skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: REFINING CERAMIC CHRONOLOGY AND EPICLASSIC REOCCUPATION AT LA VENTILLA, TEOTIHUACAN USING TRAPEZOIDAL BAYESIAN MODELING
Accelerator mass spectrometry radiocarbon (AMS 14C) dates ( n = 78) from human bone collagen were analyzed in the largest high-resolution chronology study to date at the ancient city of Teotihuacan in central Mexico (ca. AD 1–550). Samples originate from the residential neighborhood of La Ventilla, located in the heart of this major urban center. Here, a trapezoidal model using Bayesian statistics is built from 14C dates combined with data derived from the stylistic analysis of ceramics from burial contexts. Based on this model, we suggest possible refinements to Teotihuacan’s ceramic chronology, at least within the La Ventilla neighborhood. We also explore the abandonment and reoccupation of La Ventilla after the political collapse of Teotihuacan in the Metepec and Coyotlatelco phases. Findings suggest that these ceramic phases began earlier than is currently projected and that the well-documented abandonment period of La Ventilla may have occurred more abruptly than originally estimated.  more » « less
Award ID(s):
1927690
PAR ID:
10405344
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
Radiocarbon
ISSN:
0033-8222
Page Range / eLocation ID:
1 to 25
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Jull, A.J.T. (Ed.)
    ABSTRACT. We present two new Bayesian 14C models using IntCal20 that incorporate 17 new calibrated AMS ages for Early Bronze IV Tell Abu en-Ni‘aj and Middle Bronze Age Tell el-Hayyat, located in the northern Jordan Valley, Jordan. These freshly augmented suites of carbonized seed dates now include 25 AMS dates from Tell Abu en-Ni‘aj and 31 AMS dates from Tell el-Hayyat. The modeled founding date for Tell Abu en-Ni‘aj strengthens an emerging high chronology for Early Bronze IV starting by 2500 cal BC, while the end of its habitation by 2200 cal BC may exemplify a regional pattern of increasingly pervasive abandonment among late Early Bronze IV settlements in the Southern Levant. In turn, our modeled date for the Early Bronze IV/Middle Bronze Age transition at Tell el-Hayyat around 1900 cal BC pushes this interface about a century later than surmised traditionally, and its abandonment in Middle Bronze III marks an unexpectedly early end date before 1600 cal BC. These inferences, which coordinate Bayesian AMS models and typological ceramic sequences for Tell Abu en-Ni‘aj and Tell el-Hayyat, contribute to an ongoing revision of Early and Middle Bronze Age Levantine chronologies and uncoupling of their attendant interpretive links between the Southern Levant and Egypt. 
    more » « less
  2. This article presents the research questions and initial results of the Project Hacienda Metepec (2021-2022). Examination of the archaeological background and the recent mapping of this peripheral neighborhood of Teotihuacan allows for a discussion about its formation process, at the margin of the city. The neighborhood could have resulted from distinct urban growth processes, including planning, following the principles applied in the central sectors of Teotihuacan or, at the contrary, less planned, or unplanned sprawl. First observations of architectural elements and spatial organization suggest planning, however, the contrast between the monumentality of the neighborhood core and its relative spatial isolation remain unclear 
    more » « less
  3. In this study, we present a comprehensive atmospheric radiocarbon (14C) record spanning from 1940 to 2016, derived from 77 single tree rings of Cedrela odorata located in the Eastern Amazon Basin (EAB). This record, comprising 175 high-precision 14C measurements obtained through accelerator mass spectrometry (AMS), offers a detailed chronology of post-1950 CE (Common Era) 14C fluctuations in the Tropical Low-Pressure Belt (TLPB). To ensure accuracy and reliability, we included 14C-AMS results from intra-annual successive cuts of the tree rings associated to the calendar years 1962 and 1963 and conducted interlaboratory comparisons. In addition, 14C concentrations in 1962 and 1963 single-year cuts also allowed to verify tissue growth seasonality. The strategic location of the tree, just above the Amazon River and estuary areas, prevented the influence of local fossil-CO2 emissions from mining and trade activities in the Central Amazon Basin on the 14C record. Our findings reveal a notable increase in 14C from land-respired CO2 starting in the 1970s, a decade earlier than previously predicted, followed by a slight decrease after 2000, signaling a transition towards the fossil fuel era. This shift is likely attributed to changes in reservoir sources or global atmospheric dynamics. The EAB 14C record, when compared with a shorter record from Muna Island, Indonesia, highlights regional differences and contributes to a more nuanced understanding of global 14C variations at low latitudes. This study not only fills critical spatial gaps in existing 14C compilations but also aids in refining the demarcation of 14C variations over South America. The extended tree-ring 14C record from the EAB is pivotal for reevaluating global patterns, particularly in the context of the current global carbon budget, and underscores the importance of tropical regions in understanding carbon-climate feedbacks. 
    more » « less
  4. In this study, we present a comprehensive atmospheric radiocarbon (14C) record spanning from 1940 to 2016, derived from 77 single tree rings of Cedrela odorata located in the Eastern Amazon Basin (EAB). This record, comprising 175 high-precision 14C measurements obtained through accelerator mass spectrometry (AMS), offers a detailed chronology of post-1950 CE (Common Era) 14C fluctuations in the Tropical Low-Pressure Belt (TLPB). To ensure accuracy and reliability, we included 14C-AMS results from intra-annual successive cuts of the tree rings associated to the calendar years 1962 and 1963 and conducted interlaboratory comparisons. In addition, 14C concentrations in 1962 and 1963 single-year cuts also allowed to verify tissue growth seasonality. The strategic location of the tree, just above the Amazon River and estuary areas, prevented the influence of local fossil-CO2 emissions from mining and trade activities in the Central Amazon Basin on the 14C record. Our findings reveal a notable increase in 14C from land-respired CO2 starting in the 1970s, a decade earlier than previously predicted, followed by a slight decrease after 2000, signaling a transition towards the fossil fuel era. This shift is likely attributed to changes in reservoir sources or global atmospheric dynamics. The EAB 14C record, when compared with a shorter record from Muna Island, Indonesia, highlights regional differences and contributes to a more nuanced understanding of global 14C variations at low latitudes. This study not only fills critical spatial gaps in existing 14C compilations but also aids in refining the demarcation of 14C variations over South America. The extended tree-ring 14C record from the EAB is pivotal for reevaluating global patterns, particularly in the context of the current global carbon budget, and underscores the importance of tropical regions in understanding carbon-climate feedbacks. 
    more » « less
  5. Abstract. Annually laminated lake sediment can track paleoenvironmental change at high resolution where alternative archives are often not available. However,information about the chronology is often affected by indistinct and intermittent laminations. Traditional chronology building struggles with thesekinds of laminations, typically failing to adequately estimate uncertainty or discarding the information recorded in the laminations entirely,despite their potential to improve chronologies. We present an approach that overcomes the challenge of indistinct or intermediate laminations andother obstacles by using a quantitative lamination quality index combined with a multi-core, multi-observer Bayesian lamination sedimentation modelthat quantifies realistic under- and over-counting uncertainties while integrating information from radiometric measurements (210Pb,137Cs, and 14C) into the chronology. We demonstrate this approach on sediment of indistinct and intermittently laminatedsequences from alpine Columbine Lake, Colorado. The integrated model indicates 3137 (95 % highest probability density range: 2753–3375) varveyears with a cumulative posterior distribution of counting uncertainties of −13 % to +7 %, indicative of systematic observerunder-counting. Our novel approach provides a realistic constraint on sedimentation rates and quantifies uncertainty in the varve chronology byquantifying over- and under-counting uncertainties related to observer bias as well as the quality and variability of the sediment appearance. The approachpermits the construction of a chronology and sedimentation rates for sites with intermittent or indistinct laminations, which are likely moreprevalent than sequences with distinct laminations, especially when considering non-lacustrine sequences, and thus expands the possibilities ofreconstructing past environmental change with high resolution. 
    more » « less