Thèse doctorat : Génie Mécanique. Biomécanique : Villeurbanne, INSA : 2004. / Thèse rédigée en anglais sauf le chapitre VIII. Titre provenant de l'écran-titre. Bibliogr. p. 247-254.

Thesis (Ph. D.)--University of Washington, 2002. / Includes bibliographical references (leaves 240-251).

published_or_final_version / Earth Sciences / Doctoral / Doctor of Philosophy

The mapped area, measuring about 400m2, is situated along the southern margin of the Archaean Kaapvaal Craton south of Melmoth in KwaZulu-Natal and comprises greenstones and metasediments forming a narrow, linear E-W trending and dominantly northerly inclined belt flanked to the north and south by various granitoids and granitoid gneisses which have been differentiated for the first time in this study. This belt is here referred to as the ILANGWE GREENSTONE BELT. The lIangwe Belt rocks are grouped into the Umhlathuze Subgroup (a lower metavolcanic suite) and the Nkandla Subgroup (an upper metasedimentary suite). The former consists of: (a) the Sabiza Formation: a lower amphibolite association occurring along the southern margin of the greenstone belt; (b) the Matshansundu Formation: an eastern amphibolite-BIF association; (c) the Olwenjini Formation: an upper or northern amphibolite-banded chert-BIF association. whereas the latter is sub-divided into: (a) the Entembeni Formation: a distinctive phyllite-banded chert-BIF association occurring in the central and the eastern parts of the belt; (b) the Simbagwezi Formation: a phyllite-banded chert-amphibolite association occurring in the western part of the belt, south-east of Nkandla; (c) the Nomangci Formation: a dominantly quartzite and quartz schist formation occurring in the western part of the belt, south-east of Nkandla. The contacts between the six major tectonostratigraphic formations are tectonic. In the eastern sector of the lIangwe Belt, the lowermost metasedimentary formation, the Entembeni Formation, cuts across both the Sabiza and Matshansundu Formations (the lower formations of the Umhlathuze Subgroup) in a major deformed angular unconformity referred to as the Ndloziyana angular unconformity. In the central parts of the belt, the Entembeni Formation structurally overlies the Olwenjini Formation in what seems to be a major local unconformity (disconformity). In the western sector of the belt, the Simbagwezi Formation occurs as a structural wedge between the lower and upper formations of the Umhlathuze Subgroup. That is, it structurally overlies the Sabiza Formation and structurally underlies the Olwenjini Formation. The uppermost metasedimentary unit, the Nomangci Formation occurs as a complex series of finger-like wedges cutting and extending into the Simbagwezi Formation and in each case showing that the Nomangci Formation structurally underlies the Simbagwezi Formation. This structural repetition of lithological units is suggestive of normal dip-slip duplex structures. Palimpsest volcanic features, such as pillow structures and minor ocelli, indicate that many of the amphibolitic rocks represent metavolcanics, possibly transformed oceanic crust. This is also supported by limited major element geochemistry which suggests that the original rocks were ocean tholeiites. Evidence suggests that the talc-tremolite schists and the serpentinitic talc schists represent altered komatiites. The nature of the metasediments (represented by banded metacherts, quartzites and banded iron formations) and their similarity to those of the Barberton, Pietersburg and Nondweni greenstone complexes suggests that they were formed in relatively shallow water environments. The lIangwe magmatism is represented by different types of granitoids and granitoid gneisses and basic-ultrabasic intrusive bodies. Based on similar geochemical and mineralogical characteristics and on regional distribution, mutual associations and contact relationships, these granitoids and granitoid gneisses can be divided into three broad associations, viz: (a) The Amazula Gneiss - Nkwa/ini Mylonitic Gneiss - Nkwalini Quartzofeldspathic Flaser Gneiss Association: a migmatitic paragneiss and mylonitic to flaser gneiss association of older gneisses of Nondweni age occurring in several widely separated areas and intruded by younger granitoids. (b) The early post-Nondweni Granitoids comprising the Nkwalinye Tonalitic Gneiss (a distinctive grey gneiss intrusive into the greenstones and older gneisses) and the Nsengeni Granitoid Suite (an association of three granitoid units of batholithic proportions flanking the greenstone belt and intrusive into the greenstones, older gneisses and Nkwalinye Tonalitic Gneiss). (c) The late post-Nondweni Granitoids comprising the Impisi-Umgabhi Granitoid Suite, a batholithic microcrystic to megacrystic association of five granitoid phases/units occurring to the north and south of the greenstone belt and intrusive into the greenstones, older gneisses and early post-Nondweni granitoids. Limited major element geochemistry suggests that the granitoids and granitoid gneisses are of calc-alkaline origin and are of tonalitic, granodioritic, adamellitic and granitic composition. An igneous derivation from material located possibly at the lower crust or upper mantle is suggested. At least three major episodes of deformation (01, O2 and 03) have been recognized in the greenstones. During 01, a strong penetrative S1 tectonic foliation developed parallel to the So primary layering and bedding. This period was characterized by intense transpositional layering, recumbent and isoclinal intrafolial folding with associated shearing,thrusting and structural repetition of greenstone lithologies. These processes took place in an essentially horizontal, high strain tectonic regime. The first phase of deformation (OG1) in the migmatitic and mylonitic gneisses was also characterized by recumbent and isoclinal intrafolial folding and is remarkably similar to the 01deformational phase in the lIangwe greenstones. Structural features of the first phase of deformation suggest that it was dominated by formation of fold nappes and thrusts and was accompanied by prograde M1 medium-grade middle to upper amphibolite facies metamorphism. During D2 deformation, the subhorizontal D1 structures were refolded by new structures with steeply inclined axial planes. This resulted in the formation of superimposed Type 3 interference folding in the amphibolitic rocks and large-scale, E-W trending, doublyplunging periclinal folds in the metasediments. These periclinal folds have steeply inclined and overturned limbs and are characterized by narrow, closed elliptical outcrop patterns well-defined by extensive banded ironstones and metacherts. The second phase of deformation in the granitoids (DG 2) was characterized by steeply plunging and steeply inclined small-scale tight to isoclinal similar folds. Large-scale folds are not present in the granitoids. Evidence suggests that the second phase of deformation was a major compressional event which resulted in the large-scale upright, flattened flexural folds. It was accompanied by widespread regional greenschist metamorphism and the intrusion of the early postNondweni granitoids. The third phase of deformation produced steeply plunging small-scale folds on the limbs and axial planes of the pre-existing large-scale F2 folds and upright open folds in the granitoid terrain. This episode was characterized by the emplacement of the late postNondweni granitoids (along the D2 greenstone boundary faults) and is associated with two significant events of prograde M3 upper greenschist facies metamorphism and retrograde M3 lower greenschist facies metamorphism. Post-D3 deformation is characterized by late cross-cutting faults and the emplacement of younger basic - ultrabasic bodies. / Thesis (Ph.D.)-University of Natal, 1997.

Thèse (D.R.Min.) -- Université du Québec à Chicoutimi, 1992. / Document électronique également accessible en format PDF. CaQCU

Mémoire (M.Sc.T.)-- Université du Québec à Chicoutimi, 1992. / Bibliogr.: f. 68-73. Document électronique également accessible en format PDF. CaQCU

Mémoire (M.Sc.T.)-- Université du Québec à Chicoutimi, 1993. / Document électronique également accessible en format PDF. CaQCU

Mémoire (M.Sc.T.)--université du Québec à Chicoutimi, 2000. / Document électronique également accessible en format PDF. CaQCU

The thesis describes the concepts related to land consolidation and hunting management, from history to the present. The work includes the possibility of using land consolidation as a tool for good game management. Furthermore, the work deals with subsidies relating to this issue, Bio-belts, and other measures for the creation and protection of the environment.

xvi, 121 p. : ill. (some col.), maps (some col.) Also includes two large-scale maps in two separate pdf files. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Deformation across plate boundaries often occurs over broad zones with relative motions between plates typically accommodated by faults of different styles acting together in a complex system. Collision of the Yakutat microplate within the Alaskan portion of the Pacific-North America plate boundary drives deformation over 600 km away where the Denali fault divides predominantly rigid crustal block motions of southern Alaska from distributed deformation in central Alaska. Quaternary geologic mapping along the Nenana River valley and the Japan Hills of the northern foothills of the Alaska Range defines zones of Quaternary thrust faulting recorded in the progressive deformation of Pleistocene fluvial terraces. I use topographic profiles of these terraces and paleoseismic trenching of fault scarps to characterize the Quaternary activity and constrain the subsurface geometry of these faults. Radiocarbon and cosmogenic exposure dating methods provide age control on the stratigraphy in the trenches and landforms offset by these faults. These observations define a 1-1.5 mm/yr slip rate for the Gold King fault which changes laterally from a north-vergent thrust into a north and south vergent thrust wedge that uplifts the Japan Hills. Along the Nenana River valley, the progressive deformation of Pleistocene surfaces defines a north-vergent critically-tapered thrust wedge. The geometry of progressive uplift and folding requires a near planar, south-dipping basal thrust fault with two major north-dipping backthrusts. All three faults were active simultaneously on a scale of 10 4 yrs with slip rates of 0.25-1 mm/yr, until the late Pleistocene when we infer the retreat of glacial ice from the main axis of the Alaska Range caused a change in thrust wedge dynamics. I use the orientation of Quaternary deformation north of the Denali fault to show that strain is highly partitioned and establish geologic constraints on the regional horizontal stress orientation. North of the Denali fault, fault-normal principal shortening accommodates 3-5 mm/yr of strain transfer across the Denali fault system. Two appendices contain additional results of paleoseismic trenching and neotectonic investigations across 4 active faults near the Nenana River. This dissertation includes previously unpublished co-authored material. / Committee in charge: Ray Weldon, Chairperson, Geological Sciences; Joshua Roering, Member, Geological Sciences; David Schmidt, Member, Geological Sciences; Douglas Kennett, Outside Member, Anthropology