Geochemical, pollen and bulk density record of MIS11-1 from Lake Petén Itzá (Site PI-6) Guatemala

We present data on bulk density, inorganic geochemistry (Ti, Ca, Al, Mn, and Fe), and pollen (Quercus, Moraceae, Pinus, tropicality index) from Lake Petén Itzá. In 2006, Lake Petén Itzá was drilled by the International Continental Scientific Drilling Program (ICDP), obtaining seven lacustrine sediment records: PI-01, PI-02, PI-03, PI-04, PI-06, PI-07, and PI-09. Here, we present data from Site PI-6 (17.00027°N, -89.78478°W), located in the northern part of the lake. At the Continental Scientific Drilling Facility at the University of Minnesota, bulk density was analyzed using a GEOTEK multi-sensor core logger with gamma-ray attenuation, with measurements taken every 0.5 cm. Inorganic geochemistry data were obtained using X-ray fluorescence (XRF) with a Cox Analytical Itrax Core Scanner. PI-6 sediments were measured with a Mo-tube at 30 kV, 20 mA, 30-second exposure, at 0.5-cm resolution. XRF data are presented in counts per second (cps). Subsequently, data were transformed to centered log-ratio (CLR). CLR values were obtained by dividing each element's concentration by the geometric mean of the elements measured at the same depth, then taking the natural logarithm of the ratio. CLR results have no units. Pollen data include a dataset of 39 samples from Site PI-6, previously published by Correa-Metrio et al. (2012). For each sample, pollen abundances were converted into percentages of the pollen sum. A "tropicality index" was calculated as ln(Moraceae% + 1) / ln(Quercus% + Pinus% + 1). Depth data correspond to the "Core composite depth below lake floor (CCLF)" or "Master composite depth (MCD)", which accounts for core recovery gaps and depth inconsistencies, while age data are based on the age-depth models presented by Martínez-Abarca et al. (2024).