Taphonomy of fossilized resins: determining the biostratinomy of amber

Comparing the maturity of fossilized resins with that of their enclosing bedrock can provide information on the maturity, relative age and biostratinomy of amber and copal. A method to determine this is presented here with examples of amber and copal from the Dominican Republic. Maturity of the bedrock was determined by vitrinite reflection and that of the fossilized resin by FTIR analysis. Vitrinite oxidation values showed maturity states corresponding to lignite and sub-bituminous coal ranks. While the samples from some mines demonstrated that the maturities of the rock and fossilized resin were syngenetic, other samples indicated that recycling of the amber may have occurred. Darkening of the amber (from yellow to red) was correlated with increased oxidation / weathering. This method can be a useful tool for understanding the biostratinomy of fossilized resins

Taphonomy of fossilized resins: determining the biostratinomy of amber

Comparing the maturity of fossilized resins with that of their enclosing bedrock can provide information on the maturity, relative age and biostratinomy of amber and copal. A method to determine this is presented here with examples of amber and copal from the Dominican Republic. Maturity of the bedrock was determined by vitrinite reflection and that of the fossilized resin by FTIR analysis. Vitrinite oxidation values showed maturity states corresponding to lignite and sub-bituminous coal ranks. While the samples from some mines demonstrated that the maturities of the rock and fossilized resin were syngenetic, other samples indicated that recycling of the amber may have occurred. Darkening of the amber (from yellow to red) was correlated with increased oxidation / weathering. This method can be a useful tool for understanding the biostratinomy of fossilized resins

Variations in chemistry of macerals as refl ected by micro-scale analysis of a Spanish coal

An Oligocene lignite (Ebro Basin, Spain) and its density fractions were analyzed petrographically and with microscale techniques (electron microprobe and micro-FTIR) to gain insight into differences between individual macerals of low rank high-sulfur coal. The density of the alginite-dominated fraction is below 1.26g/cm3, and that of the huminite-dominated fraction is above 1.38g/cm3. Densities within 1.26-1.38g/cm3 represent mixtures of liptinite and huminite macerals. With regard to elemental composition, alginite has the highest carbon content (75.6% on average) and the lowest oxygen content (6.1% on average). Corpohuminite is characterized by the lowest carbon content (62.3% on average) and the highest oxygen content (21.5% on average). Nitrogen contents for corpohuminite and ulminite (~1%) are similar, but are signifi cantly lower in alginite (0.2% on average). Sulfur content is highest in alginite (13.4% on average), followed by corpohuminite (9.8%) and ulminite (7.7%). Functional group analysis documents large differences between macerals of the huminite and liptinite group, but also indicates differences between individual macerals within both the huminite and liptinite group. These differences are most notable in aromaticity, degree of aromatic ring condensations, and hydrocarbon potential

Migmatite-Like Textures in Anthracite: Further Evidence for Low-Grade Metamorphic Melting and Resolidification in High-Rank Coals

Previous studies demonstrated that melting, initiated by supercritical fluids in the 375–400 °C range, occurred as part of anthracite metamorphism in the Appalachian Basin. Based on the known behavior of vitrinite at high temperatures and, to a lesser extent, at high pressures, it was determined that the duration of the heating, melting, and resolidification event was about 1 h. In the current study, featureless vitrinite within banded maceral assemblages demonstrates the intimate association of melted and resolidified vitrinite with anthracite-rank macerals. By analogy with metamorphosed inorganic rocks, such associations represent diadysites and embrechites, i.e., cross-cutting and layered migmatites, respectively. Even though the temperature of formation of the anthracite structures is several hundred °C lower than that seen in metamorphosed inorganic rocks, anthracites are metamorphic rocks and the nomenclature for metamorphic rocks may be appropriate for coal

Variations in chemistry of macerals as refl ected by micro-scale analysis of a Spanish coal

An Oligocene lignite (Ebro Basin, Spain) and its density fractions were analyzed petrographically and with microscale techniques (electron microprobe and micro-FTIR) to gain insight into differences between individual macerals of low rank high-sulfur coal. The density of the alginite-dominated fraction is below 1.26g/cm3, and that of the huminite-dominated fraction is above 1.38g/cm3. Densities within 1.26-1.38g/cm3 represent mixtures of liptinite and huminite macerals. With regard to elemental composition, alginite has the highest carbon content (75.6% on average) and the lowest oxygen content (6.1% on average). Corpohuminite is characterized by the lowest carbon content (62.3% on average) and the highest oxygen content (21.5% on average). Nitrogen contents for corpohuminite and ulminite (~1%) are similar, but are significantly lower in alginite (0.2% on average). Sulfur content is highest in alginite (13.4% on average), followed by corpohuminite (9.8%) and ulminite (7.7%). Functional group analysis documents large differences between macerals of the huminite and liptinite group, but also indicates differences between individual macerals within both the huminite and liptinite group. These ifferences are most notable in aromaticity, degree of aromatic ring condensations, and hydrocarbon potential

The New Albany Shale gas play in southern Indiana

This poster was presented at the 2006 Eastern Section American Association of Petroleum Geologists, 35th Annual Meeting, in Buffalo, N.Y., October 8-11, 2006.The New Albany Shale (Devonian and Mississippian) in Indiana is mostly brownish-black organic-rich shale with lesser greenish-gray shale. The formation is 100 to 140 feet thick in southeastern Indiana and dips and thickens to the southwest into the Illinois Basin, where it attains a thickness of more than 360 feet in Posey County. Gas production from New Albany Shale began in 1885 and drilling activity continued into the 1930s, when interest waned in favor of more lucrative opportunities elsewhere. Renewed activity, driven by higher gas prices, has been brisk since the mid-1990s, witnessed by the completion of more than 400 productive wells. The majority of these wells were drilled in Harrison County, where production typically occurs at depths from 500 to 1,100 feet and production rates generally range from 20 to 450 MCFGPD. In the past 2 years, Daviess County and surrounding areas have become the focus of New Albany exploration after the El Paso Production No. 2-10 Peterson horizontal discovery well was rumored to have tested 1.3 MMCFGPD at an approximate measured depth of 2,200 feet. New Albany production is mostly from the organic-rich Clegg Creek Member. Gas compositions (C1-C4 and CO2) and carbon and hydrogen isotopic signatures indicate that both purely thermogenic and mixed thermogenic and biogenic gases are produced from the New Albany. Produced water ranges from brine to water diluted through recharge by modern precipitation; the brine zones contain primarily thermogenic gas and the diluted water zones contain gas of mixed thermogenic and biogenic origin

Exhaled Eicosanoids following Bronchial Aspirin Challenge in Asthma Patients with and without Aspirin Hypersensitivity: The Pilot Study

Background. Special regulatory role of eicosanoids has been postulated in aspirin-induced asthma. Objective. To investigate effects of aspirin on exhaled breath condensate (EBC) levels of eicosanoids in patients with asthma. Methods. We determined EBC eicosanoid concentrations using gas chromatography/mass spectrometry (GC-MS) and high-performance liquid chromatography/mass spectrometry (HPLC-MS2) or both. Determinations were performed at baseline and following bronchial aspirin challenge, in two well-defined phenotypes of asthma: aspirin-sensitive and aspirin-tolerant patients. Results. Aspirin precipitated bronchial reactions in all aspirin-sensitive, but in none of aspirin-tolerant patients (ATAs). At baseline, eicosanoids profile did not differ between both asthma groups except for lipoxygenation products: 5- and 15-hydroxyeicosatetraenoic acid (5-, 15-HETE) which were higher in aspirin-induced asthma (AIA) than inaspirin-tolerant subjects. Following aspirin challenge the total levels of cysteinyl-leukotrienes (cys-LTs) remained unchanged in both groups. The dose of aspirin had an effect on magnitude of the response of the exhaled cys-LTs and prostanoids levels only in AIA subjects. Conclusion. The high baseline eicosanoid profiling of lipoxygenation products 5- and 15-HETE in EBC makes it possible to detect alterations in aspirin-sensitive asthma. Cysteinyl-leukotrienes, and eoxins levels in EBC after bronchial aspirin administration in stable asthma patients cannot be used as a reliable diagnostic index for aspirin hypersensitivity

Triptycene End‐Capped Benzothienobenzothiophene and Naphthothienobenzothiophene

Previously it was demonstrated that triptycene end‐capping can be used as a crystal engineering strategy to direct the packing of quinoxalinophenanthrophenazines (QPPs) towards cofacially stacked π dimers with large molecular overlap resulting in high charge transfer integrals. Remarkably, this packing motif was formed under different crystallization conditions and with a variety of derivatives bearing additional functional groups or aromatic substituents. Benzothienobenzothiophene (BTBT) and its derivatives are known as some of the best performing compounds for organic field‐effect transistors. Here, the triptycene end‐capping concept is introduced to this class of compounds and polymorphic crystal structures are investigated to evaluate the potential of triptycene end‐caps as synthons for crystal engineering

Sequential decoupling of negative-energy states in Douglas-Kroll-Hess theory

Here, we review the historical development, current status, and prospects of Douglas--Kroll--Hess theory as a quantum chemical relativistic electrons-only theory.Comment: 15 page