279 The Current Understanding of the Role of Wetland Hydrology in the Cycling of Elements and other Substances: A Technical Session in Memory of Paul H. Glaser

This session addresses how wetland hydrology affects the cycling of carbon and other elements from both a scientific and regulatory perspective. Contributors to this session will address how changing wetland hydrology affects geochemical cycling on a global to local basis.

Wednesday, 22 October 2025
1:30 PM - 5:30 PM
HBGCC, 214A

Tracing Sources of Discrete Groundwater Discharge to Pools in Regional Raised Northern Peat Bogs

Paper number: 279-12
Program: Technical Sessions
Time: 4:35 PM – 4:50 PM

Authors

Abstract

Pools in raised northern peat bogs are commonly attributed to solely precipitation-fed (ombrogenous) hydrology as underlying confining sediments limit minerogenous groundwater inputs. Variations in microtopography paired with lateral surficial flows to topographic lows are assumed to control pool formation. However, geophysical imaging, including ground-penetrating radar and transient electromagnetics, has identified distinct contrasts in the composition of the mineral sediments beneath raised northern peat bogs. These contrasts in the mineral sediment have been modeled to influence peat pore water flow. Hydrogeophysical observations suggest that minerogenous groundwater, plumbed from permeable glacial structures, discharges to pools. Paired point measurements of temperature and specific conductance identify local signatures (insulated temperature and higher specific conductance) characteristic of minerogenous groundwater that contrast with typical peat pore water signatures (atmospherically regulated temperature, lower specific conductance) around the pools. Thermal infrared imagery at handheld and aerial scales reveals insulated temperature signals within pools, indicating advective heat transport from depth. Temperature variations with depth were recorded over time around pools using vertical temperature profilers to estimate hydrological fluxes. Surface water samples at locations with anomalous temperature and specific conductance signals are characterized by elevated concentrations of iron and manganese, supporting the concept that they are sourced from glacial aquifers. The preponderance of data support focused, possibly pipe-driven, minerogenous groundwater upwelling occurring to pools, likely partially driven by deeper geological structures directing minerogenous groundwater flowpaths upward in underlying glaciofluvial aquifers. Discharge through the peat matrix to the pools appears to be activated by precipitation events, recharging the underlying glaciofluvial aquifers and/or enhancing peat pore water circulation around pools. Variations in temperature and ionic constituents from upwelling minerogenous groundwater may influence redox conditions, vegetation composition/abundance, and carbon-cycling around pools at an unrecognized, localized scale in bogs.

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

doi: 10.1130/abs/2025AM-412705

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