STRUCTURAL ANALYSIS AND INTERPRETATION OF DEFORMATION ALONG THE KEWEENAW FAULT SYSTEM FROM LAKE LINDEN TO MOHAWK, MICHIGAN

The Keweenaw fault is likely the most significant and most studied fault associated with the Midcontinent Rift System. The fault roughly bisects the Keweenaw Peninsula and places Portage Lake Volcanics (~1.1 Ga) over much younger Jacobsville Sandstone (~1.0 Ga). Published bedrock geology maps with cross sections from the 1950s show the fault as a single continuous trace that is locally associated with smaller cross faults and splays. The accompanying cross-sections show hanging-wall volcanic strata having a well-defined, listric geometry with dip decreasing away from the fault to the northwest. This M.S. thesis presents a structural analysis and interpretation of the Keweenaw fault system between Lake Linden and Mohawk, MI, which includes the well-known localities of Houghton-Douglass Falls, the St. Louis ravine, the Natural Wall ravine, and the anomalous rhyolite body near Copper City. Objectives of the study were to better define the geometry, movement, and slip kinematics of the Keweenaw fault while also characterizing the fold patterns associated with the fault system. Field observations and data were used to revise existing bedrock geology maps, construct new cross-sections, and analyze fold geometry and fault slip behavior to infer aspects of the tectonic regime that caused the deformation. New field mapping has refined the trace geometry of the Keweenaw fault and smaller associated faults, revised intersections between several splay faults and the main fault, and suggested the existence of several footwall splays not previously recognized. These map changes better define the Keweenaw fault system in this area as consisting of: 1) major NNE-trending segments that define the fault system’s overall trend and probably have mostly reverse slip; 2) NE-trending segments that branch off the major fault segments and define wedge-shaped fault blocks that widen to the northeast in the footwall; and 3) NNW-trending segments that connect faults of the first two types. At a point southwest of Copper City, the main fault surface abruptly changes strike from N16°E to N58°E traveling in a northeasterly direction and it shifts ~650 m deeper stratigraphically within the Portage Lake Volcanics. This abrupt change in trend and stratigraphic level of the main fault occurs at a complex junction of the Allouez Gap fault with two major segments of the Keweenaw fault at the northeast end of the Mayflower fault block. Orientation analysis of Jacobsville Sandstone strata in the footwall of the fault system defines fold axes subparallel to nearby faults and with plunge directions that change from southwest to northeast moving in the same direction. Fault-slip analysis reveals both strike slip and dip slip along the fault system rather than only reverse movement as in the generally accepted model. Measured slip directions collectively define a 0.84:1 ratio of strike-to-dip slip for the fault system, and a fault-slip inversion analysis computes a nearly north-south maximum shortening direction of 2°-182°. Fold axis trends in the current area indicate shortening along an ESE-trending line, whereas fault-slip inversion analysis indicates a north-south shortening direction

Victoria: The Story of A Western Kansas Town

This thesis is a history of the English colony at Victoria, Kansas, from the purchase of the land from the Kansas Pacific Railroad by Georg E. Grant in 1872 until the end of the colony in the early eighties. It does not attempt to deal in any complete form with history of the German- Russians who settled at Herzog, a mile north of the original town of Victoria in 1876. The history of Herzog is a story in itself, an intensely interesting one, but too long to be more than suggested in this thesis. It is given only for the years in which the two groups existed side by side and for the purpose of showing their relationships to each other and the contrast between them

SIMBOL-X: A Formation Flying Mission on HEO for Exploring the Universe

SIMBOL-X is a high energy new generation telescope covering by a single instrument a continuous energy range starting at classical X-rays and extending to hard X-rays, i.e. from 0.5 to 80 keV. It is using in this field a focalizing payload which until now was used for energy below 10 keV only, via the construction of a telescope distributed on two satellites flying in formation. SIMBOL-X permits a gain of two orders of magnitude in sensibility and spatial resolution in comparison to state of the art hard X-rays instruments. The mirror satellite will be in free flight on a high elliptical orbit and will target the object to observe very precisely, thus focusing the hard X-ray emission thanks to this mirror module. At the focal point area which is situated 20 meters behind the mirror satellite, the detector satellite maintains its position on a forced orbit thanks to a radio link with the mirror satellite and a lateral displacement sensor using a beam emitted onboard the mirror satellite. This configuration is said "formation flying". The location of the detector satellite shall be very finely tuned as it carries the focal plane of this distributed telescope. To provide science measurements, the Simbol-X orbit has been chosen High elliptic (HEO), which means elliptical orbit with a high perigee altitude. Preliminary studies where made with an orbit with an altitude of the perigee of 44000km and altitude of the apogee of 253000km. The orbit was seven days ground track repeated in order to maintain a perigee pass over the Malindi ground station to download scientific telemetry. But as studies went on, difficulties in mass budget, link budget, perigee maintenance and formation flying maintenance were raised. This was mainly due to the vicinity of the Moon and its disturbing effect on the satellites orbits. Alternative orbits have been proposed in order to demonstrate the feasibility of the mission. The problematic of bringing the two satellites from their injection orbit to their operational orbit 20 m apart from each other and then maintain this configuration is very challenging. It requires theoretical development of the relative motion between two satellites in high eccentric orbit with large differential disturbance on the two bodies. This paper will present the mission analysis for the Simbol-X satellites with the complex problematic of doing formation flying in high elliptic orbit

Solar radiation pressure effects on very high-eccentric formation flying

A real alternative to Lagrange point very low perturbed orbits, for universe observation missions, is high eccentric Earth orbits. Combination of high eccentricity and very large semi-major axis leads to orbits with an important part of flight time far from Earth and its perturbations. Modeling this particular relative motion is the scoop of this paper. Main perturbation in HEO orbits are solar radiation pressure (SRP) and lunisolar effects, but formations are mainly affected by SRP effects. The modellization of its effects is done in two ways. First we introduce the SRP effects in the equations of the relative acceleration. Second, we obtain explicit analytical expressions of the temporal evolution of the relative motion. Resulting expressions enable very fast computations. These models are used to study HEO missions. We focus on two different problems: estimation of thrust for station keeping and evaluation of collision risk. We also consider the influence of the difference of ratio surface/mass between satellites

Investigating Pterion from Two Perspectives: Phylogenetics and Biomechanics

Pterion is a skull landmark located directly behind the orbits where four cranial bones (sphenoid, parietal, temporal and frontal) articulate in 4 basic configurations: spheno-parietal, fronto-temporal, stellate and epipteric. Two hypotheses may explain the configurations and other aspects of pterion: 1) phylogenetic history reflected in conservative development in species with shared ancestry and 2) biomechanical forces due to chewing stressors on skull shape. Impacts of phylogenetics and biomechanics may be highlighted through the diversity of skull used. Skulls from UW’s Burke Museum were assessed for pterion pattern, suture length and masseter and temporalis muscles in: Canis latrans (30), Vulpes vulpes (30), Ursus americanus, (30), Puma concolor (18), Lynx rufus (30), Papio hamadryas (8), Saimiri sciureus (8), Odocoileus hemionus (14), Cervus elaphus (4), Lepus americanus (21). Chi-square tests were used to test for an association of pterion pattern x Order, Family and Genus (Phylogenetics). Chi-squares are used to test for an association between pterion pattern and suture complexity (Biomechanics). Linear regressions are used to identify biomechanical predictors on cranial suture length. The results of the analysis provide evidence to support pterion is conservative at each phylogenetic level and that biomechanical variables do predict some of the variation in cranial suture length. This analysis is one of a handful to move beyond the traditional comparative approach and highlights the importance of phylogenetic relatedness and biomechanics influences on pterion

Nécessité d’une vaccination antirabique bien conduite chez le chien

Gamet A., Toma Bernard. Nécessité d’une vaccination antirabique bien conduite chez le Chien. In: Bulletin de l'Académie Vétérinaire de France tome 123 n°6, 1970. pp. 277-281

Flying phase mask for the printing of long submicron-period stitchingless gratings

International audienceLong and stitchingless gratings are printed by means of a read/write head comprising a phase mask illuminated by an intensity modulated laser beam and a reference grating displacement sensor which dictates the modulation period real time. A nearly perfect grating copying is achieved by fixing the sensor grating scale and the written grating substrate on a long platform sliding under the read/write hea