The excursion to the Old Boolcoomata region of the Olary Domain, Curnamona Province, in South Australia presents most of the stratigraphy of the late Palaeoproterozoic Willyama Supergroup and evidence for its complex deformation during the ~1600 Ma Olarian Orogeny. The Curnamona Group is characterised by extensive albitisation of its dominantly psammitic and psammopelitic metasediments and intercalated felsic volcanics of the Abminga Subsuite, deposited in a rift basin at ~1720–1710 Ma. It was intruded by syn-rift A-type granite of the Ameroo Subsuite at ~1710 Ma. The Saltbush Group disconformably overlies the Curnamona Group, commencing with quartzite, psammite, calc-silicate and sulphidic metasiltstone of the Bimba Formation and overlying volcaniclastic Plumbago Formation (~1697 Ma), together comprising the Larry Macs Subgroup. This passes up into the dominantly pelitic Raven Hill Subgroup which contains exhalative quartz-garnet lenses similar to those in the broadly equivalent Broken Hill Group of the Broken Hill Domain. The Raven Hill Subgroup is the youngest unit intruded by the mafic Lady Louise Suite (~1685 Ma), coeval with mafic sills and dykes in the Broken Hill Domain. The Olarian Orogeny involved large-scale nappe stacking, thrusting and non-cylindrical folding. Deformation was probably continuous and progressive with overall north-west directed tectonic transport under amphibolite facies conditions, although metamorphic grade generally decreases to the north. The excursion area contains belts of different grade: the Outalpa Subdomain is lower amphibolite facies while the Bulloo Subdomain is mid- to upper amphibolite, accompanied by extensive migmatisation. S-type granites of the Bimbowrie Suite intruded late in the Olarian Orogeny, and are themselves in places deformed by the network of early Mesoproterozoic greenschist-facies shear zones that criss-cross the Curnamona Province, some of which were re-activated in the Cambrian Delamerian Orogeny.

Local sedimentary geology, resultant soil types and groundwater availability in the Clare Valley, which extends through the Mid-North region for 90-110 km north of Adelaide, are discussed in the context of suitability for vine-growing and quality wine production. The soils that have been mapped within the valley are divided into those formed on basement rocks and those formed on outwash sediments derived from basement rock highs. They can be acid, neutral or alkaline and loamy, clayey or sandy. There have been eleven soil zones identified in the valley, and twenty soil types. Each zone exhibits between two and five main soil types and between two and eleven minor soil types. Hence there is significant variability of soil types over a very short distance.

Excursion stops: Day 1 Saturday 16 July – Adelaide to Marree Day 2 Sunday 17 July – Maree to Kalamurina Day 3 Monday 18 July – Warburton River fossil sites Day 4 Tuesday 19 July – Kalamurina to Lake Palankarinna Day 5 Wednesday 20 July – Cooper Creek and Lake Palankarinna Day 6 Thursday 21 July – Lake Palankarinna to Brachina Gorge Day 7 Friday 22 July – Brachina Gorge to Burra Regional setting Stop 1 Piedmont slope Stop 2 Cambrian archaeocyath reefs Stop 3 Ediacaran–Cambrian boundary Stop 4 Ediacaran fossils Stop 5 Bonney Sandstone Stop 6 Aroona Valley Lookout Stop 7 Slippery Dip site Stop 8 Ediacaran ‘golden spike’ Stop 9 Stromatolite reefs Day 8 Saturday 23 July – Redbanks Conservation Park and back to Adelaide

The rolling hills, wheat paddocks and vineyards of the Mid-North region of South Australia conceal a geological transition between the Adelaide Hills and the Flinders Ranges. Here the landscape is subtly controlled by the Neoproterozoic bedrock geology, Delamerian deformational structures, neotectonics, and regolith development. The bedrock of the Mount Lofty Ranges, Mid-North and Flinders Ranges consists of Neoproterozoic and Cambrian sedimentary and minor igneous rocks deposited in a complex of rift and sag basins, traditionally known as the Adelaide Geosyncline (Sprigg, 1952; Preiss, 1987). Thin platformal equivalents overlying the eastern Gawler Craton comprise the Stuart Shelf, while the Torrens Hinge Zone is an openly folded zone of transition between the Stuart Shelf and Adelaide Geosyncline. In the Mid-North, rifting occurring at ~800 Ma produced regional north-south trending graben structures that became filled with very thick siliciclastic and carbonate successions of the Callanna Group and Burra Group, this deposition being interspersed by minor mafic and rare felsic magmatism. The Burra Group is unconformably overlain by the Umberatana Group, this sequence commencing with widespread glaciomarine and fluvioglacial deposits of Sturtian age. Subsequent Neoproterozoic sedimentation of the upper Umberatana and Wilpena Groups was less rift-controlled, and includes deposits of the Elatina glaciation of Marinoan age. Delamerian folding and thrusting in the mid-Cambrian involved northwest- to west-directed transport and sinistral transpression, and set up the tectonic framework for neotectonic reactivation when the Australian continent became subject to east-west compression in the Cenozoic. Ancient weathering surfaces and regolith profiles were uplifted and dissected, and terrestrial to marine Tertiary basins formed on both sides of the highlands, with Quaternary alluvial deposits flanking the ranges. The excursion will visit representative sections of the Callanna Group and Burra Group, Sturtian and Marinoan glacial deposits, evidence of Delamerian thrusting and folding, neotectonic reverse faulting, Cenozoic marine and terrestrial sediments and regolith profiles, and two of South Australia’s historic copper mines at Burra and Kapunda. Much of the visited region (the BURRA 1:250,000 map sheet area, bounded by latitudes 33°S and 34°S, and longitudes 138°00’ E and 138°30’ E) was mapped in detail by the excursion leaders during the period 1988-2001, and compiled map data (100K geology) is downloadable through SARIG.

The Adelaide Fold Belt was an elongate submeridional subsident basin that experienced at least five major rifting episodes. Commencement of rifting circa 827 Ma was accompanied by mafic intrusion and dyke emplacement. The Fold Belt comprises a thick Tonian to Cambrian rock succession that extends from Kangaroo Island to the northern Flinders Ranges. The Neoproterozoic portion of the Adelaide Fold Belt succession is subdivided, in ascending order, into the Callana, Burra, Umberatana and Wilpena groups. The Umberatana Group embraces the Sturtian and Marinoan/Elatina glaciations and therefore spans the Cryogenian. The succeeding Wilpena Goup is Ediacaran. The Adelaide Fold Belt as exposed in the Mount Lofty Ranges and Flinders Ranges records a crucial interval in the evolution of life and environments on Earth. The events documented in these relatively complete, and little deformed, Neoproterozoic and early Cambrian successions are the keys to understanding why, after 2.5 billion years of microbial life, there was a size revolution that saw the advent of large animals and plants that ultimately established the environmental limits that seem to have prevailed up until our own time. Fluctuations in stable isotopes recorded in these early formations suggest extremes of environment that restricted life to single-celled organisms. Whether the evolution of multicellular life in the Neoproterozoic was a product or a modifier of environmental extremes is still the subject of Gaia speculation. It may not be coincidental that the record of the Ediacara biota begins in the wake of the last ice age of truly global scale. Whether there was a snowball or slushball Earth prior to the explosion of animal life is still much debated. Interdisciplinary research programmes testing modes of Earth evolution will always require a return to field evidence. The aim of this excursion is to outline the key field evidence that forms a basis for current hypotheses about environment and evolutionary change during the explosion of animal life on Earth. Day 1 - Kangaroo Island: Emu Bay Shale Konservat-Lagerstätte and White Point Conglomerate archaeocyaths Day 2 - Cryogenian and Cambrian of Fleurieu Peninsula Day 3 - Adelaide to Flinders Ranges Day 4 - Brachina Gorge Geological Trail Day 5 - Parachilna to Ediacara fossil site on Nilpena station and Ediacara Conservation Park on Beltana station Day 6 - Ajax Mine archaeocyaths and AJX-M section, Mount Scott Range Day 7 - Blinman to Wirrealpa area Day 8 - Ediacaran-Cambrian boundary, Old Mern Merna railway siding

Northern Yorke Peninsula (NYP) is within the southern portion of the Olympic Domain of the eastern Gawler Craton, which is arguably the world’s most fertile IOCG belt. That such a belt existed was only realised when Western Mining Corporation (WMC) stepped northward in 1975, after many years of exploration with North Broken Hill Ltd in the the Moonta-Wallaroo Cu-Au Mining Field area. WMC’s discovery was the Olympic Dam deposit, thus the NYP represents a major step on the path to the recognition of the IOCG-U system there and the subsequent definition of the Olympic Domain. A number of conditions need to be met in order that an IOCG prone environment can exist. These include a suitable brine-prone host succession, a major thermal event including significant magmatism, and deeply penetrating fractures as channel-ways and sites for ore deposition (e.g. Hunt et al. 2007; Skirrow et al. 2007; Groves et al. 2010). These conditions are met in the Olympic Domain, and therefore also in NYP. The intention of this field trip, brief as it is, is to provide an understanding of the Palaeoproterozoic and Mesoproterozoic geology of the part of the Olympic Domain that includes the historic Moonta-Wallaroo mining area and the coastal exposure of Rex Minerals' Hillside Cu-Au Project.

As superb exposures of fossiliferous strata, refreshed by coastal erosion and winter storms and backing popular beaches in what is now suburban Adelaide, the coastal cliff sections in the Willunga Embayment have attracted the attention of naturalists and painters since the mid-19th century. For the stratigraphy and micropalaeontology that solved Adelaide’s problems of foundations and water supplies, they have been the key reference point. In the broader scene they offer something to two geohistorical enquiries, namely the birth of the Southern Ocean in the death of the Australo-Antarctic Gulf, and the impact of that development on the greenhouse-to-icehouse global transformation. The Saint Vincent Basin is approximately 15 000 square km in area, about 60% of which lies beneath Gulf St Vincent. Together with the Mount Lofty Ranges, it originated in compressive reactivation of ancient structures in the Middle Eocene, just as Australian-Antarctic separation accelerated. A series of arcuate faults broadly following the grain of Delamerian (early Palaeozoic) structures define sub-basins or embayments — wedge-shaped asymmetrical tectonic valleys: the Willunga Embayment, Noarlunga Embayment, and Golden Grove Embayment. The basin straddles the south end of the Torrens Hinge Zone, which lies between the Flinders-Mount Lofty Ranges and the Stuart-Spencer Shelf to the west. This zone is the ‘Great Valley’ of J.W. Gregory in 1906 and the ‘South Australian Rift Valley’ of Charles Fenner in 1927, with its sunklands, corridors and horsts. For essentially the same tectonic reasons, the Cenozoic basin has been denied full oceanic influence from the widening Southern Ocean owing to the position of Kangaroo Island. The modern account of the Cenozoic record begins with Glaessner’s marine micropalaeontology and stratigraphy in the 1950s (Glaessner, 1951, 1953; Reynolds, 1953; Glaessner and Wade, 1958; Wade, 1964), and continues with Lindsay’s (Lindsay, 1967; Ludbrook and Lindsay, 1969). The two decades 1950-1970 are outlined in McGowran (2012). Meanwhile, Campana and Wilson (1953) and Sprigg and Wilson (1954) produced the Geological Survey one-mile sheets. Ward (1966; 1986) described and ambitiously synthesised the geology, geomorphology and soils of the district. Cooper (1977, 1979) monographed the stratigraphy of the Willunga Embayment. Modern lithostratigraphy and mapping are to be found in Fairburn (1998, 2000) and Fairburn, Preiss, Olliver and White (2010). Jones and Fitzgerald (1984, 1986, 1987) discussed the mineralogy and significance of the unusual Priabonian silicas; James and Bone (2000, 2008) described the Palaeogene carbonates and silicas. A geological excursion to the Willunga Embayment is a flexible mixture of three components. The best known is walking the coastal traverse up-section, north to south, from Maslin Bay to Blanche Point and from Perkana Point to Aldinga Bay. A second uses vehicles from outcrop to outcrop and winery to winery and neatly brackets the embayment with the great unconformity in the north and the best view of the Willunga Fault in the south. Third is a walk to the far south beyond Sellicks Beach, to coastal outcrops and gullies exposing the neotectonic record but requiring attention to tide times.

This short field trip was designed to provide an overview of rocks of different ages in the greater Broken Hill area, as part of the Uncover Curnamona technical sessions held at the Broken Hill Resources Symposium 2015. It was run on Thursday 28 May 2015, led jointly by officers of the Geological Surveys of New South Wales and South Australia, this being work done as part of the Memorandum of Understanding that includes geoscientific collaboration between the two state surveys. The sites visited encompass some of the oldest rocks in NSW (Willyama Supergroup) through to the margins of some of the youngest sediments (mobile dunes of the Strzelecki Desert).

Recent exploration related to the South Australian Government's "Plan for Accelerating Exploration" (PACE) Initiative have resulted in a number of exciting exploration developments in the state. South Australia has long been known as being well endowed in metal-rich rocks of varying styles and ages. However, they often share one common ingredient - the prodigious Mesoproterozoc tectono-magmatic hydrothermal even at ca. 1600 - 1580 Ma in the Gawler Craton (Kararan Orogeny) and the Curnmaona Province (Olarian Orogeny) - part of a global-scale event. Many, but not all, of the state's metalliferous accumulations ranging from base metal mineralisation at Menninnie dam, IOCG deposits and Olympic Dam and Prominent Hill to magnetite rich Iron Ore deposits originated from, or were effected by, this event. Erosion or remobilisation of uraniferous basement of this age resulted ultimately in the genesis of much younger deposits at Mount Painter, Beverley and honeymoon. This excursion visits a whole range of mineral deposits and prospects that share this common thread.

The subject of this guidebook is the geology of the EATERINGINNA 1:100 000 sheet and its immediate surrounds. Field sites demonstrate the principal lithologies and geological relationships from this part of the eastern the Musgrave Province (Fig. 1). The Musgrave Province occupies a central position within Australia, and the EATERINGINNA 1:100 000 sheet is situated near the eastern end of the Musgrave Province and bounded by 26°S (SA-NT border) to 26°30’S latitude, and 132°30’E to 133°30E longitude. The Musgrave Province is a structurally controlled entity bordered on all sides by later basins (Figs 2–4). The contained rocks, the Birksgate Complex, represent the remnant of an early Mesoproterozoic volcanosedimentary basin (or basin complex). Due to the similarity of lithological assemblages Major and Conor (in Drexel et al. 1993) indicated that there was but one supracrustal succession, however isotopic evidence is now suggesting that there may be more than one. There is good evidence for an earlier depositional event approximating 1600 Ma (Gray, 1978), Maboko et al. (1991), Glikson et al. (1996), and there is some evidence for a second at about 1400 Ma (Wade et al., 2006). Subsequent to the depositional events the Birksgate Complex underwent a long and complex tectonic history, i.e. ~1200 Ma Musgravian Orogeny, ~1150 Ma development of Pitjatjantjara Supersuite (Kulgera Suite) charnockitic granites, ~1080 Ma intrusion of the Giles Complex at the base of the crust and generation of a second set of charnockitic granites (eg. Umutja Suite), local rapid exhumation for the Bentley Supergroup to be deposited at ~1060 Ma, extension at ~840 Ma recorded by the emplacement of the Gairdner Dyke equivalents, ~550 Ma the major compressional Petermann Orogeny that significantly contributes to the present day geomorphological grain, faulting during the ~380 Ma Alice Springs Orogeny. Brittle deformation has continued sporadically, and the region continues to be seismically active.

Corny Point is located on the northern coast of the southern Yorke Peninsula, South Australia (Fig. 1). Palaeoproterozoic basement is located only on coastal platforms in this region, being concealed inland beneath principally Quaternary sediment (Zang, 2006). Basement in the region consists predominantly of the 1850 Ma Donington Suite, a suite broadly adamelllite to granodioritie in composition with a subordinate amount of co-magmatic mafic lithologies. Metasedimentary lithologies are known from only a handful of occurrences across southern Yorke Peninsula, the principal being Corny Point. Here, the Corny Point Paragneiss is present, which comprises garnetiferous and migmatitic quartzo-feldspathic gneiss along with numerous metasedimentary rocks contained within boudinaged pods (Zang and Fanning, 2001). This guide presents details of geochemical, isotopic, geochronological and petrological investigations into the origin of both the Corny Point Paragneiss and the Donington Suite as a background to the ARC Linkage Field excursion, December 2006. The work presented here is largely from a study1 by A. Reid, L. Jagodzinski (PIRSA) M. Hand and D. Kelsey (Uni of Adelaide) with collaborators from GEMOC, Macquarie University (Hf data, N. Pearson). Data on the provenance of the Corny Point Paragneiss is from Howard (2006).

This field guidebook provides brief geological summaries to sites in South Australia that were visited during the 2006 Broken Hill Exploration Initiative pre-conference excursion. Figures show the location of the field area and approximate location of the geological sites. For a more detailed overview of the geology the user is referred to the draft report ?Geology of the Olary and Mulyungarie Domains, Curnamona Province, South Australia. 2006? (Conor, 2006). Radiometric ages quoted are from Page et al. (in prep.), unless specified otherwise. The geological site layout of this BHEI guidebook is different from that used in previous versions, in that the information for each site is compiled in the form of a fact sheet. The intention of this scheme is to enable the formation of a library of geological sites that can be continually updated and added to. The Curnamona Province is divided into the following eight domains: - Moolawatana Domain (new name) includes basement rocks outcropping in the Mount Painter and Mount Babbage Inliers, and a shallowly buried easterly extension of these rocks. - Erudina Domain (new name) is the deeply buried and poorly known basement beneath the Cambrian Moorowie Sub-basin. - Quinyambie Domain (new name) is the deeply buried basement beneath the Cambrian Yalkalpo Sub-basin. - Mudguard Domain (new name) in the Curnamona Province is characterised by a sheet of flat-lying, early Mesoproterozoic (~1580 Ma) A-type felsic and mafic volcanics (Giles and Teale, 1979) and minor unmetamorphosed sediments. - Olary Domain (renamed by Laing, 1996 from Olary Block) is recognised by a restricted development of the Broken Hill Group, and by the presence of the oldest known part of the Willyama Supergroup, the Curnamona Group. - Mulyungarie Domain (new name) is characterised by thick sulphidic successions, and is possibly transitional between the Olary and Broken Hill Domains. Almost entirely blanketed by younger sediments, the Mulyungarie Domain has poorly defined boundaries, apart from its eastern margin at the Mundi Mundi Fault. - Broken Hill Domain (renamed by Laing, 1996 from Broken Hill Block) is characterised by the maximum development of the lode-bearing stratigraphy of the Broken Hill Group. Much of the western boundary is defined by the Mundi Mundi Fault, but, at the southern end of the fault, the boundary diverges in a southwesterly direction (Crooks, 2001). The Broken Hill Domain thus crops out in the Broken Hill, Euriowie, Poolamacca, Mt Woowoolahra and Nardoo Inliers, as well as in the south-eastern and central eastern portions of the Kalabity Inlier. - Redan Domain is a region of high magnetic intensity lying south-east of the Broken Hill Domain, and it contains the oldest rocks known from the Broken Hill Inlier. Different aspects of geology of the Olary region were viewed during the two days of fieldwork, and the current understanding of the lithostratigraphy of the Olary Domain was explained to excursion participants. A prime aspect to which their attention was directed at the outset was to view the geology of the eastern part of Bimbowrie Station via some well-known geological sites. This is an area which was made classic by Sir Douglas Mawson (Mawson, 1912), and it has enriched the knowledge of students of geology ever since. In variance to previous field trips made in this area, a theme was followed that considered the potential for growth faulting to control facies distribution within the Willyama Supergroup, especially the westward extension of Broken Hill Group rocks into the Olary Domain. Demonstration of the presence of Broken Hill Group equivalent stratigraphy was extremely important because it countered the belief that this critically mineralised part of the succession is missing from the Olary Domain.

Numerous but small uranium prospects occur in the southern Curnamona Province and are described in this report. The source of the uranium mineralisation is related largely to partial melting of originally uranium-enriched Willyama Supergroup sediments and granitoids during the late stages of the Olarian Orogeny. uranium is concentrated in shear zones, fractures and pegmatites. A regional association with biotite-phlogopite±ilmenite-magnetite is evident. Significant sedimentary uranium accumulations have resulted from erosion of this enriched terrane. (e.g. Honeymoon Deposit and Goulds Dam Prospect).

The enigmatic Radium Ridge Breccias (Drexel and Major, 1987) of the Mount Painter Inlier in the northern Flinders Ranges have fascinated geoscientists since the first major attempt to understand the geology during and immediately after World War II. At this time, the Australian and British Governments were actively exploring the province for uranium, and a major effort was made in the Mount Gee and East Painter regions. A small amount of mining was carried out at East Painter. The resource was quoted at the time as being several million tonnes of low-grade mineralisation. The Oilmin Group and Transoil NL carried out an extensive scintillometer and drilling program during 1968-71, and defined a resource (excluding East Painter) of 3.8 Mt at 0.1% U3O8 in haematitic and minor granitic breccia. The primary uranium mineral was determined as uraninite (Youles, 1975). As well, the South Australian Department of Mines carried out a major field mapping program, including three diamond drillholes, during 1976-79. This was subsequently reported by Drexel (1980), and Drexel and Major (1987, 1990). More recent company exploration has expanded the known extent of the breccias, but has added little to the understanding of their origin. In this field guide the complex characteristics of lithological variants of granitic breccia, haematitic breccia, chloritic breccia, diamictite and the Mount Gee Sinter are well portrayed, with an accompanying summation of present ideas as to their origin, plus a mention of relevant rock age determination results. The Radium Ridge Breccias show many similarities to the Olympic Dam breccias (Youles, 1978, 1984). The epithermal (hydrothermal explosive) origin of the Radium Ridge Breccias (Drexel, 1980) was determined several years before a similar origin was determined for the Olympic Dam breccias, but a full understanding of the former is still lacking because little field exploration has been undertaken subsequently, and recent drilling has been mostly designed to upgrade known uranium resources. This field guide is designed to help geologists understand the breccias of the Mount Painter - Mount Gee area by providing locations where some of the typical, as well as unusual, lithologies can be seen. The 37 field sites discussed and illustrated in the field guide by selected outcrop photographs will highlight the difficulty of interpreting the breccias. The two-day driving-walking tour was developed from 1978 to 1984 to assist companies exploring for Olympic Dam style mineralisation. The Radium Ridge Breccias have an areal extent of almost 10 square km, and are sited in the central southern Palaeo- to Mesoproterozoic Mount Painter Inlier, with some north-easterly alignment over a distance of 11 km along an axis partly coincident with the Lady Buxton - Paralana Fault System. Surface expressions of individual breccias range from a few hundred square m to 3 square km for the Radium Ridge - Mount Gee - Mount Gee East body. Few drillholes have penetrated the full breccia pile, but the Mount Gee East and Radium Ridge prospects collectively contain at least 500 vertical m of clastics. In places, the matrix of the granitic breccia has been infused with or replaced by uraniferous haematite and chlorite to form distinct layers of haematitic and chloritic breccia. Diamictite (resembling Sturtian tillite in the adjacent Adelaidean sedimentary sequence) is a minor component of the breccias in the Mount Gee and Mount Gee East prospects. The granitic, haematitic and chloritic breccias, along with the diamictite, are collectively termed the Radium Ridge Breccias (Drexel and Major, 1987). Overlying and intruding the Radium Ridge Breccias and basement is the Mount Gee Sinter, a layered to partly clastic quartz-haematite sequence genetically related to the haematite matrix of the breccias. The two main outcrops are on Mount Gee and Mount Painter.

This 4-day excursion travelled north along the Flinders Ranges which are made of folded thick, Neo-Proterozoic Adelaide Geosyncline sediments, then passed over stable Archaean- Mesoproterozoic crystalline basement rocks of the Gawler Craton, which are covered along the route by thin flat-lying Neo-Proterozoic sediments of the Stuart Shelf - these unfolded sediments are the westerly extension of some of the folded sediments of the Flinders Ranges.

Adelaide lies towards the western margin of the Delamerian Fold Belt which extends across strike as far east as the Glenelg Province in western Victoria. Outcrop across this belt is very incomplete as most of the region of the Murray Basin is covered with Mesozoic and Tertiary and Quaternary sediments. The basement geology and structure concealed beneath the Murray Basin however is (tantalisingly) well defined by recent gravity and TMI imagery (Figs 3 & 4). In the Mt Lofty Ranges immediately to the east of Adelaide, the Late Neoproterozoic and Cambrian rocks are exposed because of relief and erosion created by Tertiary uplift. The excursion will undertake a transect across the belt, dwelling first on locally well exposed localities in the southern Adelaide Fold Belt, including coastal exposures on Kangaroo Island. We will then travel across the Murray Basin to examine the eastern margin of the belt in the Glenelg-Grampians region of western Victoria, where contact with the younger Lachlan Fold Belt is inferred. Between the SAFB and Victoria we will examine some isolated outliers of Delamerian felsic magmatic rocks in the Padthaway Ridge area.

This excursion was designed with the intent of introducing its participants to the geology, mineralisation and alteration styles present in the Moonta-Wallaroo region, through guided drill core inspection, a trip to the Wheal Hughes open pit mine, and field examination of granites and metasomatic rocks. To give attendees a better understanding of the regional tectonic evolution, the excursion group also visited some outcrops of late Palaeoproterozoic Wallaroo Group sediments, and middle Palaeoproterozoic Donington Granitoid Suite basement and paragneiss. During a two-day field trip highlighting the broad deformational history of the southeastern margin of the Gawler Craton and its mineral potential, geological features were visited and described that give evidence of: - migmatisation, metamorphism and folding events - deformation of granites and metasediments - Palaeoproterozoic bi-modal magmatism and back-veining structures - flow banding and hyaloclastics in the Wallaroo Group - Mesoproterozoic granite-mafic cumulate intrusions and related alteration; and - fault-controlled mineralisation styles. The excursion itinerary was: Day one: depart 8.00 am from Adelaide . 1.1 Wheal Hughes mine 11.00-12.00 am . 1.2 PIRSA Moonta core library 12.00-1.30 pm (lunch) . 1.3 Point Riley 1.30-2.30 pm . 1.4 North Beach 2.30-3.30 pm . 1.5 Oorlano quarry 3.30-4.00 pm . 1.6 Wallaroo mine ruins 4.00-4.30 pm . 1.7 New Cornwall mine 4.30-5.00 pm (motel, dinner) Day two: start 8.00 am from Patio Motel, Moonta Bay . 2.1 Port Victoria 9.00-11.00 am . 2.2 Corny Point 12.00-2.00 pm (lunch) . 2.3 Berry Bay 2.00-2.30 pm . 2.4 Gleesons Landing 2.30-3.30 pm . 2.5 Royston Head 3.30-4.30 pm . 2.6 Point Yorke 4.30-5.00 pm

This tour is concerned with aspects of the soils, geology, landforms, clays and mining on Yorke Peninsula, and likewise for the northern Adelaide Plains which are separated from the Peninsula by Gulf St Vincent. Both of these regions are among the most productive cereal-growing areas of South Australia, agricultural development having spread from Adelaide to these districts soon after the initial settlement of the State which took place in 1836. Sheep were first grazed on Yorke Peninsula in the early 1850s; but the main impetus to development came with the discovery of copper at Kadina (1860) and Moonta (1861), the subdivision of land for agriculture during the 1860s and 1870s, and the completion in the 1870s of railways linking the towns of Kadina, Wallaroo, Moonta, and Adelaide. The local production of copper was important until 1923, with mining ceasing in 1938; at one stage 77 mines were in operation. Specific conference topics that have been reprised, and related sites of interest visited during this tour, include: - Desert loam soil characteristics; - Dublin Waste Landfill Site; - Ardrossan Dolomite Quarry; - Pine Point kaolin deposit; - Klein Point Limestone Quarry; - Moonta copper mining district; - Wheal Hughes open cut Mine; - Association of halloysite with Cu-Au mineralisation at the Poona copper Mine; - Samphire soils of the upper Gulf St Vincent; - Saint Kilda Mangrove Walk; - Acid sulphate soils in the Barker Inlet area; and - Mineralogical and chemical changes to the University of SA tillage test track soil, following 10,000 cultivations!

This 5-day field excursion was mounted by the GSSA to inform government and industry participants about significant newly identified geological features within the central Gawler Craton which are the subjects of ongoing study. The itinerary chosen allowed inspection of Archaean ortho- and paragneisses, metabasalt and komatiite; Palaeoproterozoic banded iron formation, syn-Kimban foliated granite, syn-Kararan granites, and mineralised Palaeoproterozoic sediments; as well as Mesoproterozoic Hiltaba Suite granites, deformed granite within the Yarlbrinda Shear Zone, and a variety of Gawler Range Volcanics lithological features including a possible breccia pipe.

An integrated scientific research program addressing structural, sedimentological and metallogenic aspects of basin evolution has been conducted in the Kanmantoo Trough for the past three years. Joint collaboration in this program involved MESA, the University of South Australia and the University of Adelaide. Results of this ongoing research, and recent exploration within the Kanmantoo Trough, have the potential to change our current perceptions of the basin's genesis and its potential for hosting mineralisation. The purpose of this excursion was to re-assess the mineral potential of the Cambrian Kanmantoo Group in the light of this new research. Participants looked at the evidence for synsedimentary and structurally controlled Pb-Zn mineralisation and metamorphic Cu mineralisation within the Kanmantoo Trough, and also viewed the synsedimentary and synorogenic magmatism within the basin, thereby attempting to establish temporal and spatial links of this magmatism to mineralisation. A visit to the recently discovered stratabound Fe, Mn and P-rich gossanous outcrop associated with the base of the Karinya Shale at 'The Gorge' on Truro Creek was an important part of the excursion, because it shows that sequence boundaries in the Kanmantoo Trough are potential hosts for hitherto untapped mineralisation.

Guide covers an area extending from the western margin of Lake Torrens to Coober Pedy, and down to Ceduna. Characteristics of the silcretes in the Tertiary sequences, field relationships, and other criteria which might be used to interpret processes and environments of formation, are discussed. The workshop aims to generate discussion about silcretes, sediments, soils and landscapes, for co-operative research.