Mineral Deposits And Earth Evolution (geological Society Special Publication) (no. 248)

Mineral deposits are not only primary sources of wealth generation, but also act as windows through which to view the evolution and interrelationships of the Earth system. Deposits formed throughout the last 3.8 billion years of the Earth?’s history preserve key evidence with which to test fundamental questions about the evolution of the Earth. These include: the nature of early magmatic and tectonic processes, supercontinent reconstructions, the state of the atmosphere and hydrosphere with time, and the emergence and development of life. The interlinking processes that form mineral deposits have always sat at the heart of the Earth system and the potential for using deposits as tools to understand that evolving system over geological time is increasingly recognized. This volume contains research aimed both at understanding the origins of mineral deposits and at using mineral deposits as tools to explore different long-term Earth processes.Also available: The Timing and Location of Major Ore Deposits in an Evolving Orogen - ISBN 186239122X The Early Earth: Physical, Chemical and Biological Development - ISBN 1862391092 Fractures, Fluid Flow and Mineralization - ISBN 1862390347 Contents......Page 6 Preface......Page 8 Acknowledgements......Page 11 Economic natural resource deposits at terrestrial impact structures......Page 12 Fig. 1. (A) Schematic cross-section of a terrestrial simple impact structure. No vertical .........Page 13 Fig. 3. Logarithmic plot of shock pressure (GPa) against post-shock temperature (°C) range .........Page 14 Fig. 4. Approximately 150 m high cliffs of impact melt rock at the edge .........Page 15 Fig. 5. Some shock metamorphic effects. (A) Shatter cones at Gosses Bluff impact structure. .........Page 16 Fig. 6. Shuttle topographic radar image of digital topography over the Carswell .........Page 19 Fig. 7. Geological map of the Carswell impact structure, indicating uplifted crystalline .........Page 20 Fig. 8. Photomicrographs of lithologies at Carswell. (A) Planar deformation features in quartz .........Page 21 Fig. 9. Geological map of the Witwatersrand Basin, with partially obscuring Karoo .........Page 22 Fig. 10. Distribution of large concentric structures and gold fields, with respect to .........Page 23 Fig. 11. Geological map of the Popigai impact structure (Table 2) indicating the distribution .........Page 24 Fig. 12. Field photograph of outcrop of the sheet of diamond-bearing impact melt .........Page 25 Fig. 15. Shatter cones in Huronian quartzite at the Sudbury impact structure.......Page 26 Fig. 16. Schematic stratigraphic section (not to scale) of lithologies at the Sudbury impact structure, .........Page 28 Fig. 18. Plot of (a) osmium and (b) neodymium isotopic data of ores and .........Page 29 Fig. 19. Three-dimensional mesh diagram of residual structure on the post-impact upper .........Page 31 Fig. 20. Thickness of rim facies at Viewfield impact structure (Table 2). Black dots .........Page 33 Table 1. Genetic groups of natural resource deposits at terrestrial impact structures......Page 17 Table 2. Deposits and/or indications of natural resources in terrestrial impact structures......Page 18 Gold mineralization within the Witwatersrand Basin, South Africa: evidence for a modified placer origin, and the role of the Vredefort impact event......Page 42 Fig. 1. Simplified geological map showing the subcrop of the Central Rand .........Page 43 Fig. 2. Summary of the main features of the stratigraphy of the .........Page 45 Fig. 3. Examples of mineralogical and textural associations of gold in the .........Page 48 Fig. 5. Silver and mercury contents of gold analysed in the present .........Page 51 Fig. 6. (a) Variation in Ag and Hg contents of all analysed gold .........Page 52 Fig. 7. Locations of gold occurrences in thin sections and the Ag .........Page 56 Fig. 8. Silver and mercury contents of Samples 4,5 and 7 from the .........Page 57 Table 2. Temperatures (in degrees Celsius) of chlorite formation derived from EPMA .........Page 58 Fig. 11. Examples of brittle deformation of minerals from the different reefs .........Page 60 Fig. 12. Location of the goldfields with respect to the known distribution .........Page 64 Table 1. Mineralogical associations of gold occurrences, analyses of which are presented .........Page 49 Metallogenic fingerprints of Archaean cratons......Page 70 Table 1a. Number of mineral deposits of selected element groups across Gondwana .........Page 72 Fig. 2. Mineral diversity of selected elements of Archaean cratons, as shown .........Page 76 Table 2c. Natural log of the spatial coefficient (ρ[Sub(ij)]) with standard errors .........Page 77 Table 3c. Natural log of the spatial coefficient (ρ[sub(ij)]) with standard error .........Page 79 Table 1c. Natural log of the spatial coefficient (ρ[sub(ij)]) with the approximate standard .........Page 73 Controls on the heterogeneous distribution of mineral deposits through time......Page 82 Fig. 1. Historical figure showing distribution through time of selected mineral deposits, .........Page 83 Fig. 2. (a) Frequency distribution of juvenile continental crust based on a total .........Page 87 Fig. 3. Depth and depth variation in composition of selected Archaean, Proterozoic .........Page 88 Fig. 4. Distribution of major nickel–copper sulphide deposits with time. Major sources .........Page 89 Fig. 5. Temporal distribution of epigenetic gold ± copper ± silver deposits compared with .........Page 90 Fig. 6. Temporal distribution of VHMS deposits compared with that of orogenic .........Page 92 Fig. 7. Temporal distribution of palaeoplacer and placer gold deposits, iron oxide .........Page 93 Fig. 8. Contrasting models for the evolution of the atmosphere, adapted from .........Page 96 Fig. 9. Temporal distribution of sediment-hosted deposits of redox-sensitive metals. (a) uranium .........Page 97 Fig. 10. Temporal distribution of sediment-hosted base-metal deposits. (a) Mississippi Valley type .........Page 99 Fig. 12. Location of major mineral deposit types discussed in the text .........Page 102 Table 1. Summary of major features of deposit groups discussed in text......Page 85 Pre-mineralization thermal evolution of the Palaeoproterozoic gold-rich Ashanti belt, Ghana......Page 114 Fig. 2. Succession of the different lithological units (top) and the main tectonic .........Page 116 Table 3. Heat-production rates and their standard deviations (s.d.) for Birimian and .........Page 119 Fig. 5. Temperature field (a) before and (b) after the D[sub(1)] tectonic phase, as .........Page 124 Fig. 7. Results of numerical experiments (P–T paths) for Birim sediments, compared with the .........Page 125 Table 1. Thermobarometric data (pressure and temperature estimates) for peak-metamorphism conditions at .........Page 117 Table 2. Thermal conductivity measurements of Birimian and Tarkwaian rock samples from the .........Page 118 Table 4. Main lithological units with associated density values and thermal properties. Density .........Page 121 Geodynamic processes that control the global distribution of giant gold deposits......Page 130 Fig. 1. Location of all known giant gold deposits. Symbol size relates to .........Page 131 Fig. 2. Schematic cross-section of an accretionary subduction zone, with a shaded area .........Page 133 Table 1. Definition of the consolidated domain classification.......Page 136 Fig. 4. Crustal sections of the type-examples of the six orogenic domains, .........Page 138 Table 3. General features of each domain classification.......Page 137 Table 4. Summary of fluid-type potential in each domain.......Page 139 Table 5. Giant gold deposits of the world in 2000 (see text for limitations).......Page 140 Table 6. Distribution of gold in giant deposits by tonnage and by number .........Page 141 Terrane and basement discrimination in northern Britain using sulphur isotopes and mineralogy of ore deposits......Page 144 Fig. 1. Pre-Atlantic configuration of the Caledonide orogen and adjacent regions, outlining .........Page 145 Fig. 2. Schematic vertical sections through the four terranes that were studied in detail. .........Page 146 Fig. 3. Summary bar charts of δ[sup(34)]S for Palaeozoic and older mineralization in Caledonide .........Page 154 Fig. 4. Sulphur isotope characteristics of granitoid-hosted mineralization in Caledonian terranes of northern .........Page 156 Table 1. Mean δ[sup(34)]S data for granitoids within four Caledonide terranes of northern Britain......Page 148 Table 2. Comparison of δ[sup(34)]S and granitoid-related mineralization styles between the British terranes and those .........Page 158 A reassessment of the tectonic zonation of the Uralides: implications for metallogeny......Page 164 Fig. 1. Proposed schematic map of tectonic domains of the Urals (modified from various .........Page 166 Fig. 2. Magnetic map and proposed correlations (map sourced from National Geophysical .........Page 167 Fig. 3. (a) Above: URSEIS section (after Echtler et al. 1996). EMSMF, .........Page 168 Fig. 4. Strike–slip faults of the Urals and major orogenic gold deposits .........Page 172 Fig. 5. Palinspastic reconstruction of the Urals with major mineral deposits located .........Page 173 The terrestrial record of stable sulphur isotopes: a review of the implications for evolution of Earth's sulphur cycle......Page 178 Fig. 1. Plot of δ[sup(33)]S versus δ[sup(34)]S for terrestrial sulphide and sulphate (data from .........Page 179 Fig. 2. Plots of (a)Δ[sup(33)]S versus δ[sup(34)]S (b) and Δ[sup(36)]S versus Δ[sup(33)]S for closed .........Page 180 Fig. 3. Plot of Δ[sup(33)]S versus time using published data (Farquhar et al. 2000a; .........Page 181 Fig. 4. Plots of (a) Δ[sup(33)]S versus Δ[sup(34)]S (b) and Δ[sup(36)]S versus Δ[sup(33)]S for .........Page 182 Fig. 5. Histograms of Δ[sup(33)]S for samples older than 2.45 Ga. The .........Page 183 Fig. 6. Plot of Δ[sup(33)]S versus Δ[sup(34)]S for published data for sulphide and sulphate .........Page 184 Fig. 7. Plot of Δ[sup(33)]S versus Δ[sup(34)]S for published data for sulphide and sulphate .........Page 185 Reactive iron enrichment in sediments deposited beneath euxinic bottom waters: constraints on supply by shelf recycling......Page 190 Fig. 1. Schematic diagram of the processes involved in enriching iron in deep-basin sediments.......Page 192 Fig. 2. Flux of iron required to be delivered to the deep basin .........Page 193 Fig. 3. Schematic model for the diffusive flux of diagenetically recycled iron .........Page 194 Table 1. Variation in the apparent first-order rate constant (k[sub(1)]) for Fe[sup(2)]+ .........Page 195 Fig. 6. Variations in the diffusive flux of diagenetically recycled iron with oxygenated .........Page 197 Fig. 7. Variations in the diffusive flux of diagenetically recycled iron with .........Page 198 Table 2. Ratios of shelf area ( 200 m) .........Page 199 Distinguishing biological from hydrothermal signatures via sulphur and carbon isotopes in Archaean mineralizations at 3.8 and 2.7 Ga......Page 206 Fig. 1. Map of Isua Greenstone Belt (3.7–3.8 Ga) showing the five structural .........Page 208 Fig. 3. Distributions of δ[sup(13)]C[sub(red)] for whole rocks from the IGB. The .........Page 210 Fig. 4. Map of the Belingwe Greenstone Belt (2.7 Ga) (modified from Grassineau et .........Page 214 Fig. 5. Vertical stratigraphic profiles of (a) δ[sup(34)]S and (b) δ[sup(13)C(red)] in the NERCMAR .........Page 215 Fig. 6. Detailed sulphur isotopic study of the BES50 sample, a core .........Page 216 Fig. 7. Comparison between δ[sup(34)]S of sulphide minerals in sedimentary sequences in (a) .........Page 218 Fig. 8. Comparison between δ[sup(13)]C[sub(red)] values for sedimentary rocks in (a) Early, .........Page 219 Table 1. δ[sup(13)]C[sub(red)] and δ[sup(34)]S ranges obtained in this study of the Isua .........Page 211 Diamond mega-placers: southern Africa and the Kaapvaal craton in a global context......Page 224 Table 1. Statistics for both diamond placer and primary deposits (for source see text)......Page 225 Fig. 2. Types of placers.......Page 226 Fig. 3. Examples of residual placers. (A) The internal, diamond-bearing, Kalahari basin .........Page 227 Fig. 4. Residual and transient type placer deposits in the eroded northern .........Page 228 Fig. 5. Distribution of transient placers along the lower Orange River valley. .........Page 229 Fig. 6. Diagrammatic section through the Lower Orange River terraces (Fig. 5) along with .........Page 230 Fig. 8. (A) Variations in diamond grade between kimberlites mined by De .........Page 232 Fig. 9. The convergence of orogens peripheral to the cratons of (A) .........Page 234 Fig. 10. Distribution of diamond-bearing kimberlites through time for the cratons of .........Page 235 Fig. 12. Means of concentrating and retaining diamonds on cratons. (A) Gradual .........Page 236 Fig. 14. The relationship between craton area, drainage basin area and the .........Page 238 Fig. 15. The importance of retaining diamonds on the craton in order to .........Page 239 Fig. 16. Large river systems known to have drained parts of the .........Page 240 Fig. 17. Distribution of kimberlites and alluvial deposits with respect to the .........Page 241 Fig. 18. The variation in diamond size along the SW African coast .........Page 242 Fig. 19. A reduced sediment input (cf. Fig. 21) enters a neutrally buoyant .........Page 243 Fig. 20. The changing diamond sizes along the Namibian coast. In B .........Page 244 Fig. 21. Soft Karoo cover is easily removed and deposited in two .........Page 245 Fig. 22. The area covered by possible sea-level fluctuations and the areal .........Page 246 Fig. 23. Summary of the requirements needed to form a diamond mega-placer.......Page 252 The formation of economic porphyry copper (–gold) deposits: constraints from microanalysis of fluid and melt inclusions......Page 258 Fig. 1. The principle of laser-ablation ICP mass spectrometric analysis of microscopic .........Page 260 Fig. 2. Reconstructed cross-section of the Farallón Negro Volcanic Complex at the .........Page 261 Fig. 3. View of the Bajo de la Alumbrera deposit in 1994, .........Page 262 Fig. 4. Typical rock, mineral and fluid inclusion relationships observed in porphyry .........Page 263 Fig. 5. Cu concentration (on a logarithmic scale) against silica content, comparing .........Page 264 Fig. 6. Schematic cartoon of a cylindrical porphyry copper orebody forming in .........Page 266 Fig. 7. (a) Cathodoluminescence (SEM-CL) image of quartz crystals in a main-stage stockwork .........Page 268 Fig. 8. (a) Log–log plot comparing the Cu and Au concentrations in .........Page 270 C......Page 276 G......Page 277 M......Page 278 S......Page 279 Z......Page 280 The Timing And Location Of Major Ore Deposits In An Evolving Orogen: The Geodynamic Context / D. J. Blundell -- Global Comparisons Of Volcanic-hosted Massive Sulphide Districts / R. L. Allen And P. Weihed / The Global Vhms Research Project Team -- Tectonic Controls On Magmatic-hydrothermal Gold Mineralization In The Magmatic Arcs Of Se Asia / M. E. Barley, P. Rak And D. Wyman -- Timing And Tectonic Controls In The Evolving Orogen Of Se Asia And The Western Pacific And Some Implications For Ore Generation / C. G. Macpherson And R. Hall -- Correlating Magmatic-hydrothermal Ore Deposit Formation Over Time With Geodynamic Processes In Se Collision Europe / A. L. W. Lips -- Contrasting Late Cretaceous With Neogene Ore Provinces In The Alpine-balkan-carpathian-dinaride Collision Belt / F. Neubauer --^ Auriferous Arsenopyrite-pyrite And Stibnite Mineralization From The Siflitz-guginock Area (austria): Indications For Hydrothermal Activity During Tertiary Oblique Terrane Accretion In The Eastern Alps / G. Amman, W. H. Paar, F. Neubauer And G. Daxner -- The Elatsite Porphyry Copper Deposit In The Panagyurishte Ore District, Srednogorie Zone, Bulgaria: U-pb Zircon Geochronology And Isotope-geochemical Investigations Of Magmatism And Ore Genesis / A. Von Quadt, I. Peytcheva, B. Kamenov, L. Fanger, C. A. Heinrich And M. Frank -- [superscript 40]ar/[superscript 39]ar Geochronology Of Magmatism And Hydrothermal Activity Of The Madjarovo Base-precious Metal Ore District, Eastern Rhodopcs, Bulgaria / P. Marchev And B. Singer -- Multiple Generations Of Extensional Detachments In The Rhodope Mountains (northern Greece): Evidence Of Episodic Exhumation Of High-pressure Rocks / A. Krohe And E. Mposkos --^ The Relationship Between Ore Deposits And Oblique Tectonics: The Sw Iberian Variscan Belt / F. Tornos, C. Casquet, J. M. R. S. Relvas, F. J. A. S. Barriga And R. Saez -- Permo-mesozoic Multiple Fluid Flow And Ore Deposits In Sardinia: A Comparison With Post-variscan Mineralization Of Western Europe / M. Boni, P. Muchez And J. Schneider -- The Timing Of W-sn-rare Metals Mineral Deposit Formation In The Western Variscan Chain In Their Orogenic Setting: The Case Of The Limousin Area (massif Central, France) / M. Cuney, P. Alexandrov, C. Le Carlier De Veslud, A. Cheilletz, L. Raimbault, G. Ruffet And S. Scaillet -- Discrimination Criteria For Assigning Ore Deposits Located In The Dinaridic Paleozoic-triassic Formations To Variscan Or Alpidic Metallogeny / I. Jurkovic And L. Palinkas --^ Example Of A Structurally Controlled Copper Deposit From The Hercynian Western High Atlas (morocco): The High Seksaoua Mining District / A. Chauvet, L. Barbanson, A. Gaouzi, L. Badra, J. C. Touray And S. Oukarou -- The Baikalide-altaid, Transbaikal-mongolian And North Pacific Orogenic Collages: Similarity And Diversity Of Structural Patterns And Metallogenic Zoning / A. Yakubchuk -- Tectonics, Geodynamics And Gold Mineralization Of The Eastern Margin Of The North Asia Craton / V. Yu. Fridovsky And A. V. Prokopiev -- 1.05-1.01 Ga Sveconorwegian Metamorphism And Deformation Of The Supracrustal Sequence At Saesvatn, South Norway: Re-os Dating Of Cu-mo Mineral Occurrences / H. J. Stein And B. Bingen -- Fluorine In Orthoamphibole Dominated Zn-cu-pb Deposits: Examples From Finland And Australia / L. Rajavuori And L. M. Kriegsman. Edited By D.j. Blundell, F. Neubauer, And A. Von Quadt. Based On A Symposium Organized By Geode, A Program To Investigate Geodynamics And Ore Desposit Evolution, And Sga, The Society For Geology Applied To Mineral Deposits, Held During The European Union Of Geosciences Assembly In March 2001. Includes Bibliographical References And Index. The Hadean Earth (before c. 4 Ga) was abiotic, possibly steering a bumpy course between brief periods of hot inferno after meteorite impacts, and long episodes of Norse ice-hell. The earliest Archaean life would probably not have been planet-altering, but restricted to particular habitats. One of the first may have been hot regions around hydrothermal systems where redox contrasts between ocean water and magmatic fluids could be exploited. Molecular evidence suggests that with the evolution of anoxygenic photosynthesis, life became able to occupy wider regions, although focused in the vicinity of hydrothermal systems. Oxygenic photosynthesis by cyanobacteria allowed life fully to occupy the planet, not only forming coastal microbial mats but also possibly inhabiting the broad oceans with abundant photosynthetic bacterial picoplankton, underlain by deeper archaeal picoplankton. In the Belingwe belt, Zimbabwe, textural and isotopic evidence suggests that a complex microbial ecology existed in the late Archaean (2.7 Ga), which was essentially modern in its biochemical abilities and which sequestered into the biosphere the same fraction of primitive carbon emitted from mantle as today. To do this, by the late Archaean the biological productivity must have been significant; not necessarily as large as today, but capable of managing the global carbon budget. When this began is unknown, possibly earlier than 3.5 Ga ago. The controls on the oxidation state of the late Archaean atmosphere-ocean system are not self-evident. Although inorganic controls dominate the long-term balance, short-term biological management of the air may have been crucial. Methane may have played a major role in the pre-metazoan biosphere. The modern atmosphere is a biological construct: oxygen and its reverse, carbon dioxide, are managed by rubisco; nitrogen, its oxides and hydrides mainly by nitrifying and denitrifying bacteria, with a small input from lightning in an oxygen-rich atmosphere; and water (itself the most important greenhouse gas) by its complex interdependence with other greenhouse gases and albedo, including clouds. Earth's air is highly improbable. In controlling surface temperature a subtle interplay between organic and inorganic controls has operated, perhaps to the extent that it is invalid to ask which was the dominant factor. But there is a reasonable uniformitarian argument that life has constructe Although volcanic-associated massive sulphide (VMS) deposits have been studied extensively, the geodynamic processes that control their genesis, location and timing remain poorly understood. Comparisons among major VMS districts, based on the same criteria, have been commenced in order to ascertain which are the key geological events that result in high-value deposits. The initial phase of this global project elicited information in a common format and brought together research teams to assess the critical factors and identify questions requiring further research. Some general conclusions have emerged. (1) All major VMS districts relate to major crustal extension resulting in graben subsidence, local or widespread deep marine conditions, and injection of mantle-derived mafic magma into the crust, commonly near convergent plate margins in a general back-arc setting. (2) Most of the world-class VMS districts have significant volumes of felsic volcanic rocks and are attributed to extension associated with evolved island arcs, island arcs with continental basement, continental margins, or thickened oceanic crust. (3) They occur in a part of the extensional province where peak extension was dramatic but short-lived (failed rifts). In almost all VMS districts, the time span for development of the major ore deposits is less than a few million years, regardless of the time span of the enclosing volcanic succession. (4) All of the major VMS districts show a coincidence of felsic and mafic volcanic rocks in the stratigraphic intervals that host the major ore deposits. However, it is not possible to generalize that specific magma compositions or affinities are preferentially related to major VMS deposits world-wide. (5) The main VMS ores are concentrated near the top of the major syn-rift felsic volcanic unit. They are commonly followed by a significant change in the pattern, composition and intensity of volcanism and sedimentation. (6) Most major VMS deposits are associated with proximal (near-vent) rhyolitic facies associations. In each district, deposits are often preferentially associated with a late stage in the evolution of a particular style of rhyolite volcano. (7) The chemistry of the footwall rocks appears to be the biggest control on the mineralogy of the ore deposits, although there may be some contribution from magmatic fluids. (8) Exhalites mark the ore horizon in some districts, but Continued studies of xenolith suites found in kimberlites on and around the Kaapvaal Craton, together with those from newly discovered localities on other cratons, are providing new insights into the generation and evolution of the Earth's oldest continents. Comparison of modal abundance data with melt depletion models, together with trace element and isotope systematics in Kaapvaal low-temperature peridotites, suggest that much or all of the diopside and garnet in these rocks may have formed significantly after initial melt depletion. The Re-Os isotope system has been instrumental in providing an improved understanding of the timing of the formation of cratonic lithospheric keels. New studies that focus on carefully selected whole-rock peridotites and use combined platinum group element (PGE) and Re-Os isotope analysis provide better constraints on the significance of Re-Os model ages. The large database of Re-Os isotope analyses for peridotites for the Kaapvaal Craton indicate formation of significant amounts of lithospheric mantle in Neoarchaean time, associated with voluminous mafic magmatism. Formation of lithospheric mantle in Neoarchean time (3.0-2.5 Ga) follows the cessation of major crustal differentiation events at c. 3.1 Ga and marks the onset of craton stabilization. Some lithospheric mantle was produced in Palaeo- to Mesoarchaean time (3.8-3.0 Ga) in southern Africa, which preserved ancient crustal fragments. Large-scale preservation of Archaean continental masses was effective only after the formation of substantial, buoyant, rigid, deep lithospheric keels and their stabilization in Neoarchean time. Formation of lithospheric mantle beneath the surrounding Proterozoic crustal regions occurred in Mesoproterozoic time, with lower degrees of mantle melting than associated with the cratonic peridotites. This circum-cratonic mantle is of similar age to the oldest overlying crust and has been coupled to the margins of the craton since its formation. Major magmatic events, some coincident with the formation of circum-cratonic mantle, added new lithosphere to the Kaapvaal mantle root but failed to destroy it. The mechanically strong, buoyant lithospheric keels beneath cratons protect their crust from subduction and recycling over 3 Ga time periods Formation And Evolution Of Archaean Cratons : Insights From Southern Africa / D.e. James & M.j. Fouch -- Seismic Heterogeneity And Anisotropy In The Western Superior Province, Canada : Insights Into The Evolution Of An Archaean Craton / J.-m. Kendall [and Others] -- The Structure Of The Upper Mantle Beneath Southern Africa / K. Priestly & D. Mckenzie -- The Development Of Lithospheric Keels Beneath The Earliest Continents : Time Constraints Using Pge And Re-os Isotope Systematics / D.g. Pearson [and Others] -- Strange Partners : Formation And Survival Of Continental Crust And Lithospheric Mantle / N.t. Arndt, É. Lewin, & F. Albarède -- Pb Isotope Variations In Archaean Time And Possible Links To The Sources Of Certain Mesozic-recent Basalts / B. Luais & C.j. Hawkesworth -- Seismic Evidence For A Mantle Source For Mid-proterozoic Anorthosites And Implications For Models Of Crustal Growth / G. Musacchio & W.d. Mooney -- Deflection Of Mantle Plume Material By Cratonic Keels / N.h. Sleep, C.j. Ebinger & J.-m. Kendall -- Archaean Tectonics : A Review, With Illustrations From The Slave Craton / W. Bleeker -- Tectono-magmatic Evolution Of The Zimbabwe Craton / H.a. Jelsma & P.h.g.m. Dirks -- Formation And Early Evolution Of The Atmosphere / B. Marty & N. Dauphas -- Carbon Dioxide Cycling Through The Mantle And Implications For The Climate Of Ancient Earth / K. Zahnle & N.h. Sleep -- Global Modelling Of Continent Formation And Destruction Through Geological Time And Implications For Co2 Drawdown In The Archaean Eon / J.d. Kramers. Fermor Lecture : The Influence Of Life On The Face Of The Earth : Garnets And Moving Continents / E.g. Nisbet -- Stable Isotopes In The Archaean Belingwe Belt, Zimbabwe : Evidence For A Diverse Microbial Mat Ecology / N.v. Grassinaeu [and Others] -- The Metamorphic History Of The Isua Greenstone Belt, West Greenland / H. Rollinson. Edited By C.m.r. Fowler, C.j. Ebinger, C.j. Hawkesworth. This Book Arose From A Discussion Meeting In February 2000--pref. Includes Bibliographical References And Index. Economic Natural Resource Deposits At Terrestrial Impact Structures / Grieve, R.a.f. -- Gold Mineralization Within The Witwatersrand Basin, South Africa: Evidence For A Modified Placer Origin, And The Role Of The Vredefort Impact Event / Hayward, C.l. ... [et Al.] -- Metallogenic Fingerprints Of Archaean Cratons / De Wit, M Thiart, C. -- Controls On The Heterogeneous Distribution Of Mineral Deposits Through Time / Groves, D.i. ... [et Al.] -- Pre-mineralization Thermal Evolution Of The Palaeoproterozoic Gold-rich Ashanti Belt, Ghana / Harcouët, V. ... [et Al.] -- Geodynamic Processes That Control The Global Distribution Of Giant Gold Deposits / Leahy, K. ... [et Al.] -- Terrane And Basement Discrimination In Northern Britain Using Sulphur Isotopes And Mineralogy Of Ore Deposits / Lowry, D. ... [et Al.] -- A Reassessment Of The Tectonic Zonation Of The Uralides: Implications For Metallogeny / Herrington, R.j. ... [et Al.] -- The Terrestrial Record Of Stable Sulhpur Isotopes: A Review Of The Implications For Evolution Of Earth's Sulphur Cycle / Farquhar, J. Wing, B.a. -- Reactive Iron Enrichment In Sediments Deposited Beneath Euxinic Bottom Waters: Constraints On Supply By Shelf Recycling / Raiswell, R., Anderson, T.f. -- Distinguishing Biological From Hydrothermal Signatures Via Sulphur And Carbon Isotopes In Archaean Mineralizations At 3.8 And 2.7 Ga / Grassineau, N.v. ... [et Al.] -- Diamond Mega-placers: Southern Africa And The Kaapvaal Craton In A Global Context / Bluck, B.j. ... [et Al.] -- The Formation Of Economic Porphyry Copper (-gold) Deposits: Constraints From Microanalysis Of Fluid And Melt Inclusions / Heinrich, C.a. ... [et Al.]. Edited By I. Mcdonald ...[et Al.]. Includes Bibliographical References And Index. Hydrothermal mineralization is usually structurally controlled so it is important to understand the role of faulting and fracturing in enhancing rock permeability and facilitating fluid flow and mass transfer. This is the main theme of this interdisciplinary volume and the papers included are intended to provide an overview of current ideas at the interfaces of structural geology, fluid flow and mineralization research. The volume includes some speculative but provocative ideas which should stimulate a re-examination of existing concepts regarding fluid flow in fracture systems and the genesis of hydrothermal mineral deposits. It also highlights recent advances which show the importance of the development of fracture connectivity in focusing fluid flow. The volume concludes with a thematic set of papers presenting new research results on the genesis of the world famous Carboniferous base metal deposits of Ireland. This volume is intended for geoscientists studying the flow of fluids through fault, vein and fracture systems or the genesis of mineral deposits and will be of interest principally to those involved in the minerals industry and in academia.