83-7 The Fingerprint of Fire on Quartz Luminescence in the Critical Zone

Abstract:

Fire is an important agent in shaping critical zone processes related to ecosystem dynamics, sediment generation and transport and hillslope hydrology. Remote sensing, geomorphic and hydrologic tools have been deployed to assess regions of greatest post-fire hazards from debris flows and landslides and to characterize the impact wildfires on catchments. Key to understanding the magnitude of post-fire hazards is to characterize fire intensity (heat energy released by combustion), which is commonly reflected as a burn severity metric based on impacts to vegetation. The luminescence sensitivity (intensity of luminescence signal generated per dose of absorbed radiation) of quartz sand may provide an alternate metric to characterize fire intensity and identify thermal exposure of soils and sediment. Although quartz sensitivity is partly controlled by source rock type, it is also enhanced through repeated exposure to Earth-surface processes during weathering, transport, and sediment recycling. Exposure of quartz sand to high thermal temperatures has been shown to change quartz sensitivity, perhaps in proportion to the intensity and duration of heat exposure.  Here we compile quartz sensitivity results from surface soils that were exposed to a range of fire conditions and compare with adjacent samples collected from non-burned settings. Results test if the quartz in burned soils have greater luminescence sensitivity and if the magnitude of sensitivity is related to burn severity.

Geological Society of America Abstracts with Programs. Vol. 58, No. 5, 2026

doi: 10.1130/abs/2026AM-20387

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