Burn Deposit Stratigraphy
Definition
The layered sequence of ash, charcoal, collapsed structural elements, and debris produced by a fire, recording the temporal order of combustion events and structural failure.
- Records
- Temporal order of combustion and structural collapse
- Typical layers
- Ash, charcoal, collapsed debris, floor covering
- Method
- Excavated in horizontal spits like an archaeological trench
- Use
- Distinguishes single-event burns from repeated or accelerant-fed events
Common questions
Why excavate a burn scene in layers rather than just clearing debris?+
Clearing debris in bulk destroys the sequence information. Excavating in thin, mapped spits preserves which layer sits above which, so investigators can tell whether a ceiling collapsed before or after the fire reached a given room, which helps reconstruct fire spread and origin.
Can burn deposit stratigraphy show more than one fire event?+
Yes. A buried ash layer sealed beneath later charcoal and collapse debris can indicate an earlier, separate burn episode at the same location, which is relevant when a scene shows evidence of repeated ignition attempts.
Related terms
- Calcined Bone
- Bone heated to above approximately 700°C, resulting in complete combustion of the organic component (collagen), leaving only mineral hydroxyapatite; characterised by white...
- Peri-Mortem Burning
- Burning that occurred at or very close to the time of death, while green (fresh) bone still contains its organic matrix. Distinguished...
- Pugilistic Posture
- The post-mortem flexion of the limbs and clenching of the hands caused by heat-induced differential contraction of flexor muscles. It indicates exposure...
- Seat of the Fire
- The point of ignition or the area of maximum burn intensity, identified by fire investigators from char patterns, spalling, and burning vectors....
- Wet Sieving
- The process of washing material through a mesh with water to separate and recover small fragments. Preferred for fire debris that has...