Lithostratigraphy, Structure, and Metamorphism of a Crystalline Thrust Terrane, Western Inner Piedmont, North Carolina

The geology of the western Inner Piedmont of North Carolina, from knowledge gained in an area called the Columbus Promontory, is characterized by a stack of crystalline thrust sheets. In this study the stratigraphic, structural, and metamorphic development of this crystalline thrust terrane was examined. The lithostratigraphic framework of the Columbus Promontory is divisible into four distinct and mappable rock units that include the Henderson Gneiss, Sugarloaf gneiss, Poor Mountain Formation, and the Mill Spring Complex. This lithostratigraphic framework helps define three crystalline thrust sheets within the Columbus Promontory herein, called the Tumblebug Creek, Sugarloaf Mountain, and Mill Spring thrust sheets. Rocks of the Poor Mountain Formation and Mill Spring complex are similar to lithostratigraphic units recognized elsewhere in the southern Appalachian eastern Blue Ridge and Inner Piedmont. Similarities in physical stratigraphy indicate that the Poor Mountain Formation and Mill Spring complex rocks are representatives of two regionally extensive (Virginia to Alabama) lithostratigraphic sequences that record deep-to shallow-water deposition along the Laurentian margin and include: a lower sequence consisting of Lynchburg-Ashe-Tallulah Falls-Mill Spring-Sandy Springs/New Georgia-type rocks, and an upper sequence consisting of Evington-Alligator Back-Coweeta-Chauga River/Poor Mountain-Jackson\u27s Gap/Ropes Creek-type rocks. By analogy to these rocks, the Poor Mountain Formation and Mill Spring complex are also interpreted as part of the deep-water facies rocks deposited along the Laurentian margin. Including the rocks of the Columbus Promontory into this regionally correlative lithostratigraphy further supports previous interpretations (Hatcher, 1978a, 1989) that the same lithostratigraphy occurs in the eastern Blue Ridge and Inner Piedmont. In addition, this correlation also supports the interpretation (Hatcher, 1978a, 1989) that the same rock units occur on both sides of the Brevard fault zone and suggests that this feature, although recognized as a major structural discontinuity, does not represent a terrane boundary. Amphibolite comprises a significant component of the lithostratigraphy of the Columbus Promontory and is intercalated with other lithostratigraphic units of the Poor Mountain Formation and Mill Spring complex. Because relict igneous textures, sedimentary features, and contact relationships have been destroyed by high grade regional metamorphism and transposition, a whole-rock geochemical approach was undertaken to determine the protolith as well as fractional trends, and possible paleotectonic settings. Niggli trends, AFM relationships, and normative mineralogy suggest an igneous protolith for amphibolite in both stratigraphic units, which was tholeiitic basalt. Covariation diagrams indicate that both suites are fractionated and that the trends can be explained by fractionation of olivine, plagioclase, clinopyroxene, garnet, and magnetite. This assemblage is similar to the low-pressure fractionation sequence commonly observed in mid-ocean ridges and suggests the Columbus Promontory amphibolites are MORB. Zr/Nb, Y/Nb ratios further define the suite as N-type MORB, with a possible P-type MORB component. Other tectonomagmatic discriminant diagrams employed in this study indicate a correlation of the Columbus Promontory suite primarily with ocean-floor basalts, but also indicate some island-arc influence. The possibility of mixed N- and P-type MORB components suggests extrusion of these basalts along a mid-ocean ridge adjacent to a mantle plume, whereas the combination of MORB and island-arc characteristics indicate a back-arc basin setting. In either case, an oceanic setting is indicated for the Columbus Promontory suite. These observations further support the interpretation that the Poor Mountain Formation, Mill Spring complex, and correlative rock units in the eastern Blue Ridge and Inner Piedmont were deposited, at least partly, on oceanic crust. The dominant structure of the western Inner Piedmont of North Carolina, South Carolina, and northeast Georgia is a stack of penetratively deformed ductile to semi-brittle crystalline thrust sheets. The structural development of this part of the Inner Piedmont is examined herein using data from crystalline thrust sheets in the Columbus Promontory in North Carolina, and the Tamassee area in adjacent South Carolina and NE Georgia. Structural analysis in both areas reveals a regionally consistent, five-phase deformation history. Although the western Inner Piedmont is polydeformed (D1 to D5), the D2 and D3 episodes were the most important and represent a deformation continuum. D2 was penetrative and synchronous with the principal (Acadian?) metamorphic even in the western Inner Piedmont. D3 generally represents late-to post-peak final emplacement of thrust sheets as coherent masses. The emplacement history and internal deformation of this crystalline thrust complex involved coeval D2-D3 orogen-parallel (SW-directed) displacement within the westernmost Inner Piedmont and Brevard fault zone and orogen-oblique (W-directed) displacement in thrust sheets in the Inner Piedmont. Importantly, this geometry indicates that early (middle Paleozoic) Brevard fault zone motion was kinematically linked to the crystalline thrust sheets in the adjacent Inner Piedmont. It is proposed that these dominant flow paths (W and SW directed) in the foreshortening crust were driven by large-scale transpression or oblique convergence during the amalgamation of the crystalline southern Appalachians. S2 mylonitic foliation is the most characteristic and kinematically important structural element within the Inner Piedmont. S2 also strongly controlled development of other D2-D3 structural elements in the western Inner Piedmont. Internal deformation and variations in orientation, kinematics, and geometry of D2-D3 structural features are interpreted to result from gradients of flow within S2. This resulted in a partitioned thrust-wrench transport parallel to the plane of S2 mylonitic foliation driven by larger-scale tectonic processes. These observations indicate that S2 is a regionally extensive shear surface along which extensive D2-D3 displacement occurred and suggests the Inner Piedmont represents a region of crustal-scale shear. The metamorphic history, and the relationship between metamorphism and deformation in the thrust sheets of the Columbus Promontory are best recorded by pelitic schist within the Sugarloaf Mountain thrust sheet. The Sugarloaf Mountain sheet thrust rocks of the Poor Mountain Formation and upper Mill Spring complex over the Henderson Gneiss and other rocks of the western Inner Piedmont. Pelitic schist in the Sugarloaf Mountain thrust sheet contain a sillimanite-muscovite assemblage that is characteristic of thrust sheets throughout the western Inner Piedmont (e.g., Alto allochthon, Six Mile thrust sheet). Metamorphic textures and mineral zoning suggest sillimanite growth was the result of continuous reactions involving both garnet consumption and garnet growth following the metamorphic peak. These relationships also suggest that this sillimanite-muscovite assemblage is a post-peak rather than a prograde or peak metamorphic assemblage. Metamorphic textures and microstructural analysis indicate that growth of the sillimanite-muscovite was synkinematic with the development of microstructures related to emplacement of the Sugarloaf Mountain thrust sheet. The implication of these observations is that emplacement of the Sugarloaf Mountain thrust sheet occurred along the retrograde portion of the P-T path followed by these rocks. Qualitative constraints on the nature of this retrograde P-T path, gained from field criteria, petrographic observations, mineral zoning and geothermobarometric estimates, indicate a general path of decompression and cooling, but with episodes of near isobaric cooling

Shock wave loading and spallation of copper bicrystals with asymmetric Σ3〈110〉tilt grain boundaries

We investigate the effect of asymmetric grain boundaries (GBs) on the shock response of Cu bicrystals with molecular dynamics simulations. We choose a representative Σ3〈110〉tilt GB type, (110)_1/(114)_2, and a grain size of about 15 nm. The shock loading directions lie on the GB plane and are along [001] and [221] for the two constituent crystals. The bicrystal is characterized in terms of local structure, shear strain, displacement, stress and temperature during shock compression, and subsequent release and tension. The shock response of the bicrystal manifests pronounced deviation from planar loading as well as strong stress and strain concentrations, due to GBs and the strong anisotropy in elasticity and plasticity. We explore incipient to full spallation. Voids nucleate either at GBs or on GB-initiated shear planes, and the spall damage also depends on grain orientation

Global Stratigraphy and the Fossil Record Validate a Flood Origin for the Geologic Column

The geologic column has been under the scrutiny of numerous creationists for many decades. Critics have claimed the column is intimately tied to the evolutionary worldview and deep time, and cannot be trusted or used by creation scientists. Other creation scientists have argued that the geologic column, although incomplete at most locations, can provide useful correlations of rocks and fossils across the globe. This paper examines the sedimentary rocks across three continents in an attempt to test the validity of the global geologic column. We attempted to assess the data primarily from a lithologic viewpoint, and as independent of the fossil data as possible. To accomplish this, we constructed a new data set of over 1500 local, stratigraphic columns across three continents, recording the detailed lithologic information and Sloss-type megasequence boundaries at each site. A detailed 3-D lithology model was created for each continent using the local columns. We also constructed maps of the basal lithology for each megasequence. Unique lithologic units, like salt and chert-rich layers were also tracked from column to column. Results show extensive lithologic units (i.e. blanket sandstones) covered portions of every continent and are correlative across vast regions and even continent to continent. The correlation of these stacked basal megasequence units, and other unique lithologies (i.e. salt and chert layers) within the megasequences, confirm the validity of the geologic column on a global scale. The observable pattern in the fossil record further confirms these findings. Indeed, a global Flood could produce globally extensive, stacked lithologic units on an intercontinental scale. Creationists should not be critical of the geologic column, but embrace it as evidence of a global Flood event

Use of Sedimentary Megasequences to Re-create Pre-Flood Geography

Knowledge of pre-Flood geography and the location of the Garden of Eden have eluded Bible-believing scientists and theologians. This study attempts to reconstruct the gross geography of the pre-Flood world by examining the detailed stratigraphy that was deposited during the Flood. Over 1500 stratigraphic columns were constructed across North and South America and Africa, recording the lithology and stratigraphy at each location. Sedimentary layers were examined using Sloss-type megasequences which allowed detailed analysis of the progression of the Flood in six discrete depositional segments. The three earliest megasequences, Sauk, Tippecanoe and Kaskaskia, were the most limited in areal coverage and volume and contain almost exclusively marine fossils, indicating a likely marine realm. The 4th megasequence (Absaroka) shows a dramatic increase in global coverage and volume and includes the first major plant and terrestrial animal fossils. The 5th megasequence (Zuni) appears to be the highest water point of the Flood (Day 150) as it exhibits the maximum global volume of sediment and the maximum areal coverage, compared to all earlier megasequences. The final megasequence (Tejas) exhibits fossils indicative of the highest upland areas of the pre-Flood world. Its rocks document a major shift in direction reflective of the receding water phase of the Flood. Results include the first, data-based, pre-Flood geography map for half of the world. By comparing the individual megasequences to the fossil record, patterns emerge that fit the concept of ecological zonation. The paper concludes with a new ecological zonation-megasequence model for Flood strata and the fossil record

Teaching Macro Practice Through the Use of Experiential Instruction and Collaboration: A Formula to Create Sustainable Community Resources

While delivering an organizations and communities class to a cohort of students in an outlying rural area, a social work program explored ways to educate students effectively while simultaneously exploring and devising strategies to fill local gaps in community services. The project utilized evidence-based learning strategies focusing on experiential instruction and collaboration with local community agencies. Using aspects of the flipped classroom as well as service learning, the course was particularly interested in engaging with community stakeholders to identify issues arising from the realities of a rural service environment. Students identified a project, worked with community partners, and delivered recommendations at completion. The findings were then used to write a grant to assist with prisoner reentry into the community. This resulted in an award nearing $300,000 to bridge gaps in services. The grant funded two social work positions to provide strengths-based family centered case management, funds for community mentor/volunteer training, released prisoner group meetings aimed at improving released prisoner social and moral functioning, and funds aimed at transportation assistance. The article discusses all aspects of the project and provides an outline to assist social work educators to integrate similar projects into other programs. The project was completed in and is especially well suited for rural areas, where services, resources, and expertise are often lacking. The authors specifically discuss the challenges and strategies of completing a project of this type in a rural setting

Anisotropic shock response of columnar nanocrystalline Cu

We perform molecular dynamics simulations to investigate the shock response of idealized hexagonal columnar nanocrystalline Cu, including plasticity, local shear, and spall damage during dynamic compression, release, and tension. Shock loading (one-dimensional strain) is applied along three principal directions of the columnar Cu sample, one longitudinal (along the column axis) and two transverse directions, exhibiting a strong anisotropy in the response to shock loading and release. Grain boundaries (GBs) serve as the nucleation sites for crystal plasticity and voids, due to the GB weakening effect as well as stress and shear concentrations. Stress gradients induce GB sliding which is pronounced for the transverse loading. The flow stress and GB sliding are the lowest but the spall strength is the highest, for longitudinal loading. For the grain size and loading conditions explored, void nucleation occurs at the peak shear deformation sites (GBs, and particularly triple junctions); spall damage is entirely intergranular for the transverse loading, while it may extend into grain interiors for the longitudinal loading. Crystal plasticity assists the void growth at the early stage but the growth is mainly achieved via GB separation at later stages for the transverse loading. Our simulations reveal such deformation mechanisms as GB sliding, stress, and shear concentration, GB-initiated crystal plasticity, and GB separation in nanocrystalline solids under shock wave loading

Introduction

It didn\u27t seem so wrong. It seemed as though I worked my whole life to get where I am, and at the same time, when it was presented to me, it was like this was the time I could start to get back some of the fruits of my labor. 1 —Paul Palmer, former star college football running back, regarding cash payments of more than $5,000 he received while a college senior from sports agent Norby Walters. This epigraph has remained in our text through multiple editions. Its continued relevance is underscored by the irony that, in a recent court ruling, a judge pegged the minimum dollar figure for college athletes to received from licensing revenues at$5,000. This book, meanwhile, focuses on the evolving sports agent industry, the issues affecting it, and how to improve and regulate it. Key issues and problems associated with sports agents are visible at the high school, collegiate, and professional levels. Whatever the concerns that lie at the center of the sports agent storm, it is a business that captures the attention of many

Structural Classification of Metal Complexes with Three-Coordinate Centres

Attempts to describe the geometry about three-coordinate silver(I) complexes have proven difficult because interatomic angles generally vary wildly and there is no adequate or readily available classification system found in the literature. A search of the Cambridge Structural Database shows that complexes formed between any metal centre and three non-metal donors (18001 examples) usually adopt geometries that are quite different than ideal ‘textbook’ extremes of either trigonal planar (∼4% with α = β = γ = 120 ± 2°), T-shaped (∼0.05% with α = 180 ± 2°, β = γ = 90 ± 2°), or trigonal pyramidal (∼0.3% with α = β = γ = 110 ± 2°). Moreover, there are multiple variations of “Y-type” and “other” shapes that require elaboration. Thus, to assist in future structural descriptions, we developed a classification system that spans all known and yet-to-be-discovered three-coordinate geometries. A spreadsheet has also been constructed that utilizes the “shape-space” approach to extract the structural description from a user input of three angles about a tri-coordinate centre and the number of atoms in a plane. The structures of two silver(I) complexes of new N-donor ligands p-NH2C6H4C6H4CH(pz = pyrazol-1-yl)2, L1, and 2-ferrocenyl-4,5-di(2-pyridyl)imidazole, L2, illustrate the utility of this classification system

The SPADE Symptom Cluster in Primary Care Patients with Chronic Pain

Objectives: Sleep disturbance, pain, anxiety, depression, and low energy/fatigue, the SPADE pentad, are the most prevalent and co-occurring symptoms in the general population and clinical practice. Co-occurrence of SPADE symptoms may produce additive impairment and negatively affect treatment response, potentially undermining patients’ health and functioning. The purpose of this paper is to determine: (1) prevalence and comorbidity (ie, clustering) of SPADE symptoms; (2) internal reliability and construct validity of a composite SPADE symptom score derived from the Patient-Reported Outcomes Measurement Information System (PROMIS) measures; and (3) whether improvement in somatic symptom burden represented by a composite score predicted subsequent measures of functional status at 3 and 12 months follow-up. Methods: Secondary analysis of data from the Stepped Care to Optimize Pain care Effectiveness study, a randomized trial of a collaborative care intervention for Veterans with chronic pain. Results: Most patients had multiple SPADE symptoms; only 9.6% of patients were monosymptomatic. The composite PROMIS symptom score had good internal reliability (Cronbach’s alpha=0.86) and construct validity and strongly correlated with multiple measures of functional status; improvement in the composite score significantly correlated with higher scores for 5 of 6 functional status outcomes. The standardized error of measurement (SEM) for the composite T-score was 2.84, suggesting a 3-point difference in an individual’s composite score may be clinically meaningful. Discussion: Brief PROMIS measures may be useful in evaluating SPADE symptoms and overall symptom burden. Because symptom burden may predict functional status outcomes, better identification and management of comorbid symptoms may be warranted