T252 Lakes of the World through Time and Space II

Friday, 30 October 2020
10:00 AM - 2:00 PM
Meeting Rooms

A ~9.5-KYR RECORD OF PALEOENVIRONMENTAL CHANGES IN THE EASTERN LOWLANDS, GUATEMALA: NEW INSIGHTS FROM LAKE IZABAL

Paper number: T252-13
Program: Technical Sessions
Time: 12:45 PM – 1:00 PM

Authors

Abstract

Sedimentological information obtained from lake sediment cores has been widely used to infer environmental conditions around the world. As new Holocene records from Central America have become available, new hypotheses have emerged that potentially explain differences in environmental conditions inferred from closely spaced paleoclimate records. Here we present data from a 760-cm long sediment core obtained from Lake Izabal, eastern Guatemala, which covers the last ~9,500 years. We integrated radiocarbon, sedimentological, elemental abundances, and principal component analyses (PCA) to infer changes in erosion/precipitation, lake productivity, and lake water chemistry. During the early Holocene, from ca. 9,500 to ca. 8,300 cal yr BP, Lake Izabal was a shallow lake with minimal catchment erosion/precipitation, as indicated by the abundance of woody fragments, peat, and organic-rich mud, coupled with low PC-1 scores and Ti abundance values. Precipitation/erosion increased until 4,800 cal yr BP and remained high until 1,200 cal yr BP as indicated by an overall increase in the PC-1 scores and a progressive increase in Ti. There was then a decrease in precipitation/erosion ~1,200 years ago, as evident by a sharp decrease in magnetic susceptibility, terrigenic-derived elements, and PC-1 scores, which coincides with the well-known Maya droughts. Our results provide an almost complete Holocene sedimentological record from an area previously unstudied and show that the thick sedimentary infill in Lake Izabal can be used to improve our understanding of Neotropical climate.

Geological Society of America Abstracts with Programs. Vol. 52, No. 6

doi: 10.1130/abs/2020AM-357004

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