Amber Samples Research Articles

Geographical classification of amber based on pyrolysis- and infra-red spectroscopy data

Geographical classification of amber samples, based on the relative yield of 18 pyrolysis products generated through pyrolysing of the single samples at 700°C, is discussed, the pyrolysis data being applied as the input parameters for principal component and hierarchical cluster analyses. For comparison analogous analyses were carried out based on the relative intensities of 18 characteristic infra-red absorption bands as input parameters. The two analytical techniques apparently lead to virtually identical results, although the analysis based on pyrolysis data appears to be somewhat more conclusive. The single amber samples originating from different geographical locations could clearly be distinguished through statistical treatment. The possible linkage between an amber sample found on the Danish island Fur and samples found in Greenland is discussed.

Physicochemical structural characterization of ambers from deposits in Poland

The physical and chemical properties of 8 samples of amber from different localities in Poland (Baltic Coast, Bełchatów Tertiary brown coal, and Jaroszów clay mine) were investigated by N 2 sorption at 77 K, positron annihilation spectroscopy for chemical analysis (PASCA) and by organic geochemical methods (FT-IR, 1H and 13C NMR, GC, and GC-MS). The porosity of the ambers as determined by PASCA consists of narrow micropores with diameters ranging from 0.8 to 0.9 nm and a volume 0.025 cm 3 g −1. In the external eroded part of the amber samples (rind) the concentration of pores where positronium atoms can form is lower and consists of approximately12 the concentration as in their interior. Values of pore parameters determined from sorption of N 2 are comparable with those found by the PASCA method. The average diameter of pores ranges from 2 to 12 nm, while their volume varies from 0.018 to 0.048 cm 3 g −1.. The chemical character of the ambers is similar based on FT-IR spectroscopy. However, noticeable differences in concentrations of ester and hydroxyl groups are observed in both exterior and interior regions, where the abundances of the ester groups are lower in the exterior rind. The proportion of organic material extractable with chloroform-methanol (1:1, v/v) ranges from 15 to 50% and correlates inversely to the average reflectances (R r) of polished amber surfaces which range from 1.7 to 0.1 %. These variations are attributed to differing concentrations of oxygenated groups in the respective amber samples. The FT-IR spectra of the non-polar fractions (NP) from the extracts resemble the spectra of the source ambers. However, the intensities of the absorbance for the hdroxyl group are much lower, while absorbances for exomethylene groups are not present. The 1H and 13C NMR data of NP fractions showed a complex diversity of components in mixtures with different relative concentrations but predominantly aliphatic in character for the respective samples. GC and GC-MS analyses of these fractions revealed that they are comprised of a mixture of compounds typical for Baltic amber but with variable relative concentrations. Two groups of compounds are found to be common to all NP fractions. The first is a minor concentration of homologous n-alkanes with a characteristic Gaussian distribution in the range from C 22 to C 32 and maximizing at C 26–C 27. In addition C 22 is characteristically slightly higher in concentration compared to C 23. The second group of compounds is comprised of succinates with methyl, fenchyl, bomyl and isobornyl alcohols. The composition of these diesters revealed the same equilibrium ratio between compounds with fenchyl, bornyl and isobornyl alcohols in all NP fractions. We suggest an early enzymatically controlled (bacterial) process in the formation of succinates during resin diagenesis from the biotic precursors, yielding the same characteristic ratio of the respective succinates in these ambers. These results show that all the ambers analyzed here fall into a common class of fossil resin, succinite (class Ia) independent of the sample location in Poland.

Fourier transform-Raman spectroscopy of amber

The FT-Raman spectra of specimens of genuine amber and of those of unknown origin are reported. Vibrational assignments are made for the genuine species and characteristic bands are identified. Comparison with the Raman spectra of samples of modern pine resin has facilitated the vibrational description of the bands; the unknown specimens were identified as being false ambers of acrylate and polyurethane origin. The presence of small amounts of sulphur and succinic acid in the genuine amber samples have provided a guide to the geographical origin of these samples.

Enantiomeric composition and prevalence of some bicyclic monoterpenoids in amber

Among the more prevalent chiral monoterpenoid compounds in conifers are α-pinene, β-pinene, and smaller amounts of camphene and limonene. The most prevalent chiral monoterpenoid compounds in fossilized resin (referred to as amber in this paper) appear to be borneol, isoborneol, and camphene. Most of these compounds have easily measured enantiomeric excesses. The borneol and isoborneol in some amber samples have pronounced enantiomeric excesses despite the fact that they are tens of millions of years old. The enantiomeric ratios of the monoterpenoids in different ambers vary tremendously and often are distinct. However, in any single amber sample, the stereochemistry (absolute configuration) of the excess monoterpenoid enantiomers appears to be identical. The camphene in amber may be a secondary reaction product formed over time, possibly from the dehydration of borneol. Although a compound's original stereochemistry can be preserved, it also may diminish with the number and type of chemical transformations over geological time. The monoterpene enantiomeric ratios in modern conifer resins vary tremendously. Future stereochemical studies are outlined that could provide the data necessary for more exact geochemical interpretations and possibly for obtaining pertinent paleobiological information. © 1996 Wiley-Liss, Inc.

The nature and fate of natural resins in the geosphere—IV. Middle and Upper Cretaceous amber from the Taimyr Peninsula, Siberia—evidence for a new form of polylabdanoid of resinite and revision of the classification of Class I resinites

Analysis of three amber (resinite) samples collected from Middle and Upper Cretaceous sediments in the Taimyr Peninsula, Siberia, indicates that these materials are based on copolymers of biformene (I) and communol (II). These resinites represent a previously undescribed form of Class I (polylabdanoid) resinite. Definitions of the sub-classes of Class I resinites have been revised (generalized) to recognize the general relation between these samples and other Class Ib resinites, and to facilitate classification of polylabdanoid resinites which do not necessarily incorporate communic (or ozic) acids.

Transfers of algal, microfossil, plant, and vertebrate materials to the University of California Museum of Paleontology

The university of California Museum of Paleontology (UCMP), located on the Berkeley Campus, is a major repository of fossils and paleontological materials. The collection, one of the largest in the nation, originated in 1873 and has been added to continuously since then. In 1921, the Museum of Paleontology was officially initiated with an endowment though the generosity of Annie Alexander of Oakland, California (Grinnell, 1958). The UCMP collections are divided into four specimen collection management units and one collection of paleontological materials, such as rock, sediment, and amber samples, and various teaching collections. The specimen collection units are Fossil Prokaryotes and Protists, Fossil and Recent Invertebrates, Paleobotany and Palynology, and Vertebrate Paleontology. Each of these units has its own manager and each consists of hundreds of thousands of specimens or more and thousands of primary and secondary type specimens. The Museum is supported by the Annie Alexander Endowment and the University of California, Berkeley. It has a staff of 11, and a group of faculty curators, affiliate faculty curators from other University of California campuses, research associates, and associated graduate and undergraduate students. It is a general purpose research museum open to the scientific community and, although it does no formal instruction, it provides instructional exhibits and teaching collections at Berkeley and other campuses. It publishes Paleobios (ISSN 0031-0298), an occasional publication containing a variety of paleontological, peer-reviewed papers. UCMP is also involved in public and school activities at the Museum in Berkeley and at the University of California, Berkeley, Museum of Science, Art and Culture, at Blackhawk Plaza, Danville, California.

Does the gas content of amber reveal the composition of palaeoatmospheres?

WHAT does the gas content of amber indicate? It has been suggested that bubbles in amber preserve the composition of the atmosphere at the time the amber was exuded from trees1,2, while others suggest that the gas content is controlled by solubility relationships3, diffusion4 or chemical reactions involving oxygen consumption5. Here I describe a combined study of nitrogen, argon and oxygen in amber which makes it possible to distinguish bubble gas from matrix gas in amber by considering N2/Ar and O2/Ar ratios of the first gas released during the crushing of individual amber samples. Crushing experiments do not indicate high oxygen levels in Cretaceous amber as have been recently reported1. Neither Baltic nor Cretaceous amber has even the amount of oxygen expected for equilibration with the modern atmosphere. Successive crushings of individual amber pieces show that the first crush has the highest oxygen content and that both bubble and matrix oxygen is consumed as crushing continues. These results suggest that the oxygen content of amber does not have a bearing on the composition of the palaeoatmosphere.

Use of pyrolysis mass spectrometry in the identification of amber samples

Use of pyrolysis mass spectrometry in the identification of amber samples

Thin-layer chromatography of amber samples

Thin-layer chromatography of amber samples

Massenspektrometrische und Emissionsspektroskopische Untersuchungen an Bernstein zur Herkunftsbestimmung

Amber samples of different provenance have been investigated by electron impact and fieldionisation mass-spectrometry. Whereas electron-impact mass-spectra are not specific enough, fieldionisation spectra enable one to identify amber from Baltic-, Sicilian-, Canadian- and Libanese areas. Fe, Na, B, Ca, Mn, Al, Ti, Cu, Cr, V and Si could be determined by emission spectroscopy. Baltic amber shows a smaller trace-element content than all other samples investigated. Canadian amber shows a higher manganese content.

The analysis of archeological amber and amber from the Baltic Sea by thin-layer chromatography

Compares archaeological samples of amber, found in Slovenia, with amber from the Baltic Sea by density and solubility measurements and by thin-layer chromatography. The archaeological amber has a 1. 1544 specific gravity, compared to 1.1159 and 1.0360-1.0643 for red-brown and yellow specimens, respectively, of Baltic Sea amber. The solvent solubility of archaeological amber (g./ml.), and solubility of Baltic amber (g./ml.), respectively, are: MeOH, 3.5, 0. 7; EtOH, 4.9, 1.2; EtOAc, 4.1, 1.2; amyl acetate, 5.4, 1.4; Me 2 CO, 6.2, 1.1; CHCI 3 , 4.0, 1.3; turpentine, 1.0, 1.4; C 6 H 6 , 0. 8, 0.3. Powdered amber samples are washed with dilute HCl, then with H 2 O, to remove CaCO 3 and earth impurities, dried over CaCl 2 , and analyzed chromatographically as solutions in the above organic solvents. Silica gel G plates and 95:5 C 6 H 6 -MeOH developing solvent are used. The spots can be located under ultraviolet light or by spraying with SbCl 3 reagent of E. Stahl (1967). The archaeological samples do not originate from Baltic Sea amber, but probably from a tree resin which was produced similarly to present-day colophony. -- AATA