title: Structural changes in amber due to uranium mineralization.
abstract: The presence of uranium, with a bulk mass fraction of about 1.5 wt% and radiolytic alterations are a feature of Cenomanian amber from Křižany, at the northeastern edge of the North Bohemian Cretaceous uranium ore district. Pores and microcracks in the amber were filled with a mineral admixture, mainly in the form of Zr-Y-REE enriched uraninite. As a result of radiolytic alterations due to the presence of uranium, structural changes were observed in the Křižany amber in comparison with a reference amber from Nové Strašecí in central Bohemia; this was of similar age and botanical origin but did not contain elevated levels of uranium. Structural changes involved an increase in aromaticity due to dehydroaromatization of aliphatic cyclic hydrocarbons, loss of oxygen functional groups, an increase in the degree of polymerization, crosslinking of CC bonds, formation of a three-dimensional hydrocarbon network in the bulk organic matrix, and carbonization of the organic matrix around the uraninite infill.
authors.affiliation: Institute of Rock Structure and Mechanics, AS CR, V Holešovičkách 41, 182 09 Praha 8, Czech Republic. Electronic address: havelcova@irsm.cas.cz.
authors.forename: Martina
authors.initials: M
authors.lastname: Havelcová
authors.affiliation: Institute of Rock Structure and Mechanics, AS CR, V Holešovičkách 41, 182 09 Praha 8, Czech Republic; Institute of Chemical Technology Prague, Technická 5, 166 28 Praha 6, Czech Republic.
authors.forename: Vladimír
authors.initials: V
authors.lastname: Machovič
authors.affiliation: Nuclear Physics Institute, AS CR, Hlavní 130, 250 68 Řež, Czech Republic; Institute of Rock Structure and Mechanics, AS CR, V Holešovičkách 41, 182 09 Praha 8, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Mizera
authors.affiliation: Institute of Rock Structure and Mechanics, AS CR, V Holešovičkách 41, 182 09 Praha 8, Czech Republic.
authors.forename: Ivana
authors.initials: I
authors.lastname: Sýkorová
authors.affiliation: Institute of Rock Structure and Mechanics, AS CR, V Holešovičkách 41, 182 09 Praha 8, Czech Republic.
authors.forename: Miloš
authors.initials: M
authors.lastname: René
authors.affiliation: Institute of Rock Structure and Mechanics, AS CR, V Holešovičkách 41, 182 09 Praha 8, Czech Republic.
authors.forename: Lenka
authors.initials: L
authors.lastname: Borecká
authors.affiliation: Institute of Chemical Technology Prague, Technická 5, 166 28 Praha 6, Czech Republic.
authors.forename: Ladislav
authors.initials: L
authors.lastname: Lapčák
authors.affiliation: Institute of Rock Structure and Mechanics, AS CR, V Holešovičkách 41, 182 09 Praha 8, Czech Republic.
authors.forename: Olga
authors.initials: O
authors.lastname: Bičáková
authors.affiliation: Severočeské doly, a.s., Doly Bílina (North Bohemian Mines, Bílina Mines), 5. května 213, 418 29 Bílina, Czech Republic.
authors.forename: Oldřich
authors.initials: O
authors.lastname: Janeček
authors.affiliation: Severočeské doly, a.s., Doly Bílina (North Bohemian Mines, Bílina Mines), 5. května 213, 418 29 Bílina, Czech Republic.
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Dvořák
mesh_terms: D018647:Amber / Q000737:chemistry*; D018153:Czech Republic; D005580:Fossils; D008401:Gas Chromatography-Mass Spectrometry; D015394:Molecular Structure; D014501:Uranium / Q000032:analysis / Q000737:chemistry*
chemical_list: D018647:Amber; D014501:Uranium
keywords: Amber; Fossil resin; Mapping; Micro-FTIR; Radiolytic alteration; SEM/EDX; Uranium