Lake Peten-Itza (Guatemala) Drilling Project http://plaza.ufl.edu/hodell
Transcription
Lake Peten-Itza (Guatemala) Drilling Project http://plaza.ufl.edu/hodell
Lake Peten-Itza (Guatemala) Drilling Project Website: http://plaza.ufl.edu/hodell Sponsored by: International Continental Drilling Program (ICDP) Peten Lake District Peten, Guatemala Guatemala Yaxha Perdida Sacnab Sacpuy Macanche Peten-Itza Quexil Petenxil Salpeten Latitude 16o55’N Longitude 89o50’W Elevation 110 m Surface area 99.6 km2 Length >20 km Width 3-4 km Max. depth 160 m Why drill Lake Peten-Itza? Legend ! Primary Sites ") Secondary Sites Depth (m) NoData 0 - 15 N 15 - 30 Jobompiche Launch 30 - 45 Site 45 - 60 60 - 75 Camino Real 75 - 90 90 - 105 105 - 120 120 - 135 135 - 160 El Remate San Andreas Flores 0 4 8 Kms Tropic of Cancer 17oN Equator Annual Rainfall (mm/yr) Peten-Itza Water depth 60.9 m •Holocene piston cores have demonstrated the potential of Lake Peten Itza sediments for paleoclimatic studies and their correlation to the Cariaco Basin. Gypsum Haug et al. (2001) Subtropical Dry Broadleaf Subtropical Moist Broadleaf Mangrove Tropical/Subtropical Moist •The Peten is set within the Maya forest, which is the largest continuous expanse of tropical forest remaining in Central America and Mexico today. •Pollen is generally well preserved in Peten lake sediments, providing an opportunity to study changes that occurred in lowland Neotropical vegetation in response to climate change, fire, and human disturbance. •The Peten has had a 4000-yr history of human occupation by the Maya civilization. •Cores from the deep basins of Peten-Itza will permit comparative studies of the complex interactions among humans, climate, and environment. HCO Ca 3 SO Mg 4 Cl Na pH = 8.0 Ca 2+ Mg 2+ K+ Na + Cl SO 42HCO 3- 3.68 meq l-1 1.88 meq l-1 0.10 meq l-1 0.45 meq l-1 0.32 meq l-1 3.05 meq l-1 2.74 meq l-1 Total 12.22 meq l-1 •High organic matter, high temperature, and presence of dissolved and solid sulfate (CaSO4) constitute a “bio-reactor” for subsurface microbial activity. CaCO3 CaMg(CO3)2 CaSO4 OrgC •The sediments and pore waters of Lake Peten-Itza provide an opportunity to conduct integrated studies of microbial ecology, biogeochemistry, and mineral authigenesis/diagenesis. 1. Paleoclimatic history of the northern lowland Neotropics on orbital to suborbital time scales emphasizing marineterrestrial linkages (e.g., Cariaco Basin, Greenland ice cores, etc.). 2. Paleoecology and biogeography of the Maya tropical lowland forest and the response of vegetation to disturbance by humans, climate change, and fire. 3. Biogeochemical cycling in deep lake sediments including integrated studies of subsurface microbiology, geochemistry (interstitial waters), and mineral authigenesis/diagenesis. N 1999 2002 (t) Gypsum Core 11A (60.9 m) Scanning XRF (1-mm spatial resolution) ) m 440 c ( 7,025 cal yr BP e460 r o C 7,470 cal yr BP n480 i 8,720 cal yr BP h t 500 p e D 9,475 cal yr BP 520 Holocene Pleistocene 540 10,820 cal yr BP 11,015 cal yr BP 0 6000 Sulfur (cts) Sulfur (cts) 12000 (t) (Holocene)