Geo 215

Taphonomy

The study of the process that occurs from the death of an organism to its fossil discovery

Basic transition to a fossil

• Death

• Scavenging/Decay of soft tissue

• Transport and breakage of hard tissues

• Burial and modification of the hard tissues

Body Fossils

Partial or complete remains

Trace Fossils

Activity of past life (ex. pollen, poop, etc)

Savaging

Large organism consuming the dead organism

Decaying

Microbes (fungi & prokaryotes) eating dead organisms

First Factor of decay

Supply of carbon: In aerobic conditions, glucose is easier to break down and covert to carbon dioxide and water. In Aerobic conditions, nitrate, manganese dioxide, iron dioxide, or sulfate are needed.

Second Factor of decay

Temperature and PH.

High temp, Neutral ph = Rapid decay as the environment is suitable for microbes.

Unusual ph, Cold temp = slow decay

3rd Factor of decay

Nature of organic carbon. Highly liable (volatile) carbons that break down readily are decay prone. Highly resistant (refectories) are much less lible to breakdown and are harder to decay.

Reminralization

When organic matter in a dead organism is replaced by minerals, either by a cast or mold.

Permineralization

a common fossilization process where mineral-rich groundwater fills the empty pores, cells, and spaces.

Pyritization

original organic or shell material of an organism is replaced or replicated by pyrite (iron sulfide, or "fool's gold") in low-oxygen, iron-rich marine environments. Requires a high burial rate, low organic content, and the presence of sulfate.

Phosphatization

organic materials and soft tissues are replaced or coated by calcium phosphate minerals.

1st mode of mineralization

Mineral coats, fillings of tissue in phosphates, carbonates, and pyrite.

2nd mode of mineralization

Bacteria leaving a mineral byproduct from decay.

3rd mode of mineralization

formation of tissue casts during sediment compaction