The primary objective of this thesis was to date the age of gold mineralization in the Jiaodong and Liaodong Peninsulas, China. Based on SHRIMP U-Pb zircon ages of dykes and host rocks at 13 gold deposits in the two peninsulas and the 40(subscript)Ar-39(subscript)Ar dating of sericite at the Cangshang deposit in the Jiaodong Peninsula, a single gold mineralization event at ca. 122 - 119 Ma has been identified.Ten gold deposits in the Jiaodong Peninsula and three gold deposits in the Liaodong Peninsula were examined. Gold mineralization can be divided into the disseminated-and-veinlet type (Jiaojla-style) and vein type (Linglong-style) and all these deposits are strongly controlled by faults. The most common host rocks are granitoids, with a SHRIMP 206(subscript)Pb/238(subscript)U age of 150 - 165 Ma. The youngest host rocks in the Jiaodong Peninsula are granodiorite, with an age of ca. 128 Ma. The oldest dated host rock in the Jiaodong Peninsula is amphibolite with a metamorphic zircon age of 1852 plus or minus 37 Ma; in the Liaodong Peninsula, the oldest host rock is metasandstone with the youngest detrital zircon giving an age of 1886 plus or minus16 Ma. The Jiaodong and Liaodong Peninsulas are underlain by Precambrian basement with components up to ca. 3.7 Ga old and these are reflected in the zircon population. There are three main peaks of inherited zircons, which yield Late Archaean (ca. 2500 Ma), Palaeoproterozoic (1800-2200 Ma) and Early Mesozoic (ca. 200-250 Ma) ages.The close spatial and temporal relationships between dykes and gold mineralization has only recently been recognized in China. Based on the cross-cutting relationship between dykes and gold lodes (and the alteration style of dykes), three types of dykes are recognized: pre-, syn- and post-mineralization dykes. Premineralization dykes yield an age of ca. 124 Ma; syn-mineralization dykes give an ++ / age of ca. 122-119 Ma, which can also be interpreted as the time of gold mineralization; further work is needed to date post-mineralization dykes, since no suitable samples were identified during this study.40(subscript)Ar-39(subscript)Ar dating of sericite has been used to determine the timing of gold mineralization at the Cangshang Gold Deposit. It gives a well-defined 40(subscript)Ar-39(subscript)Ar age of 121.3 plus or minus 0.2 Ma.The second objective of this thesis was to understand why the tectonic setting of the Jiaodong and Liaodong Peninsulas is favourable for gold formation and what is a sound genetic model for these gold deposits. Based on this study, it is interpreted that multiple orogenic events created a favourable tectonic environment for the Jiaodong and Liaodong gold deposits. It is suggested that delamination related to orogenic events occurred beneath the Jiaodong and Liaodong Peninsulas. The substantial heat and fluid transfer caused by delamination allowed mantle-derived magma and auriferous fluids to be channelled along deep faults to favourable structures within the crust. This probably explains why the dykes and gold lodes are closely associated in both time and space.

Ok Tedi Mining Limited generates a copper and gold concentrate from its porphyry and skarn ore deposits located at Mt. Fublian, Western Province, PNG. The predominant porphyry ore-type is blended with high grade skarn ores to optimize copper and gold feed grades to the concentrator. Current operation (2003) is to blend 80% porphyry with 20% skarn ores, resulting in an acceptable concentrate grade and recovery. However, when the proportion of skarn ore in the plant feed exceeds 20%, low flotation recovery is often observed. Approximately 20% of the copper and 30% gold losses occur through the rougher flotation circuit. However, losses via the cleaner tailing stream are 8% and 9% for copper and gold, respectively, and augment value mineral losses to the final tailing. It may be noted that the cleaner tailing stream contains value minerals which have already been successfully floated in the rougher section of the concentrator, and are therefore recoverable. This study has the objective of determining the reasons for copper and gold loss in the cleaner tailing. The focus is therefore on the cleaner flotation bank and related streams. The project strategy commenced with characterization of the cleaner circuit performance under various operating conditions. This would provide evidence for any proposed mechanisms to explain the losses of valuable minerals to the cleaner tailing. The second part of the project strategy was to evaluate potential methods for improvement of cleaner flotation performance via laboratory flotation tests. To complete the work, plant trials of methods showing benefit in the laboratory were conducted. / Characterisation surveys of the cleaner flotation bank were conducted as a function of ore blend, pulp and surface chemistry, mineralogy, flotation kinetics, particle size distribution, cleaner flotation cell hydrodynamic characterisation and residence time. These studies indicated that for greater than 20% pyrite skarn in the concentrator feed blend, lower than expected gold and copper recoveries were achieved in the cleaner bank. Pulp and surface chemical analytical techniques indicated layers of oxide coatings existed on all particles, depressing flotation. Oxide coatings had also resulted in the copper activation of pyrite (CuS rimming), making separation from copper sulfides difficult. Losses included coarse composite particles, also suggesting possible liberation issues. However, liberated copper sulfides were also lost, supporting the notion of depression via oxide coatings. Residence time calculations for the cleaner flotation bank suggested that the flotation capacity was less than adequate, particularly at high mill throughput rates. Hydrodynamic characterisation indicated improvements in cell hydrodynamics were warranted. In contrast to the oxidised ore feed blend described above, when less than 20% pyrite skarn was contained in the ore blend, high copper and gold recoveries were achieved in the cleaner bank. Laboratory tests suggested that increasing cleaner feed pH from 10.5 to 11.5, and 1 or collector addition to the cleaner feed, would result in improved cleaner flotation performance. These changes were trialed in the plant, with the pH adjustment being successful. High cleaner feed pH continues as a permanent modification to plant operating conditions.

The purpose of this study was to prepare concentrated and stable gold colloids for the enhancement of the signal response of the SPR technique for detecting small molecules such as progesterone. The gold colloids developed in this study were prepared by hydrazine hydrate, sodium borohydride, and tri-potassium citrate reduction routes. The study revealed that the sodium borohydride reduced gold colloids were extremely stable and it was able to be utilised in the progesterone immunoassay developed previously by Mitchell et al. The experiment was carried out on BIAcore 3000 using two different sensor surfaces (CM5 and SAM). The results showed that the enhancement species prepared from the borohydride-reduced gold colloids were able to improve the SPR signal response by 13 times higher than SPR signal produced without the enhancement species on the CM5 surface. The signal enhancement on the SAM surface using the same enhancement species was even greater at 29 times higher. The sensitivity of the assay was, however, unable to be determined due to time constraint. The limit of detection (LOD) of the progesterone assay using the CM5 chip was estimated to be ca. 5-20 pg/mL. Whilst for the SAM chip, the LOD of the progesterone assay was estimated to be ca. 5-20 fg/mL. Further work is required to confirm these estimated LOD values.

This study explored the interface between the forces of globalization and a given place, at a given time, the Gold Coast during the 1980s. The global economic boom of the 1980s was one in which the role of Japan was particularly important. In less than half a decade capital flows from Japan surged to make it the world's largest investor. Locations in the Pacific Basin were favoured destinations for Japanese investment, one of the most significant was the Gold Coast. Japanese capital and tourism helped transform its urban area from a national resort to an international tourist destination and resort centre, The surge of capital arriving to the Gold Coast was a function of economic conditions in Japan, as was its steep reduction after November 1989, Thus the Gold Coast became integrated into global capital flows and so dependent on decisions made in Tokyo, one of the main financial centres of the world. However this study has also sought to explore a more complex reality; namely, that this place also became the interface of complex cultural forces and perceptions. The wealth of the Japanese investors on the Gold Coast enabled them to realize their dream of developing projects in the most fashionable global styles. These styles were essentially Western, and it was onto these that their Japanese owners ascribed their own meanings; meanings that reflected the cultural baggage that they had brought from Japan, and through which were filtered the economic and environmental realities of the Gold Coast. The Gold Coast as locality also included residents. Hence it became an interface between two different groups of people, the Japanese and the strongly Anglo-Celtic local community. Some in the local community perceived the Japanese presence as a threat to their perception of the Gold Coast, in fact, a threat to their perception of Australia's national identity. A campaign based on the politics of memory of the Japanese developed on the Gold Coast. Within weeks it became a national debate in which isolationalist, if not xenophobic traditionalists, concentrated on the Gold Coast challenged the economic rationalism and multicultural tolerance of the self-interested and ideologically convinced advocates of globalization. Governments at all levels sought to arbitrate, to legitimize standpoints, but more often than not were seen to move into positions of ineffectual flexibility. The forces of globalization on the Gold Coast were catalysts for change that in turn provoked local opposition which rapidly became a debate about national identity and direction. It is in the exploration of the complex and contradictory economic, cultural and political forces engendered by globalization that this study has sought to make a distinctive contribution.

Hydrothermal fluid flow is spatially and genetically associated with deformation in the earth�s crust. In the Otago Schist, New Zealand, the circulation of hydrothermal fluids in the Cretaceous formed numerous mesothermal gold-quartz vein deposits. Otago schist rocks are largely L-S tectonites in which the penetrative fabric is the product of more than one deformation phase/transposition cycle. Regional correlation of deformation events allowed mineralised deposits to be related to the structural evolution of the Otago Schist. Compilation of a detailed tectonostratigraphy of New Zealand basement rocks reveals that extensional mineralisation correlates with the onset of localised terrestrial fanglomerate deposition, thermal perturbation and granitic intrusion that mark the beginning of New Zealand rifting from the Antarctic portion of Gondwana. Laminated and breccia textures in mineralised veins suggest that host structures have experienced repeated episodes of incremental slip and hydrothermal fluid flow. However, analysis of vein orientation data in terms of fault reactivation theory (Amontons Law) shows that most deposits contain veins that are unfavourably oriented for frictional reactivation. Repeated movement on unfavourably oriented structures may involve dynamic processes of strain refraction due to competency contrasts, the effect of anisotropy in the schist, or localised stress field rotation. Deposits have been classified on the basis of host structure kinematics at the time of mineralisation into low angle thrust faults, and high angle extensional fault - fracture arrays. Low angle deposits have a mapped internal geometry that is very different from conventional imbricate thrust systems. This study applied ⁴⁰Ar/�⁹Ar geochronology to selected deposits and has identified at least three distinct mineralisation events have occurred within the central axial belt during the Cretaceous. Relationships between radiometric apparent age and inferred crustal depth reveal that after metamorphism, the onset of cooling and rapid exhumation of the schist belt coincides temporally and spatially with the age of mineralisation and structural position of a regional scale low angle shear zone in Otago.

Biogeochemistry has been utilized successfully in Australia as a regional or fellow-up geochemical exploration techniques in the arid terranes of Australia. This Master's study is based on the biogeochemistry approach, which relies on the chemical analysis of plant tissues to obtain information on the geology and geochemistry of the underlying rocks. The project involved the systematic sampling and chemical analysis of plant materials and the supporting soils to establish the suitability of using particular tree species for environmental monitoring and their potential as a sample medium in geochemical exploration in the vicinity of the Temora Gold Mine, NSW, Australia. Working on 168 plant tissues (leaves, twigs and bark) in 54 plants species from 8 families at the three sites of background area, mineralized area and tailings area, and 54 supporting soil samples from three strata of 0-5 cm, 20-30 cm, and 30-40 cm, found that there was a good agreement between soil geochemistry and plant geochemistry on the result of a strong geochemical association between Au and As. The As-Au pattern was suggestive of the presence of the Au-As mineralization. Black cypress pine (Callitris endlicheri) LEAVES show a higher ratio of Asminjn/Aumin in the mineralized area than ASbkg/Aubkg in the background area, up to 7 times. The research finding suggests that the LEAVES of Black cypress pine (Callitris endlicheri) have a potential to be a biogeochemical sample medium as better indicators for Au. Golden wattle (Acacia pycnantha) BARK and Yellow box (E. melliodora) BARK appear to be better indicators for Au but more research is required. The most occurrence of anomalies of As, Au, Sb, Cu and Fe were found in Red box (E. polyanthemos) BARK. Red box (E. polyanthemos) BARK may have the potential to be an Au indicator in the area when Red box (E. polyanthemos) is present. Results on test-tolerant plants show that Eucalyptus species: Red box (E. polyanthemos), Coral gum (E. torquata), and Yellow box (E. melliodora) have a higher rate of uptake trace elements from the tailings soils. Therefore, Eucalyptus family generally adapted to metal-rich soils and can be used as cleaning-up indicators and environmental monitors for the tailings area of metal contaminated soils in the Temora Gold Mine.

The majority of economic gold deposits in NSW are associated with Ordovician-aged igneous rocks and are examples of the Cu-Au porphyry-skarn-epithermal association commonly developed in convergent margin to orogenic settings. They are among the oldest porphyry Cu-Au deposits in the Pacific Rim region. They are similar to younger deposits in terms of tectonic setting and structure, but the largest are chemically distinct, being associated with shoshonite magmas (Cadia, Ridgeway and Northparkes). The Lachlan Fold Belt (LFB) porphyries are subdivided into four sub-groups based mainly on their age relative to development of the Lachlan Transverse Zone (LTZ) structure. Two subgroups pre-date the LTZ, one group is syn�LTZ and one group post-dates the LTZ. No mineralisation has been found or reported among pre-I.TZ porphyries. but it is common in post- . l Z_ porphyries. Petrographic analysis and microprobe results establish a wide range of primary and secondary features within the Ordovician rocks examined in this study. Cale alkaline to shoshonitic affinities are supported by the variable abundance of primary K-feldspars. Primary mineral phases such as pyroxenes and igneous magnetite provide an indication of fractioning mineral assemblages responsible for igneous trends in magma chemistry. The hydrothermal mineral assemblages documented in these LFB study areas are characteristic of younger Cu-Au Porphyry style mineralisation. As expected, the most pervasive alteration is associated with highly mineralised shoshonitic Ordovician rocks at Ridgeway, and Cadia. the less strongly mineralised calc alkaline Ordovician rocks at Cargo. Copper Ilill and Fairholme. are correspondingly less strongly altered overall. although secondary mineral assemblages are locally abundant. Many varieties of oxides and carbonates are observed at the different study localities. Most of the studied samples conform to igneous chemical trends because they are weakly altered, although post magmatic processes, such as veining, are detectable in certain trends. The K2O enrichment of the studied samples is consistent with subductionmoditied mantle wedge sources. A few effects, such as the high Fe203 contents of some Ridgeway samples, probably reflect porphyry-style hydrothermal alteration processes. Host rocks at the Cadia and Ridgeway are entirely alkalic on the K2O versus SiO2 plot and shoshonitic on the Total Alkalies versus SiO2 plot. Igneous rocks at the other deposits display a range of compositions between low K tholeiites to shoshonites that in some cases reflects multiple igneous suites. The LREE and L1LE enrichments, and HFSE depletions (Nb, Ta and Ti) of the magmas associated with these deposits are characteristics of a subduction-related tectonic setting. They all fall in the volcanic-arc granite and syn-collisional granite field of the Nb-Y tectonic discrimination diagram. Several magma types are identified by differences in the HFSE and REE trends. Differences in the extent and style of magma fractionation are evident in the trace element data. The Ridgeway samples define a wider range of trace element concentrations than the Cadia samples that may indicate a greater extent of fractionation during emplacement of the Ridgeway magmas. Fairholme samples display a high Nh and /If trends that are distinct from the main fields on Zr variation diagrams. Compositional differences between larger Cu-Au deposits, Cadia-Ridgeway and smaller deposits, Copper Ifill, Cargo and Fairholme are evident in terms of Nb-Ta depletion and variation. The smaller deposits show constant Nb/Ta or negative Nb/Ta trends that extend to high Nb. The larger deposits display positive Nb/Ta trends that do not extend to high Nb. This distinction reflects a difference of preferential incorporation of Nb in a mineral phase (magnetite). Comparisons between Cadia-Ridgeway and other shoshonite (altered samples of Bajo de la Alumbrera, Argentina), calc alkaline magmas from New Zealand and rocks from other areas indicate that Nb/Ta is not directly correlated with the shoshonitic classification, K2O vs. SiO2, and that the Cadia-Ridgeway Nb and Ta variation is not the result of alteration. The fact that the weakly altered LFB Capertee shoshonites exhibit a narrow range of Nb and low Nb/Ta suggest the shoshonite trend for the LFB as a whole is a steep one on the Nb/Ta versus Nb plot. The results of this study could provide important information for exploration within the LFB. Only the Cadia and Ridgeway deposits display a wide range of Nb/Ta values and lack the near-horizontal trend seen for other localities associated with smaller deposits. The tectonic evolution of the LFB is a major factor contributing to occurrence of large porphyry Cu-Au deposits. The sequence of important events, however, commences with sub-crustal generation of oxidised magma and finishes with efficient Cu-Au accumulation by hydrothermal processes at favourable structural sites. The increase in Au-Cu deposit size from small (Copper Hill-Cargo) to world class (Cadia-Ridgeway) indicates the importance of magma composition during this process. The most obvious differences between the Cadia-Ridgeway and New Zealand rocks is that the latter are volcanic in origin and associated with an arc-back arc system. Therefore, they did not form in a tectonic regime suitable for the evolution of porphyries and the focussed movement of hydrothermal fluids during dilatant episodes. As a result, they are not linked to mineralisation despite having Nb-Ta and Nb/Ta variations that are typical of the high oxidation states in Au-prospective magmas of the LFB.

The dinuclear cyclometallated gold(I) complex [Au2(μ-2-C6F4PPh2)2] was prepared in high yield from the reaction of 2-LiC6F4PPh2 with either [AuBr(AsPh3)] or [AuCl(tht)], and from the reaction of 2-Me3SnC6F4PPh2 with [AuCl(tht)]. The digold(I) complex undergoes oxidative addition reactions with halogens to give the metal-metal bonded dihalodigold(II) complexes [Au2IIX2(μ-2-C6F4PPh2)2] (X = Cl, Br, I), which on warming or exposure to light, isomerise to give the heterovalent gold(I)-gold(III) species [XAu(µ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuX] containing a four-membered cyclometallated ring on a gold(III) centre. Unlike its protio analogue, [Au2(μ-2-C6F4PPh2)2] did not undergo oxidative addition of methyl iodide or dibenzoyl peroxide. The dihalodigold(II) [Au2IIX2(μ-2-C6F4PPh2)2] and gold(I)-gold(III) compounds [XAu(µ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuX] (X = Cl, Br) are further oxidised by halogens to give the digold(III) species [Au2X4(μ-2-C6F4PPh2)2] and [X3Au(μ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuX], respectively. The complexes [Au2X4(μ-2-C6F4PPh2)2] are reduced to the dihalodigold(II) complexes in the presence of one equivalent of zinc powder; further addition of zinc gave the parent digold(I) dimer. Treatment of [Au2IICl2(μ-2-C6F4PPh2)2] and [ClAu(µ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuCl] with an excess of silver nitrate, benzoate, acetate, trifluoroacetate or triflate gave the corresponding oxyanion complexes. Slow crystallisation of the di(benzoato)digold(II) complex from dichloromethane and methanol gave the parent digold(I) complex derived by reductive elimination. The di(triflato)digold(II) complex behaved similarly, although in this case the novel gold(I) tetramer [Au4(μ-2-C6F4PPh2)4] was formed together with the dimer. Two closely related gold complexes containing the chelating κ2(C,O) phosphine oxide ligand, 2-C6F4P(O)PPh2, were isolated from the reaction of [ClAu(µ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuCl] with an excess of silver nitrate. The reaction of [Au2IICl2(μ-2-C6F4PPh2)2] with two equivalents of potassium trifluoroethoxide failed to give the corresponding digold(II) bis(alkoxo) complex; instead, reduction took place to form the digold(I) dimer [Au2(μ-2-C6F4PPh2)2]. Treatment of a solution of the di(benzoato)digold(II) complex with C6F5Li gave the pentafluorophenyl complex [Au2(C6F5)2(μ-2-C6F4PPh2)2] which, when heated in toluene, rearranged to the gold(I)-gold(III) complex [(C6F5)Au(µ-2-C6F4PPh2)(κ2-2-C6F4PPh2)Au(C6F5)], analogous to the behaviour of the dihalodigold(II) complexes. The heterovalent, gold(I)-gold(III) dimethyl compound [Au2I,III(CH3)2(μ-2-C6F4PPh2)2] was obtained from the reaction of the di(benzoato)digold(II) complex with dimethylzinc. This compound is structurally similar to its tetraprotio analogue. The cycloaurated dinuclear gold complexes [Au2(μ-C6H3-n-F-2-PPh2)2] (n = 5, 6) were made similarly to the 2-C6F4PPh2 analogue from the appropriate lithium or tin reagents, though in some cases the dimers were formed in admixture with the corresponding gold(I) tetramers. Like their tetrafluoro analogues, the 6-fluoro complexes [Au2X2(μ-C6H3-6-F-2-PPh2)2] (X = Cl, Br, I) rearrange on heating to give the heterovalent gold(I)-gold(III) species [XAu(µ-C6H3-6-F-2-PPh2)(κ2-C6H3-6-F-2-PPh2)AuX]. Thus, the presence of a fluorine atom in place of hydrogen in the 6-position of the bridging aryl group is sufficient to stop the isomerisation of the digold(II) complexes [Au2X2(μ-2-C6H4PPh2)2] at the gold(I)-gold(III) stage and to prevent subsequent C-C coupling of the aryl groups at the gold(III) centre. In contrast, the dihalodigold(II) complexes containing the 5-fluoro substituted ligand undergo reductive elimination and coupling of the metallated aryl groups to give the digold(I) biphenyldiyl complexes [Au2X2(2,2'-Ph2P-5-FC6H3C6H3-5-F-PPh2)] (X = Cl, Br, I). The described complexes were characterised using 1H NMR, 31P NMR, 19F NMR spectroscopy, elemental analysis, mass spectroscopy, IR spectroscopy, X-ray diffraction and 197Au Mössbauer spectroscopy.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.