Collaborative Research: Chemical Equilibria Involving Iron and Hydrogen in Metapelites From Western Maine

The primary goal of this research is to evaluate the chemical equilibria involving ferrous and ferric iron and hydrogen in metapelitic rocks from western Maine and related rocks at Black Mountain, New Hampshire. We will study samples from graphite, magnetite, and hematite-bearing rocks at three different metamorphic grades: garnet, lower sillimanite, and staurolite zone. This will permit the determination of: (1) in situ partition coefficients for Fe3+ and Fe2+ among all the Fe-bearing phases and for H among hydrous phases;(2) the temperature and fO2 dependence of Fe3+/Fetotal and effects of Fe3+ substitution on other cation substitutions plus their implications for geothermometry; and (3) the cation substitutions that charge balance variations of H and Fe3+. We will also characterize and seek to understand Fe3+/Fetotal zoning within individual mineral grains as well as variation of Fe3+/Fetotal among grains of the same mineral in the same rock; ultimately, we will assess the effects of assemblage on Fe3+/Fetotal in the constituent mineral phases present. These measurements will be made on standard 1 round petrographic thin sections using beam sizes of less than 10 x 15 micrometers and the relatively rapid, non-destructive techniques of synchrotron microXANES spectroscopy (SmX) for Fe3+/Fetotal, ion microprobe (SIMS) for H, and the electron microprobe (EPMA) for other major elements. With our analytical results in hand, we can begin to address the competing effects of assemblage and crystal chemistry on the incorporation of Fe2+ and Fe3+ in metapelite minerals. We also hope to effectively and quickly demonstrate the potential importance of SmX as a petrologic tool

Metamorphic Petrology, Mineralogy and Polymetamorphism in a Portion of N.W. Maine

Guidebook for field trips in the Rangeley Lakes - Dead River Basin region, western Maine: 62nd annual meeting October 2, 3, and 4, 1970: Trip B-

MRI: Acquisition Of A Modern Electron Microprobe At The University of Maine

This award, made through the Major Research Instrumentation (MRI) Program, provides support for the acquisition of a state-of-the-art electron microprobe (EMP) for the microchemical characterization of geological materials. A new EMP will replace an aging (vintage 1981) ARL SEMQ in the Department of Geological Sciences at the University of Maine. The instrument will facilitate research on a range of topics in metamorphic petrology including, the speciation of Fe and distribution of OH- in metapelites, and light element (i.e. Li, B, Be) partitioning in granulite facies rocks. Research in paleoclimatology will also be enhanced by this instrument. The probe will be used to analyze volcanic glass shards in ice core samples for trace and major element compositions. Coupled with analyses of suspected source tephras, such chemical analyses offer the strong possibility of verifying the provenance of ice core tephra and therefore relating these discrete events to climate proxies also recorded simultaneously in ice cores. This facility will be the only modern EMP in the state of Maine and will serve not only the needs of faculty and students from several departments at the University of Maine , but also the needs of faculty and students from nearby regional institutions (i.e. Bowdoin, Univ. of Southern Maine, Bates)

The Geology of the Camden-Rockland Area

Guidebook for field trips in east-central and north-central Maine: 66th annual meeting October 12 and 13, 1974: Trip A-

Acquisition of an Automated Powder X-Ray Diffraction System

This grant provides $70,295 as one-half support of the costs of acquiring a state-of-the-art powder X-ray diffractometer (XRD) that will be housed in a newly constructed Global Sciences building on the Orono campus of the University of Maine. This acquisition will allow these PI\u27s to continue their internationally recognized research programs in petrologic mineralogy including studies of the phase equilibria of solid solutions in metamorphic rocks and borosilicates. The characterization of both structural properties and mineralogic identification of unknowns is fundamental to these researchers and the establishment of a modern XRD facility at the University of Maine will benefit a number of other faculty both within the Department of Geological Sciences and within the departments of Physics and Engineering

Geology of the Lower Paleozoic Rocks in the Boundary Mountain Anticlinorium

Guidebook for field trips in the Rangeley Lakes - Dead River Basin region, western Maine: 62nd annual meeting October 2, 3, and 4, 1970: Trip A-

Poly(Alkylene 2,5-thiophenedicarboxylate) polyesters: A new class of bio-based high-performance polymers for sustainable packaging

In the present study, 100% bio-based polyesters of 2,5-thiophenedicarboxylic acid were synthesized via two-stage melt polycondensation using glycols containing 3 to 6 methylene groups. The so-prepared samples were characterised from the molecular point of view and processed into free-standing thin films. Afterward, both the purified powders and the films were subjected to structural and thermal characterisation. In the case of thin films, mechanical response and barrier properties to O2 and CO2 were also evaluated. From the results obtained, it emerged that the length of glycolic sub-units is an effective tool to modulate the chain mobility and, in turn, the kind and amount of ordered phases developed in the samples. In addition to the usual amorphous and 3D crystalline phases, in all the samples investigated it was possible to evidence a further phase characterised by a lower degree of order (mesophase) than the crystalline one, whose amount is strictly related to the glycol sub-unit length. The relative fraction of all these phases is responsible for the different mechanical and barrier performances. Last, but not least, a comparison between thiophene-based homopolymers and their furan-based homologues was carried out