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PFP c .i* THE ORIGIN OF ROCKS Particulate Fluids Processing Centre AND MINERAL DEPOSITS ' USING CURRENT PHYSICAL CHEMISTRY OF SMALL PARTICLE SYSTEMS

by

Mineral Industry Consultants Assnciation Founded 1980 John Elliston

AUSTRALIAN PREYIEW EDITION

This project is proiidly supported by

An Australian Government Initiative Ausindustry, REMARKABLE OPPORTUNITIES AVAILABLE FOR EVERYONE Use of the current physical chemistry of small particle systems has provided simple and logical explanations for over 750 records of the minoráis, rock textures and structures illustrated in this e-book. This considerable body of observational data provides conclusive evidence that the crustal rocks and mineral deposits of today were derived from ancient sediments in which the small charged particles had the same properties and were subjected to the same diagenetic processes as those occurring in large accumulations of basin sediments today. The significant results of this extensivo research can be used to advantage by everyone.

EXPLORATION MANAGERS STUDENTS Successful mineral exploration cannot be Explanations for geological phenomena such as achieved without using appropriate high-quality the occurrence of fossiis within granito feidspars geophysical, geochemical techniques, and best and the details of all inorganic structures and surveying, sampling, and drilling prácticos. textures preserved in the rocks and mineral However, it has been shown that success ratos deposits are straightforward, satisfactory and and cost effectiveness can be improved up to easy to understand. With the current physical 300% or more by recognising the relationship of chemistry of small particle systems in use you prospectivo source rock volumes to ore localising will find teaching or professional work as a structures and host rocks. The challenge of geologist satisfying and rewarding. developing new resource remains, but understanding the ore forming process makes GEOCHEMISTS, GEOPHYSICISTS, AND the task much easier. EARTH SCIENCE PROFESSIONALS FIELO AND MINE GEOLOGISTS Most professionals who can retain an impartial and objective view will wonder why geologists Interpreting outcrops, logging drill core, selecting generally have not realised that the nature and material for assay, understanding the successive properties of ancient particle systems could be deposition of ore minoráis (paragenetic relevant to the formation of rocks and mineral sequence) and the nature of their distribution in deposits. Consideration of the static and large mineralised zones is relatively simple if the dynamic interactions between charged particles ore forming processes are understood. in these ancient systems and between the particles and the fluids that surrounded them is ACADEMIC GEOLOGISTS clearly a simple and logical approach to The use of current physico-chemical principies to understanding their origin. define the diagenetic processes by which the rocks and mineral deposits were formed now ANYONEINTERESTED IN THE WAY próvido a magnificent opportunity to make teaching of geological sciences attractive to THAT ROCKS ARE FORMED students. Their interest can be captured by interest in attractive granito facings, bench tops, providing realistic and logical answers to and in the colourful and decorativo stoneware questions of génesis for all the inorganic patterns that have intrigued us for years wili structures and textures preserved in the rocks. sharply increase. Details of modern physical The need for many conflicting or dubious chemistry and the geological processes hypotheses is eliminated, and the teaching of involved can still be left to competent straightforward simpler principies will attract professionals but simple explanations of their many more curious young students to geology origin are now available for school pupiis and courses. Many exciting new avenues are now anyone who is interested. opon for post-graduate research.

1 are blinded by what we think we know; disbelieve (your present convictions) if yOU can. " Samuel Warren Carey, 1911 - 2002.

This Australian Preview Edition and the book on CD herewith has been produced by:- ELLISTON RESEARCH ASSOCIATES PTY LTD,

All rights reserved 10 (B) The Bulwark, CASTLECRAG, N. S.W. 2068

© John Elliston, 2003. Except as provided by the ISBN 978-0-9804081-0-2 Copyright Act 1968 no part of this publication may be reproduced, stored in a retrieval position, or transmitted in First printing 2007 any form or by any means without the prior written Printed in Australia by: - permission of the publisher. Dobson's Printing Pty Ltd, 72-74 Gibbes Street, Chatswood, NSW. 2067

2 An introauction to: - The Origin of Rocíes ana Mineral Deposits - using current physical chemistry of small particle systems

by John Elliston from sediments has been identified. It contains 756 RESEARCH OBJECTIVE photographs of ore and rock textures as examples of The technical objective of this research from the the factual data that support the economically outset has been to define the physical and chemical important and far-reaching new conclusions. mechanisms by which mineral deposits were Over a long period of time the central hypothesis is formed. An understanding of these processes can be possibly the most rigorously tested new development used to achieve higher success rates and cost in the earth sciences in Australia's history. effectiveness in mineral exploration. THE NATURE OF THIS BOOK- THE CENTRAL HYPOTHESIS LENGTH RECORD OF ROCK AND The central hypothesis is that the features and ORE MINERAL TEXTURES structures observed in all rocks and mineral deposits that have ultimately been derived from ancient The research is interdisciplinary. It depends as much sediments (including porphyroids, metamorphics, on current developments in surface chemistry, and granites) must reflect and be consistent with the rheology, and colloid science as it does on factual principies of physical chemistry currently geological observations such as those recorded in established for small particle systems. the book. To colloid and surface chemists it appears This hypothesis has been tested by systematically logical that very large high-energy particle systems recording the observational data for a very wide like ancient natural sediments should exhibit the range of rocks and mineral deposits in different same rheological behaviour, particle interactions, geological environments. Each of these actual rock and chemical attributes as other particulate matter textures and structures has then been considered as that has been so thoroughly subjected to to whether or not .it is consistent with the experimentation and testing. composition, properties and behaviour of particulate For geologists, however, this approach is new. There precursors that could lithify or crystallise to result in has been no occasion in the past to apply the the minerals, shapes, patterns, structures and principies now established in colloid and surface textures now preserved in the rocks. chemistry to the origin of rocks and mineral deposits. The central hypothesis is fundamental in nature and The current knowledge of the physical chemistry of global in its application. The comprehensive inves• small particle systems did not exist when traditional tigation of the origin of rocks and mineral deposits geological assumptions about the origin of rocks and has extended over many years. A very large number mineral deposits were first made. of mine openings, drill cores, and specimens have been examined and features indicative of sediment The diagram on the opposite page indicates the mobility and colloidal processes during diagenesis growth of the very long history of development of have been recorded in approximately 6,500 photo• geological theory and the more recent independent graphs. Some 4,500 of these have been selected and growth of colloid and surface chemistry largely digitized during the preparation of progress reports. foUowing the pioneering work of Freundlich in 1936. Fourteen published and sixty-five unpublished Demarcation between specialised áreas of theoretical reports and scientific papers by the author of this geology and current colloid and surface chemistry book record details of how various geological has been called the "interdisciplinary barrier". This phenomena (such as framboids, oolites, or geodes) has been maintained in the present context of "Infor• result from physico-chemical processes and how the mation overload" by the real and increasing inability current principies of colloid and surface chemistry of scientists generally to keep abreast of relate to the reléase of ore minerals in various developments in disciplines other than their own. geological environments. In the earth sciences an opportunity has therefore This book represents an overview of the whole been left for a major advance in understanding the research program and brings together for the first origin of rocks and mineral deposits by applying the time sufficient Information to demónstrate that the principies of physical chemistry that relate to small origin of all rocks and mineral deposits derived charged particles and colloidal systems.

4 James Hutton, 1785 (provisional hypothesis) DATE 1800

GROWTH OF INDEPENDENT MAINSTREAM GROWTH OF EARTH SCIENCE COLLOID AND 1850 THEORY SURFACE CHEMISTRY Graham 1864 (confined to theory of (approximately one third of al! Solutions and behaviour physical chemistry not yet of silicate melts) applied in the earth sciences)

1900 Einstein Perrin 1910 1920 Peterfi 1930 CHEMISTS Freundlich Derjaguin 1940 Langmuir Kuenen Verwey Overbeek 1950 Alexander BosweII 1960 Vine and Mathews Lebedev Dietz Eitel 1970 ÍHess (píate tectcnics) Healy Seismic refiection profiles ller /Óceanographic surveys 1980 Stumm 1990 Healy Hunter 2000 2006 Technologlcal gap Development of earth science theory in Earth Science without current colloid and surface chemistry l^nowledge wlder theoretical base resolves problematic" rock textures and the origin of ore deposits

Seismic data has increased our knowledge of large-scale sediment movements and rheologists have now clarified the cohesive, plástic and fluid nature of aqueous slurries and of fme-grained particle systems generally. Colloid and surface chemists have defined the interactions between charged particles, ions, and solvent in these systems. During diagenesis (the formation of rocks by consolidation of sediments), it is a simple fact that all chemical reactions that occur in interparticle spaces or within the pores of semi- consolidated sediments must take place in the immediate vicinity of a surface. The presence of charged surfaces is the essential difference between what actually happens in nature and "hydrothermal solution theories" that are based on normal chemical reactions established for bulk solution such as those in open test tubes or in laboratory reaction vessels. A wider theoretical basis is now available for interpreting geological phenomena. It has been found that this additional basis in colloid chemistry and rheology can now be applied to achieve more effective exploration and development of mineral resources. The "breakthrough" has been achieved by filling the technological gap in the theoretical base of the earth sciences.

5 EVALUATION OF ABOUT THIS BOOK MULTIDISCIPLINARY This book is not a textbook. For the first time it is RESEARCH documenting the results of meticulous long-running research that has the potential to form the basis of Significant research is innovative. Unquestioning many textbooks. However, this preview edition adherence to popular concepts or the existing might best be described as a presentation of a majority viewpoint would stultify scientific progress. selection of primary data that is used to test and The new approach to resolution of long-standing establish the central hypothesis as correct. It is geological problems (using the current physical definitely not a new theory or idea propounded by a chemistry of small particle systems) clearly has the single scientist. The author has applied existing potential for Australian scientific institutions to standard theory (now developed in colloid science) achieve world leadership in the earth sciences. to interpret existing geological observations. Any major discovery or significant development in The book summarises the results of a series of science must necessarily differ from present widely research projects undertaken by Peko-Wallsend held views. The new work is based on physico- Limited and CRA-Rio Tinto over the last 45 years. chemical principies that have not been applied From the beginning this work has been subjected to before. Detailed examination of the factual data, detailed academic scrutiny. Its extraordinary success, supporting experimentation, and references by both in practical application and in achieving a individual scientists with the required skills has completely new perception of the origin of rocks and therefore been essential. mineral deposits, would not have been possible with• out continuing advice and guidance from leading It would certainly be expected that ancient natural academics and specialists in their respective fields. sediment accumulations behaved in accord with the The far-reaching conclusions could not have been principies now established in physical chemistry substantiated without the high quality experimenta• and rheology. However, this has led to significant tion, supporting research projects, and technical serv- findings that could not have been foreseen when ices that have been made available to the companies. classical theories in earth science were developing. The concept that preconsolidation structures and Over the last five decades, Information relating to textures can be preserved in lithified and crystalline basin sediments has increased dramatically. Static rocks is a radical, almost revolutionary departure and dynamic particle interactions that were first from long-held traditional assumptions. It is no suggested by Dutch chemists in the 1940's have longer necessary to believe that the observed plástic now been confirmed by adapting an atomic forcé deformation was all due to extreme pressure and microscope to record measurements of interparticle forces. The Particulate Fluids Processing Centre, an heat or that crystalline rocks showing evidence of Australian Research Council funded special former fluidity must have been fused by selective research centre at Melboume University, achieved application of heat from an unknown source such this remarkable new development in colloid science that very large masses of pre-existing refractory in 1998. rock minerals were melted.

The wider theoretical basis now available for The nature of this research and the economic and interpreting geological phenomena has been used in scientific importance of the conclusions have this research to review historie and current problems required extensive and appropriate "refereeing" or of geological theory. Longstanding problems evaluation by experienced scientists in both geology relating to the origin of mineral deposits and and colloid chemistry. In view of its significance in associated rocks can now be resolved by application geological science, it is considered important and in of the additional theoretical principies. The behav• the national interest that further competent iour and properties of small particles provide simple evaluation of the conclusions reached in this book explanations for the previously unknown geological should be extended to involve as many leading phenomena that are illustrated in this book. Some scientists in both disciplines as possible. Immediate features could only resuh from particle interactions application in general exploration practice is highly in high-energy aqueous particle systems. desirable.

6 SUPPORTING AND CONTRIBUTING SCIENTISTS

A number of outstanding scientists have encouraged and supported the interpretation of porphyroidal rocks as lithified mudflows or intrusions in which accretionary ovoids have crystallised. In many cases they have undertaken the personal studies and fíeld work necessary to confirm it. Leading scientists who have acknowledged the importance and recognised the far-reaching consequences of the initial discoveries at Tennant Creek in central Australia include: -

Professor A.E. Alexander Professor T.W. Healy Professor S.W. Carey Assoc. Professor R.J. Hunter Professor T.F.W. Barth Professor J.C. Jaeger Sir John Proud Professor David Williams Professor Beryl Nashar Dr. H.W. Fander Professor R.L. Stanton Professor Antón L. Hales Sir Rutherford Robertson Dr. Ralph K. ller Professor John Bradley Dr. S.J. van Biljon Professor S.S. Augustithis Professor Z. Pouba Assoc. Professor K.L. Williams Mr. Dominic O'Sullivan Mr. John Collier Dr. Haddon F. King Mr. K. Wright Mr. G.R. Ryan Dr. G.H. Sherrington Mr. R.L. Richardson Mr. John Love Dr. E.E. Swarbrick Mr. R.D. McNeil Mrs. Wendy L. Corbett Mr. Paul LeMessurier Dr. Phil McSharry Mr. Jacob Rebek Dr. lan Gould Mr. Phil Rosengren Dr. Timothy McConachy Dr. Neil Herriman Dr. Marjorie Muir Mr. Dermot Ryan Mr. Ray Twist Dr. Joe Ostwald Dr. Mike Doyle Dr. K.H. Wolf Dr. Don Findlay Professor Barry Ninham Dr. Nevil Byrne Dr. Tom Honeyman The Industrial Research and Development Board of AusIndustry

Over the years many more coUeagues, friends, and staff have made significant contributions to various aspects of the work. These include fumishing photographs, specimens, literature references, technical books, maps and diagrams. The writer has been assisted with travel arrangements, visits to mines, prospects, and with access to drill core, and field locations. Visits to some extremely remote locations and otherwise inaccessible mine workings and field outcrops have been achieved. The courtesy, encouragement, and material contributions of all these supporters are gratefully acknowledged.

7 Professor A.E. Alexander CONCEPT ProfessorS.W. Carey International Svmposium GENERATION Sir John Proud Geopeko staff Professor David Wiliams Professor S.W. Carey Dr. W. Fander John Elliston Professor Beryl Nashar Professor J.C. Jaeger Professor R.J.Hunter Professor T.F.W. Barth EXPERIMENTATION 23rdlGC. Praaue. 1968 AND FIELD TRIAIS Professor TF.W. Barth Sir Charles Kingsley-Dunham Dr. Leonard G. Love Professor Z. Pouba Kim Wright David Duncan Dr. S.J. van Biljon Professor T.W. Healy John Love (14 reports 1967- 1977)

Mrs. Wendy Corbett RE-CLASSIFICATION McKinsey & Co comparison report OF ROCKS

Professor R.L. Stanton Professor R.K. ller Mr. John Collier Assoc. Prof. K.L. Williams Peter Savio

APPLICATION OF CURRENT Dermot Ryan PHYSICAL CHEMISTRY TO Professor R.L. Stanton ORE FORMATION Elliston Research IN VARIOUS Dr. Neil Herriman Associates Pty. Limited GEOLOGICAL Dominic O'Sullivan PROmCES Contributions and experimentation supporting systematic research program 1959-2005 LINKING EXPERIMENTS ESSENTIAL INPUT DOCUMENTATION, Dr. KarI Wolf SIGNIFICANT COMMERCIALISE, CONTRIBUTION PUBLISHAND EFFECTIVE PROMULGATION Jacob Rebek Dr. lan Gould Rob Ryan SPECIAL ACKNOWLEDGEMENTS

A single scientist working alone could not have Dr. Ralph K. ller, Comell University and E.I. achieved the significant results of this series of duPont de Nemours & Co., Wilmington, interdisciplinary research projects. The writer of this Delaware, 1984, introduced the aqueous e-book has been responsible for recording most of chemistry of silica and the particulate the factual observations presented and has examined nature of naturally occuring silica a very large number of scientific publications to polymers and confirmed that the principies ensure they contain no factual data, observations, or of this colloid chemistry were correctly measurements that would contradict or negate the applied in the case of the Tennant Creek central hypothesis. However he has been privileged porphyroids. to co-ordinate the work of many sénior scientists who Professor R.L. Stanton, University of New have contributed basic concepts, ideas, and England, Armidale, 1989, published the Information that have made it possible to achieve results of independent studies in which he these fundamental and successful far-reaching had used a microprobe analyser to identify research results. the composition of hydrous precursor The following essential contributions that have been minerals from which an extensive suite of the key to success are gratefiilly acknowledged: - metamorphic minerals had crystallised. Professor A.E. Alexander, Professor of Physical Professor T.W. Healy and his coUeagues at Chemistry, University of Sydney, 1959, Advanced Mineral Products Research identified the siliceous phenocrysts in the Centre (now Particulate Fluids Processing Black Angel porphyroid at Tennant Creek Centre), University of Melboume, 1998, as accretions. had adapted an atomic forcé microscope to Professor S.W. Carey, Professor of Geology, measure forces between charged particles University of Tasmania, 1960 to 1972, to confirm that the particle interactions emphasised the importance of factual were as predicted by DLVO theory. observational data and encouraged the Professor Healy personally communicated revisión of traditional concepts relating to the results of this outstanding achievement the origin of igneous-looking rocks and on 2ndJuly 1999. mineral deposits in accord with current Sir John Proud, Chairman and Chief Executive developments in the physical chemistry of of Peko-Wallsend limited, 1959 to 1975, small particle systems. was primarily responsible for encouraging Professor T.F.W. Barth, University of Oslo, and financing the research from its early 1965, confirmed that the feldspars in the stages. He introduced and took advice Tennant Creek porphyroids are of from many eminent scientists to ensure authigenic origin and that their that the new approach was properly based composition is such that a corresponding on the principies of colloid chemistry and molten magma becomes a "physico- the rheology of aqueous pastes. chemical impossibility". Many staff members and executives of Geopeko Professor T.W. Healy, University of Melboume, Limited and CRA Exploration have actually made 1967 to 1977, introduced the greater contributions to this research in time and physico-chemical processes that occur effort and the study of examples but introduction of during the diagenesis of sediments: with critical concepts and Information on which the particular emphasis on the role of colloids whole research program is based are acknowledged and colloidal processes in geology. He above. conducted the necessary experimental work to demónstrate the formation of accretions in mobilised aqueous pastes. 10 INDEPENDENT VERIFICATION This research has been reviewed by leading colloid chemists, rheologists, geochemists, sénior academic geologists, exploration managers, company executives and the Australian Government Department responsible for resources and industrial research, AusIndustry. Summaries, extraéis, and formal evaluation reports relating to this e-book are set out in a sepárate document 'Verification Rpts.pdf on the CD. This independent verification by over 40 scientists relates to this book and to the unpublished progress reports. All assessments have been poshive where the relevant physico-chemical principies have been considered in relation to the actual photographic record. The evaluation reports therefore should now be sufficient to encourage other earth scientists and students to examine the textures and structures in rocks and mineral deposits. Chemists have no trouble with the basic colloid and surface chemistry but the fundamental nature of this new approach to earth science research has made it necessary to extend the evaluation of this work to as many impartial and competent geologists as possible. If the task and responsibility of reviewing an important new Australian discovery is accepted, every intellectually honest earth scientist can now avoid any implied challenge to the professional integrity of the IR&D Board, or to the individual scientists who have already assessed this work. Key statements from current assessments include: - "There is no substitute for understanding the geological processes that have led to the creation and subsequent modifications of ore deposits. John Elliston's book provides that understanding." Jacob Rebek, Group Chief Geologist (now retired), Rio Tinto Exploration Limited. Sydney. "John Elliston is a scientist who has never shirked the responsibility all scientists should have of challenging the established ideas, theories and paradigms in our various fields of scientific endeavour. This work is interdisciplinary, based as much on colloid science as on his careful geological observations and meticulous review of the literature in both disciplines. The principies of colloid and surface chemistry are impeccably well represented in the text of this book." Thomas W. Healy, FRACI, FAA, FTSE, Emeritus Professor of Physical Chemistry, The University of Melboume. "His persistence and the linkage of geology with the enabling science of fine particle and colloid chemistry are particularly worthy of praise. Australia needs innovative thinking like this to find the next and more elusive generation of orebodies and thereby sustain the minerals industry that is both the foundation and the fiiture of our national prosperity." lan G. Gould, BSc (Hons), PhD, FAusIMM., President, The AusIMM, 2004-2005. Adelaide. "It is a tribute to John Elliston that he has the tenacity to have absorbed such a large slice of the theory and observadons of colloid and surface chemistry and has been able to use it so effectively in his own field. ... He has elaborated over the years on the many aspects of colloid and surface chemistry, which are involved in this génesis. Here it is all coUected together in a format that is not merely plausible but compelling." Dr Robert J. Hunter, FAA. FRACI, Honorary Associate Professor of Chemistry, The University of Sydney. [Note: All open-minded people who are curious about how rocks and mineral deposits were formed will certainly find this documentation of the relevant chemistry and acUial rock textures "compelling".] "I have now had a chance to work through the sections that fall more into my own área of science, viz, non-Newtonian fluid mechanics and rheology of particulate fluids. 1 am most impressed with the understanding John Elliston displays in these sections. It is refreshing to see interest by geoscientists in processes well known to rheologists." David V. Boger, Lauréate Professor of Chemical Engineering, Director, Particulate Fluids Processing Centre, The University of Melboume. 1) The photographs it contains are a direct RESEARCH METHODS AND result of the ongoing experimental activities. RECORDING OF DATA They record and measure the real features to New knowledge of the origin of rocks and orebodies be seen in the rocks. Each photograph has been achieved by recording actual textures and includes a scale and the features recorded structures preserved in the rocks, extensive investi• clearly indícate that they were taken for the gation of the relevant literature, and appropriate purpose of testing the central hypotheses. experimentation. This successful and commercially The scope of the project has involved a large valuable research is based on the simple premise that number of such tests. the origin of rocks and the important energy and 2) Documentation of this factual observational mineral resources they contain inust depend on the data and details of the relevant physical physical and chemical properties of the natural chemistry is necessarily book-length because materials from which they were initially formed. the principies of physical chemistry apply to Classical geology recognises two ultímate sources all rocks and mineral deposits initially derived from which rocks and rock minerals are derived. from sedimentary materials. The immense Basalt related rocks are believed to origínate from the amount of Information reflects the wide scope Earth's mantle beneath the crustal rocks and to be and duration of the project and many emplaced directly at mid ocean ridges on the sea examples from different locations are floor or through volcanic vents. All other rocks on necessary to demónstrate the universal this ocean-covered planet are thought to have derived application of the principies. from materials that were initially deposited after one 3) This book-length record provides full details or more cycles of weathering and sedimentation. of how mineral deposits were fonned. It This includes the traditional view that metamorphic points out how trace levéis of metal ions are rocks and granites were derived by a series of sparsely adsorbed on the surfaces of sediment physical and chemical changes to original sediments. particles. It explains how these are The properties and behaviour of natural sedimentan/ sulphidised, released from surfaces as soluble particle systems has therefore been adopted as the hydroxy-sulphide species and concentrated by starting point for defming the processes by which precipitation from outflowing brines. rocks and orebodies are fomied 4) Scientific texts and papers listed as references The electrical charge on the surfaces of natural for the work in this book have not been sediment particles is demonstrated by phenomena as chosen as examples of other sciendsts whose simple and well known as the cohesión of potter's conclusions support those of the author. They clay or mud sticking to one's boots! Discovery of this have been used as a source of Information and physical property of fine particle systems and recog- closely examined to ensure that they contain nition of the way that charged particles interact with no factual data or observation that is not in each other and with water and ions in surrounding accord with the new interpretations using the Solutions was achieved in the 1930's and 40's. From physical chemistry of small particles systems. the considerable progress since that time it has now Very few authors of the papers listed have been found that structures and textures preserved in considered the application of current colloid the rocks provide clear evidence that ancient sedi• and surface chemistry at all, but references ments were hydrolyzed and had the same colloidal cited in this book all record the page numbers properties as those in the sedimentar/ basins of today. for quotations or from which specific reliable This book is a record of primary data. These Information has been obtained. accumulated records are now sufficient to 5) Diagrams in this book are used to show how substantiate the central hypothesis and introduce macromolecular species and charged particles new knowledge. The book points out the way that interact with water, ions, and other charged rocks and mineral deposits were formed when the particles in the pore fluids round them. Sixty- current physical chemistry of small particle systems one of the 144 diagrams in the book have been is used and for many different rock types in various re-drawn or copied from scientific papers and geological environments. texts to relate current physical chemistry to

11 small particle systems. This routine collection observed rocks and mineral deposits were formed of Information from published work and should therefore be considered when interpreting all commissioned experimental activities in rocks and mineral deposits that have been derived colloid and surface chemistry is an essential from sedimentary materials. part of the R&D process. Eighty-three original There is nothing more basic to their origin than the diagrams in the book illustrate how this Infor• chemical and physical properties of the precursor mation is specifically related to the properties and surface interactions in natural sediments substances from which they lithified and crystallised. and to the origin of ore forming fluids. It is therefore essential to compare the elementary properties and behaviour of the natural sedimentary 6) The book is not an attempt to promúlgate an particle systems of today with those of the distant unsupported conclusión. The scientific past. Because sedimentary materials contain method has been applied in a systematic extraordinarily large internal surface áreas, progression of work properly based on the consideration of their surface chemistry can not be principies of colloidal chemistry and the neglected. rheology of aqueous pastes to test the central hypothesis and to reach logical conclusions. This pre-view edition is presented so that Australian scientists can take advantage of these 7) An unsupported opinión or conclusión that new discoveries. Internationally millions of dollars differs materially from the present level of scientific understanding could simply be are spent annually on ore deposit research. The discounted. A significant advance in science Information in this e-book is highly sought after. can only be achieved by an objective open- minded consideration of the factual data (in TESTING A LOGICAL this case the actual structures, textures and HYPOTHESIS features preserved in the rocks and mineral If rocks and mineral deposits originated from former deposits such as those illustrated in the book). water saturated sediments, structures and textures 8) This book-length record is a highly innovative preserved in these materials after lithification should new record of R&D. Sir Rutherford Robertson, reflect the nature and properties of the original high- former President of the Australian Academy of energy particle systems. This central hypothesis is Science, has likened this type of presentation to fundamental and must be considered. We should Charles Darwin's "Origin of Species". expect to see features in the crystalline rocks and mineral deposits indicating their former plasticity, AVAILING THE OPPORTUNITY diffusion, rimming structures, mobilisation, OF THE RESEARCH OUTCOME brecciation, aggregation, syneresis, concretion, ptygmatic vein intrusión, etc. The current colloid and surface chemistry used in this book has been described as "all standard This hypothesis has therefore been tested in many textbook stuff. Together with the Information now different locations and geological environments by available from geophysical surveys, offshore oil recording thousands of examples of the resulting drilling, óceanographic surveys, and deep-ocean textures and structures. Evidence of the nature and drilling programs it provides a valuable opportunity properties of original high-energy particle systems to understand the origin of ore deposits and to has now been found in rocks and mineral deposits significantly improve success rates in exploration everywhere. Hundreds of features that have for new resources. remained problematic for traditional geological theory are now resolved by extending this theory to It is clear from the many examples of resulting include the current physical chemistry of small structures and textures in this book that the particle systems. This has led to the significant new principies of modern colloid and surface chemistry conclusions that radically increase the existing state must have applied to ancient sediments as well as to of knowledge in the earth sciences. present-day high-energy particle systems. Diagenetic processes in the ancient natural The research also takes currently accepted and sediment accumulations from which the presently applied geological theory forward to include recent

12 developments in the rheology of non-Newtonian palingenesis, oolitic ore textures, post- fluids. The extensions are additive. The new work depositional re-mobilisation of ore minerals, does not negate or contradict any physical or chemi• intrusive ironstone bodies, framboids, etc., cal process, measurement, or facUial observation. etc., be explained by any other natural However, in-depth investigations using the additional processes? experimental results and theory have now defíned the Competent evaluation of this long-running colloidal, rheological, chemical and physical program of industrial research is of paramount processes by which rocks and mineral deposits are importance for the advancement of science and for formed from sedimentary materials. improved cost effectiveness of future mineral Since this research depends on the inherent exploration. properties of high-energy particle systems that have now been established in colloid science, all APPROPRIATE SCIENTIFIC crustal rocks that have been derived directly or ASSESSMENT indirectly from sedimentary materials of all ages This interdisciplinary research has the potential to (including porphyroids, metamorphics, and revolutionise our understanding of how rocks and granites) require re-consideration with regard to ore bodies are formed. In reality, fundamentally the more recently established principies. challenging questions of basic science today are The basic questions to be addressed in considering often determined by "popular vote". Expedient this work are simple: - adoption of the current majority view can avoid the considerable effort involved in evaluating any 1) Did ancient sedimentary materials from significant new hypothesis. Every member of a which rocks and mineral deposits were scientific convention, board, or committee formed have the same or very similar concemed with assessing scientific issues should be properties as have now been established for acutely conscious of the fact that any major advance the high-energy particle systems of today? in science must reveal an unexpected conclusión, a 2) Leading chemists have claimed that the finding that by its very nature must be a departure physical chemistry of small particle systems from what has been believed to date. It will require is properly represented in this book. Are rigorous and competent evaluation. they correct? The results of this long-running program of industrial 3) Is it appropriate to apply the principies of research are potentially very significant indeed. It is colloid and surface chemistry to particle quite inappropriate to assess it by comparison with the systems such as ancient sediments? Is it existing level of scientific knowledge. The object of logical to assume they should have similar or any assessment must be to ensure that the primary the same properties as large sediment data or evidence is factual, and then to idenüfy any accumulations today? technical defects in the reasoning or in the scientific principies on which it is based. 4) Is there any reason why the properties and behaviour of small charged particles should All assessments that have had regard to its basis in continué to be disregarded in fínding a colloid and surface chemistry have resulted in solution to the problem of the origin of rocks increasing support for the new concepts. Wider and mineral deposits? recognition of the new approach by teaching institutions, govemment departments responsible for 5) Could any single altemative hypothesis or resource assessment, and by exploration companies other basic set of unifying principies provide is needed so that the new work can be confidently complete and satisfactory explanations for and more immediately applied in Australian mineral the 259 problematic factual observations exploration. Teaching will be more effective and illustrated in this book? Can examples such wasteful research projects re-directed towards more as orbicules, rapakivi textures, fossiis in a advantageous outcomes. Further examination of granite feldspar, ptygmatic vein injections. this initial documentation is also desirable to

13 increase the number of verification reports and to 2) Diffusion gradientS. The removal of recdfy any errors or omissions (see 'Verification ions, molecules, macromolecules, or charged Rpts.pdf on the CD). particles from dispersión or solution in pore fluid by If Australia is to establish leadership in any branch physical or chemical processes such as adsorption, of science there is no more important task than coagulation, concretion, or chemical reactions addressing the proper and competent evaluation of reduces the concentradon of the species involved at new and innovadve concepts. This task cannot be and near the reaction site. This depletion of a left to a group, committee, or board who might particular species at the site of a reaction or determine the technical merit of a submission by interaction creates a concentration gradient along consensus based on their current perspectives and which more dispersed units of the same species present level of understanding. The assessment of diffuse to equalise their concentration. Diffusion is a innovative new concepts is clearly the task and phenomenon well known to all scientists. The responsibility of all individual earth scientists who concept of ions, molecules or very small particle are actually concerned with advancing their difflising at different rates through porous media was profession and its standing in this country. introduced by a Scottish chemist, Thomas Graham in 1829. He formulated Graham's Law for the difhision A NEW APPLICATION OF rate of gases through porous media, which varíes PREVIOUSLY ESTABLISHED inversely with the square root of their densities. PRINCIPIES He also proposed the term 'colloid' to distinguish dispersions of particulate matter from what he called The seven most important physico-chemical 'crystalloids' that are now regarded as electrolytes or processes and principies that have now been used to ordinary solutes. define the origin of rocks and mineral deposits are: - GRAHAM, T., 1864. On the Properties of Silicic Acid and Other I) The precursor principie. The Analogous Colloidal Substances. (See Alexander, A.E., and Johnson, P,, 1950. Colloid Science. Oxford University Press, p.5.) concept that most common ore and rock minerals crystallised by simple dehydration reactions from 3) Accretion. This process is the rapid hydrous minerals of corresponding composition formation of clusters of similar shaped particles to form 'cióse packed' and pre-ordered aggregates at (such as feldspars from clays) was developed by net lower surface energy. The formation of Professor R.L. Stanton during his studies of Broken accretions is dynamic. It occurs in any remobilised Hill metamorphic rocks 1978 to 1983. He then fluid paste where particles of each colloidal measured the composition of the substances that component have similar or the same shapes that were crystallising to metamorphic minerals with a enable them to be packed closely together. There is microprobe analyser. He established the importance a critical concentration of particles at or above of this geological process as the precursor principie which cióse packing occurs. Crystallisation of these in his 1989 review paper. It has never been disputed pre-ordered aggregates subsequently occurs to then that crystalline metamorphic rocks and granites were form a 'porphyroblastic' texture where the large originally derived from sediments but classical crystals are set in a finer grained matrix of theory assumes the sediments were lithified to lower- crystallised sedimentary material. The development energy refractory rocks and rock minerals that then of accretions as a general principie is demonstrated by their occurrence in formerly re-mobilised required massive later inputs of energy to liquefy or sediments and lodes of many different types and re-crystallise them. Stanton has been first to compositions. They occur in greywackes, shales, determine the ordered precursor hydrates from which limestone, banded iron formations, slip complexes, metamorphic minerals actually crystallise. spotted shales, sheared zones, granites, rapakivi STANTON, R.L., 1989. The precursor principie and the possible granites, porphyroidal "clay clot" rocks, significance of stratiform ores and related chemical sediments in the elucidation of processes of regional metamorphic mineral porphyroids, jasper, chert, porcelanite, deep marine formation. Phil. Trans. R. Soc. Lond., A 328: 529-646. oozes, sandstone, dolomite, marble and greenstone.

14 Professor A.E. Alexander, Department of Physical definite non-random structures that can only be Chemistry, University of Sydney, identified cherty formed in aqueous particle systems. 'porphyroblasts' or ovoids from the intrusive Mielenz and King, 1955, were first to point out that porphyroid lenses at Black Angel in Tennant Creek, the synerectic contraction of a gelatinous aggregate N.T, as accretions in 1959. He pointed out that resulted in the exudation more highly concentrated rapid formation of physically stronger aggregates of electrolytes than that in the surrounding pore fluids. cióse packed particles was due to the operation of However, concretions as sub-spherical accumulations van der Waal's forces at cióse interparticle spacing of one of the very fine grained constituents of the rock in accord with DLVO theory and gave as references: in which they occur have been well known and ALEXANDER, A.E., and JOHNSON, R, 1946. Colloid described for over a century. An early reference is: Science. Vol 2, Clarendon Press, Oxford, England, p. 607. DALY, R.A., (1900) The calcareous concretions of Kettie Point, FRISCH, H.L., and SIMHA, R., 1957. The Viscosity of Lambton County, Ontario, J. Geol., vol. 8, pp. 135-150. Colloidal Suspensions and Macromolecular Solutions. In Rheology, Theory and Applications (ed. F.R.Eirich), Vol.l, pp. 5) Synerectic desorption. This is one 525-613. Academic Press, New York. of the most important properties of close-packed HAUSER, E.A. and LeBEAU, D.S., 1941. Studies in Colloidal particle aggregates (accretions and concretions). As Clays; II. Jour. Phys. Chem., 45: 54-64. the particles in these clusters are drawn together by MIELENZ, R.C. and KlNG, M.E., 1955. Physical-Chemical van der Waal's strong forces of attraction at very Properties and Engineering Performance of Clays. Calif Dept. cióse interparticle separation (primary mínimum), Nat. Resources, Bull. 169, pp. 196-294. the particles or particle chains achieve greater 4) Concretion. This is the slow or co-ordination. Total surface energy is lowered and step-wise accumulation of material about a central internal surface and adsorptive capacity are nucleus to produce a banded-textured spherical or reduced. Species adsorbed on surfaces are elliptical accumulation of higher particle density and desorbed. Polar water molecules, ions, and smaller compaction than the médium in which the particles charged particles are exuded from the clusters into are diffusing. The active process of concretion the matrix brines. This results in Liesegang depends on colloidal particles individually diffusing banding, rimming of synerectic aggregates towards the precipitating surface represented by the (rapakivi texture and concretion), and discharge to boundary of a higher density gel aggregate within the pore fluid brines of exceedingly small metal the less dense surrounding médium through which hydroxide and hydroxy-sulphide particles. the particles are diffusing. They form by diffusive Precipitates of these metastable colloids from brines migration of dispersed sol particles to the surface of migrating out of the system accumulate as a contracting gel aggregate. Precipitation at this economic orebodies. Syneresis in accretionary 'internar surface is a consequence of a marked aggregates is independent of the chemical change in electrolyte concentration that is produced composition of the particles. Therefore, any large by synerectic exudation of the interparticle fluid volume of limestone, chert, argillaceous sediment from the densifying gel. Concretions require a (shale), or greenstone that has been re-textured is a synerectic nucleus on which the metastable sol potential source of ore mineral sois. These disper• particles can precipítate. The additional layers of sions seep out of the compacting sediment pile as precipitated particles then in the 'cióse packed' synerectic desorption increases brine strengths that condition, draw together under van der Waal's strong will keep them displaced into the fluid phase. attractive forces to desorb their own adsorbed Thomas Graham identified the spontaneous species so that the concretion continúes to grow. contraction of colloidal aggregates and dense gels in Concretion is therefore a diffusive process 1861 and introduced the term "syneresis" to describe dependent on the concentrations of electrolytes and this process. The desorption of ions and polar water smaller particles dispersed within the gel meshwork. molecules that result from reduction of surface área It does not depend on the operation of extemal within close-packed synerectic gels was identified agencies such as shearing. The characteristic form later following the work of Freundlich, 1936, and of polyrimmed concretions is an important and the development of DLVO theory in the 1940's. reliable indication of the environment in which these structures are formed. They are complex but FREUNDLICH, H., 1936. Structures and Forces in Colloidal Systems. Proc. Royal Inst., 29: 232-252.

15 6) Critical Cluster. Analyses of the 7) Rheological separation. This is an processes involved in nucleation and crystal growth important principie by which components of shows that initiation of the solid phase is achieved gelatinous materials such as semi-consolidated by chemical reaction between ions or molecules sediments sepárate by differences in their fluid that would lead to the formation of a solid precipí• properties. When the gel structure or meshwork is tate. Where the reacting substances are at low physically disrupted or disturbed the more mobile concentration or the reaction is controUed by components simply "flow out" of the agitated or diffusion rates, this leads to the formation of a disturbed pastes. They are less viscous, water-rich critical cluster or nucleus that has special properties and therefore lighter or more "sloppy" components at the point where a liquid-solid interface is first of the mixed hydro-silicates. They tend to form formed. The orientation of insoluble molecules in veins or dykes that intrude upward. Iron hydroxides relation to each other as a crystal lattice or nucleus and hydrous ferromagnesian minerals such as begins to form results in "dangling bonds" or chlorite, glauconite, or serpentinite apparently retain unsatisfied chemical linkages where additional water of hydration later in diagenesis than clays and molecules could join the developing lattice. The silica gels. However, late separation and injection of extraordinarily high surface energy of such nascent polymeric silica globules as water-rich thixotropic nuclei or critical cluster of molecules is sufficient to liquid is common. The separation usually occurs at dissociate water molecules. The "dangling bonds" a stage where the other major components would re- are satisfied with or OH' to form hydroxide or assume a non-fluid or more viscous gel condition. hydroxy-sulphide particles. Rheological separation can involve large volumes of Critical clusters are centres from which spontaneous the mobilised pastes or occur on a very small scale. growth can occur. This growth results in the Fluid hydrous chlorite oozing from flow sheared formation of a stable charged particle with a surface Conasauga shale into microscopically small but the initial growth of exceedingly small and sparsely separated charged particles means that the ptygmatic veins has been illustrated by Weaver charged hydroxide and hydroxy sulphide particles (Fig. 5.35 in this book). Glauconite dykes and sills are, like the sparsely positioned metal ions from have separated from tertiary limestone near White which they were formed, again adsorbed on sediment Rock in New Zealand (illustrated in Figures 13.20 to substrate surfaces. Hydroxide, hydroxy-sulphide, 13.26). The separation of the hydrous precursor of metal, and gangue mineral species are successively high-grade iron ore from disturbed banded iron released (paragenetic sequence) by ion - charged formations is an important economic result of particle exchange as the concentration of pore fluid rheological separation (Figures 6.2 and 8.33). brine increases with the depth of burial and WATERHOUSE, J.B., and BRADLEY, J., 1957. Redeposition progressive diagenesis. The exceedingly small size and slumping in the Cretaceo-Tertiary strata of S.E. Wellington. of the dispersed ore metal sulphide particles enables Trans. Roy. Soc. N.Z., 84: 519-594. them to pass through the smallest openings and WEAVER, CE., 1984. Shale-slate Metamorphism in Southern Appalachians. Elsevier, Amsterdam. Developments in Petrology diffiise out of the system with the fluids. 10, p. 49. The concept and special properties of a 'critical TH£ QUESTION OF cluster' as a first stage in the formation of a PROFESSIONAL HONESTY precipítate by a chemical reaction was introduced to this research by Professor T.W. Healy in 1972. It There is no better evidence of origin than what we has since been reproduced in other textbooks on actually see preserved in the rocks. This is physical chemistry. recognised by all progressive and competent geologists. However, in some cases geologists HEALY, T.W., 1972. Physico-Chemical Processes in the Diagenesis of Sediments. Unpublished Paper, Dept. of Physical appear to avoid examining "inconvenient" factual Chemistry, University of Melboume, Vic. p. 13. observations that do not accord with accepted theory! STUMM, W., 1992. Chemistry of the solid-water interface; Processes at the mineral-water and particle-water interface in nat• For example, some petrologists are disinterested in ural systems. A Wiley-lnterscience publication, New York, p. 212. occurrences of large orbicules in granite. These

16 structures appear mysterious and completely Sederholm (1928, p. 43) pointed out "They convey inconsistent with the formation of a succession of the impression that this outermost shell at the time of concentric mineral layers by cooling of molten their formation was a kind of emulsión of small silicates. However, it is sdll reasoned that the crystals of biotite in a gelatinous mass consisting of concentrically layered orbicules must have formed still at least partly fluid feldspathic constituents." this way because we all "know" that granites are igneous rocks! The problem is compounded if we Competent earth scientists find these observations then demónstrate a cióse similarity with other challenging. Precipitation of altemate concentric concentric structures such as orbicules in dolomites, layers of biotite and plagioclase around a central siliceous shale, mineral lodes, limestones, serpentine, core or nucleus is simply not consistent with the peridotite, amphibolite schist, porphyroids, etc. crystallisation of molten silicates. Biodte doesn't melt, h is a hydrous mineral that decomposes at Similarly, this book shows that porphyroidal textures about 800°C and plagioclase melts in the range developed by mobilisation of ordinary unconsolidated 1100°C (albite) to 155rC (anorthite) in accord with argillaceous sediments are similar to the crystalline its composition. Feldspars all have melting points at textures developed by mobilisation of limestone, least 300°C higher than temperatures at which sandstone, chert, jasper, banded iron formations, biotite is stable. mineral lodes, greenstone, verde marble, porcelanite, etc. However, this is sometimes also "put off by The way the orbicules are formed by concretion of those who can only defend their present beliefs by hydrous chlorite and montmorillonite deposited in total disinterest in the puzzling things we see. successive layers round a synerectic nucleus can If our existing theory and belief does not fit with now be explained by the behaviour of colloidal what we see, is our present level of understanding particle systems and the surface chemistry of the defective or is it the observation that is wrong? Is it original hydrous sedimentary components. intellectually honest if we simply ignore any problem that could be central to our understanding of rocks and mineral deposits? WHY NOT TRY TO EXPLAIN PUZZLING PATTERNS? The intriguing pattem of fine concentric bands of dark biotite and white plagioclase forming the ovoidal nodules illustrated here is a classic occurrence of granite orbicules. This slab on display at the museum of the Geological Survey of Finland in Helsinki, is from Kangasala.

The altemating plagioclase and biotite rims have developed around a variety of different cores including a schist fragment. The size of each orbicule is different, the rim pattem in each is different, and the cores are individual to each spheroid. They show evidence of former plasticity, flexible rimming layers fold away from inner bands and some of the orbicules are broken or their outer layers eroded. In some occurrences, the core granite is mobilised to form a coarsely crystallised irregular intrusión outward through the pre-existing rim pattern that endoses it. DEMONSTRATED ECONOMIC ADVANTAGE Discovery of the authigenic nature of the This report did not identify participants by porphyroid underiying the Peko gold- ñame but it provided information on copper orebody at Tennant Creek led to the exploration costs per find and the gross realisation that synerectic desorption of valué of metal found per exploration dollar adsorbed trace nnetal species during expended to find it. Geopeko's exploration diagenesis and consolidation of this large costs included ore definition drilling to the volume of porphyroidal rock had been the point where a decisión could be made to source of the economic mineralisation. mine the deposit. Its internal figures at the Recognition of this relationship between time showed $4,254,507,000 in gross syneresis in porphyroidal source rocks and metal valué had been discovered for a economic mineralisation resulted in the total exploration cost of $15,464,061. This discovery of five new mines (locally) from is a ratio of 275.12, which clearly identified the first fifteen prospects drilled. the position of that company in the Applied generally this new understanding comparativo report. led to further discoveries. By 1975 an additional new mine and a total of thirty- The significance of the comparison of three mineable orebodies had been success rates for that period is that discovered at Tennant Creek, a new mine Geopeko's outstanding cost effectiveness for an additional tUngsten orebody at King was achieved in relation to nine new mines Island, and four major orebodies resulting in in quite different localities. Most other new mines at Parkes, NSW and Ranger in successful explorers had found only one the Alligator Rivers province, NT. This mine in relation to their total expenditure. outstanding success established a significant lead in cost effective exploration The application of a better understanding of and attracted the attention of competitors. ore forming processes has obvious advantages in mineral exploration. The cost Sir Roderick Carnegie, Chairman, and Mr. effectiveness demonstrated by the John Collier, executive responsible for McKinsey report later resulted in the offer of exploration in CRA, commissioned research contracts to further test and independent consultants to compare the effectiveness of Australian mineral develop the original findings and to exploration programs and identify the introduce the new concepts to CRA-RTZ factors leading to success. exploration staff. Because of the demonstrated potential economic McKinsey & Company, Inc. Management advantage, the initial two-year contracts Consultants, New York, conducted a survey were exclusive and confidential. CRA was and furnished a report dated 20th June 1975 never opposed to eventual publication but entitled "Successful Management of Mineral Exploration in Australia". Participating sought to introduce the new principies to companies were provided with copies. their own exploration teams first.

Page 2 from the report "Successful Management of Mineral Exploration in Australia" by McKinsey & Company, Inc. Management Consultants, New York, is reproduced on the opposite page.

18 Extract from "Successful Management of Mineral Exploration in Australia", a report by McKinsey & Company, Inc. Management Consultants, New York, 20th June 1975: -

For the purpose of this survey, we have defined success in exploration in three ways:

f High gross metal valué per dollar of exploration

y Low exploration cost per find

y High ranking by peers in response to the question, "Who are your best competitors? "

Not surprisingly, the above three measures have a fair degree of correlation. This makes it possible to distinguish between the more successful and the less successful companies with a fair degree of confidence. Since we were mainly interested in success, our sample of companies tends to be biased towards the enes who have been reasonably successful (Exhibit 1).

"EXHIBIT 1" Measures of success GROSS METAL VALUE/EXPL. $ COST/FIND (SIVIILLION) RANKING BY PEERS Partici• 50 100 150 200 20 40 60 80 10 pants A 3 B 3 C • • D —1 E F j G H _i • I • • J D K • L M

McKinsfy & Company, Inc.

Note: - Geopeko (A) was the most the most successful explorar in terms of cost effectiveness using various exploration techniques in different environments. Its low "RANKING BY PEERS" reflects a lack of realisation by competitors that new criteria for the selection of exploration áreas and prospects were being applied. Companies attempting to introduce the new work to their exploration staff regarded this as a competitive advantage but both companies allowed progressive publica- tionn of significant scientific results to allow earth scientists generally to develop this exciting new avenue of investigation.

19 John Elliston has been involved in the conduct and supervisión of mineral exploration and research for over 45 years. After early experience as a chemist and consulting geologist he joined a progressive mining company in 1956 where studies led to develop• ing an understanding of the nature and origin of the local mineral deposits. His work and application of the new concepts led to a series of exploration successes and the opening of these new mines resulted in dramatic growth of the company. He was appointed to the board of the parent company in 1969. As an Executive Director he was responsible for the activities of a number of technical subsidiarles including Geopeko Limited and he also became a director of several large mining and industrial companies. He directed the exploration and mine geological teams who went on to develop further significant Australian resources. Throughout John Elliston's 28 year career with Peko-Wallsend Limited there had always been a high degree of academic and research involvement. On leaving that company in 1984 he then undertook a series of research contracts for CRA Exploration Pty. Limited which provided the opportunity to further develop, record, and apply the principies of petrogenesis and ore formation resulting from John N.W. Elliston, AM, BSc.(Chem), BSc the earlier discoveries. He has prepared 103 Hons.(Geol), FAusIMM, CPGeo, MMICA. scientific papers and reports but as most of these relate to commercially sponsored research, only 25 papers have been published. Significantly improved cost effectiveness of the exploration for which he was responsible was recognised by an externally commissioned and independent consultants analysis in 1975. His contribution to the Australian mining industry was acknowledged by a civil award in 1981.

20 KEY POINTS FROM THE EXTENDED STUDIES

The author has coordinated the work of many large volumes of consolidating re-textured scientists in both the earth sciences and chemistry in sediment, desorption of trace metal hydroxy- order to assemble sufficient basic data to adequately sulphides and hydroxides from ordered support the far-reaching conclusions. Key points particle aggregates (synerectic accretions) from both the accompanying documents and content releases ore mineral dispersions for transport of the book include: - and concentration by the natural outflow of brines as the sediments lithify. 1) The immense physical and chemical energy required to breakdown and erode uplifted 6) It is concluded that granite magmas do not crystalline and lithified rocks produces large melt by fusión and re-crystallisation of volumes of sediment particles in which the pre-existing rock. Melting and liquefaction energy is retained as chemical energy and the of large volumes of hydrated sedimentary surface energy of the enormous surface área materials is like that of other particulate within small particle systems. systems in which the cohesión of the visco-elastic solids (gelatinous materials) 2) Because of the alkalinity and excess volume depends on electrostatic and van der Waal's of sea water, subaqueous sediment attraction between particles. movements, and the extremely long soakage times, further breakdown and chemical 7) Elevation of temperature commensurate with hydration of sediment grains and silicate par• the geothermal gradient for deep burial in ticles continúes under the sea. thick sediment accumulations provides the thermal agitation to weaken interparticle 3) High-energy particle systems have many linkages. The material softens to slurry by properties and attributes that are due to the 'melting' or because the Bingham yield point size and shape of the particles, their chemical is lowered by elevated temperatures at depth, composition, and the atomic geometry of it more readily reverts to a non-Newtonian their surfaces. Most features preserved in fluid or more fluid gel in response to the rocks result from only fourteen of the earthquake shocks. characteristic properties and behaviour of charged particles. Many of these 8) Earthquakes can trigger successive episodes characteristics are not new to geologists and of thixotropic liquefaction or pasty flow and soil scientists. each incidence of flow disrupts, re-aggregates and refínes accretions. More hydrous mobile 4) Many rock textures and structures including components of the semi-fluid "magma" occurrences of economic mineral deposits physically sepárate (flow out) as lighter have resulted from sequential or concurrent (water-rich) fluids of lower viscosity to form interactions between the charged particles of dykes, veins, and associated bodies of hydrolysed sediments. These interactions are different composition. described as colloidal processes and they 9) Subsequent chemical dehydration reactions occur as natural sediments dehydrate, lithify, by which metastable high-energy and ordered and progress to the low energy crystalline colloidal particle aggregates crystallise are state. exothermic. Crystallising rock masses reach 5) The most significant discovery from this much higher temperatures and the higher research appears to be the recognition and temperature non-saline water produced as a confirmadon by experiment of the formation reaction product results in alteration of of accretions in mobilised sediment pastes. In surrounding rocks.

21 Concretions form in particle systems before they become rocks! Each year several thousand tourists see these curious rounded boulders exposed on the beach at Moeraki near Timaru in the South Island of New Zealand. These giant carbonate concretions are weathered out of the limy shale at the back of the beach. Even if none of the tourists are able understand how they were formed in the shale, it is immediately apparent to every intelligent viewer that the high-energy limy sediment particles from the shale have been able to arrange themselves in the form of the massive spherical boulders. These carbonate concretions have a concentric structure indicating that growth was within the sediment after it was deposited. Equally, if any earth scientist were to visit the outcrop or view this pichare of the orbicular dolomite from Gunpowder Creek in NW Queensland, it would be realised immediately that the sedimentary materials comprising the dolomite were able to arrange themselves around the dolomitic shale fragments to form the orbicular pattem. Clearly, the orbicular stmcture was not formed as the sediment was deposited. It has developed later when the wet sediment was sufficiently cohesive to break into fragments yet the mud was still fluid enough for the rather thin fragments to be supported in it, moved relative to each other, and broken up by the movement. It is apparent that the orbicular layers have been deposited round fragments and groups of fragments after these existed in the sedimentary material. The orbicular layers are also part of the surrounding dolomite. The precursor sediment particles of the matrix have been able to arrange themselves in successive layers round the fragments.

A classic oolitic limestone from Short Creek, Missouri (Lindgren, 1933, p.267), also shows that the particles in the original limy mud were able to arrange themselves in concentric patterns and small nodules. These are indented where they have been pushed against each other indicating they were still soft yet able to break into pieces after they were first formed. With outstanding clarity, these three examples demónstrate that natural high-energy limy mud particles were able to assume these shapes and pat• terns that have now lithified and crystallised to rocks and rock minerals. The current physical chemistry of small particle systems by which orbicular and oolitic stmctures are formed in natural sediments is detailed in the accompanying e-book (pp. 113 to 128). They can only be formed in aqueous particle systems.

22 Concretions can only form in particle systems before they become rocks!

This section through a cannon ball size concretion from a siliceous porphyroid (technically a quartz latite) in the Mount Morgan district, Queensland, shows the typical concentric layering. The matrix is chert or crypto-crystalline silica that is formed by compaction and dewatering of particulate colloidal silica (naturally occurring impure silica gel). This concretion has been formed by the hydrated precursor silica particles in the same way as the limy mud par• ticles formed the Moeraki boulders.

This concretionary overgrowth round a schist fragment from the orbicular granite at Kangasniemi in Finland was first described by Sederholm in 1928 (p. 37). The specimen is on display at the museum of the Geological Survey of Finland in Helsinki. It has always been recognised that schists and the granites to which they grade, were derived originally from sediments. The layers of precursor sediment particles (hydrous chlorite and clay) in this orbicule have been deposited round the pre-crystalline core fragment in the same way as those round the dolomitic shale fragment from Gunpowder Creek (opposite).

Light coloured dykes intruding the Ellendale Granite are exposed in a cutting on the Tarago to Bungendore Road, N.S.W., 200m before the tumoff to Mt. Fairy. They have been called aplites but they do not contain typical fine-grained pink granite minerals. These dykes and veins are composed of very impure chert with a high content of kaolinite and sericite/chlorite and they contain oolitic concretions similar in structure to those in the oolitic limestone at Short Creek, Missouri. The particles in the originally intruded particulate colloidal silica-kaolinite-hydrous chlorite mixture were able to arrange themselves in the concentric patterns and small nodules observed.

If these porphyroidal rocks and granites have been derived from original re-liquefied sedimentary materials (mainly clays, colloidal silica particles, and hydrous ferromagnesian minerals), the occurrence of concretions plainly demonstrates that they crystallised from aqueous particle systems.

23 Accretions normally form in any mobilised fine-grained sediment paste

The accretion of colloidal particles in liquefied dense slurries and pastes is a simple, natural phenomenon. Fluid movement in a concentrated paste (charged particles in cióse proximity to each other) aligns the particles and brings them together so that van der Waal's attractive forces exceed the normal Coulombic repulsión between similarly charged particles. This repulsión normally keeps less concentrated colloids in metastable dispersión. Instead of repelling, there is a critical inter-particle distance at which the particles "lock on" to each other. Surface energy is reduced by the formation of ordered dense clusters. This porphyritic limestone from the Rosebery Mine in westem Tasmania has resulted from thixotropic liquefaction of the original semi-consolidated calcareous mud. The hydroxy-carbonate particles have formed ordered accretions that have now crystallised to the rounded, aggregated and broken calcite accretions illustrated. Clay-rich natural mud from a number of places has been passed through a fine meshed sieve and then re- liquefied to demónstrate the formation of accretions experimentally. The mud slurry illustrated is from the Waggarigee Dam in Tennant Creek, N.T. The inset on the right also shows a section through an accretion from the same series of experiments. One type of ordered packing is shown by the radial arrangement of very large (compared with individual particles) "books" of clay platelets round the synerectic accretionary nucleus. This accretion was clearly formed during the reliquefaction after sieving, which would have removed or destroyed any original 1 mm structure or lump of this size. Clay accretions in the other inset are from a later series of experiments undertaken at the University of Sydney. The occurrence of accretions in ordinary sediments is fijrther illustrated by these accretions of quartz from the matrix of a pipe-like intrusive sandstone body outcropping near the Mammoth Mine in Tennant Creek, N.T. The pre-consolidation polymeric silica of the matrix has aggregated into coarse globules to form porphyritic sandstone. This hydrated silica has then crystallised by chemical dehydration reactions or silanol to siloxane condensation. Central crystal cavities have developed in most of the larger accre• tions (inset). They are due to spontaneous synerectic contraction of the precursor polymeric silica compris• ing the nodule and final unimpeded crystal growth from the residual dispersión of monomeric and oligomeric silicic acids in the cavity fluid. Accretions crystallise to metamorphics, porphyroids and granites

Mobilised pelitic sediments crystallise to a wide variety of metamorphic, porphyroidal, and granitic rocks. This is because of their variable original composition, liquefaction at various stages of consolidation, and the conditions such as temperature, extent of hydrolysis, and the number times that liquefaction has occurred. This example of precursor jasper, chert, milky white, and 'blue' varieties of polymeric silica that were moulded together to form a siliceous accretion in what has now crystallised to schist, is from the Explorer 7 drilling at Tennant Creek, N.T. The large rounded illitic clay accretion that has now crystallised to microcline is from the Great Westem porphyroid at Tennant Creek. It has a well-developed syneresis crack pattem resulting from spontaneous shrinkage in the ordered close-packed precursor clay. These tubular shrinkage cracks are usually filled with chlorite, chert, or sericite but they may also contain some biotite, epidote, apatite, or iron oxides. Occasional characteristic oolitic patterns of circular concentric bands of sericite and fme-grained quartz have been found in the filled syneresis cracks (inset). Some of these oolitic stmcUires have cores of biotite or chlorite but the thin encircling layers of white mica cut across the grain boundaries of the quartz mosaic to which the precursor polymeric silica has now crystallised. The concentric concretionary bands were formed before the silica crystallised. Rapakivi granite texture in which most of the potassic feldspar ovoids are rimmed with plagioclase is recognised as inconsistent with the longstanding tra• ditional hypothesis that granite minerals crystallised by cooling the same minerals from a fluid molten condition. The origin of rapakivi texture including this example of classic Wiborgite from an omamental stone in Lienz, Austria, has remained as a mysterious unresolved problem. The formation of precursor accretions, their syneresis, and subsequent crystallisa• tion of ordered particle aggregates as now established by the current physical chemistry of small particle systems, completely resolves the problem. The illustration shows many of the potassic feldspar ovoids rimmed with darker plagioclase and the breaking and re-aggregation of the 'sticky' clay precursors into irregular and sometimes quite large composite clusters. Quite large rapakivi ovoids have been recorded and Wahl (1925, p. 47) records the occurrence of an exceptionally large rapakivi ovoid 27 cm in diameter! The mixture of ovoidal and irregular shapes and a wide range of sizes in the same matrix is evidence that these potassic feldspar crystals were not formed by melt cooling.

25 HUNDREDS OF PROBLEMATIC OBSERVATIONS ARE SIMPLY EXPLAINED BY USING CURRENT PHYSICAL CHEMISTRY!

The small synerectic hydroxy-sulphide gel core of this framboid from Hall's Peak Mine, NSW, was originally rimmed A syneresis crack pattern in an accretionary clay nodule in the with a concretionary layer of hydrated remobilised zone at Plum Mine is apparently filled with iron-copper sulphide particles that were chlorite and chert. Similar crack patterns filled with chlorite then overgrown by an outer layer of are commonly developed in the unweathered microcline mainly iron hydroxy-sulphide particles. feldspars as in this example from the Great Western From England and Ostwald, 1992, fig. porphyroid at Tennant Creek. 10, p. 393.

Concretions which are described as 'orbicular spherulites' occur in a gold bearing quartz vein from the Golden Plateau Mine at Cracow in Queensland. The central synerectic cores of these concretions are richer in chlorite and the 'cióse packed' concentric layers of further quartz and chlorite have precipitated round them from the surrounding gel. The quartz has crystallised radially from surfaces of the nucleus. 1 cm Successive layers clearly indícate that the con• cretionary structure and its concentric layers were formed before the quartz crystallised.

This concretionary quartz-magnetite was found in drill core through the lower part of the Peko diapiric ore pipe at Tennant Creek, N.T. The texture was formed by the precipitation of original lepidocrocite and polymeric silica around synerectic nuclei. This is a sol-gel transition rather than a chemical reaction. It is not precipitation from super-saturated solution. Later quartz veins that cut the oolites reflect the soft gelatinous nature of the precursors.

26 Parts of the massive haematite deposits associated with the mineralisation at the Olympic Dam Mine are completely oolitic. These polyrimmed oolites display the characteris• tic features of concretions. This large diapiric iron ore deposit has crystallised directly by the dehydration of precursor ferric hydroxide and the quartz it contains was originally a particulate amorphous gel of polymeric silica. 1 cm

The internally banded chert ovoids from the Black Angel porphyroid at Tennant Creek that were not concretions but considered to be accretions!

These plagioclase rims round a "granite ball" core close• ly resemble very large 'rapakivi' ovoids that have been described as having 'granite ball' cores mantled by plagioclase. The synerectic shrinkage and desorption of electrolytes and smaller montmorillonite particles from the precrystalline core aggregates is the same. However, this polyrimmed orbicule displayed in the museum of the Geological Survey of Finland built up most of the original smectite layers and a littie chlorite from the surrounding matrix by concretion. Syneresis of the formerly gelatinous core is indicated by its finer grained margin just inside the inner rim and by weakiy developed radial syneresis cracks filled with chlorite The concentric zones of inclusions in rapakivi ovoids which has now crystallised to biotite. are formed by addition of more illitic clay to earlier aggregations at the pre-crystalline stage. They often include complete rims or pieces of rimming plagioclase from the previous ovoids.

27 Using ttiis pdf e-boolc format with Adobe Reader Versions 6.0 or 7.0

The main headings and definitions in the boolt are listed in the BOOKIVIARKS. Click on text highiighted in blue to move to destination indicated and Previous View button to return. Clicl< on text enclosed in|blue rectanglesjto see enlargements or explanation of terms. Technical terms highiighted in magenta are explained or defined in the Glossary. Access to alphabetical sections of the Glossary is by the BOOKI\/IARKS. References highiighted in green are accessible with the BOOKMARKS.

The key to the origin of ore depositing fluids and the password for the file SED_ORES.pdf on this CD is: - synerectic desorption

2í CCI, 2008

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Elliston Research Associates Pty Limited (ACN 000 547 900) has been an Approved Research Organisation and registered research agency (No. R2002937 for 2005-2006) since Ist July 1984. The company warrants that the images reproduced in this e-book and associated documents are truc photographic records of the structures, textures and geological phenomena observed in the rocks, mineral deposits, drill cores and specimens at the locations recorded for each example. The company's image library has been assembled in the course of numeróos field studies to test the central hypothesis and scales or objects that have been included in the photographs indícate sizes. The company further warrants that the scientific method applied at all times in this research is through a program of systematic, investigative and experimental activities based on principies of current physical chemistry and rheology from hypothesis to practical testing of the hypothesis by direct observation and evaluation of factual data to reach logical conclusions.

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