Resinites derived from labdatriene structures (Class I) are ubiquitous throughout the geosphere. A soluble polylabdanoid material has been isolated by sequential extraction with organic solvents. Solid- and liquid-state NMR spectroscopy, and Py-GC-MS, indicate that at least for immature resinites, the extractable polymer is representative of the insoluble, polylabdanoid material, which constitutes the bulk of most Class I resinites. With increasing maturity, the dominant chemical transformation that occurs in these materials is the {open_quotes}loss{close_quotes} of exomethylene structures and depletion of olefinic character from {approximately}two to {approximately}one olefin per monomer unit. To investigate the fate of olefinic structures and to determine the nature of the residual olefin distribution in these materials, two-dimensional NMR correlation spectroscopies (COSY and HMQC) and nuclear Overhauser experiments (NOESY) have been undertaken. Results from these analyses and their implications to the maturation of Class-I resinites will be discussed.

Ambers are well known and abundant in terrestrial sediments all over the world. However, due largely to the absence of definite morphological characteristics, the precise botanical origin of most amber samples are, at best, often a matter of speculation. This has severely restricted the usefulness of amber in paleobotanical and paleoecological interpretations. The molecular composition and structural characteristics of fossil resins however, may preserve evidence of their botanical origin, which could be of great value in geochemical, paleobotanical and paleoenvironmental studies. The remains of a number of exceptionally well-preserved Taxodiaceae-dominated swamp-forest communities have been discovered in the sediments of the middle Eocene (45 million years old) Buchanan Lake Formation of Axel Heiberg Island, Canadian Arctic Archipelago. Amber collected from these ancient in situ forests provides a unique opportunity to characterize these resins chemically and taxonomically. Resinite associated with Metasequoia Miki ex Hu & Cheng, Pinus L. and Pseudolarix Gordon has been characterized using Pyrolysis-Gas Chromatography-Mass Spectrometry. This method provides a direct analysis of the molecular structure and composition of the resin. In several cases, both bled and cone-resin samples have been characterized. The results of these analyses are presented and discussed. The implications of these results for the botanical origins of other ambers represented in the fossil record (including succinite) are also discussed.

Pyrolysis-Gas Chromatographic-Mass Spectrometric (Py-GC-MS) analysis of a range of Class I resinites indicates that the macromolecular structures of these resinites are typically derived from copolymers of labdanoid carboxylic acids, alcohols and hydrocarbons. Class Ia and Ib resinites are derived from copolymers of regular [1S, 4aR, 5S, 8aR] labdanoid diterpenes, especially communic acid, communol and/or biformenes. Class Ic resinites are based on structures derived from enantio [1S, 4aS, 5R, 8aS] labdanoids, especially ozic acid, ozol and/or enantio biformenes. The monomeric components of Class I resinites are readily determined in Py-GC-MS analyses by recognition of characteristic bicyclic products derived from the A/B ring system of the original labdanoid monomers. In addition to bicyclic products derived directly from the labdanoid A/B ring system, products derived by modification of this ring system are also observed in Py-GC-MS analyses of some Class I resinites. These include: bicyclic methyl ethers produced by pyrolytic hydrolysis/O-methylation of succinylated (esterified) communol monomers within the macromolecular structure of Class Ia resinites; and, in samples of moderate maturity, C13 and C14 bicyclic products derived from A-ring defunctionalized labdanoids. The existence of these A-ring defunctionalized products indicates the existence of a heretofore unrecognized maturation pathway in polylabdanoid resinites.

Aluminosilicate smectite clays have been ion-exchanged with water-soluble, cationic porphyrins and metalloporphyrins. Characteristics of their thermal stability were measured by thermal gravimetric analysis in an inert atmosphere, which yielded approximately 60% weight loss of organics. Detailed structural information about the decomposition products was obtained by performing pyrolysis-gas chromatography-mass spectrometry on the clay-organic complexes.