics. Cambridge University Press, Cambridge,pp. 113e129.

Pearsall, D.M., 2000. Paleoethnobotany. A Handbook of Procedures. Academic Press,San Diego.

Pearsall, D.M., Chandler-Ezell, K., Chandler-Ezell, A., 2003. Identifying maize inneotropical sediments and soils using cob phytoliths: formalizing and testingtypes. J. Archaeol. Sci. 30, 611e627.

Pearsall, D.M., Piperno, D.R., Dinan, E.H., Umlauf, M., Zhao, Z., Benfer Jr., R.A.,1995. Distinguishing rice (Oryza sativa Poaceae) from wild Oryza speciesthrough phytolith analysis: results of preliminary research. Econ. Bot. 49 (2),183e196.

Piperno, D.R., 1984. A comparison and differentiation of phytoliths from maize andwild grasses: use of morphological criteria. Am. Antiq. 49, 361e383.

Piperno, D.R., 1989. The occurrence of phytoliths in the reproductive structuresof selected tropical angiosperms and their significance in tropical paleo-ecology, paleoethnobotany and systematics. Rev. Palaeobot. Palynol. 61,147e163.

Piperno, D.R., 2006. Phytoliths. A Comprehensive Guide for Archaeologists andPaleoecologists. Altamira Press, San Diego.

Piperno, D.R., Pearsall, D.M., 1993. Phytoliths in the reproductive structures of maizeand teosinte: implications for the study of maize evolution. J. Archaeol. Sci. 20,337e362.

Piperno, D.R., Pearsall, D.M., 1998. The Silica Bodies of Tropical American Grasses:Morphology, Taxonomy and Implications for Grass Systematics and FossilPhytolith Identification. Smithsonian Contributions to Botany 85. SmithsonianInstitution Press, Washington, D.C.

Piperno, D.R., Andres, T.C., Stothert, K.E., 2000. Phytoliths in Cucurbita and otherneotropical Cucurbitaceae and their occurrence in early archaeological sitesfrom the lowland American tropics. J. Archaeol. Sci. 27, 193e208.

Plazas, C., Falchetti, A.M., 1990. Manejo Hidráulico Zenú. Ingenierías Prehispánicas.Fondo FEN Colombia. Instituto Colombiano de Antropología, Bogotá.

Plaziat, J.-C., Augustinus, G.E.F., 2004. Evolution of progradation/erosion along theFrench Guiana mangrove coast: a comparison of mapped shorelines since the18th century with Holocene data. Mar. Geol. 208, 127e143.

Pohl, M.D., Pope, K.O., Jones, J.G., Jacob, J.S., Piperno, D.R., deFrance, S.D., Lentz, D.L.,Gifford, J.A., Danforth, M.E., Josserand, J.K., 1996. Early Agriculture in the MayaLowlands. Lat. Am. Ant. 7, 355e372.

Prost, M.T., 1989. Coastal dynamics and chenier sands in French Guiana. Mar. Geol.90, 259e267.

Roosevelt, A.C., 1980. Parmana, Prehistoric Maize and Manioc Subsistence along theAmazon and Orinoco. Academic Press, New York.

Rostain, S., 1991. Les Champs Surélevés Amérindiens de la Guyane. ORSTOM,Cayenne.

Rostain, S., 1994. L’occupation amérindienne ancienne du littoral de Guyane. TDM129. Editions d’ORSTOM. 2 volumes.

Rostain, S., 2008a. Agricultural earthworks on the French Guiana coast. In:Silverman, H., Isbell, W. (Eds.), Handbook of South American Archaeology.Springer/Kluwer/Plenum, New York, pp. 217e233.

Rostain, S., 2008b. The archaeology of the Guianas: an overview. In: Silverman, H.,Isbell, W. (Eds.), Handbook of South American Archaeology. Springer/Kluwer/Plenum, New York, pp. 279e302.

Rostain, S., 2010. Archéologie de l’ouest guyanais: le site de Sable Blanc. In: Barone-Visigalli, E., Roosevelt, A., Police, G. (Eds.), Amaz’hommes. Sciences de l’hommeet sciences de la Nature en Amazonie. Ibis Rouge Éditions, Cayenne.

Rostain, S., Versteeg, A.H., 2004. The Arauquinoid tradition in the Guianas. In:Delpuech, A., Hofman, C.L. (Eds.), Late Ceramic Age Societies in the EasternCaribbean. International Series 1273. British Archaeological Reports, Oxford, UK,pp. 233e250.

Saavedra, O., 2009. Culturas Hidráulicas de la Amazonía Boliviana. Oxfam, La Paz.Sanders, W.T., Parsons, J.R., Santley, R., 1979. The Basin of Mexico: Ecological

Processes in the Evolution of Civilization. Academic Press, New York.Siemens, A.H., Hebda, R.J., Navarrete Hernández, M., Piperno, D.R., Stein, J.K., Zola

Baez, M.G., 1988. Evidence for a cultivar and a chronology from patternedwetlands in central Veracruz, Mexico. Science 242, 105e107.

Twiss, P.C., Suess, E., Smith, R.M., 1969. Morphological classification of grass phy-toliths. Soil Sci. Soc. Am. J. 33, 109e115.

Van den Bel, M., 2009. The funerary deposits of Iracoubo: results of a preventiveexcavation of a pre-Columbian necropolis in French Guiana. Amazônica 1,230e249 (translated from French).

Versteeg, A.H., 2003. Suriname before Columbus. Stichting Surinaams Museum,Paranaibo.

Watling, Iriarte. n.d. Phytolith reference collection of modern plants from FrenchGuiana coastal savanas. Manuscript on file. Archaeobotany and PaleoecologyLaboratory, Department of Archaeology, University of Exeter.

Whitmore, T.M., Turner II, B.L., 2001. Cultivated Landscapes of Middle America onthe Eve of Conquest. Oxford University Press, Oxford.

Wiseman, F.M., 1983. Analysis of pollen from the fields at Pulltrouser Swamp. In:Turner II, B.L., Harrison, P.T. (Eds.), Pulltrouser Swamp: Ancient Maya Habitat,Agriculture and Settlement in Northern Belize. University of Texas Press, Austin,pp. 105e119.

Zucol, A.F., 2000. Fitolitos de Poaceae de Argentina III. Fitolitos foliares de especiesdel genero Paspalum (Paniceae) en la Provincia de Entre Ríos. Darwiniana 38,11e32.