60-34 12,000 Years of Environmental Change in New England: A Dual-Site Paleolimnological Study

Session: 2YC and 4YCU Geoscience Student Research Poster Showcase

Presenting Author:

Authors:

Abstract:

Middle Mountain Bog (MMB), at 44°02'05.8"N, 71°05'09.6"W, and Black Spruce Pond (BSP), at 43°50'20.5"N, 71°13'54.2"W, are in the White Mountain region of New Hampshire. In 2024, MMB sediment cores (~2.1 and ~1.6-meters-long) were collected using a piston corer from the soil surface. In 2025, BSP sediment cores were collected using a Uwitec surface corer and a piston corer, ~0.32 and ~3.4-meters-long respectively, from the ice surface in 4.78 m water depth. MMB and BSP represent different depositional environments. BSP is a kettle pond on flat land beside White Lake and multiple rivers, 139 m asl. MMB is a peat bog fed solely by surface runoff, at 511 m asl in a saddle on Middle Mountain, ~20 miles northeast of BSP. We report the environmental records of MMB and BSP from deglaciation to the present day using standard paleolimnological methods: split core descriptions, loss-on-ignition (LOI), magnetic susceptibility, and radiocarbon dating. MMB LOI increases steadily after deglaciation except for prominent changes at ~85, ~130, and ~150 cm. Changes at ~85 and ~130 cm may be evidence of a sedimentation hiatus or local fires. BSP LOI increases erratically after deglaciation until ~245 cm, after which LOI is constant. Noticeably, LOI of both BSP and MMB is very high (up to 100%). This data will be combined with charcoal counts, pollen, and tree ring-fire-scar chronologies to reconstruct Holocene wildfire history throughout the White Mountain region. The goal of this larger project is to improve future USFS forest management in New Hampshire. 

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-8533

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