Indiana Geological Survey

Indiana, Indiana, United States

Indiana Geological Survey

Indiana, Indiana, United States
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Lahann R.W.,Indiana Geological Survey | Swarbrick R.E.,GeoPressure Technology
Geofluids | Year: 2011

Basin model studies which have addressed the importance of smectite conversion to illite as a source of overpressure in the Gulf of Mexico have principally relied on a single-shale compaction model and treated the smectite reaction as only a fluid-source term. Recent fluid pressure interpretation and shale petrology studies indicate that conversion of bound water to mobile water, dissolution of load-bearing grains, and increased preferred orientation change the compaction properties of the shale. This results in substantial changes in effective stress and fluid pressure. The resulting fluid pressure can be 1500-3000psi higher than pressures interpreted from models based on shallow compaction trends. Shale diagenesis changes the mineralogy, volume, and orientation of the load-bearing grains in the shale as well as the volume of bound water. This process creates a weaker (more compactable) grain framework. When these changes occur without fluid export from the shale, some of the stress is transferred from the grains onto the fluid. Observed relationships between shale density and calculated effective stress in Gulf of Mexico shelf wells confirm these changes in shale properties with depth. Further, the density-effective stress changes cannot be explained by fluid-expansion or fluid-source processes or by prediagenesis compaction, but are consistent with a dynamic diagenetic modification of the shale mineralogy, texture, and compaction properties during burial. These findings support the incorporation of diagenetic modification of compaction properties as part of the fluid pressure interpretation process. © 2011 Blackwell Publishing Ltd.


Blieck A.,Lille University of Science and Technology | Turner S.,Monash University | Burrow C.J.,Queensland Museum | Schultze H.-P.,University of Kansas | And 3 more authors.
Episodes | Year: 2014

The term vertebrate is generally viewed by systematists in two contexts, either as Craniata (myxinoids or hagfishes + vertebrates s.s., i.e. basically, animals possessing a stiff backbone) or as Vertebrata (lampreys + other vertebrae-bearing animals, which we propose to call here Euvertebrata). Craniates are characterized by a skull; vertebrates by vertebrae (arcualia); euvertebrates are vertebrates with hard phosphatised tissues in the skeleton. The earliest known possible craniate is Myllokunmingia (syn. Haikouichthys) from the Lower Cambrian of Chengjiang, south China. Euvertebrates appear in the Ordovician. C. H. Pander is sometimes thought to have been the first to propose that conodonts are vertebrates, but he did have doubts about the fish affinities of conodonts. This proposal was revived in the 30s and especially in the 80s of the 20th century and given elevated status in 2000 through a cladistic analysis based upon interpretation of conodont mineralized tissues as homologous to those of vertebrates. This analysis resolved conodonts within the clade Vertebrata s.s., and incorporated a 'Total Group Concept' (TGC), including conodonts in the TG Gnathostomes (= jawed vertebrates). This resulted in the unusual scenario in which "teeth" appear before jaws. We reject the TGC nomenclature as applied to early vertebrates. In addition, based on all existing evidence, we consider that conodont hard tissues and several other anatomical structures in conodonts are not homologous with those of vertebrates. Making a revised cladistic analysis, eliminating characters unknown in fossils, conodonts appear stemward (i.e. more basal) to craniates and are thus interpreted as basal chordates at best. To help resolve the phylogenetic relationships of conodonts and chordates, the analysis should be extended to include non-chordate taxa.


Turner S.,Monash University | Burrow C.J.,Queensland Museum | Schultze H.-L.,University of Kansas | Blieck A.,Lille University of Science and Technology | And 4 more authors.
Geodiversitas | Year: 2010

An evidence-based reassessment of the phylogenetic relationships of conodonts shows that they are not "stem" gnathostomes, nor vertebrates, and not even craniates. A signifi cant group of conodont workers have proposed or accepted a craniate designation for the conodont animal, an interpretation that is increasingly becoming established as accepted "fact". Against this prevailing trend, our conclusion is based on a revised analysis of traditional morphological features of both discrete conodont elements and apparatuses, histological investigation and a revised cladistic analysis modifying that used in the keystone publication promoted as proof of the hypothesis that conodonts are vertebrates. Our study suggests that conodonts possibly were not even chordates but demonstration of this is beyond the scope of this paper. To summarize, in conodonts there is low cephalization; presence of simple V-shaped trunk musculature and unique large-crystal albid material in the elements; lack of a dermal skeleton including characteristic vertebrate hard tissues of bone, dentine and enamel; lack of odontodes with bone of attachment and a unique pulp system; lack of segmentally-arranged paraxial elements and dermal elements in median fins, all of which supports neither a vertebrate nor a craniate relationship for conodonts. Publications © Scientifiques du Muséum national d'Histoire naturelle, Paris.


Zirogiannis N.,Indiana University Bloomington | Alcorn J.,Indiana University Bloomington | Piepenburg J.,Indiana University Bloomington | Rupp J.,Indiana Geological Survey
Agricultural and Resource Economics Review | Year: 2015

We investigate geospatial and socio-demographic attributes that explain differences in community-level policies affecting unconventional gas development (UGD) in New York. We examine local policy decisions (i.e., municipal bans, moratoria, and pre-emptive resolutions supporting development) through ordered probit models and middle-inflated and zero-inflated ordered probits to account for communities without UGD policies and estimate a spatial ordered probit to address spatial correlations between communities' decisions. Our findings suggest that New York communities near Pennsylvania UGD are more likely to support UGD. Communities that are predominantly Democrat or have more citizens who have bachelor's degrees are more likely to adopt policies opposing UGD. Copyright © 2015 Northeastern Agricultural and Resource Economics Association.


Carley S.R.,Indiana University Bloomington | Krause R.M.,University of Texas at El Paso | Warren D.C.,Indiana University Bloomington | Rupp J.A.,Indiana Geological Survey | Graham J.D.,Indiana University Bloomington
Environmental Science and Technology | Year: 2012

While carbon capture and storage (CCS) is considered to be critical to achieving long-term climate-protection goals, public concerns about the CCS practice could pose significant obstacles to its deployment. This study reports findings from the first state-wide survey of public perceptions of CCS in a coal-intensive state, with an analysis of which factors predict early attitudes toward CCS. Nearly three-quarters of an Indiana sample (N = 1001) agree that storing carbon underground is a good approach to protecting the environment, despite 80% of the sample being unaware of CCS prior to participation in the two-wave survey. The majority of respondents do not hold strong opinions about CCS technology. Multivariate analyses indicate that support for CCS is predicted by a belief that humankind contributes to climate change, a preference for increased use of renewable energy, and egalitarian and individualistic worldviews, while opposition to CCS is predicted by self-identified political conservatism and by selective attitudes regarding energy and climate change. Knowledge about early impressions of CCS can help inform near-term technology decisions at state regulatory agencies, utilities, and pipeline companies, but follow-up surveys are necessary to assess how public sentiments evolve in response to image-building efforts with different positions on coal and CCS. © 2012 American Chemical Society.


Medina C.R.,Indiana Geological Survey | Rupp J.A.,Indiana Geological Survey | Barnes D.A.,Western Michigan University
International Journal of Greenhouse Gas Control | Year: 2011

The Upper Cambrian Mount Simon Sandstone is recognized as a deep saline reservoir that has significant potential for geological sequestration in the Midwestern region of the United States. Porosity and permeability values collected from core analyses in rocks from this formation and its lateral equivalents in Indiana, Kentucky, Michigan, and Ohio indicate a predictable relationship with depth owing to a reduction in the pore structure due to the effects of compaction and/or cementation, primarily as quartz overgrowths. The regional trend of decreasing porosity with depth is described by the equation: φ(d)=16.36×e-0.00039*d, where φ is the porosity and d is the depth in m. The decrease of porosity with depth generally holds true on a basinwide scale. Bearing in mind local variations in lithologic and petrophysical character within the Mount Simon Sandstone, the source data that were used to predict porosity were utilized to estimate the pore volume available within the reservoir that could potentially serve as storage space for injected CO2. The potential storage capacity estimated for the Mount Simon Sandstone in the study area, using efficiency factors of 1%, 5%, 10%, and 15%, is 23,680, 118,418, 236,832, and 355,242 million metric tons of CO2, respectively. © 2010 Elsevier Ltd.


Krause R.M.,University of Kansas | Carley S.R.,Indiana University | Warren D.C.,Indiana University | Rupp J.A.,Indiana Geological Survey | Graham J.D.,Indiana University
Risk Analysis | Year: 2014

Carbon capture and storage (CCS) is an innovative technical approach to mitigate the problem of climate change by capturing carbon dioxide emissions and injecting them underground for permanent geological storage. CCS has been perceived both positively, as an innovative approach to facilitate a more environmentally benign use of fossil fuels while also generating local economic benefits, and negatively, as a technology that prolongs the use of carbon-intensive energy sources and burdens local communities with prohibitive costs and ecological and human health risks. This article extends existing research on the "not in my backyard" (NIMBY) phenomenon in a direction that explores the public acceptance of CCS. We utilize survey data collected from 1,001 residents of the coal-intensive U.S. state of Indiana. Over 80% of respondents express support for the general use of CCS technology. However, 20% of these initial supporters exhibit a NIMBY-like reaction and switch to opposition as a CCS facility is proposed close to their communities. Respondents' worldviews, their beliefs about the local economic benefits that CCS will generate, and their concerns about its safety have the greatest impact on increasing or decreasing the acceptance of nearby facilities. These results lend valuable insights into the perceived risks associated with CCS technology and the possibilities for its public acceptance at both a national and local scale. They may be extended further to provide initial insights into likely public reactions to other technologies that share a similar underground dimension, such as hydraulic fracturing. © 2013 Society for Risk Analysis.


News Article | November 3, 2015
Site: phys.org

No one knew the holes under Mount Baldy existed until a six-year-old boy fell into one in the summer of 2013 and was buried. Emergency responders successfully rescued the boy after three and a half hours, but the accident left Indiana University Northwest coastal geologist Erin Argyilan, who was there at the time, struck by the concept that deep, stable holes could form and survive in loose sand. The subsequent study by Argyilan and her co-authors, which will be presented at the Geological Society of America meeting on Tuesday in Baltimore, Maryland, concludes that the holes formed when trees, buried by wind-blown sands, rotted away. A cement formed by fungi-produced minerals and chemical weathering lines the walls of the hole and temporarily maintains the branching shape of the tree hollows. "These are living systems. There is a real interaction between biologic and geologic properties," said Argyilan. "We have to look at these dunes with an interdisciplinary mindset or we will miss how the system works." Scientists know Mount Baldy is on the move. Geologists estimate that winds shift the crescent-shaped dune, which reaches 38 meters (126 feet) above the south shore of Lake Michigan, roughly 1.0-1.2 meters (3-4 feet) inland a year, although the actual movement is highly variable. Blowing sands overwhelm and bury vegetation, buildings and parking lots on the dune's windward side, and the tree hollows are being exhumed on the hill's leeward slope. To learn how Mount Baldy's holes formed, the team first had to find some holes. Park Service personnel spotted some, while the Indiana Geological Survey used ground-penetrating radar to search for others. Argyilan and her colleagues even found one or two using paintbrushes and trowels. At one point they even found a fungus-ridden oak limb that terminated in a tree-shaped hollow. "At that point, I was sold that we had trees being buried and decomposition driven by fungus," said Argyilan. "But I did not know why the holes would stay open." The scientists turned to scanning electron microscopy, which helps ascertain the surface texture and chemistry of minerals. Not only were the walls of the tunnels littered with hyphae, the equivalent of fungal roots, but they also were covered with a cementing mineral. Fungi were likely living inside the trees prior to the plants' burial. Once the trees were entombed, the fungi decomposed the tree, and the long-lasting cement maintained the structural integrity of the hollow even after the tree had decomposed, according to the study. The cement is a byproduct of the fungal decomposition process and the result of chemical weathering, but the scientists are still studying the precise biological and chemical pathways that form the cement. "The next step is to examine how involved the fungi are in creating the cement," said Argyilan. Since starting to explore Mount Baldy's holes, Argyilan has learned of similar holes in Oregon coast dunes and at two other locations along the Great Lakes. The Oregon dunes appear to have been caused by smaller trees compared to the oaks at Mount Baldy. "The oaks make significantly more hazardous holes," said Argyilan, "especially when you can't see them from the surface." Scientists have identified eleven holes on Mount Baldy, but Argyilan suspects they will find more as the dune migrates, partially the result of human activity in the area. A local harbor blocks sands from reaching the dune, while historic mining and tourists have eroded the dune's sandy slopes. Erosion has also increased during winter; shrinking lake ice—a product of climate change—does not protect the dune from winter winds as it has in the past. "What's happening at Mount Baldy is basically the perfect storm for destroying and reactivating [the movement of] a dune," said Argyilan. "Here, and in general, I think it is a real possibility that we will see more holes as more dunes are reactivated by human activity."


Neufelder R.J.,Purdue University | Bowen B.B.,Purdue University | Lahann R.W.,Indiana Geological Survey | Rupp J.A.,Indiana Geological Survey
Environmental Geosciences | Year: 2012

Concerns about potential climate change related to greenhouse gas emissions have spurred researchers across the world to assess the viability of geologic storage of CO2. In the Illinois Basin in the United States, the Cambrian Mount Simon Sandstone has been targeted as a reservoir for carbon capture and storage (CCS). In this CCS system, the Eau Claire Formation is expected to serve as the primary seal to prevent upwardmigration of the CO2 plume; however, little work has been done to specifically determine how well it will function as a seal. Although the lateral extent and thickness of the Eau Claire Formation, along with its generally low permeability, certainly make it a prime candidate to serve in this capacity, the primary depositional fabric and mineralogy, which are the fundamental controls on the petrophysical charter of this unit, remain poorly constrained. Therefore, the purpose of this study is to investigate the lithologic, mineralogical, and petrophysical properties of the Eau Claire Formation in an effort to characterize its potential as a functional seal in a CCS system. Sixty-six core-derived Eau Claire Formation samples from seven wells within the Illinois Basin are described using a combination of petrography, reflectance spectroscopy, x-ray diffraction, geochemical, and petrophysical analyses. These analyses show that the Eau Claire Formation contains five different lithofacies (sandstone, clean siltstone, muddy siltstone, silty mudstone, and shale) with fine-scale heterogeneities in fabric and mineralogy that greatly influence the petrophysical properties. Porosity, permeability, and entry-pressure data suggest that some, but not all, lithofacies within the Eau Claire Formation have the capability to serve as a suitable CCS seal. Abundant authigenic minerals and dissolution textures indicate that multiple generations of past fluid-rock interactions have occurred within the Eau Claire Formation, demonstrating that much of the formation has behaved as a fluid conduit instead of as a seal.Minerals that would be potentially reactive in a CCS system (including carbonate, glauconite, and chlorite) are common in the Eau Claire Formation. Dissolution of these and other phases in the presence of carbonic acid could potentially jeopardize the sealing integrity of the unit. Although complexities in the sealing properties exist, the dynamics of the CCS system and the potential for precipitation of new minerals should allow the Eau Claire Formation to serve as an adequate seal. Copyright © 2012. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.


Medina C.R.,Indiana Geological Survey | Rupp J.A.,Indiana Geological Survey
Environmental Geosciences | Year: 2012

The Mount Simon Sandstone (Cambrian) has significant potential for use as a reservoir for geologic carbon sequestration in the Midwest region, but lithologic variations within the unit remain poorly understood. Petrophysical heterogeneities controlled by the changes in lithologic and diagenetic character challenge the process of estimating the storage capacity of this reservoir. Geophysical logs from wells across the Midwest region were interpreted to define three lithostratigraphic subunits within the Mount Simon Sandstone: an upper unit that has relatively high gamma-ray (GR) values caused by the admixture of argillaceous material; a middle unit defined by relatively lower GR values that result from a cleaner quartzose sandstone and potentially constitutes the main reservoir and flow unit within the formation (the GR values of this unit also display the lowest amount of vertical variability through the section); and a lowermost unit defined by GR values that, in general, progressively increase with depth toward the base of the formation. This downward increase is caused by the increased nonquartz fraction in the formation as the top of the Precambrian basement is approached. In all three units, but especially in the lowermost one, the admixture of feldspars and the presence of dissolution porosity complicate storage capacity calculation. In addition to quartz overgrowths and compaction phenomena that reduce pore volume, the presence of other diagenetic products further complicates the distribution of porosity and permeability within the unit. Storage capacity was calculated only for the middle unit within the Mount Simon Sandstone using values derived from GR and porosity geophysical logs (sonic, neutron, and density). The range of storage capacity found in this study is primarily controlled by reservoir thickness because the variation in porosity within this middle unit is less than that in the other units. However, an assessment of the vertical distribution of porosity and permeability at each site will be required to determine the best intervals with the best flow and storage properties. Copyright © 2012. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

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