Thesis (Ph. D.)--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 107-109).

Thesis (M. Arch.)--University of Hong Kong, 2000. / Includes special report study entitled: Spiritual path : towards the scared world. Includes bibliographical references.

No description available.

Renosterkop is a large low grade tin-tungsten-zinc deposit located 85km WSW of Upington in the northern Cape Province, South Africa. The mineralization is hosted by a number of shallow-dipping, sheeted greisen bodies that are surrounded by, and partly intercalated with a well foliated granite gneiss country rock. The gneiss is taken to belong to the intrusive Riemvasmaak gneiss of the Namaqualand Metamorphic Complex. The mineralized host (referred to as TBQ) is a grey, homogeneous, fine to medium grained rock composed predominantly of quartz, biotite and topaz with minor amounts of fluorite and accessory opaque minerals, zircon and secondary chlorite. The unmineralized granite gneiss country rock is medium-to coarse-grained, pinkish in colour and composed primarily of microcline, plagioclase, quartz and biotite, with or without hornblende. Rock types, transitional in mineralogy but with clearly distinguishable contacts, are present between the TBQ and the granite gneiss. A prominent chemical and mineralogical halo, 20m to 50m wide, envelopes the Renosterkop deposit. There is a gradational transition from an unaltered hornblende biotite gneiss, through gneiss containing greenish-brown biotite to an approximately 2 m wide transition zone, characterized by the partial replacement of the greenish-brown biotite by chlorite. The transition zone in turn yields to the TBQ in which reddish-brown biotite forms at the expense of the chlorite, and topaz, quartz and fluorite are formed at the expense of the feldspar. Major and trace element analyses show a spectrum of chemical compositions with coherent trends that support a gradational transition from the hornblende-bearing granite gneiss, through the transitional rock types to the TBQ. The mineralogical and chemical characteristics of the Renosterkop rock types are consistent with an origin by progressive greisenization of a "within plate" A- type granitoid host rock. A genetic model is proposed which involves the formation of the TBQ greisen during intense metasomatic alteration and replacement of the granite gneiss within a zone of structural weakness that provided conduits for migrating, F-rich, metal-bearing solutions, and thereby inherited the foliation and structural features present in the original granite gneiss. / Thesis (MSc)--PU vir CHO, 1987.

No description available.

No description available.

Renosterkop is a large low grade tin-tungsten-zinc deposit located 85km WSW of Upington in the northern Cape Province, South Africa. The mineralization is hosted by a number of shallow-dipping, sheeted greisen bodies that are surrounded by, and partly intercalated with a well foliated granite gneiss country rock. The gneiss is taken to belong to the intrusive Riemvasmaak gneiss of the Namaqualand Metamorphic Complex. The mineralized host (referred to as TBQ) is a grey, homogeneous, fine to medium grained rock composed predominantly of quartz, biotite and topaz with minor amounts of fluorite and accessory opaque minerals, zircon and secondary chlorite. The unmineralized granite gneiss country rock is medium-to coarse-grained, pinkish in colour and composed primarily of microcline, plagioclase, quartz and biotite, with or without hornblende. Rock types, transitional in mineralogy but with clearly distinguishable contacts, are present between the TBQ and the granite gneiss. A prominent chemical and mineralogical halo, 20m to 50m wide, envelopes the Renosterkop deposit. There is a gradational transition from an unaltered hornblende biotite gneiss, through gneiss containing greenish-brown biotite to an approximately 2 m wide transition zone, characterized by the partial replacement of the greenish-brown biotite by chlorite. The transition zone in turn yields to the TBQ in which reddish-brown biotite forms at the expense of the chlorite, and topaz, quartz and fluorite are formed at the expense of the feldspar. Major and trace element analyses show a spectrum of chemical compositions with coherent trends that support a gradational transition from the hornblende-bearing granite gneiss, through the transitional rock types to the TBQ. The mineralogical and chemical characteristics of the Renosterkop rock types are consistent with an origin by progressive greisenization of a "within plate" A- type granitoid host rock. A genetic model is proposed which involves the formation of the TBQ greisen during intense metasomatic alteration and replacement of the granite gneiss within a zone of structural weakness that provided conduits for migrating, F-rich, metal-bearing solutions, and thereby inherited the foliation and structural features present in the original granite gneiss. / Thesis (MSc)--PU vir CHO, 1987.

Mechanisms which may play a role in superplastic deformation (grain strain mechanisms, grain boundary sliding (GBS) mechanisms) are reviewed. Two well-known lattice dislocation mechanisms are re-evaluated for grain boundary dislocations (GBDs). The manner in which the deformation mechanisms interact, or are inhibited or obscured, is discussed. Mechanisms of anelastic deformation are outlined, with particular reference to fine-grained materials. Expressions for anelastic recovery caused either by grain boundary (GB) tension or by the relaxation of GBD pile-ups are derived. The plastic properties of Sn-38.1w/o Pb and Sn-2w/o Pb are measured. They are similar in both alloys. No threshold stress for plastic deformation is detected, for stresses and strain rates as low as 0.IMPa and 10^-10s^-1 respectively. The presence of GB diffusion creep (Coble creep) is established experimentally in Sn-2w/o Pb with grain sizes ≥ 50μm. Coble creep is inhibited for small grain sizes (~10μm). The inhibition is explained by GBS caused by GBDs. In disagreement with the measurements, high threshold stresses are predicted for Sn-38.1w/o Pb. This implies that GBD line tensions are lower than those of lattice dislocations. The anelastic properties of Sn-2w/o Pb and Sn-38.1w/o Pb are determined from the elastic after-effect (anelastic recovery after unloading). They are remarkable: anelastic contractions larger than 0.2% and relaxation strengths (= ratio of anelastically recovered to elastically recovered strain) in excess of 100 are found. The anelastic strains are approximately proportional to the stress and the inverse grain size. A wide range of relaxation times (~ 6 decades) is observed. A mechanism based on the relaxation of GBD pile-ups is in qualitative agreement with the measured anelasticity. The high measured relaxation strengths, however, imply that the interaction between GBDs is much weaker (~ 2 orders of magnitude) than that between lattice dislocations. This could be due to a relatively low self-energy of GBDs and would be in qualitative agreement with the low GBD line tensions suggested above. The influence of anelasticity on transients (e.g. stress relaxation, dip test) is investigated using a rheological model with three Voigt elements (anelasticity) and a nonlinear dashpot (plasticity). Using independently determined plastic and anelastic parameters the 4-th order differential equa tion corresponding to the model is solved numerically for several examples. Measured transients are much more accurately predicted with the present model than with models neglecting anelasticity.

No description available.

Thesis (M.Arch.)--University of Hong Kong, 2000. / Includes special report study entitled : Spiritual path : towards the scared world. Includes bibliographical references. Also available in print.