Náplní práce bude studium mikrofosílií z podkladových vrstev uměleckých děl. Očekává se přítomnost vápnitého nannoplanktónu a foraminifer. Kvantitativní analýza mikrofosílií umožní určení původu těchto materiálů, proto v rámci řešení práce bue studován i refernční materiál z regiónu s historicky zaznamenanou těžbou. Kromě klasických mikropaleontologických technik, budou mikrofosílie studovány i moderními nedestruktivními metodami (např. mikroCT)
Preliminary scope of work in English
Within this interdisciplinary project, carbonate-containing artistic materials will be studied in order to describe their regional provenance. It is well-known, for example, that in the Gothic period white soft chalks (calcium carbonate) of the Mesozoic age were used as for preparatory layers (grounds) of paintings and polychrome statues and it is also generally assumed that this material came probably just from easily accessible outcrops and quarries on the Baltic coast. However, nothing is known about sources in foregoing periods (Pre-Romanesque and Romanesque), when the trade was not as much developed. There are some rare indices of using local sources, but the evidence is poor. The same applies for the period of 16th to 18th centuries, when the technology was changing and coloured clays has started to be used as for the grounds. Some of them, particularly the Italian ones, were calcareous, with a substantial content of calcite and dolomite. By means of mineralogy it was already proved that the composition of these clays is regionally specific and could help, therefore, to identify the place of creation of numerous anonymous paintings from this period. More detailed provenance analysis is always limited by availability of microsamples from artworks, their internal heterogeneity and their size, which usually do not exceed 1 mm in average. Because of the rarity of samples micro-destructive techniques are applied only sporadically, but with very promising results – as, e.g. LA ICP-MS for trace elements and isotopes etc. This project aspires to develop, optimize and apply novel procedures, which will finally lead to implementation and systematic use of micro-palaeontology within the provenance studies of natural carbonates in the fine arts. Particularly, it will include advanced non-destructive approaches, as e.g. micro- and nano-CT, and also micro-destructive methods of segregation of nannofossils from aged paints, which have to be done in micro-volumes only. The optimized methodology will then be applied to analysis of microsamples from actual paintings and to reference materials as well. The micro-palaeontological record will be compiled with other characteristics (chemical, mineralogical, technological) within carefully pre-selected case studies.
- assigned by the advisor