Final Report Summary - INTERARCHIVE (Interred with their bones - linking soil micromorphology and chemistry to unlock the hidden archive of archaeological human burials)
InterArChive involved a detailed study of archaeological grave soils spanning a wide range of ages, soil types and burial styles. The grave soils are the most poorly studied part of the system in current excavation practice which focuses mainly on visually recognised remains including the skeleton, coffin and grave goods. The research aim was to determine if the soils contain a hidden archive that can add information to the interpretation of burials that is not currently available to the archaeological community. The central approach employed in the research involved examination of the physical and compositional characteristics of the soil by microscopy (micromorphology) and development of a comprehensive inventory of the organic chemical remains in the soils through their isolation, separation and mass spectrometric analysis.
The research has identified in grave soils a wide range of signatures that can be related to the human burials. Signatures identified in the mineral matrix of the soils relate to the activity of organic matter degraders, providing a long-term record for the existence of organic matter buried in the soil. Remains of complex biopolymers from degraded wood provide information on the presence of a coffin and reveal information on the nature of the wood from which it was constructed. Chemical compounds derived from the fatty tissues of the body reveal its presence and, through analysis of the transformation pathways, relationships to the environmental conditions within different burials have been identified. Ratios of particular steroidal compounds have been used to assess contributions of signatures specific to the gut. Detailed analysis further reveals the nature of ingested food, discriminating ingestion of animal-derived foods from exclusively plant-based foods. The use of processed pine resins as coffin treatment has been shown to limit the degree of degradation thorough inhibition of the microbial degrader community.
The signatures have been distinguished from soil background through the use of controls from the overlying grave fill. Hence, clear evidence has been obtained that a hidden archive of information exists in the signatures contained in archaeological grave soils.
The importance of sampling position has been illustrated by comprehensively sampling a wide variety of positions. Analysis reveals differences in the content of organic matter and the preservation of the signatures. Differences in the porosity of controls and underlying sampling positions reveal significant differences relating to the transport of particles through the soil profiles, influencing the preservation potential of the organic matter from the buried remains.
The complementarity of the micromorphological and chemical approaches has allowed interpretation of the importance of the soil hydrology on the alteration and preservation of organic signatures in the grave soils. Hence, differences in porosity and soil composition exert important controls on water movement and the agents that degrade the organic matter. The development of reducing conditions, evidenced from both micromorphology through the presence of redoximorphic nodules and organic marker ratios of selected steroidal components, is associated with selective preservation of organic signatures from the buried remains. Recognition of factors affecting the preservation of signatures in the grave soils provides an evidence base to guide future studies of grave soils. As such, this can focus efforts to recover signatures from the soil to soil types and locations most likely to yield informative results.
The research has identified in grave soils a wide range of signatures that can be related to the human burials. Signatures identified in the mineral matrix of the soils relate to the activity of organic matter degraders, providing a long-term record for the existence of organic matter buried in the soil. Remains of complex biopolymers from degraded wood provide information on the presence of a coffin and reveal information on the nature of the wood from which it was constructed. Chemical compounds derived from the fatty tissues of the body reveal its presence and, through analysis of the transformation pathways, relationships to the environmental conditions within different burials have been identified. Ratios of particular steroidal compounds have been used to assess contributions of signatures specific to the gut. Detailed analysis further reveals the nature of ingested food, discriminating ingestion of animal-derived foods from exclusively plant-based foods. The use of processed pine resins as coffin treatment has been shown to limit the degree of degradation thorough inhibition of the microbial degrader community.
The signatures have been distinguished from soil background through the use of controls from the overlying grave fill. Hence, clear evidence has been obtained that a hidden archive of information exists in the signatures contained in archaeological grave soils.
The importance of sampling position has been illustrated by comprehensively sampling a wide variety of positions. Analysis reveals differences in the content of organic matter and the preservation of the signatures. Differences in the porosity of controls and underlying sampling positions reveal significant differences relating to the transport of particles through the soil profiles, influencing the preservation potential of the organic matter from the buried remains.
The complementarity of the micromorphological and chemical approaches has allowed interpretation of the importance of the soil hydrology on the alteration and preservation of organic signatures in the grave soils. Hence, differences in porosity and soil composition exert important controls on water movement and the agents that degrade the organic matter. The development of reducing conditions, evidenced from both micromorphology through the presence of redoximorphic nodules and organic marker ratios of selected steroidal components, is associated with selective preservation of organic signatures from the buried remains. Recognition of factors affecting the preservation of signatures in the grave soils provides an evidence base to guide future studies of grave soils. As such, this can focus efforts to recover signatures from the soil to soil types and locations most likely to yield informative results.