Studies to determine the location of antique quarries, from where building stones were obtained, are done by comparison of the properties of antique stones and the possible quarry sources around them. In the case when no stonemason marks exists, geologic formations that may be used as building stone should be investigated and properties of antique building stones and geologic formations should be correlated. The aim of this study was the investigation of tuff quarries that could be the source of tuffs used in the construction of Apollon Smintheus Temple. For this purpose, the studies were carried out about the geology of the region, and possible three quarries selected around Smintheion. Durability properties of stones in Temple and quarries were determined with the analyses of physical, physico-mechanical properties and artificial weathering tests of wetting-drying, salt crystallization / Effective porosity, bulk density, water absorption capacity, dry and saturated unit weight, salt content, ultrasonic pulse velocity, modulus of elasticity, uniaxial compressive strength, pore size distribution, capillary absorption and moisture absorption capacities were determined for Temple tuffs and possible quarry tuffs in fresh and artificial weathering cycles. Microstructural investigations were done by mineralogical, petrographical and chemical analyses which were optical microscopy, stereomicroscopy, XRD, SEM, FTIR, MBA and XRF. The results indicated that Temple tuffs and two of the three quarries (Fatma Gerdan and Kizilke&ccedil / ili) had similar engineering geological and micrstructural properties. Therefore, they could be used as building stone during the construction of Temple.

Eruption dynamics are sensitive to ash aggregation, and ash aggregates (e.g. accretionary lapilli) are commonly found in eruptive deposits, yet few experiments have been conducted on aggregation phenomena using natural materials. Experiments were developed to produce a probabilistic relationship for the efficiency of ash aggregation with respect to particle size, collision kinetic energy and atmospheric water vapor. The laboratory experiments were carried out in an enclosed tank designed to allow for the control of atmospheric water vapor. A synthetic ash proxy, ballotini, and ash from the 2006 eruption of Tungurahua, in Ecuador, were examined for their aggregation potential. Image data was recorded with a high speed camera and post-processed to determine the number of collisions, energy of collisions and probability of aggregation. Aggregation efficiency was dominantly controlled by collision kinetic energy and little to no dependence on atmospheric water vapor was seen in the range of relative humidity conditions tested, 20 to 80%. Equations governing the relationships between aggregation efficiency and collision kinetic energy and the related particle Stokes number, respectively, were determined for implementation into large scale numerical volcanic models.

Yucca Mountain was designated as the proposed high-level radioactive waste repository by the U.S. Government in 1987. The proposed repository design requires high safety for a long maintenance period of 10,000 years. To satisfy this requirement, evaluation of the influence of earthquakes on the repository is necessary. Prediction of earthquake-induced ground motions around the repository requires knowledge of the dynamic properties of the geologic materials around the repository. The main geologic materials in the vicinity of Yucca Mountain are tuffs (ignimbrites) which are formed by the deposition of volcanic ash mixed with erupted volcanic gas, water vapor and pyroclastic material. Two types of dynamic tests, (1) the free-free, unconfined, resonant column and direct arrival test (freefree URC test) and (2) the fixed-free resonant column and torsional shear test (fixed-free RCTS test), were used to measure the dynamic properties of tuffs. The emphasis in this dynamic testing was evaluation of shear modulus (G) and material damping ratio (D) of the tuffs in the small-strain (linear) and mildly nonlinear (to strains of about 0.02 %) ranges. To evaluate the influence of various parameters on G and D of tuffs, correlations with other features such as total unit weight, porosity and stratigraphic unit were performed and general relationships between them are proposed. In addition, an unconfined, slow-cyclic torsional shear (CTS) device was developed and used to measure the cyclic shear properties of the tuffs from Yucca Mountain at larger strain amplitudes than possible in the fixed-free RCTS tests. Additionally, the CTS device was also used to determine the shear failure strength of the tuffs. By combining the cyclic shear properties of the tuffs from the CTS tests and the dynamic properties of the tuffs from the fixed-free RCTS tests, complete dynamic property curves from small-strain to failure strain were evaluated. / text

Fluid flow rates and pathways in partially-welded, fractured, unsaturated tuff are investigated in a sloping borehole (DSB-1) cored from the surface to a perched aquifer at the Apache Leap near Superior, Arizona. Suspected water-bearing fractures were identified in the borehole using video and geophysical logs. Pore water extracted from cores associated with these fractures proved to have elevated ¹⁴C activity relative to pore waters from intermediate depths. Pore water from the deepest fracture interval contained post-bomb ¹⁴C. Low tritium concentrations in most samples indicates imbibition from each flow is small relative to the volume of water in the pores, but cumulative imbibition over time is significant based on ¹⁴C distribution through the unsaturated zone. The saturated zone beneath DSB-1 is a mixture of fracture flows with older aquifer water. Estimates based on ¹⁴C and ³H data indicate half of the water in the local aquifer originated from fractures near DSB-1. Geochernical models incorporating pore-water, surface-runoff, aquifer-water and mineral chemistry suggest that fracture flow may also be the predominant source of recharge for the older aquifer water. Water and carbon are extracted from core samples using uni-axial compression and a new vacuum distillation technique. Distillation is shown to be an effective method when carbon extraction is not possible by other methods. Mass yields from distillation provide evidence that there may be a substantial reservoir of carbon adsorbed to mineral phases. Carbon-14 activity of formation air samples from intervals with low air permeability reflect the composition of water imbibed from fracture flows at those depths. In zones of higher permeability, atmospheric contamination is suspected even though SF₆ (injected as a tracer during drilling) concentrations had not diminished. An independent investigation on the carbon isotopic composition of soil-zone CO₂ demonstrates the need to correct soil-respired CO₂ samples for CO₂ contamination in base reagents and for fractionation during sample collection. The minimum δ¹³C-shift from soil CO₂ to soil-respired CO₂ is also shown to be a function of the δ¹³C of soil organic material rather than a fixed 4.4%₀ as previously thought.

published_or_final_version / Earth Sciences / Master / Master of Philosophy

Understanding climatic and water-mineral chemistry affecting hominin habitats duringthe period 1.92 to 1.80 Ma in Paleolake Olduvai basin, Tanzania is of social and scientific interest. Previous Olduvai research reported climate cycles in bulk sample mineral analyses. Xray diffraction, X-ray fluorescence, and color analyses of Locality 80 Tuff Bed I samples tested the null hypothesis: Alteration mineralogy of Central Basin volcanic Tuffs IA through IF reflect salinity/alkalinity cycles. Such cyclicity was not found. Several primary authigenic minerals were confirmed, but not as previously reported. Tuffs are thoroughly altered, mostly to potassium-feldspars, zeolites, and carbonates, plus other feldspars and clay minerals (clays not in this study). Nevertheless, other findings reveal there is more to be learned. Results imply a majorgeochemical shift around 1.869-1.857 Ma, from non-zeolite forming environments to zeolite forming environments. A newly developed age model could aid re-analysis of past work and assist future research.

This thesis attempts to seek a relationship between the joints developed in the ignimbrites and the rock settlements carved in the same units. Orientation of rooms, directions of walls and joints (both in the rooms and in the field) are input data used in the study. Two sites in Cappadocia (Eskig&uuml / m&uuml / Sler and &Ccedil / anlikilise) are selected to investigate the relationship. Both sites are carved within the same ignimbrite (Kizilkaya) and are located on the south-southeastern slopes of the ignimbrite scarp. Measurements taken from 61 rooms of the former and 27 rooms of the latter are analyzed for the room and joint directions, joint locations in the room and joint densities both in the rooms and in the field. Conclusions derived from the analyses are: 1) The rooms are oriented oblique to joint strike to get the maximum sunlight, 2) Joint directions in the rooms strike in one single direction and greatly differ from the field joint directions, 3) Density of the room joints is less than the field joints indicating that joint spacing is an important factor in the selection of sites, 4) Joints in the Eskig&uuml / m&uuml / Sler sites are concentrated towards the margins of the room while an opposite observation is made for the &Ccedil / anlikilise site, 5) Total length of joints in the largest rooms are relatively shorter.

Yucca Mountain was designated as the proposed high-level radioactive waste repository by the U.S. Government in 1987. The proposed repository design requires high safety for a long maintenance period of 10,000 years. To satisfy this requirement, evaluation of the influence of earthquakes on the repository is necessary. Prediction of earthquake-induced ground motions around the repository requires knowledge of the dynamic properties of the geologic materials around the repository. The main geologic materials in the vicinity of Yucca Mountain are tuffs (ignimbrites) which are formed by the deposition of volcanic ash mixed with erupted volcanic gas, water vapor and pyroclastic material. Two types of dynamic tests, (1) the free-free, unconfined, resonant column and direct arrival test (freefree URC test) and (2) the fixed-free resonant column and torsional shear test (fixed-free RCTS test), were used to measure the dynamic properties of tuffs. The emphasis in this dynamic testing was evaluation of shear modulus (G) and material damping ratio (D) of the tuffs in the small-strain (linear) and mildly nonlinear (to strains of about 0.02 %) ranges. To evaluate the influence of various parameters on G and D of tuffs, correlations with other features such as total unit weight, porosity and stratigraphic unit were performed and general relationships between them are proposed. In addition, an unconfined, slow-cyclic torsional shear (CTS) device was developed and used to measure the cyclic shear properties of the tuffs from Yucca Mountain at larger strain amplitudes than possible in the fixed-free RCTS tests. Additionally, the CTS device was also used to determine the shear failure strength of the tuffs. By combining the cyclic shear properties of the tuffs from the CTS tests and the dynamic properties of the tuffs from the fixed-free RCTS tests, complete dynamic property curves from small-strain to failure strain were evaluated.

Mémoire (M.Sc.T.)-- Université du Québec à Chicoutimi, 1991. / Bibliogr.: f. 83-86. Document électronique également accessible en format PDF. CaQCU

Mémoire (M.Sc.T.)--Université du Québec à Chicoutimi, 1991. / Document électronique également accessible en format PDF. CaQCU