The Olympic Cu-Au province on the eastern margin of the Gawler Craton includes three major regions of hydrothermal alteration and mineralisation: Stuart Shelf basement (including the Olympic Dam Cu-U-Au deposit), Mount Woods lnlier and the Moonta-Wallaroo-Roopena region. Each of these regions contains high-, moderate- and low-temperature Fe-oxide rich alteration, Cu-Au+U mineralisation, and felsic to mafic Mesoproterozoic (-1590 Ma) intrusions of the Hiltaba Suite with or without coeval Gawler Range Volcanics. The three regions are interpreted to represent the 'footprints' of separate crustal-scale thermal anomalies. Three key hydrothermal alteration and ore mineral assemblages are recognised in the metallogenic province: (1) CAM: calcsilicate - alkali feldspar ± magnetite ± Fe-Cu sulphides (generally minor); (2) MB: magnetite-biotite + Fe-Cu sulphides; and (3) HSCC: hematite-sericite-chlorite-carbonate ± Fe-Cu sulphides ± U, REE minerals. Ore grade Cu-U-Au mineralisation is generally associated with the HSCC assemblage, which is paragenetically later than the CAM and MB assemblages in most deposits and prospects. The crustal level of exposure of the hydrothermal systems may vary significantly between and within the three mineralised regions. The CAM, MB and HSCC assemblages and associated Cu-Au mineralisation represent a possible spectrum of settings from deeper, higher temperature, shear-hosted environments to near-surface, low-temperature breccia and fault settings.

Геологическая структура, распределение и контроль железооксидно-медно-золотой минерализации в кратоне Гоулер, Южная Австралия: Часть I - Геологическая и тектоническая структура

The Archaean to Mesoproterozoic Gawler Craton hosts a range of economic mineral commodities, including Au (central Craton), Ag-Pb-Zn (eastern Eyre Peninsula) and iron ore of the Middleback Ranges. A major iron-oxide copper-gold province containing the world class Olympic Dam Cu-U-Au-Ag-REE deposits extends ~ 500 km along the eastern margin of the Craton, from the Mount Woods Inlier in the north to the Moonta-Wallaroo district in the south. This paper presents new advances in our understanding of the structure, deformation history and tectonic evolution of the Gawler Craton, which may lead to a better understanding of the distribution of these mineral systems. The Craton is subdivided into tectonic domains, each encompassing an area of crust containing similar lithological and structural associations. New tectonic events have been defined within the three major orogenic cycles of the Gawler Craton (the Sleaford, Kimban and Kararan Orogenies). The recent discovery that much of the craton comprises relatively juvenile Proterozoic crust has improved our understanding of cratonic evolution. We propose growth through accretion in magmatic arc settings along the eastern margin of an arcuate Archaean core at ~ 1850 Ma (Donington Suite), and along the southwestern margin at ~ 1680 Ma (Tunkillia Suite) and 1620 Ma (St Peters Suite). We suggest an alternative model to a largely anorogenic setting for emplacement of the Hiltaba Suite, an intracontinental, extensional back-arc, located behind a northeast dipping subduction zone, south of the Nuyts Domain, which produced the arc-related magmatism of the St Peters Suite.

The Hiltaba Suite magmatic event was widespread across the Gawler Craton, and is broadly associated, both temporally and in places spatially with a major mineralising event. At the Olympic Dam deposit, a close spatial and temporal association is recognised between its host rock, the Roxby Downs Granite, and iron-oxide copper-gold mineralisation. Other mineral prospects related to Hiltaba Suite magmatism include Tarcoola, Tunkillia, Myall, Sheoak, Barns, and possibly Weednana, and Menninnie Dam. The presence of Hiltaba Suite granites is an important factor for exploration companies in tenement selection.

This preface presents the background to this book, the second volume of the "Hydrothermal Iron Oxide Copper-Gold & Related Deposits - A Global Perspective" series, and briefly discusses the rationale for inviting the papers it contains, their format and what it is hoped the volume will achieve. It also offers some observations on the unifying characteristics of the iron oxide copper-gold family of deposits and what they may represent in a broader context.

Эффективность принятия решений при управлении процессами разработки месторождений нефти и газа в значительной мере определяется достоверностью гидродинамических расчетов показателей разработки залежей на стадиях анализа и проектирования. Важным условием обеспечения этого процесса является построение математических моделей фильтрации жидкостей и газа, адекватным образом описывающих свойства реальных систем нефтедобычи. При этом в связи с расширением диапазона изменения термодинамических и геологических характеристик месторождений углеводородов и стремлением к интенсификации нефтегазодобычи растет потребность в расширении класса рассматриваемых фильтрационных моделей. Процессы разработки нефтегазовых месторождений связаны с движением многофазных многокомпонентных сред, которые характеризуются неравновесными и нелинейными реологическими свойствами. Реальное поведение пластовых систем определяется сложностью реологии движущихся жидкостей и морфологического строения пористой среды, а также многообразием процессов взаимодействия между жидкостью и пористой средой. Учет этих факторов приводит к обогащению физического содержания моделей фильтрации за счет нелинейности, неравновесности и неоднородности, присущих реальным системам. При их рассмотрении выявляются новые синергетические эффекты (потеря устойчивости с возникновением колебаний, образование упорядоченных структур и т.д.), которые подтверждаются специально поставленными экспериментами и позволяют предложить новые методы контроля и управления сложными природными системами. Пластовая система представляет собой сложную динамическую систему для анализа, проектирования и управления которой необходимы подходы, основанные на принципах и методах теории больших систем [147]. В соответствии с принципом целостности для описания большой системы недостаточно одной, пусть даже самой изощренной модели. Необходимо использование целой иерархии моделей, способных адекватно описать различные уровни организации системы. В настоящей работе на ряде конкретных примеров (по И. Ньютону, "при изучении наук примеры полезнее правил") показано, как создается иерархия моделей подземной гидродинамики и как они взаимодействуют друг с другом. При построении математической модели реального объекта исследователь привлекает большой объем априорной информации, сформулированной в виде универсальных физических законов (например, законов сохранения массы, энергии, уравнений движения и т.д.), феноменологических и полуэмпирических законов (например, законов Дарси и Фурье в теории фильтрации и теплопроводности, Дарси-Вейсбаха в трубной гидравлике и т.д.), а также чисто эмпирических законов (например, формул, определяющих зависимость давления насыщения от температуры и мольного состава газа). К априорной информации относится также информация, содержащая данные об объектах, аналогичных рассматриваемому, а также интуитивные представления исследователя и заключения экспертов. Как правило, эта информация менее формализована, чем физические и эмпирические законы.

Книга содержит материалы специального научного симпозиума, посвященного геологии и генезису магматических рудных месторождений и происходившего в университете Стенфорда в США в 1966 г. В перевод включены те из них, которые представляются наиболее содержательными и интересными для геологов нашей страны. Читатели будут иметь возможность познакомиться с фактическими данными по важнейшим магматическим месторождениям и с представлениями исследователей о существенных сторонах процессов, определяющих условия формирования этих месторождений.

В книге освещаются месторождения знаменитого магматического комплекса Бушвельд в Южной Африке, месторождения хромитовых руд, титаномагнетитов и сульфидные магматические месторождения.

Наша страна располагает уникальными магматическими месторождениями, и информация о геологии и генезисе их классических зарубежных аналогов способна содействовать прогрессу в изучении и освоении этих исключительных природных образований. Книга представит несомненный интерес для геологов широкого профиля.

Phalaborwa is the second largest copper mine in the world and the largest in Africa. The orebody is hosted by the Loolekop pipe within the Phalaborwa Complex, and is also mined for magnetite, apatite, vermiculite with a large array of by-products including gold, silver, phosphate, rare earth elements and uranium. The Phalaborwa Complex intruded Archaean basement at the edge of the Kaapvaal Craton in early Proterozoic times (2060±lMa) and consists of concentrically zoned, multiple intrusions which decrease in age from the margin to the core. The outer parts are predominantly clinopyroxenites, which have been variably metasomatised. Younger pegmatoidal pyroxenites intruded at three centres, including Loolekop, where foskcritc and a banded carbonatite were also emplaced, followed by a transgressive carbonatite that intruded as the last magmatic phase along fracture and shear zones. Economic copper mineralisation is hosted predominantly within the transgressive carbonatite as disseminated grains and veinlets of chalcopyrite, with lesser bornite and cubanite. Magnetite is a primary igneous phase in all rocks and is paragenetically earlier than the copper sulphides. The quality and quantity of magnetite is zoned and its distribution is antithetic to that of copper. Ore fluids are high temperature, highly saline, CO,-rich, magmatic-water dominated brines. The Complex and the mineralisation are interpreted to be products of the interaction of multiple pyroxenitic to carbonatitic magmas and their volatiles, which were ultimately derived from decompression melting of metasomatised mantle during extension at a transition from thick Archaean to thinner post-Archaean lithosphere. The orebody at Loolekop has many features including its age, giant size, pipe-like form, low ore grade, minor and major element associations and ore-fluid properties that are consistent with it being a proximal endmember of the widely recognised iron-oxide copper-gold deposit group. As such it helps explain characteristics such as the pipe-like brecciation as well as the common siting of these deposits at craton edges or other lithospheric boundaries.

Felsic rocks of the Rooiberg Group, which constitutes the roof of the Bushveld Complex., host the discordant volcanic pipe and associated surrounding pyroclastic and sedimentary rocks, called the Vergenoeg suite. The volcanic pipe is situated at the crossing of strong aerial photo and magnetic lineaments, about in the centre of the four lobes of the Bushveld Complex in the Republic of South Africa.

The Vergenoeg suite constitutes of an uppermost stratiform sedimentary unit, followed by fragmental conformably stratified hematite and hematite-fluorite units. This is followed by a breccia agglomerate and then a basal unit of ignimbrites. A discordant volcanic pipe completes the suite. The Vergenoeg volcanic pipe has a vertical funnel-like shape. At the surface this is about 900 m in diameter, tapering sharply in depth to where it is still open-ended at more than 650 m. Horizontal zoning exists in the pipe, with a hematite-fluorite or gossan cap at surface, followed by a deeper zone of unoxidised magnetite-fluorite, then a magnetite-fayalite transition zone and finally a fayalite zone at the deepest levels. Fluorite, siderite and pyrite veins, dykes and lenses are present throughout all the zones. Contacts between zones are gradual but are sharp with the felsic host rock. Felsite breccias, cemented by fluorite, siderite and pyrite are found at depths.

The major Iron Oxide Copper-Gold (IOCG) deposits in Australia (Olympic Dam, Ernest Henry) are 'blind' deposits that were discovered under younger cover. Exploration for this style of mineralisation presents a new set of problems to the explorationist, and involves target definition applying criteria gleaned from work in known areas and extrapolating into new target areas.

Equinox applies a model for IOCG mineralisation principally derived from studies of known mineralisation in the Cloncurry region and the Stuart Shelf/Gawler Craton of South Australia. This model was initially applied in Australia, and was later extrapolated to Zambia in Central Africa and the Norrbotten region in Sweden.

The Lower Proterozoic succession in Northern Sweden, hosts a major iron oxide province with a widespread and diverse base metal sulphide mineralisation. A large amount of geological and exploration data exists, but fundamental questions remain regarding the distribution and relationship of the iron and predominantly copper rich sulphide mineralisation. Detailed field, isotopic, mineralogical, petrological, fluid inclusion and structural observations are now providing new data on this historically important and significant province. Genetic concepts can now be reassessed and specific deposits re-evaluated to investigate the interrelationship of base metal mineralisation, iron oxide deposits, rock alteration, metamorphism, orogenic cycles, structural development and igneous activity.

The Bayan Obo Fe-REE-Nb deposit is currently the world's largest REE resource. It has estimated reserves of up to 1500Mt of iron oxides (35 wt. % Fe), 48-1 OOMt REE (6 wt. % REE,03) and IMt Nb (0.13 wt. % Nb). The deposits are hosted in the Proterozoic Bayan Obo group sediments, mostly in dolomite marble, although the deposits themselves are principally Caledonian in age (555-420Ma). Fe occurs as magnetite and hematite, whilst the REE occur principally as monazite and bastnasite, although over 16 individual REE-minerals and 17 REE-bearing niobium minerals are also present. The deposits are accompanied by an alteration assemblage of apatite, aegirine, aegirine-augite, fluorite, alkali amphibole, phlogopite and barite. Albite and K-feldspar occur in the overlying slates and schists.

The deposits were formed by multistage hydrothermal replacement of marble during Caledonian subduction. The source of metals and fluids is uncertain, although carbonatites, alkaline igneous rocks, A-type granites and subduction-derived fluids have all been suggested as possibilities. Late stage, low salinity fluids were responsible for extensive modification of the deposit, and an overprint of sulphide and barite alteration. The deposits show many similarities in processes to others of the Fe-oxide class, but there are important differences including the absence of significant base metal sulphide mineralisation, no enrichment in U, and the absence of evidence for the involvement of hypersaiine brines in ore genesis.