An experimental investigation, into the effects of thermal alteration on microstructures in mammalian long bones.

Abstract

Thermally altered skeletal remains are among the most common categories of material recovered both from archaeological excavations and within forensic contexts. When burnt remains are encountered during a forensic investigation estimating age at death on the remains and creating a biological profile is one of the focal points of analysis. When macroscopic techniques are not viable, investigators may be obliged to turn to microscopic methods, of which the most commonly used method involves counting intact osteons and measuring their diameter. The current project presents the results of experiments in which animal proxies for human remains were subject to varying conditions of burning; the intention of which was to establish the extent of changes apparent in bone microstructure through the varying temperatures and types of burn. The results demonstrated that bones burnt in controlled circumstances displayed a varied degree of change in osteon diameter from the unburnt transverse sections and the samples burnt at 800oC, along with various other environments of thermal alteration. Other variables, including the exposure of the cortical bone during the defleshing process were found to give results that hindered the distinction of the osteon structures and showed the diameter of the osteons changed before thermal alteration. These findings can assist in reconsidering the application of methods of estimating age at death specific to thermally altered remains from both forensic and archaeological contexts.