MODULE 4 Buried and Surface Remains

• Science of Pedology


  It is primarily the domain of agricultural and engineering concerns, but it also is a component of geological, geomorphological, archaeological, and forensic concerns. In Layman's terms, it is the study of soils.
• Layers of Soil: O-horizon


  The uppermost layer which consists primarily of decomposing accumulated plant matter
• Layers of Soil: A-horizon


  Equated with the topsoil, the organic-rich horizon that often is only centimeters deep and sit of the majority of biotic activity. Commonly encountered sub horizon is the AP subhorizon (also known as plow zone) which has undergone plowing disturbance.
• Layers of Soil: B-horizon


  Characterized by the accumulation of soluble base minerals dissolved from the A horizon and is usually lighter in color due to its lesser amounts of organically derived carbon.
• Layers of Soil: C-horizon


  Consists of the less-altered parent material that formed locally from the physical and chemical breakdown of the bedrock
• Layers of Soil: R-horizon


  Consists of the broken-up local bedrock (or regolith)
• Parent Material


  The main source of mineral and/or organic materials in a given location, which may derive from sources including local bedrock, alluvial deposits, aeolian deposits, volcanic ash, or glacial deposits.
• Generally, soils are their most acidic in the A-horizon.
• Common Soil Orders

  1. Mollisols - deep soils found in plains/steppe environment
  2. Histosols - organic soils
  3. Oxisols - heavily oxidized, red soils often encountered in the tropics and subtropics
  4. Spodosols - often found in areas of pine forest
• Soils form naturally through the complex interactions of parent materials.
• Actual burial depths can vary from 1.5 to 12 feet
• High water tables can result in poor preservation through softening of the bone due to chemical and mechanical erosion. It also displaces the skeletal remain from its anatomical position.
• Soil acidity is perhaps the most pervasive long-term destructive force acting upon bones.
• Soil pH highly influence preservation of bones.
• Acidic soil corrosion often results in significant changes in the bone's morphology, often creating a scooped, irregular surface where there was once smooth cortical bone. The loss is most apparent on epiphyses of long bones, where the cortical bone is thinnest.
• High temperature, acidity, and humidity increases the rate of breaking down of bone.
• Slightly acidic to neutral soil allows better preservation.
• In acidic soils, bones can be severely degraded.
• Effects of Soft Tissue Decomposition upon Soil pH

  • Decomposition increases soil acidity temporarily in its immediate vicinity.
  • Base ions influx follows generally decreasing acidity of the burial fill during the next phase of decomposition.
• Boot/Glove Taphonomy

  Presence of boot/glove, most specially leather, decreases potential disturbance and protects the remain as they are often preserved in acidic soils.
• Boreal Forests

  Over years of exposure to acidic soil of skeletons from shallow burials often lead to a melted face pattern of skeletal recovery i.e., having acidic erosion on some portions of the skeleton while the remaining portion are in much better state of preservation.
• Plant Root Invasion

  • Plant roots are attracted to bones due to its nitrogen and phosphate contents.
  • This event makes it hard to retrieve bones because it made the bones brittle thus, requiring proper documentation.
  • However, it helps in PMI determination since tree roots develop annual rings that can be counted.
• Root Etching


  This are the patterns of surface damage in cortical bone. They are typically meandering and branching, with a U-shaped profile to the individual surface scores.
• Fungi

  • major decomposers
  • can invade the porous structure of bones
  • Hyphae - thread-like major structures of fungi that gives many molds their fuzzy appearance
• Termites also have the potential to consume buried bones, likely due to dietary nitrogen deficiencies.
• Bioturbation

  • process wherein species living within the soil may disperse bone or wherein species activity cause significant shift in the position of bones
  • deals with the displacement of bones
  • may mislead interpretation of peri-mortem actions
  • should not be mistaken for the natural displacement of the skeletal remains as the connective soft tissues decompose and disappear
• Soil Staining


  Bones tend to take on the color of the medium into which they are deposited. This may indicate the previous burial location of the bone.
• Adipocere Formation

  • sometimes referred to as grave wax
  • develops from any body fat tissue under moist, anaerobic condition
  • indicates lack of oxygen in the location of burial
  • can persist for centuries
• Mass Burial

  • process of decomposition are slowed
  • If buried in soil, decomposition may continue more or less as usual. However, in events of commingling, decomposition are enhanced.
  • Feather Edge Effect - bodies at the periphery decompose faster than those at the center
• Effects of Plowing on Buried Remains

  Plowing of agricultural fields both benefits and imperils forensic anthropological practice. It may also cause damage mistaken as post-mortem trauma.
• Mummification

  1. Artificial (deliberate) mummification - most famously from ancient Egypt, it is done typically as part of an elaborate post-mortem ritual.
  2. Natural mummification - occur in dry environment e.g., very well-drained soils in acid climates
• Ice Burial

  • preservative effect of frozen environment
  • Otzi - well-known example discovered in the Italian Alps and was carbon dated to around 3300 BC
• Bogs Burials

  • characterized by the accumulation of decomposing plant remains, typically mosses of the genus Sphagnum
  • characterized by acidic water high in tannins, aerobic conditions, and large scavenger exclusion
• Effects of Coffin Environment

  • remains placed in coffin decompose more slowly
  • coffin do not present a constant burial environment, as coffins also proceed through a process of gradual breakdown
• Coffin Wear


  The patterned, localized destruction of some portions of a skeleton brought about by contact with a coffin. It is usually observed on bones that are least likely to move e.g., innominate, scapula, and femoral.
• Warping


  It is likely caused by the same factors as coffin wear but with the added weight of the mass of sediments pushing downward on the remain. This is particularly prominent on the cranium due to its weak structure.
• Staining

  • bones are darkly stained, chocolate-brown color
  • intensified by the pooling of water and organic bleach from the coffin
• For embalmed remains, decomposition occurs first on the extremities because preservative chemicals often fails to reach these areas.
• Autopsy


  It is routinely performed where there is any questioned regarding the cause or manner of death of an individual. It is also a frequent taphonomic characteristics of remains from modern cemetery burials.
• Coffin Hardware

  • 6 major categories: handles, thumbscrews and escutchions, plates, caplifters, decorative studs, and white metal screws and tacks
  • crucial in determining the age of burials especially when there is no dated headstone
  • viewing window - famous between late 19th century to early 20th century