Reconstruction of Mayan induced soil erosion during the Pre-Classic and Classic period from world’s
largest beach ridge plain.
References: Cioffi-Revilla, C. and T. Landman, 1999. Evolution of Maya Polities in the Ancient Mesoamerican System. International Studies Quarterly 43(4), 559-598
Nooren, C.A.M., Hoek, W.Z., Tebbens, L.A. and Martin del Pozzo, A.L., 2009. Tephrochronological evidence for the late Holocene eruption history of el Chichón Volcano, Mexico. Geofisica Internacional 48, 97-112.
Hypothesis: Deforestation and periods of intensive land use in the watershed accelerated soil erosion and increased sediment supply to inland lakes and depressions.
In the hinterland eroded soil forms marked beds of so called ‘Maya Clay’ in many lake records. We hypothesise that human induced soil erosion also resulted in large supply of sandy sediment to the rivers and contributed to the development of the extensive beach ridge plain at the Gulf of Mexico coast.
Pages 2014
grant 821.01.007
1. Utrecht University; 2. Groningen University; 3. Michigan State University; 4. VU University Amsterdam
Kees Nooren
1, Wim Z. Hoek
1, Hans van der Plicht
2, Remke L. Van Dam
3, Maarten Prins
4, Tim Winkels
1and Hans Middelkoop
1c.a.m.nooren@uu.nl
Results
- Very high accumulation rates (average 3 million m
3/yr) compared to other large beach ridge systems (0.1 - 1.7 million m
3/yr);
- no significant differences in rates between the Pre-Classic, Classic and Post-Classic period;
- no clear indications for human induced sediment supply to the beach ridge system during the Pre-Classic and Classic period;
- beach ridge sands are dominated by volcaniclastic sediments;
- high progradation rates occurred after volcanic eruptions of El Chichón volcano and during erosion of the SP y SP promontory.
Acknowledgement:
INEGI is thanked for providing the LIDAR data.
Conclusion
The data so far is not supporting our
hypothesis.
Transect B
Transect A-HR
A large promontory was formed between ~2500 BC and AD 1050 when the San Pedro y San Pablo was the main river outlet of the Usumacinta drainage basin.
Millennial - Centennial time-scale
We use the beach ridge progradation rate as a proxy-
measure of received sediment fluxes. Progradation rates are transformed to accumulation rates using the 3D geometry of the beach ridges to account for the effects of changes in
accommodation space.
1.7 4.3
2.8 2.4
3.6
4.1
2.5
0 1 2 3 4 5 6 7
-2500 -1500 -500 500 1500
calibrated age (yr AD) accumulation rate (*106 m3 /yr)
0 20 40 60 80 100
number of Mayan polities
Pre-Classic Classic
Early Middle Late Early L. T. Early Late
Post-Class.
average 2200 BC - AD 2008
Figure 1B: Estimated accumulation rates compared to the number of Mayan polities
(kingdoms) in the Mesoamerican system (modified from Cioffi-Revillia and Landman, 1999)
Figure 1A: Location map of the study site. The last 4200 years of beach ridge formation is divided into seven periods. For each period the accumulation rate has been estimated (see figure 1B).
0 5 10 15 20 25
10 100 1000
particle diameter (um)
volume (%)
End Member 1 End Member 2 End Member 3 End Member 4
125
180 220
325
90 % of the grain size variability can be explained by a four end member model.
Centennial - Decennial time-scale
We are currently investigating a 3 km long section of transect A, covering the Classic period. The section has been sampled at very high resolution and a detailed age-distance model is under construction based on AMS dated leaf fragments found in organic
debrislayers and supported by Ground Penetrating Radar measurements that reveal the internal architecture of the beach ridges. To determine the provenance of the sand, grain size and heavy mineral analyses are carried out on selected samples. End member
modeling is used to ‘unmix’ the samples and to define the composition and relative abundance of the individual sediment populations.
~ AD 1050
erosion of the SP y SP promontory increases?
~ AD 539 eruption of
El Chichón volcano
Figure 2: Age distance model for Transect A-HR. Figure 3: Cross section of transect A-HR. Notice clear trends in grain sizes, like the coarsening upward trend. The hatched areas indicate samples with elevated concentrations of magnetite.
