Frank Laboratory of Neutron Physics

Joint Laboratory Seminar

Leader – Shvetsov V.N.

Date and Time: Wednesday, 15 May 2019, at 11:00 AM

Venue: Conference hall (3rd floor), Frank Laboratory of Neutron Physics

Seminar topic: «Study of fossilization process by neutron scattering»

Speaker: Pakhnevich Alexey (Ph.D., senior researcher of Borissiak Paleontological Institute of RAS)

Abstract:

One of the actual research topics of modern palaeontology is the study of fossilization processes. Palaeontologists are interested how the organic and mineral matters of biogenic origin changing for the millions of years. The investigations related to the search for preserved organic matter using neutron tomography are recently having been fulfilled in FLNP JINR.
Using neutron diffraction one can obtain information on the changes in the mineral matter of skeleton remains. The changes can occur with the mineral matter of shells and bones over the million years. During the life of an animal, the stability of the mineral skeleton component is controlled by the cellular matrix, but after the death of the cells various processes take place up to complete destruction of shells and bones. Nevertheless, primary minerals may remain, recrystallization may occur, for example, a transformation of aragonite to calcite, the crystals of the same mineral but of abiogenic origin may appear, and the original mineral can be replaced by another. It is important to understand whether a change in the orientation of the crystals of the same mineral occurs after the death of the stabilizing matrix. How strong are these changes? These tasks substantiate the need to study the texture of the shells of modern, subfossil (semi-fossil) and fossil bivalve mollusks. It is interesting to conduct the investigations on the shells of the same mollusk species but belonging to different geological epochs. Besides, the questions concerning the influence of habitat conditions on the texture of shell mineral crystals as well as the strict taxonomic affiliation of texture to a particular genus or bivalve mollusks family are solved. The results of the first experiments to study the texture of bivalve mollusks shells carried out at FLNP JINR are presented in the report.