We report a new sampling strategy for collecting representative samples of drill core. By splitting the core with a diamond saw into working and archive halves, the saw cuttings constitute a "channel" sample, the best subsample from which to obtain an average mineralogical and geochemical composition of a core. We apply this procedure to sampling core of the lower oceanic crust in the Hess Deep obtained during Expedition 345 of the Integrated Ocean Drilling Program (now International Ocean Discovery Program). Our results show that particles produced by sawing range from sand to clay sizes. Sand- and silt-sized cuttings can be sampled with a spatula, whereas clay-sized particles remained in suspension after 12 h and could be collected only by settling, aided by centrifuge. X-ray diffraction (XRD) analysis and Rietveld refinement show that phyllosilicates were fractionated into the clay-sized fraction. Thus, collection of both the sedimented fraction and the clay-sized suspended fraction (commonly > 15 wt% of the total) is necessary to capture the whole sample. The strong positive correlation between the recovered sample mass (in grams) and length of core cut demonstrates that this sampling protocol was uniform and systematic, with almost 1.4 g sediment produced per centimeter of core cut. We show that major-element concentrations of our channel samples compare favorably with the compositions of billet-sized samples analyzed aboard the JOIDES Resolution, but the results show that individual billet analyses are rarely representative of the whole core recovered. A final test of the validity of our methods comes from the strong positive correlation between the loss on ignition (LOI) values of our channel samples and the H2O contents calculated from the modal mineralogy obtained by X-ray diffraction and Rietveld refinement. This sampling procedure shows that grain-sized fractionation modifies both mineralogical and chemical compositions; nevertheless, this channel sampling method is a reliable method of obtaining representative samples of bulk cores. With the ever-increasing precision offered by modern analytical instrumentation, this sampling protocol allows the accuracy of the analytical results to keep pace.

The Paleozoic rocks underlying the western third of the New Haven Quadrangle, Connecticut, are mapped at a scale of 1:24,000. This area of ∼41.5 km2, previously mapped only in reconnaissance, contains polymetamorphic argillites and mafic rocks. The northern portion of the mapped area contains the pelitic Wepawaug schist, whereas the southern portion is underlain by the pelitic Savin Schist. Between them lies the Maltby Lakes Complex (MLC) that contains newly identified fault slivers of variably metamorphosed mafic phyllites and amphibolites. Metamorphic foliations in both the MLC and the Savin Schist are truncated by a swarm of basalt dikes: the Allingtown porphyry, which is itself commonly schistose and locally mylonitic. Previous interpretations held that these rocks constitute a conformable, northwest-topping stratigraphic sequence. In contrast, we propose that Ordovician(?) oceanic rocks of the MLC were variably metamorphosed and faulted against the Ordovician(?) Savin Schist. These were intruded by a swarm of stitching Allingtown dikes. This package of rocks was then faulted against Siluro-Devonian(?) Wepawaug forearc sediments. Existing thermochronology indicates a Devonian age of the subsequent regional metamorphism, overprinted by low-grade Permian fabrics associated with dextral transpression and final terrane assembly.

Over the past billion years, Indiana has experienced many climate extremes. In this talk, we will review some climate change events from Indiana’s deep paleoclimate history, like ice ages and thermal maxima, along with more recent climate events like the year without a summer, and the recent cold winters in the Northeast. We will discuss why Bloomington enjoys the climate it does now, sample some current topics in climate science literature today, and explore what climate change means for us in Indiana. MARTIAN GLOBAL SOIL: INSIGHTS INTO AMORPHOUS PHASES C. N. Achilles 1* , D. L. Bish 1 , E. B. Rampe 2 , R. V. Morris 3 1 Department of Geological Sciences, Indiana University 2 Aerodyne, Houston, TX 3 NASA Johnson Space Center, Houston, TX * achillec@indiana.edu Martian global soil and dust are the most widespread and comprehensively studied component of the planet’s geology, yet after decades of robotic exploration, the amorphous materials, which comprise ~50 wt% of this global soil, remain poorly understood. Soils on Mars have been analyzed by the Mars Exploration Rovers (MER) and most recently by the Mars Science Laboratory (MSL) rover. The CheMin X-ray diffraction (XRD) instrument has revealed crystalline phases and a broad, elevated background, indicating the presence of amorphous or poorly ordered materials. Here, we explore the scattering profiles of potential amorphous materials comprising the global soil using pair distribution function (PDF) analysis to determine the short-range order of analog phases. These data will help better constrain the amorphous material detected by CheMin and build a thorough understanding of Mars’s past geological processes. SULFUR CONTENTS AND GEOCHEMICAL CHARACTERIZATIONS OF THE MARINE, HIGH ORGANIC MATTER, HIGH GAMMA RAY SHALE: NEW ALBANY, USA Alrowaie, M. A 1 , Pratt, L.M. 1 , and Haluska, M.A 1 1 Department of Geological Sciences, Indiana University, IN 47405, USA * malrowai@indiana.edu During early diagenesis and the deposition of the Devonian-Early Mississippian New Albany Shale, complex biological processes occurred including sulfate reduction, disproportionation, and sulfide oxidation. These processes are strongly influenced by the change in the depositional environment including redox condition, reactivity of organic matter and metals. Organic geochemistry, photomicroscopic, and sulfur geochemistry for whole rock samples that were obtained from well cores drilled in 2006 in Pike County, Indiana, were used to (i) understand the depositional environment of the New Albany Shale “Hot Shale interval”, (ii) to understand the role of sulfur in OM preservation, (iii) to investigate the proportion of the metallic sulfides and organic-sulfur and their relationship to the depositional environment. Camp Run and Clegg Creek Members of the NAS show linear Corg to Stot correlation in the studied core. Camp Run Mbr shows wider isotope fractionation for  34 Spyrite compared to the overlying Clegg Creek Mbr which might indicate more varied environments for Camp Run Mbr. The most depleted values of  34 Spyrite are −27.9 ‰ and −23.4 ‰, for Camp Run Mbr and occur at 2804 ft and 2812 ft respectively. At 2757 ft of the Clegg Creek Mbr, sulfide is characterized by extremely depleted value, −38.2 ‰  34 Spyrite. These depleted values in both members could be resulted from the process of repeated microbial disproportionation. Evidences from microscopic analysis indicate that the sample from 2757 ft is characterized by more opened marine condition compared to other analyzed samples. High fractionation in  34 Spyrite of the repeated chrome reducible sulfides, CRS, extraction for the same samples could be as a result of different processes of pyritization at different time. The presence of sulfate in the New Albany shale is due to the oxidation of disulfides and monosulfides. The smallest  34 Ssulfate-pyrite values are 5.7 ‰ at 2755 ft and 2.7‰ at 2785 ft respectively. These values are in corresponding to the highest absolute gamma ray values measured for the studied interval. The correlation between low  34 Ssulfate-pyrite and the high gamma ray might indicate abiotic oxidation of pyrite from radiation sourced from decaying of uranium in the presence of water. The overlying Ellsworth Mbr is dominated by sulfate originated from carbonate-associated sulfate, CAS, which gives extremely heavy  34 Ssulfate value of + 27.8 ‰. RECONSTRUCTION OF EAST AFRICAN PALEOENVIRONMENT BASED ON STABLE ISOTOPES Silvia Ascari 1* , Jackson Njau 1 1 Department of Geological Sciences, Indiana University * sascari@umail.iu.edu The Olduvai Gorge is a valley situated along the East African Rift Valley where many early hominin fossils have been exposed and found due to the rifting. The paleoenvironment of the Olduvai Gorge is important for determining what factors influenced early human evolution. One way of determining the paleoenvironmnet of a given region is by conducting isotopic studies on the bones of animals that lived in that region. Animals tend to incorporate the isotopic composition of what they eat and drink into their tissues. Trees and shrubs have lower concentrations of 13C whilst grasses, which can tolerate hotter, arid climates with low atmospheric CO2 levels, have higher 13 C concentrations. Higher 18 O concentrations from the water that the animals drink are likewise associated with aridity. We can use the collagen from fossil bones and teeth to analyze their isotopic composition and thereby reconstruct the paleoenvironments that the animals lived in. For this study we used both fossil and modern teeth and bones from the Olduvai Gorge to determine their isotopic compositions. We used 32 modern and fossil crocodile teeth and herbivore bones and teeth. The fossil specimens were from beds aged 1.8 and 1.85 Ma. We were able to do a comparative analysis between the modern and fossil bones and teeth to determine how the climate in East Africa was different in the past. The oxygen isotope composition of the samples indicate that the paleoenvironment at 1.8 and 1.85 Ma had higher precipitation levels than in the present, with slightly higher levels at 1.85 than at 1.8, indicating an overall increase in aridity through time. The carbon isotope composition of both crocodiles and mammal herbivores indicate that the environment in the past was dominated by woodlands, whereas in the present it is dominated by arid grasslands. Multiple Sulfur Isotope Studies of the Stillwater Complex, Montana Ayre, A. , Ripley, E.M., Li, C., Underwood, B. Indiana University, Bloomington, Indiana, 47405 U.S.A. Models for the genesis of the J-M Reef of the Stillwater Complex include magma mixing and the attainment of high R-factors to produce PGE-rich immiscible sulfide droplets (e.g., Campbell et al., 1983), leaching of trace sulfides in the Ultramafic Series and concentration at the level of the Reef by magmatic fluids (e.g., Boudreau and McCallum, 1992; Boudreau and Meurer, 1999), and the emplacement of PGE-rich magmas that had been upgraded via sulfide dissolution at depth (e.g., Keays and Lightfoot, 2013). In order to better evaluate the extent to which crustal sulfur was key for PGE enrichment we have initiated a multiple sulfur isotope study of the Complex. The work compliments the early S isotope studies of the Complex by Zientek and Ripley (1990), but the utilization of both 33 S and 34 S permits the detection of deviation from the terrestrial fractionation line that may be due to assimilation of S from Archean country rocks and was previously undetectable. We have measured Δ 33 S values for samples of country rocks and sulfides within country rocks, as well as rocks of the Reef Package in the area of the Stillwater Mine. Δ 33 S values for both massive sulfides in country rocks and pyroxene-hornfels below the Basal Series range from 0 to 0.25 ‰. δ 34 S values generally range from -1.3 to +1.3 ‰, with one massive sulfide sample having a value of 3.9 ‰ Samples of sulfides from the J-M Reef have δ 34 S values from -1 to +1.5 ‰. J-M Reef samples have Δ 33 S values from 0.005 to 0.05 ‰. The Δ 33 S values of sulfides so far measured from the J-M Reef are not considered to be anomalous, however the range of sulfur isotopic values found in the metasedimentary country rocks does not preclude a contribution of country rock sulfur to the magmas that produced the Stillwater Complex. The relative uniformity of Δ 33 S values in the igneous rocks of the Reef is consistent with no country rock contribution of sulfur, and exclusive incorporation of mantle S or, alternatively, contribution of country rock S characterized by similar ∆ 33 S values. A multi-component mixing process involving sulfur from various country rocks and that of mantle derivation remains feasible. Samples of Archean gneisses and other intrusive rock types are being analyzed to further constrain the involvement of country rock S in the formation of the J-M Reef. EXPLORING THE DALY GAP THROUGH A ONE ATMOSPHERE EXPERIMENTAL STUDY OF BASALTS FROM THE HUE-HUE FLOW OF 1801, HUALALAI VOLCANO, HAWAII Veronica Biesiada 1* , James Brophy 1 1 Department of Geological Sciences, Indiana University, Bloomington, IN, USA * vbiesiad@indiana.edu, brophy@indiana.edu Oceanic islands formed from hot spots are characterized by lavas that range from basalt to trachyte in composition. This range is believed to be produced by progressive fractional crystallization of magmas prior to eruption. However, a bimodal distribution of these rocks is often observed; most rocks fall in the basaltic or trachytic with very few intermediate composition lavas. These missing compositions is referred to as the Daly Gap. Clague (1978) proposed that silica content varies non-linearly with increasing fractionation with an initial period of essentially constant low Si02 (basalt), followed by a rapid rise in SiO2 (intermediate), and ending with another period of constant, higher SiO2 (trachyte). This means th