Radiometric dating school class

08-Jun-2017 15:50

The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ages of rocks and the fossils they host.

There are many processes that lead to fossilization, including permineralization, casts and molds, authigenic mineralization, replacement and recrystalization, adpression, carbonization, and bioimmuration.

In many cases, however, compressions and impressions occur together.

For instance, when the rock is broken open, the phytoleim will often be attached to one part (compression), whereas the counterpart will just be an impression.

In this case the fossil consists of original material, albeit in a geochemically altered state.

This chemical change is an expression of diagenesis.

In 2014, Mary Schweitzer and her colleagues reported the presence of iron particles (goethite-a Fe O(OH)) associated with soft tissues recovered from dinosaur fossils.

Based on various experiments that studied the interaction of iron in haemoglobin with blood vessel tissue they proposed that solution hypoxia coupled with iron chelation enhances the stability and preservation of soft tissue and provides the basis for an explanation for the unforeseen preservation of fossil soft tissues.

Small scale permineralization can produce very detailed fossils.If this happens rapidly before significant decay to the organic tissue, very fine three-dimensional morphological detail can be preserved.Nodules from the Carboniferous Mazon Creek fossil beds of Illinois, USA, are among the best documented examples of such mineralization.to dinosaurs and trees, many meters long and weighing many tons.A fossil normally preserves only a portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates, or the chitinous or calcareous exoskeletons of invertebrates.

Small scale permineralization can produce very detailed fossils.

If this happens rapidly before significant decay to the organic tissue, very fine three-dimensional morphological detail can be preserved.

Nodules from the Carboniferous Mazon Creek fossil beds of Illinois, USA, are among the best documented examples of such mineralization.

to dinosaurs and trees, many meters long and weighing many tons.

A fossil normally preserves only a portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates, or the chitinous or calcareous exoskeletons of invertebrates.

The totality of fossils is known as the fossil record.