No description available.

No description available.

La tesis tiene como objetivo principal en evaluar y analizar el comportamiento en la adición de la ceniza volcánica en 5%, 7%, 9%, 11% y 13% para el mejoramiento de la subrasante con fines de cimentación o pavimentación, donde se tomará un suelo con clasificación SUCS GC-GM como referencia, bajo esta combinación incrementará su resistencia al corte, mediante el indicador de la capacidad portante y el grado de CBR. Así mismo, mediante los ensayos de laboratorios de suelos del material adicionado juntamente con la muestra de subrasante, tales como SUCS, Proctor Modificado, CBR, Corte Directo y el cálculo de la Capacidad portante. Por tanto, se realizará una comparación de las capacidades portantes y el grado del CBR de ambas muestras. Obteniendo la siguiente información. La adición del 5% con ceniza volcánica, obtuvo una capacidad portante de 7.53 kg/cm2, incrementando en un 13% con respecto a la muestra patrón. La adición del 7% con ceniza volcánica, obtuvo una capacidad portante de 15.7 kg/cm2, incrementando en un 135% con respecto a la muestra patrón. La adición del 9% con ceniza volcánica, obtuvo una capacidad portante de 13.73 kg/cm2, incrementando en un 105% con respecto a la muestra patrón. La adición del 11% con ceniza volcánica, obtuvo una capacidad portante de 16.09 kg/cm2, incrementando en un 141% con respecto a la muestra patrón. La adición del 13% con ceniza volcánica, obtuvo una capacidad portante de 14.66 kg/cm2, incrementando en un 119% con respecto a la muestra patrón. / The thesis has as main objective in evaluating and analyzing the behavior in the addition of the volcanic scenario in 5%, 7%, 9%, 11% and 13% for the improvement of the substrate with the cementation ends or the pavement, from where it will be taken a product with SUCS GC-GM classification as a reference, so this combination will increase its cutting resistance, by means of the indicator of the carrying capacity and the degree of CBR. Likewise, by means of laboratory tests of the material added together with the subrasant sample, such as SUCS, Modified Proctor, CBR, Corte Directo and the calculation of the carrying capacity. Therefore, a comparison of the carrying capacities and the degree of CBR of both experiments will be carried out. Obtaining the following information. The addition of 5% with volcanic scenery, obtained a carrying capacity of 7.53 kg / cm2, increasing by 13% with respect to the master pattern. The addition of 7% with volcanic scenery, obtained a carrying capacity of 15.7 kg / cm2, increasing by 135% with respect to the master pattern. The addition of 9% with volcanic scenery, obtained a carrying capacity of 13.73 kg / cm2, increasing by 105% with respect to the master pattern. The addition of 11% with volcanic scenery, obtained a carrying capacity of 16.09 kg / cm2, increasing by 141% with respect to the master pattern. The addition of 13% with volcanic scenery, obtained a carrying capacity of 14.66 kg / cm2, increasing by 119% with respect to the master pattern. / Tesis

No description available.

During the mid Cenozoic, the Chocolate Mountains region of southeastern California experienced crustal extension slightly before, during, and after the main pulse of magmatism. This combined with mid-late Cenozoic faulting to locally uplift plutonic rocks interpreted to represent the plumbing system(s) for volcanic units, allowing an examination of both the extrusive and intrusive result of magmatism. Zircon U-Pb ages of from six magmatic units yield late Oligocene to early Miocene ages and correlate better with stratigraphic relationships than previously compiled ages. These units are four silicic volcanic units – Quechan volcanic rocks, tuff of Felipe Pass, ignimbrite of Ferguson Wash, and tuff of Black Hills – and two plutonic units – the granites of Mount Barrow and Peter Kane Mountain. Regarding contemporaneous plutonic systems as baseline comparisons, zircons from the volcanic units commonly record plutonic temperatures; interpreted to be solidus or near solidus temperature. Remobilization may be a common process leading to eruption. Quartz and zircon thermometers reveal the ignimbrite of Ferguson Wash and tuff of Black Hills magmatic systems evolved differently. Quartz yields temperatures of 700°C to ~750°C in both units with no core-rim trends. Cores of zircons from the ignimbrite of Ferguson Wash yield temperatures between 750°C and 890°C. Zircon rim temperatures are between 875°C and 950°C. Tuff of Black Hills zircon cores generally record temperatures of ~850°C and zircon rim temperatures are ~700°C. Rims from tuff of Black Hills zircon record the same temperature range as zircons from coeval granites. The temperature increase from core to rim in zircons from the ignimbrite of Ferguson Wash indicates reheating and that zircon grew later than and at higher temperatures than quartz. The low zircon temperatures from tuff of Black Hills reveals a system that was growing quartz and zircon at the same low, nearly solidus temperatures. Reasons for its eruption are not readily apparent in the thermal history of zircon and quartz. These two systems record different thermal histories than previously studied, younger systems like the Bishop tuff, in which quartz records late reheating just prior to eruption and a system that was growing quartz later and at higher temperatures than zircon.

Development of homes, roads, and commercial buildings in northern Utah has grown significantly during the last several decades. Construction has expanded from the valley floor to higher elevations of benches, foothills, and other elevated regions of the Wasatch Mountain Front. Construction in the higher elevation areas are a concern due to potential for landslides, both new and reactivated. Landslides have been identified in this region and are dated as Pleistocene to historical in age. A possible landslide of about 0.5 km2 on the south slope of Traverse Mountain has been mapped by the Utah Geological Survey in 2005. Its surface exhibits hummocky topography and is comprised of Oligocene-age volcanic ash, block and ash flow tuffs, and andesite lava. Landslides along the Wasatch Mountain Front are complex features usually characterized by dense vegetation and poor outcrop and require a combination geological and geophysical methods to study their thickness, slope, lateral extent, and style of emplacement. Our study incorporates trenching, boreholes, and LiDAR aerial imagery. Unique to the study of landslides is our use of seismic reflection with a vibroseis source over the mapped landslide deposit. The seismic parameters of source, station spacing, and processing method provide a coherent, albeit low-resolution, image of the upper 500 m of the subsurface beneath the landslide. A major reflector boundary in our seismic profiles has an apparent dip of 4° to the south, approximately parallel with the surface topography. Its elevation and seismic character are indicative of a contact between the Oligocene-age volcanic rocks on top of a portion of the Pennsylvanian-age Bingham Mine Formation, a mixed carbonate and siliciclastic sequence. The reflector defines an asymmetric graben-like structure bounded by a north-northwest-trending normal fault system. Analysis of trenches, boreholes and local geology reveals a faulted, chaotic body of block and ash flow tuffs, surrounded by andesite lavas. Using LiDAR and surface geological reconnaissance, a possible toe or margin of a landslide has been interpreted in the north-west portion of the study area. The combination weakened block and ash flow tuffs and abundant clay production from this unit contribute to the likelihood of a coalescence of landslides in this mapped landslide area. The integration of LiDAR, trenching, boreholes and reflection seismology provides the range and resolution of data needed to assess the complex geology of landslides.

Primitive magmas can provide important details about the mantle from which they are derived. In this thesis, petrographic observations and new mineral chemistry analyses of the Sälskär breccia from the Alnö alkaline complex, central Sweden, are reported. The rock is a volcanic breccia in which three main constituents were identified: spheroidal melilititic lapilli, angular sövite fragments and a carbonatedominated matrix. The mineralogy of the juvenile lapilli (i.e., with olivine, phlogopite, diopside, titanomagnetite, Cr-spinel, monticellite, perovskite, apatite and calcite) are consistent with what is expected to form by small degrees of partial melting of a volatile-rich, metasomatized, mantle source (indicated by the presence of phlogopite and primary calcite). The melilititic lapilli are frequently cored by a large crystal of olivine or phlogopite with concentrically aligned lath-shaped pseudomorphs after melilitite. During ascent the melilititic magma entrained mantle debris and traveled rapidly through the crust without significant fractionation.  The pyroclast textures indicate an explosive eruption, similar to those that produce pelletal lapilli in kimberlite-type volcanism. The sövite fragments and carbonate-dominated matrix were explosively fragmented during the eruption, which also dispersed the melilite mineralogy throughout the matrix. During the eruption a diatreme formed of within the uppermost 1.5 kilometers of the crust. A mismatch between the model of diatreme formation and a previous erosional model of the area leads to the conclusion that the Sälskär diatreme is either: (i) very deep, or (ii) that the diatreme volcanism took place significantly later than the rest of the complex / Primitiva magmor kan ge viktiga detaljer om manteln som de härstammar ifrån. I denna avhandling redovisas petrografiska observationer och nya mineralkemiska analyser av Sälskärsbreccian från Alnö alkalina område, Mellansverige. Bergarten är en vulkanisk breccia där tre huvudbeståndsdelar identifierades: sfäroidala melilitiska lapilli, kantiga sövitfragment och en karbonatdominerad matrix. Mineralogin hos de juvenila lapilli (dvs med olivin, flogopit, diopsid, titanomagnetit, Cr-spinel, monticellit, perovskit, apatit och kalcit) överensstämmer med vad som förväntas att det bildas av små grader av partiell smältning av en volatilrik, metasomatiserad, mantelkälla (indikeras av närvaron av flogopit och primär kalcit). De melilitiska lapilli är ofta kärnade av en stor kristall av olivin eller flogopit med koncentriskt riktade list-formade pseudomorfer efter melilitit. Under uppstigningen tog den melilitiska magman med sig mantelfragment och färdades snabbt genom skorpan utan betydande fraktionering. Pyroklastexturer indikerar ett explosivt utbrott, liknande de som producerar pelletala lapilli i kimberlitvulkansim. Sövitfragmenten och den karbonatdominerade matrixen fragmenterades explosivt under utbrottet, vilket också spred melilit mineralogin genom matrixen. Under utbrottet bildades en diatrem i de översta 1,5 kilometerna av skorpan. Detta betyder att modellen för diatrem-bildning och den tidigare erosionsmodellen av området inte överensstämmer. Detta leder till slutsatsen att Sälskärsdiatremen är antingen: (i) mycket djup, eller (ii) att diatrem-vulkanismen ägde rum betydligt senare än den sopm bildade resten av området.

Thin fallout tuffs in the Duchesne River Formation in the Uinta Basin, Utah are evidence that volcanism was active in northern Nevada and Utah in the late Eocene. The Uinta Basin is a sedimentary basin that formed during the Laramide orogeny. Ponded lakes of various salinity filled and emptied and during the late Eocene the northern rim was dominated by a wetland/floodplain depositional setting. Most of the tuffs have rhyolitic mineral assemblages including quartz, biotite, sanidine, and allanite. Rhyolitic glass shards were also found in one of the ash beds. Biotite compositions have Fe/(Fe+Mg) ratios typical of calc-alkaline igneous rocks and clusters of biotite compositions suggest 3 or 4 volcanic events. Sanidine compositions from five samples grouped at Or73 and Or79. Only one sample had plagioclase with compositions ranging between An22 - An49. Some beds also contained accessory phases of titanite, apatite, and zircon. Whole rock compositions of the altered volcanic ash beds indicate these tuffs underwent post-emplacement argillic alteration, typical of a wetland/floodplain depositional setting. Immobile element ratios and abundances, such as Zr/Nb and Y are typical of a subduction zone tectonic setting and rhyolitic composition. 40Ar/39Ar ages constrain the timing of volcanism. One plagioclase and one sanidine separate from two different tuff beds yielded ages of 39.47 ± 0.16 Ma and 39.36± 0.15 Ma respectively. These dates, along with the compositional data seem to limit the eruptive source for these fallout tuffs to the northeast Nevada volcanic field. These new ages, along with previously published ages in the Bishop Conglomerate which unconformably overlies the Duchesne River Formation, constrain the timing of two uplift periods of the Uinta Mountains at 39 Ma and 34 Ma. Finally, the ages also date the fauna of the Duchesnean Land Mammal Age to be about 39.4 Ma as opposed to less precise earlier estimates that placed it between 42 and 33 Ma.

Thin fallout tuffs in the Duchesne River Formation in the Uinta Basin, Utah are evidence that volcanism was active in northern Nevada and Utah in the late Eocene. The Uinta Basin is a sedimentary basin that formed during the Laramide orogeny. Ponded lakes of various salinity filled and emptied and during the late Eocene the northern rim was dominated by a wetland/floodplain depositional setting. Most of the tuffs have rhyolitic mineral assemblages including quartz, biotite, sanidine, and allanite. Rhyolitic glass shards were also found in one of the ash beds. Biotite compositions have Fe/(Fe+Mg) ratios typical of calc-alkaline igneous rocks and clusters of biotite compositions suggest 3 or 4 volcanic events. Sanidine compositions from five samples grouped at Or73 and Or79. Only one sample had plagioclase with compositions ranging between An22 - An49. Some beds also contained accessory phases of titanite, apatite, and zircon. Whole rock compositions of the altered volcanic ash beds indicate these tuffs underwent post-emplacement argillic alteration, typical of a wetland/floodplain depositional setting. Immobile element ratios and abundances, such as Zr/Nb and Y are typical of a subduction zone tectonic setting and rhyolitic composition. 40Ar/39Ar ages constrain the timing of volcanism. One plagioclase and one sanidine separate from two different tuff beds yielded ages of 39.47 ± 0.16 Ma and 39.36± 0.15 Ma respectively. These dates, along with the compositional data seem to limit the eruptive source for these fallout tuffs to the northeast Nevada volcanic field. These new ages, along with previously published ages in the Bishop Conglomerate which unconformably overlies the Duchesne River Formation, constrain the timing of two uplift periods of the Uinta Mountains at 39 Ma and 34 Ma. Finally, the ages also date the fauna of the Duchesnean Land Mammal Age to be about 39.4 Ma as opposed to less precise earlier estimates that placed it between 42 and 33 Ma.

Betong är ett av världens mest använda byggnadsmaterial, men kan också vara en stor miljöbov. Cementklinker är en betydande beståndsdel i betong som vid tillverkning frigör stora mängder koldioxid, av den anledningen optimeras betongrecept idag genom att ersätta en del av cementen med flygaska som är en restprodukt från kolkraftsindustrin. I takt med att samhället rör sig mot en fossilfri produktion beräknas tillgången till flygaska att avta och material med liknande egenskaper undersöks som alternativa bindemedel i betong.  Syftet med studien är att, genom litteraturstudier och laboratoriska tester, undersöka huruvida naturliga puzzolaner kan ersätta mängden flygaska i en cementsammansättning utan att försämra betongens hållfasthetsegenskaper. Tryckhållfastheten samt hållfasthetsutvecklingen har undersökts hos 150x150x150 mm provkuber med varierande mängd flygaska samt vulkanaska av isländsk pimpsten respektive jordanska tuffer. Målet med studien är att minska mängden, eller helst ersätta hela andelen flygaska i en klimatförbättrad betongsammansättning.  De laboratoriska testerna har utförts enligt svensk standard där totalt 48 provkroppar gjutits. Referenskuben i undersökningen består av 80% portlandkalkstencement och 20% flygaska. Totalt har 6 olika kombinationer av provkuber gjutits där andelen flygaska ersätts med 20%, 15% eller 10% vulkanaska. Vardera provkub har utsatts för tryckhållfasthetsmätning efter 2, 7 samt 28 dygn.  Resultatet av provtryckningen visade att provkuberna innehållande isländsk pimpsten gav en ökad eller oförändrad hållfasthet vid samtliga mätningar, jämfört med referenskuben. Provkuberna innehållande jordanska tuffer medförde däremot en reducering av hållfastheten vid samtliga mätningar, jämfört med referenskuben. Provkuberna innehållande vulkanaska från isländsk pimpsten gav högst sluthållfasthet då ingen flygaska förekom i sammansättningen och något sämre värden vid inblandning av flygaska, till skillnad från provkuberna innehållande vulkanaska från jordanska tuffer som utan flygaska i princip stannade av i sin hållfasthetstillväxt efter 7 dygn. Skillnaden i resultatet mellan vulkanaska av pimpsten respektive tuffer antyder att vilken typ av material det är samt dess ursprung har betydelse för hur det presterar som bindemedel i betong. / Concrete is one of the most widely used building materials in the world, but it can also be a major environmental culprit. Cement clinker is a significant component of concrete that releases large amounts of carbon dioxide during production. For this reason, concrete recipes are now optimized by replacing some of the cement with fly ash, which is a byproduct from the coal power industry. As society moves towards fossil-free production, the availability of fly ash is expected to decrease, and materials with similar properties are being investigated as alternative binders in concrete.  The purpose of the study is to investigate, through literature review and laboratory tests, whether natural pozzolans can replace the amount of fly ash in a cement composition without deteriorating the strength properties of the concrete. The compressive strength and strength development have been studied on 150x150x150 mm test cubes with varying amounts of fly ash and volcanic ash from Icelandic pumice and Jordanian tuffs. The goal of the study is to reduce the amount, or preferably replace the entire portion, of fly ash in a climate-improved concrete composition. The laboratory tests have been performed according to Swedish standards, where a total of 48 test specimens have been cast. The reference cube in the study consists of 80% Portland limestone cement and 20% fly ash. A total of 6 different combinations of test cubes have been cast, where the proportion of fly ash is replaced with 20%, 15%, or 10% volcanic ash. Each test cube has been subjected to compressive strength measurement after 2, 7, and 28 days. The results of the compression testing showed that the test cubes containing Icelandic pumice provided increased or unchanged strength at all measurements, compared to the reference cube. However, the test cubes containing Jordanian tuffs resulted in a reduction of strength at all measurements, compared to the reference cube. The test cubes containing volcanic ash from Icelandic pumice provided the highest final strength when no fly ash was present in the composition, and slightly lower values when fly ash was added, unlike the test cubes containing volcanic ash from Jordanian tuffs which essentially plateaued in their strength development after 7 days without fly ash. The difference in results between volcanic ash from pumice and tuffs suggests that the type and origin of the material are significant factors in how they perform as a binder in concrete.