Physical Sciences and Mathematics Commons^™

Bacterial Residues In Coprolite Of Herbivorous Dinosaurs: Role Of Bacteria In Mineralization Of Feces, Thomas C. Hollocher, Karen Chin, Kurt T. Hollocher, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The Cretaceous Two Medicine Formation of northwestern Montana has yielded blocky, calcareous coprolites that contain abundant fragments of conifer wood and were produced by large herbivorous dinosaurs. The coprolites are generally dark gray to black in color due to a dark substance confined chiefly within what originally were the capillaries of tracheid and ray cells of xylem. This substance is a kerogen which consists in part of thin-walled vesicles 0.1-1.3 µm in diameter. Pyrolysis products of this kerogen are diagnostic of a bacterial origin with a possible contribution from terrestrial plants. The vesicular component is interpreted as the residue of …

Fossil Charcoal In Cretaceous-Tertiary Boundary Strata: Evidence For Catastrophic Firestorm And Megawave, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Organic matter separated from calcareous sandstone from the upper portion of a deep-water tsunami deposit at Arroyo el Mimbral, Taumalipas (Mexico), which marks the biostratigraphically-defined Cretaceous-Tertiary boundary, consists primarily of fossil charcoal, including semifusinite and pyrofusinite. Analytical pyrolysis-gas chromatography-mass spectrometry revealed the highly aromatic and polyaromatic character of the organic matter assemblage, typical of the products of partial combustion. The organic matter probably originated as terrestrial vegetation that was caught in a firestorm and subsequently transported far offshore in the backwash of a megawave. These data are consistent with the hypothesis of combustion of large masses of vegetation triggered by …

Geochemical Characterization Of Maceral Concentrates From Herrin No. 6 Coal (Illinois Basin) And Lower Toarcian Shale Kerogen (Paris Basin), B Artur Stankiewicz, Michael A. Kruge, John C. Crelling

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Density gradient centrifugation (DGC) is a physical method for the separation of sedimentary organic matter into its constituents. Using DGC, it is possible to prepare maceral concentrates from a single sample, which are amenable to microanalysis. DGC fractions from a coal sample from the Illinois Basin (Herrin No. 6, Upper Carboniferous) and from the kerogen of a marine shale sample from the Paris Basin (Lower Toarcian) were analyzed by flash pyrolysis-gas chromatography-mass spectrometry, after extraction by CH₂Cl₂.

Chemical differences between the coal DGC fractions are the easiest to recognize, indicating very distinctive biological precursors. For example, …