The analysis of ceramic fragments from the site of Puerto Nuevo (1000-500 AC), on the south coast of Peru, reveals a diversified ceramic production and possible long distance interaction networks for ceramics along the coast during the first half of the first millennium before our era. Macroscopic analysis with a hand-held digital low power microscope of fresh cross-sections conducted by Alejandro Rey de Castro allowed classifying the ceramics in different paste groups as well as identifying atypical ceramics. Petrographic analysis conducted by Isabelle Druc on 120 ceramic thin sections of these fragments helped refine this classification into six compositional groups, providing more details on the production and provenance of the wares. Comparison with 30 thin sections of clay-tiles collected in the lower and middle valley of the Ica and Pisco Rivers and on the littoral between the two rivers, showed that a majority of ceramics was manufacturedwith local sediments without much sorting. Different resource areas were exploited around Puerto Nuevo, on the littoral and in the Lower and Middle Ica and Pisco valleys. Based on these results, we propose the existence of severalcommunities of potters working in the Puerto Nuevo region. One (or more) of these communities must have used coastal sandy clays with no need to ad temper, another mined inland clay deposits with natural inclusions of charophyte algae, and other(s) used materials rich in granodioritic rock fragments. Thirteen atypical ceramics were singled out based on different composition, texture, or firing, suggesting other production modes. Their composition, however, still suggests a coastal provenance, indicating that the interaction network extended along the coast, rather than with the highlands. / El análisis de fragmentos de vasijas de cerámica del sitio de Puerto Nuevo (1000 a 500 a.C.), en la costa sur del Perú, revela la existencia de una producción diversificada y la probable existencia de redes de intercambio a larga distancia de vasijas de cerámica a lo largo de la costa durante la primera mitad del primer milenio antes de nuestra era. El examen macroscópico con lupa digital sobre cortes frescos realizado por Alejandro Rey de Castro permitió agrupar inicialmente los fragmentos en diferentes grupos de pasta, así como identificar varios fragmentos atípicos. A partir del análisis petrográfico de 120 láminas delgadas de estas cerámicas, Isabelle Druc refinó esta agrupación inicial en seis grupos de composición que brindan informaciones más detalladas sobre la producción y la procedencia de las vasijas de cerámica de las cuales provienen estos fragmentos. El análisis petrográfico de estas 120 láminas delgadas de fragmentos de cerámicas con 30 láminas delgadas de muestras de arcilla de los valles bajo y medio de los ríos Ica y Pisco, y del área de litoral entre lasdesembocaduras de ambos evidencia que la mayoría de las vasijas de cerámica estudiadas fueron producidas con sedimentos locales sin mucha selección granulométrica. Diversas fuentes de materias primas fueron explotadas, tanto en el área de litoral alrededor de Puerto Nuevo, como en los valles bajo y medio de los ríos Ica y Pisco. A partir de estos resultados, proponemos la existencia de varias comunidades de alfareros que trabajaban en la región de Puerto Nuevo —al menos, una caracterizada por el uso de una arcilla arenosa a la que no se agregaba temperante; otra, por el uso de una arcilla rica en algas carofitas; y otra a la que se le agregaba un temperante granodiorítico—. Trece fragmentos de vasijas de cerámica petrográficamente atípicos —con una composición, textura o cocción distintas a las de los grupos identificados para Puerto Nuevo— sugieren la existencia de otros modos de producción, mientras que el hecho de que en todos estos casos la composición sea de tipos costeños podría indicar la existencia de redes de intercambio de vasijas de cerámica preferentemente a lo largo de la costa, en lugar de entre la costa y la sierra.

abstract: This project examines the social and economic factors that contributed to the development of a specialist-based economy among the Phoenix Basin Hohokam. In the Hohokam case, widespread dependence on the products of a few concentrated pottery producers developed in the absence of political centralization or hierarchical social arrangements. The factors that promoted intensified pottery production, therefore, are the keys to addressing how economic systems can expand in small-scale and middle-range societies. This dissertation constructs a multi-factor model that explores changes to the organization of decorated pottery production during a substantial portion of the pre-Classic period (AD 700 - AD 1020). The analysis is designed to examine simultaneously several variables that may have encouraged demand for ceramic vessels made by specialists. This study evaluates the role of four factors in the development of supply and demand for specialist produced red-on-buff pottery in Hohokam settlements. The factors include 1) agricultural intensification in the form of irrigation agriculture, 2) increases in population density, 3) ritual or social obligations that require the production of particular craft items, and 4) reduced transport costs. Supply and demand for specialist-produced pottery is estimated through a sourcing analysis of non-local pottery at 13 Phoenix Basin settlements. Through a series of statistical analyses, the study measures changes in the influence of each factor on demand for specialist-produced pottery through four temporal phases of the Hohokam pre-Classic period. The analysis results indicate that specialized red-on-buff production was initially spurred by demand for light-colored, shiny, decorated pottery, but then by comparative advantages to specialized production in particular areas of the Phoenix Basin. Specialists concentrated on the Snaketown canal system were able to generate light-colored, mica-dense wares that Phoenix Basin consumers desired while lowering transport costs in the distribution of red-on-buff pottery. The circulation of decorated wares was accompanied by the production of plainware pottery in other areas of the Phoenix Basin. Economic growth in the region was based on complementary and coordinated economic activities between the Salt and the Gila River valleys. / Dissertation/Thesis / Ph.D. Anthropology 2013

O Batólito Acandí é um corpo intrusivo com grandes variações de composição (Gonzalez e Londoño, 2002) que data do Oligoceno (Toussaint e Restrepo, 1976), por sua vez intruído por corpos de andesitos, dacitos, e diques de basalto. Devido às diferenças de composição deste corpo na Cordilheira Ocidental, a integração e interpretação dos dados da análise petrográficos, geoquímicos e isotópicos amostras coletadas no norte do Golfo de Urabá entre as cidades de Acandí e Unguía, no departamento foi feito. Para esta área, as rochas do Batólito são gabros: rochas melanocráticas, massivas, equigranulares de grão fino a meio, subhedrales, de textura fanerítica; e os corpos e diques são rochas leucocráticas, massivas, inequigranulares de grão fino a meio, subhedrales, com textura porfirítica e rochas melanocráticas afaníticas (basaltos). Petrografia detalhada mostra que as rochas do Batólito são compostas de plagioclásio, piroxênio e anfibólio, como acessórios pirita disseminada, apatita, magnetita e ilmenita. São rochas holocristalinas, melanocráticas, inequigranulares, subhedrales, de fino a groso granular, com a presença de texturas subofíticas e ofíticas, com coroas de reação e zoneamento em plagioclásios. As rochas subvulcânicas que intrudem o Batólito são basaltos afaniticos e andesitos e dacitos com texturas porfiríticas, com plagioclásio e hornblenda como principais minerais. São inequigranulares, de tamanho muito fino a grosso, com texturas cumulo-porfiríticas, vesiculares e amigdulares. Análises geoquímicas e isotópicas indicam que tanto as rochas do Batólito como os corpos que intrudem, são de afinidade sub-alcalina da série cálcio-alcalina de baixo para meio K, metaluminosas com ligeiro enriquecimento de elementos de terras raras em relação ao as terras raras pesadas. Dados de geoquímica e isotópicos de Nd e Sr sugerem que estas rochas são formadas a partir de processos em arcos insulares associados com zonas de subducção, sendo posteriormente acrecentadas à margem continental. / The Acandi’s batholith is a large intrusive body with a wide compositional variation (Gonzalez and Londoño, 2002) dating from the Oligocene (Restrepo y Toussaint, 1976), and intruded by andesites and dacites bodies and basalt dikes. Due to the compositional difference of this body in the Western Cordillera, it is performed integration and interpretation of new petrographic, geochemical and isotopic data from samples collected in the northern Gulf of Urabá between the towns of Acandí and Unguía it is done in Choco Department. For this area, batholith rocks are gabbros: melanocratic rocks, massive, equigranular fine to medium grained, subhedral, phaneritic texture; and the bodies and dikes are: leucocratic, massive and inequigranular rocks, fine to medium grained, subhedral, with sporphyritic texture and aphanitic melanocratic rocks (basalts).. Detailed petrography shows that the rocks from the Batolith are constituted by plagioclase, pyroxene and amphibole, with disseminated pyrite, apatite, magnetite and ilmenite as accessory phases. The batholith rocks are holocrystalline, melanocratic, inequigranular, subhedral, from fine to granular roughly, with the presence of ophitic and subophitic textures, with reaction rings (coronas) and zoning in plagioclase. The intrusive subvolcanic rocks that crosscut the Batholith are afanitic basalts, dacites, and andesites with porphiritic textures, having plagioclase and hornblende as main minerals. They are inequigranular, very fine to coarse grained, with glomeroporphyritic texture and also vesicular and amygdular textures. Geochemical and isotopic analyses indicate that both batholiths and intrusive rocks are sub-alkaline from the calc-alkaline series of low to medium K, metaluminous with light rare earth elements enrichment in relation to the heavy rare earth elements. The geochemical and Nd and Sr isotopic data suggest that these rocks are formed in island arcs, associated with subduction zones, being later added to a continental margin.

>Magister Scientiae - MSc / Pletmos Basin is a Mesozoic half graben located in the southern part of South Africa and has undergone numerous tectonic changes which involve alteration of structure and reworking of sediments. Clay diagenesis has become a more prominent factor affecting the quality of the tight shaly sandstone reservoirs in the southern Pletmos Basin. The present study focused on Block 11a as a primary area of interest .The tight sandstone reservoirs encountered in the four wells, viz. Ga-Q1, Ga- Q2, Ga-Z1 and Ga- E2 were studied using four different methods to incorporate and infer the overall diagenetic effect on the reservoirs, caused by materials of argillaceous origin. The methods adopted in the present research are formation evaluation using wireline logs and calibration of core data using Interactive Petrophysics software, thin section petrography, X-Ray Diffraction (XRD) and, Scanning Electron Microscope (SEM) along with Energy Dispersive X-Ray Spectroscopy (EDS). The availability of core samples were limited to wells Ga- Q1 and well Ga- Z1. Four reservoirs within the Cretaceous age were identified in each well and the best reservoirs were associated with facies B and D. / 2022-04-30

Near Logan, Utah, the Fish Haven Formation is a thick-bedded, dark-gray dolostone. The Laketown Formation, which rests on the Fish Haven, is a less resistant, medium-gray dolostone. The Ordovician-Silurian boundary has been placed locally at the top of the Fish Haven by stratigraphers, and in the lower Laketown Formation by paleontologists. Four sections of the Fish Haven and Laketown dolostones were measured near Logan, Utah. The samples from these four sections were examined using petrography, insoluble residue analyses, x- ray diffraction, quantitative and qualitative x-ray fluorescence spectroscopy, and statistical analysis. Petrography appears to be the best lab technique for distinguishing the two dolostones. This technique shows the grain size decreases in going from the Fish Haven Formation to the Laketown Formation. This decrease in grain size is also seen in the field. All other laboratory techniques show that the two dolostones are very similar and cannot, in general, be distinguished. To summarize, the percent insoluble residue and the percent of quartz and illite found in each formation are independent of formational boundaries. X-ray diffraction, X-ray fluorescence spectroscopy, and statistical analysis all show that the two formations are geochemically similar. A comparison of dolostones shows that they may, in general, be divided into two categories of pure and impure. The Fe2O3 content of pure dolostones may be less than the Fe2O3 content of impure dolostones. Other than the change in Fe2O3 content dolostones tend to be the same geochemically. This suggests that the process of dolomitization tends to obliterate any differences which may have originally existed and make all dolostones essentially uniform in composition.

An enhanced coal-bed methane facility in Russell County, Virginia is targeting lower Pennsylvanian coals for CO2 storage, but the shallow sandstone units intercalated with the coals may also prove to be potential CO2 reservoirs, since the injection apparatus is already in place. Using samples from a continuous core in southwestern Virginia, this detailed review of the petrography and local volume of the Breathitt Formation sandstone units examines their diagenetic alterations in order to assess the units' reservoir quality. The high-frequency sequences of immature sandstones, heterolithics, shales and coals in Russell County represent deposits from the transverse fluvial facies association of a broad braided-fluvial drainage system in the central Appalachian Basin. The sandstone units within these sequences are laterally extensive, maintaining similar thickness and gamma ray signature across the study area. Lower Pennsylvanian sandstone units are consistently sublitharenite with a diagenetic mineral assemblage including siderite, chlorite, kaolinite, albite, illite, silica and calcite. Primary porosity is not preserved, but secondary porosity (5 ± 3.1 %) has developed at the expense of feldspars and unstable lithic fragments. Permeability assessments collected in Grimm (2010) measured impervious values (0.005-0.008mD) for the medium-coarse grained sublitharenites. At the temperatures and pressures present within these units, CO₂ is unlikely to react with either the primary or diagenetic mineralogy in a way that negatively impacts continued injection on human time scales. Low pore volume and permeability due to the timing of certain authigenic mineral emplacement are the main hindrance to reservoir quality. Lower Pennsylvanian sandstones are not viable potential reservoirs for carbon sequestration. / Master of Science

<p> A detailed petrographic, geochemical and strontium isotope study of the rocks representing the variations observed across the Coe Hill granite, Grenville Province, southeastern Ontario provides the basis for the determination of the age and possible origin of this pluton. This study also provides insight into the relationships between similar granitoid plutons in the immediate vicinity.</p> <p> The Coe Hill granite is a medium to coarse grained hypidiomorphic to allotriomorphic, leucocratic quartz monzonite with subordinate isolated inclusions of dioritic and gabbroic gneiss. Variations upon this otherwise homogeneous granitoid occur in discordant aplite dykes, assimilating mafic xenoliths and along brecciated contact boundaries.</p> <p> Generally the rocks of this pluton are more basic than the average for similar granitoids in the area (12.4% vs. 6.0% mafics) as observed in both thin section and major element oxide diagrams. Besides this trend major element diagrams have uniform distributions. A Rb-Sr isochron was determined for the rocks of the pluton proper which gave an age representative of the emplacement of these rocks (t = 1063 ± 21 M.a.; Ri = 0.7040 ± 5). Trace element Rb shows a value similar to the norm for granitoids yet is enriched in comparison to values acquired from similar granitoids in the area (144 ppm vs. 63 ppm).</p> <p> Through a synthesis of the available data, and that which was acquired from this study on the Coe Hill granite, a comparison with the available data on the Loon Lake quartz monzonite can be made. This comparison illustrates a great deal of strikingly similar trends which have been taken to represent a lower crustal, or upper mantle origin, cogenetic relationship between these two granitoids.</p> / Thesis / Bachelor of Science (BSc)

<p> The McBean Mine is a small gold producer located along the Larder Lake Break. Ore from the open pit consists of massive and gneissic syenite. The highest go I d grades come from highly carbonitized syenitic rocks with abundant fine grained, euhedral pyrite. Petrographic observation shows gold to be found as inclusions in pyrite, platings on pyrite and as free grains in the gangue. XRD analyses show the major carbonate type to be dolomite. In addition to dolomite, minor amounts of calcite are found in auriferous syenitic rocks. SEM microscopy shows carbonate composition to vary with rock types and grain location. Geochemical studies show a high intensity of carbonate alteration and the association of gold with tungsten and uranium. Auriferous syenites were determined to have elevated HREE element abundances compared with unaltered syenite. The mine is therefore characterized by extensive hydrothermal carbonate alteration related to the Larder Lake Break. </p> / Thesis / Bachelor of Science (BSc)

Impact spherules are sand-sized spherical particles that have been interpreted to have formed by the cooling, crystallization, and quenching of melt droplets condensed from vapor plumes that are created during large meteor impacts. Spherules may be deposited globally as unique marker beds, such as at the K-Pg boundary. A minimum of 11 spherule beds have been identified in the Archean and Paleoproterozoic, and provide a record of impact events that predate any known craters. This study of 3.24 Ga impact spherules from the S3 spherule layer in the Barberton Greenstone Belt (BGB) in the Kaapvaal Craton of South Africa focuses on the heterogeneity of textures and geochemistry produced during the cooling and crystallization of spherules within a vapor plume. Type 4b spherules are layered phyllosilicate spherules with discrete differences in texture and composition between the inner and outer layer, even after alteration. Compositionally layered phyllosilicate spherules were analyzed using Energy Dispersive X-ray Spectroscopy (EDS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) to measure major, trace, and rare earth element (REE) concentrations. Backscatter Electron (BSE) images and elemental X-ray maps indicate a range of compositional differences between the inner and outer layers of type 4b spherules. The majority of REE plots have nearly flat patterns, with little to no light to heavy REE fractionation; however, the outer layers consistently have higher concentrations, averaging about 10x chondritic, whereas the interiors are at or below chondritic levels with a mid-REE enrichment. The trace and REE patterns of the type 4b spherules are consistent with a more mafic inner layer and a more intermediate outer layer. Mechanisms to produce this layered texture may include: (1) accretion of less mafic material from the plume onto existing melt droplets as the plume continues to fractionate, (2) collision of melt droplets of different viscosities, (3) by differentiation within the melt droplet prior to crystallization, or (4) by diagenetic effects. Based on textures, such as distinct boundaries between layers, and compositional patterns, such as an enrichment of Ti and REE in the outer layer, the data best fits the particle collision formation mechanism hypothesis, which has important implications for impact plume studies, such as plume density, turbulence, temperature, and opacity. / Geology

This paper examines the styles, shapes, and chemical composition, and ceramic fabric of Minoan Barbotine Ware. During the Middle Minoan period, Barbotine Ware exemplifies the creative ingenuity of the Minoan potter. The vessels’ elaborate decorative motifs play an integral part in the development of Minoan pottery. Barbotine Ware remains an ill-defined tradition. This paper will analyze the styles and shapes of Barbotine Ware vessels, as well as provide a chemical and petrographic study of Barbotine Ware from Kommos. The ultimate goal is to provide a thorough study of all aspects of the Ware in the hopes that future scholars may better understand its place within Minoan pottery and appreciate how it exemplifies the spirit of experimentation during the Middle Bronze Age on Crete. / Art History