A MULTI-PROXY RECORD OF LATE-GLACIAL TO HOLOCENE CLIMATE FROM LAKE BLAUVELT, NEW JERSEY

Lake Blauvelt is a deglacial lake created during the retreat of the Laurentide ice sheet (LIS), in the Feltville sedimentary formation of the Piedmont province of New Jersey. We present a lacustrine record from a six-meter sediment core of Lake Blauvelt, which provides organic geochemical evidence for the retreating time of LIS and reconstructs paleoclimate changes since the last deglaciation.

The six-meter sediment core was constrained in absolute time by ten radiocarbon dates on seeds and wood fragments and revealed a complete paleolimnology record back to ~15,000 years BP. The core was divided into ten-centimeter sections, and one-gram samples were extracted at 3-4 cm intervals for analysis. Particle size analysis, total organic carbon, and total nitrogen were analyzed on the same subsamples. In addition, n-alkanes were extracted and measured together with their carbon and hydrogen isotopes.

These proxies reveal similar patterns of variability, indicating that the time of vegetation began to cover the region as the Southeastern portion of the LIS retreated from the area ~15-16 kyr. After that, the lake experienced a short-wet period of ~14-13 kyr. Lake recharge increased following the termination of the Younger Dryas as the LIS was undergoing the final stages of melting. From 8 kyr, the LIS deglaciation was completed, and the lake experienced a dry period. It is worth noting that the source of precipitation has also changed, which contributes to the sudden isotopes sharp change. This was followed by a wet period of 4-1.7 kyr before the vegetation might be changed by European settlement.