No description available.

No description available.

Forest fires are an increasing concern under climate change. Substantially increased fire vulnerability could become a reality for many areas, including the Rocky Mountains. Forest fire hazard was examined in the upper North Saskatchewan and St. Mary watersheds for the period of 1960 to 2100. Ensemble climate scenarios were chosen to represent a wide range of possible future climates. The GENGRID meteorological model and the Canadian Forest Fire Weather index System were combined to assess possible changes in forest fire hazard in the Rocky Mountains. A wind model was developed to estimate daily wind speed variation with elevation. It was found that under most climate scenarios, fire hazard is predicted to increase. If future temperatures are warm, as expected, it could offset future precipitation increases, resulting in greater severity of fire weather and an in increase the number of days per year with high fire hazard. / xiii, 130 leaves ; 29 cm

A wide area assessment of forecast changes in wintertime synoptic conditions over western North America is combined with a meso-scale alpine hydrometeorology model to evaluate the joint impact(s) of forecast climate change on snowpack conditions in an alpine watershed in the southern Canadian Rockies. The synoptic analysis was used to generate long-term climate time series scenarios using the CCCma CGCM1. An alpine hydrometerology model is used to predict changes in wintertime precipitation at the watershed scale. A mass balance snow model is utilized to predict the overall snow accumulation throughout a watershed. A vapour transfer model has been incorporated in the snow model to estimate snow volumes more accurately. The synoptic analysis and GCM output forecasts a modest increase in both winter precipitation and temperatures in the study area, resulting in a decline of winter snow accumulations, and hence an expected decline in spring runoff. / ix, 87 leaves : ill. ; 28 cm.

[No abstract available] / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

A completely new Upper Cambrian formational nomenclature is proposed for the southern Rocky Mountains of Alberta. The formations designated as Upper Cambrian are: Corona, and Mount Synge, Dresbachian; Bison Creek, Franconian; and the Mistaya, Trempealeauan. Two additional formations are referred to the Middle Cambrian sequence immediately underlying the Upper Cambrian; the Chephren and the Waterfowl. These latter formations were previously included in the Arctomys formation considered to be Upper Cambrian in age. The lowest Lower Ordovician formation is designated as the Howse River formation. In addition to the above mentioned new formations, the Arctomys, Sullivan, Lyell, Mons, Bosworth, Paget, Sherbrooke, Tangle Ridge, and Sabine formations are discussed in detail. All are considered obsolete, except the Sabine formation, the use of which, it is recommended, be confined to the Canal Flats area, British Columbia. The limits of the Upper Cambrian series in Alberta are more precisely determined, and tentative correlation of the Upper Cambrian of Alberta, Montana, and British Columbia is outlined. Trilobite faunas from all the Upper Cambrian zones, except the Crepicephalus zone, are described and illustrated. The Cedaria zone faunas contain fifteen genera and eighteen species, among them Bolaspidelia wellsvillensis, Nixonella montanensis, several species of Arapahoia and Cedarina, and Kingstonia mucro. Abundant topotype material of K. mucro has made redefinition of this species possible. The Aphelaspis zone is recognized by the discovery of Aphelaspis walcotti, and one questionable species of Aphelaspis. The Franconian zones are represented by Irvingella major, Taenicephalus shumardi, Parabolinoides cordiIlerensis, Maustonia nasota, KendalIina eryon, Ptychaspis striata, Prosaukia lonqicornis and Prosaukia curvicostata, to mention only the more important index species. The Saukia zone of the Trempealeauan is represented by species of Eurekia, StenopiIus, Bynumiella. Hardyia and IlIaenurus. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The lower Rocky Mountain Supergroup of Pennsylvanian age contains five formations which in ascending order are: Todhunter, Tyrwhitt, Storelk, Tobermory and Kananaskis. All except the Kananaskis are new formations that are equivalent to the Tunnel Mountain Formation. The Todhunter, Tyrwhitt and Tobermory consist mainly of brown weathering, dolomitic and quartzitic, very fine- to fine-grained, pure, quartz-chert sandstones with some interbedded, locally f ossiliferous, sandy dolomite. The Storelk is quartzitic, very fine- to medium-grained, very massive, cross-bedded, white wheathering quartzi-chert sandstone. All these formations contain varying amounts of scattered medium and coarse sand. The Kananaskis consists of sandy and cherty, dense, microcrystalline, grey dolomite. The Todhunter, Tyrwhitt and Storelk Formations are interpreted as being Early Pennsylvanian (Morrowan) in age, and the Tobermory and Kananaskis Formation, which regionally may be facies equivalents, as early Middle Pennsylvanian (Atokan) in age. The contact between the lower Rocky Mountain and the underlying Etherington Formation (Late Mississippian Chesterian) is conformable and locally gradational. Contacts between the Todhunter and Tyrwhitt, and between the Storelk and Tobernory are unconformable, whereas that between the Tyrwhitt and Storelk may be conformable or unconformable. The lower Rocky Mountain is unconformably overlain by Permian, Triassic or Jurassic strata. The lower Rocky Mountain sediments were deposited in a structural basin which may have been partially isolated from adjacent basins to the north, west and south by low barrier arches. Individual formations in the succession thin in a northwesterly and southwesterly direction towards the basin flanks, where as little as 160 feet of the five formations was deposited and remains, whereas at least 1,175 feet of equivalent strata is preserved in the central part. The quartz sand was probably transported by rivers and longshore marine currents from a source lying to the east within the continental interior. Chert and phosphorite fragments ranging up to pebble size were probably locally derived. The strata of Chesterian and Morrowan age represent a regressive sequence. After Morrowan time, gentle warping, emergence, and erosion caused truncation of Lower PennsyIvanian and Upper Mississippian strata towards the east. Angular truncation, and local conglomerates composed of chert, phosphorite, sandstone and dolmite granules and pebbles mark this unconformity. Strata of Atokan age thicken westward and represent a transgressive, sequence which onlaps and truncates the underlying strata. The Pennsylvanian sandstones are a potential source of pure silica sand. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

A total of 34 lead ore samples from selected hydrothermal deposits in Wyoming, Montana, and Idaho have been isotopically analyzed and geochronological interpretations made from the results. Leads from along the southeastern flank of the Idaho Batholith appear to have a primary component 2500 my old. Leads from Butte and Cassia counties, Idaho, may be interpreted as having this same primary component with an added component that is estimated to be 1400 to 1600 my old. The radiogenic component of leads along the southeastern flank of the Idaho Batholith commenced development in a closed system 2500 my ago. Radiogenic components of the leads from Butte and Cassia counties commenced development 1900 and 2700 my ago respectively. Preliminary results of analyses from the south end of the Wind River Mtns, Wyoming, and the Little Belt Mtns, Montana, show primary lead ages of about 3200 and 2200 my respectively. Common lead geochronology indicates that the basement rocks of Southern Idaho may be assigned to the Superior Province of North America as defined by Kanasewich (1965). A second Precambrian event was recorded by a change in the lead isotope abundances during the Penokian era. Thus, Southern Idaho had been subjected to several uplifts during parts of Early and Middle Precambrian time. The ages of the anomalous leads from Butte and Cassia counties could represent the times of formation of sedimentary layers which remained closed systems until the time of formation of the ore bodies. A model for continental accretion and growth is discussed. The contribution of the present report to tectonic development models is in the suggestion of a geological sequence which may give rise to anomalous lead suites. This geological sequence is concerned with regional tectonic events which take place in the lower crust and are manifested by igneous activity. Examples of leads with apparent enrichment in the 208 isotope were found during this study and other instances are mentioned. The enrichment is tentatively considered to occur as a result of concentration of the thorium decay product in sedimentary basins. This could occur if the thorium is in more easily weathered minerals than are the uranium isotopes. Evidence supporting naturally occurring lead isotope enrichment phenomena is cited. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Coal measures of the Late Jurassic-Early Cretaceous Kootenay Formation are complexly deformed in the southeastern Canadian Rocky Mountains. The structural style and associated features of the coal measures are in part characteristic of the ‘Foothills Family’ of structures. In addition, by virtue of the major contrast in competency between the coal seams and adjacent strata, the structural features of the coal measures display considerable variation which, to some extent, can be correlated with the regional and local structural setting., The variation in the structural features of the coal measures have a marked influence on the mineability of the coal and both directly and indirectly on coal quality. During deformation the coal seams were the loci of interstratal slip, thrust faulting and detachment during folding.. The coal seams vary markedly in thickness; in some areas coal seams have been thickened as much as an order of magnitude in response to thrust faulting, normal faulting and folding, whereas in other adjacent areas, the seams may be completely pinched-off or faulted out. Structural thickening of the coal seams has been facilitated by cataclastic flow of the finely sheared coal along a myriad of discrete shear surfaces. The mesoscopic and microscopic fabric of the coal is cataclastic with the exception of local areas of apparently high strain where the vitrain and clarain components have behaved plastically. Shearing of the coal and adjacent strata has resulted in the introduction and dissemination of formerly discrete rock partings which in turn have produced abnormally high ash contents and poor washability characteristics and has made the coal more susceptible to oxidation. Measurement of vitrinite reflectance of coal in some major shear zones suggests, by comparisipn with samples heated in the laboratory for short durations, that frictional heating during shearing may have resulted in temperatures of up to 450°C. . Adjacent to and within other shear zones there is no evidence for frictional heating. The presence or absence of frictional heating may be the result respectively of stick-slip and stable sliding conditions during shear, which in turn may be a product of variable pore pressures. In underground mines the structural features of the roof rock and the coal seams have a pronounced effect on roof stability.. In the Vicary Creek mine, located in the hanging wall of the Coleman Fault, the Number 2 seam and some of the roof rock were pervasively sheared as a result of interstratal slip during flexure of the coal measures and possibly as a result of drag from overriding thrust faults. In such areas the coal pillars have low bearing strength and the cohesion between successive beds in the immediate roof rock has been destroyed, resulting in poor roof conditions. Slickenside striae on bedding surfaces, joints in the roof strata and some extension faults which cut the seam, define a kinematic and dynamic pattern which is consistent with the regional structure. In the Balmer North, Five Panel and Six Panel mines, located in the northern part of the Fernie synclinorium, the coal measures are only mildly deformed. A cleat system is present at all sample localities but no consistent pattern exists which can be related to the overall structure or to joints in the roof and floor.. In the Balmer North mine, young, gently west dipping, shear surfaces are present throughout which, in conjunction with slickensided bedding surfaces, have promoted roof and coal rib failure along north to northwesterly trends. In the Five Panel mine roof and coal rib failure have been facilitated by steep easterly dipping fractures. The absence of a consistent joint or cleat pattern in the Balmer North, Five Panel or Six Panel mines may be the result of mechanical anisotropy of the strata or of multiple episodes of deformation. Striated structures, many of which are conical in form, are common mesoscopic elements on fracture surfaces in the deformed coal. . Such structures, although rarely reported previously in the literature, occur at many localities in the study area. The structures are planar, conical and pyramidal in form, and are characterized by striae which radiate from a common apex and 'horsetail' to form subsidiary structures on the master surface. All three types of striated structures are considered the products of dynamic, brittle shear fracture which was possibly facilitated at failure by high inter- and/or intra-particle pore pressure. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

A field campaign was conducted in March and April 2015 in the Kananaskis Valley of Alberta to investigate the formation and characteristics of ice crystals and solid precipitation particles in the lee of the Rocky Mountains. This thesis examines data from 11 storms producing mainly light precipitation within generally sub-saturated surface and near-surface conditions. Instruments utilized include soundings, radar images, and surface observations, but the focus is on the analysis of 1,183 microphotographic images of precipitation particles. The particles (diameters up to 24 mm) were placed into 12 categories with rimed irregular snow particles being most common. Unrimed and rimed particles were commonly (14% of images) observed simultaneously and 62% of particles were rimed. Rimed, dense particles were less likely to sublimate before reaching the surface in the dry sub-cloud region that was at least partially a result of the air aloft being directed mainly towards the east and ‘downslope’. / February 2017