Bruce H. Dahlin

Holocene climatic and human influences on lakes of the Yucatan Peninsula, Mexico: an interdisciplinary, palaeolimnological approach

We used palaeolimnological techniques to examine effects of Holocene climate change and human influence on lakes of the Yucatan Peninsula, Mexico. The three study lakes are located along a west-east transect that represents a gradient of increasing modern precipitation and density of former Maya settlement. At Lake Coba, an 880-cm sediment core yields a complete record of lacustrine sedimentation that began when the lake first filled ∼8000 BP as groundwater level rose in response to rising sea level and increased precipi tation. Diatom, ostracod, and δ 18O evidence indicate that Lake Coba was initially shallow and saline. Coba, presently in the region of greatest rainfall, showed more episodic water-level changes than Lake San Jose Chulchaca or Lake Sayaucil. High lake level and fresh water were evident at 440 cm (∼2600 BP), followed by a decline in water levels and an increase in total ionic salinity to the present time. In a 613-cm core from Sayaucil, in the intermediate precipitation zone, total salinity was high between 600 and 400 cm (∼3050 and 2000 BP), followed by consistently higher water levels. Salinity was high in the lower portion of a 110-cm San Jose Chulchaca core (beginning ∼1860 BP), followed by a gradual and consistent freshening of water to the present time. Trophic state changes and human influence on lakes were evaluated using diatom, δ13C, total P, sedimentary organic matter, and preliminary pollen data. Maximal human disturbance at Lake Coba, a densely settled Maya urban site, occurred during a deep-water event at 440 cm, followed by a decline in human influence and trophic state to the present time. Trophic state and linear sedimentation rates in Sayaucil increased significantly above 400 cm (after ∼2000 BP), probably associated with initial Maya settlement near Xtojil and subsequent small- scale farming. Limnological disturbance may have preceded the period of maximal human occupation because initial land clearance and consequent soil erosion probably affected water quality substantially. San Jose Chul chaca lacks archaeological evidence of human occupation in the drainage, and shows gradual changes in trophic state not caused by human disturbance. With the exception of a 14C date on wood from the base of the Coba core, 14C dates and chronologies may be artificially old as a consequence of hard-water-lake error. Trophic state changes in the study lakes were generally consistent with known patterns of human settlement and popu lation change. Late-Holocene water-level fluctuations were most pronounced in Lake Coba in eastern Yucatan, where modern rainfall is currently greatest, but lake level is generally lower than during much of the past. Lake level was relatively constant in Sayaucil in the central peninsula, whereas lake level in San Jose Chulchaca in the arid western portion of the peninsula increased gradually over time.

In search of an ancient Maya market

Market economies are notoriously difficult to identify in the archeological record. This is particularly true in the subtropical Maya lowlands of Mexico, Guatemala, and Belize because most utilitarian items and consumables were made of highly perishable materials. We explore the hypothesis that ancient marketplaces can be identified through analysis of chemical residues in soils from open and easily accessible spaces in and about ancient Maya cities. We compared soil chemical signatures from a credible ancient marketplace location in the specialized trade center of Chunchucmil, Yucatan, Mexico to those from a modern marketplace at Antigua, Guatemala. We found extraordinarily high concentrations of phosphorus and zinc in the soil of Chunchucmils proposed marketplace and the same high concentrations correlate well with food preparation and vegetable sales areas at the modern marketplace. These methods hold promise in resolving the vexing question of how large ancient Maya urban populations were sustained.

RECONSTRUCTING AGRICULTURAL SELF-SUFFICIENCY AT CHUNCHUCMIL, YUCATAN, MEXICO

The Pakbeh Regional Economy Program is studying the vexing questions of economic life among the ancient Maya in northwestern Yucatan, Mexico. The region constitutes an ideal laboratory in which to investigate these questions, as it has very limited agricultural potential and fewer options for intensification than are found in the southern and central lowlands, yet many times more people lived here during the Classic period than can eke out a living today, and it has abundant evidence of market trade. Because crop yields in outfields are very low, and known intensification techniques are possibly incapable of sufficient yield enhancement, we anticipated that it would be an easy task to demonstrate that this population was dependent on imports of food and other necessities of life from beyond the region and therefore had a complex exchange economy. Twelve years later, we report on how wrong we were. We are still struggling with an evaluation of agricultural insufficiency. We explore the many and varied lines of evidence we have pursued and the confounding factors inherent in them, including problems with reconstructing ancient population size, equating contemporary and historical crop yields and farming practices, as well as ancient with modern environmental conditions, and hypothesizing potential forms of agricultural intensification, including intensive fertilization and other yield enhancement techniques, and reliance on alternative crops. The best that we can say at this juncture is that using contemporary production and consumption standards, the most conservative population estimates, and the most liberal estimates of available land in the surrounding region, we can conclude only that regional agricultural self-sufficiency remains unlikely but not proved. What initially seemed like an archaeological “no-brainer” has required us to delve into the realm of archaeological epistemology that we would like to share with our colleagues.

The Dirt on Food: Ancient Feasts and Markets Among the Lowland Maya

Archaeologists have long tended to conflate political evolutionary stages with Polanyi’s (1957) modes of exchange: bands and tribes with reciprocity, chiefdoms and early states with redistribution, and more developed states with market exchange. According to this scheme, the Classic lowland Maya (Fig. 1) are relegated to chiefdoms or an early state level of political organization with redistribution as the primary, or at least the most ostensible, mode of exchange: control of all or most labor, production, and the dominant mode(s) of exchange were concentrated in a highly centralized authority figure – a paramount chief or king and/or a polyarchy of elite kin groups – who traded exotic goods among themselves. Elites traded with each other while extracting other goods, most importantly agricultural output, from the majority population through taxes and tribute to maintain themselves and a civic/religious infrastructure they symbolized. Those at the top of the hierarchy then redistributed some of these goods down the social ladder in payment for fealty, loyal service, and the like, often at communal rituals and feasts. These Neoevolutionary concepts – bands, tribes, chiefdoms, and states, and the various forms of reciprocity, redistribution, and market exchange – are heuristic devices, or broadly conceptualized and loosely correlated classificatory forms of social and economic organization, designed to facilitate cross-cultural comparisons and to fill in holes where hard data are lacking. Obviously, they have been highly useful in constructing models. Therefore, the pocket critique of their application to the Maya that follows is not intended to challenge their utility, nor to rewrite Neoevolutionary theory, but rather to emphasize that these concepts have historically tended to narrow our perceptions and made it difficult to identify market exchange as an important facet of Classic Maya economies (see e.g., Yoffee 1977; West 2002; Sharer and Golden 2004; Rice 2008).

CLIMATE CHANGE AND THE END OF THE CLASSIC PERIOD IN YUCATAN: Resolving a paradox

Recent paleoecological research indicates that the collapse of Classic Maya civilization in the southern and central Maya Lowlands coincided with the onset of prolonged and severe drought conditions around A.D. 850. The northern Maya Lowlands is an area that receives much less rainfall today and probably did so throughout most of the recent past; nevertheless, many northern lowland sites not only persisted throughout the period of the drought but actually prospered under the hegemony of Chichen Itza. This paper attempts to resolve this obvious paradox by examining the adaptive responses made by the northern Maya. The northern lowlands had a slight edge in adapting to the climate change that apparently devastated the south because it had easy access to a diversity of resources that no doubt contributed to Chichen Itzas subsistence security and the enrichment of its realm. However, massive transformations in the political and religious domains were every bit as necessary to Chichen Itzas adaptive strategy. The seeming paradox of Chichen Itzas successful adaptation to environmental adversity represents a cautionary tale about the dangers of oversimplification that are inherent in environmental deterministic thinking. Paradoxes of this kind arise when the primacy of cultural factors in adaptive processes is ignored.

Punta Canbalam in Context

Investigations at Punta Canbalam on the Gulf Coast of Campeche reveal it is probably the largest of several important but underreported trading sites on the pan-Mesoamerican maritime trade route. The coastline has been unstable for the last thousand years, subjecting the site to sea level changes and repeated episodes of beach erosion and redeposition. The relatively dense scatter of temporally mixed, highly weathered sherds and other artifacts on an exceedingly narrow, modern beach indicates that it is all secondarily deposited and that its original location was offshore. An interdisciplinary team is beginning to recognize clues in its environmental and cultural contexts as to where this peripatetic site was originally located and the extent to which it depended upon exchanges of salt, petty commodities from inland, and canoe-borne exotics from afar. This predominantly Terminal Classic and Early Postclassic site likely served as a port of entry for obsidian, jade, fine-paste ceramics, and other goods for the nearby inland city of Chunchucmil. It also probably supplied the interior with marine and estuarine food and ornamental and ritual products in exchange for inland agricultural products and other items.

Site and Community at Chunchucmil and Ancient Maya Urban Centers

Abstract Classic Period lowland Maya urban centers often lack sharp boundaries due to progressive dispersal of residential settlement. This dispersal gives rise to questions about the concept of site and the notion of community affiliation. Research on settlement patterns at Chunchucmil, an urban center in NW Yucatan, Mexico, dating to the 5th and 6th centuries A.D., explores the issue of site boundaries and the social and economic implications of such boundaries. Detailed mapping, test pitting, and reconnaissance reveal that Chunchucmil had three densely occupied, concentric, contemporaneous zones of settlement covering between 20 and 25 sq km and inhabited by a population of up to 42,500. Data from both within and beyond the density thresholds marking the edge of the city imply the existence of communities whose boundaries do not always follow those of the site. A portion of the hinterland settlement close to the edge of the city shows stronger economic and social connections with the city, for example. These connections enable the delineation of Greater Chunchucmil, extending 5 km from Chunchucmils center. The work at Chunchucmil also allows comparison with other large Maya cities that have been systematically documented. This comparison highlights considerable variability in Maya urban forms and in how these cities relate to their peripheries.

Two millennia of tropical cyclone-induced mud layers in a northern Yucatán stalagmite : multiple overlapping climatic hazards during the Maya Terminal Classic “megadroughts”

An annually laminated stalagmite from the northern Yucatan Peninsula contains mud layers from 256 cave flooding events over 2240 years. This new conservative proxy for paleotempestology recorded cave flooding events with a recurrence interval of 8.3 years during the twentieth century, with the greatest frequency during the twentieth century and the least frequent during the seventeenth century. Tropical cyclone (TC) events are unlikely to flood the cave during drought when the water table is depressed. Applying TC masking to the Chaac paleorainfall reconstruction suggests that the severity of the Maya “megadroughts” was underestimated. Without a high-resolution radiometric geochronology of individual local TC events, speleothem isotope records cannot resolve whether the Terminal Classic Period in the northern Maya Lowlands was punctuated by several brief drought breaks with normal TCs, or whether the region was very dry and peppered by unusually severe and frequent hurricane seasons.

LIVING IN THE CITY: SETTLEMENT PATTERNS AND THE URBAN EXPERIENCE AT CLASSIC PERIOD CHUNCHUCMIL, YUCATAN, MEXICO

Abstract In this paper we illustrate the distinctive settlement patterns of the city of Chunchucmil during its largest occupation in the middle of the Classic period (a.d. 400–650). The unusually dense urban settlement showcased a network of boundary walls and chichbes surrounding residential groups and narrow streets winding between the tightly bounded houselots. Using a sample of 392 completely and unambiguously bounded houselots, we review the basic characteristics, the structural composition, and variability of late Early Classic and early Late Classic residential groups. Then, we explore how these city dwellers may have experienced their urban environment. Our focus is on understanding how the material aspects of the socially constructed space affected peoples practices and how this materiality helped create and define specific household identities as well as extra-household social bonds.