Whenever we have the opportunity, we generate or collect reference blocks of burned features to be processed into micromorphological thin sections. We use these thin sections for teaching and reference purposes.
Here is an example of a simulated hearth sequence that Susan Mentzer prepared inside a small wax cube mold. The basal layer is clay loam that was heated in an oven at 500⁰C to obtain a red color. The middle layer is charcoal. The upper layer is wood ash. Both the charcoal and wood ash were obtained by burning braches, twigs, needles and cones of Scotts pine (Pinus sylvestris) in a barbeque grill. This small reference sample is meant to simulate an ideal hearth stratigraphy of heated substrate, overlain by charcoal and ash. The resulting thin section is used for teaching purposes. Left image: PPL. Right image: XPL.