The latest publication on the geology of South Australia represents the findings of over 150 years of geological investigations that have been conducted in South Australia. It is designed to provide the reader with a comprehensive account of the products of sedimentation, deformation, metamorphism and magmatic activity in regions throughout the State, with some theoretical insights into associated crustal processes. The ultimate aim is to stimulate exploration and research, and to provide a sound geological basis for the equitable use of the State's resources. The subject Volume 2 - The Phanerozoic - describes the younger geology of the State, created from 540 million years ago to the present day. The known Phanerozoic record of SA is preserved in widespread sedimentary basins, and by igneous and metamorphic rocks; only the Silurian Period is not represented. Rocks dating from this timespan in the Earth's history contain most of the State's oil and gas reserves, as well as a variety of industrial and extractive minerals, gemstones such as opal and diamonds, groundwater, and some metallic mineral resources. The volume also discusses geology in relation to the modern environment, covering topics such as groundwater contamination and land salinisation, geological hazards, and mining and the environment. Early Cambrian marine, carbonate-dominated sediments, including algal, archaeocyathan and tabulate coral reefs, were deposited as three eustatically controlled sequences in the Arrowie and Stansbury Basins after an hiatus in sedimentation in the Adelaide Geosyncline at the end of the Neoproterozoic. During the late Early Cambrian, the Kangarooian Movements led to local uplift, and to renewed rifting, ccompanied by mafic volcanism, in the eastern Stansbury Basin to form the Kanmantoo Trough. This was rapidly filled with thick, mainly siliciclastic marine sediments. In the Arrowie Basin, marginal marine redbed clastics were deposited, with one major marine incursion, and sedimentation continued into the Middle Cambrian. In the Officer Basin, early Palaeozoic strata were deposited in epeiric sea and non-marine, partly evaporitic environments. To the northeast (western Warburton Basin), mainly marine conditions prevailed. In the northern Officer Basin, thick Neoproterozoic and early Palaeozoic sediments of the Munyarai Trough and Birksgate Sub-basin were deformed and overthrust by crustal shortening mainly during the mid-Palaeozoic Alice Springs Orogeny. In the eastern Warburton Basin, Cambro-Ordovician marine to deltaic deposition was more or less continuous. Thrusting and folding were related to the Alice Springs Orogeny, and were followed by mid-Carboniferous granite intrusion. In the Adelaide Geosyncline, mostly greenschist facies metamorphism and compressional deformation of the Cambro-Ordovician Delamerian Orogeny commenced in the Fleurieu Arc, with northwest-directed thrusts and folds and cleavage development. In the eastern Mount Lofty Ranges, the early structures were refolded by more upright, approximately meridional folds, accompanied by amphibolite facies metamorphism. These are continuous with arcuate, partly transpressional folds of the Nackara Arc, with axes swinging from north-south to east-northeast. The fold arc is separated from a similar arc in the North Flinders Zone by the less deformed Central Flinders Zone, with domes and basins formed due to fold interference. Diapirs that had risen during Adelaidean sedimentation were reactivated. Syntectonic granitoids were intruded in the eastern Fleurieu and Nackara Arcs. Migmatite developed only within the Kanmantoo Trough. Undeformed felsic and mafic intrusives of Early Ordovician age, mostly near the western margin of the Murray Basin, are post-tectonic. Stratabound gold and base metals were concentrated during orogeny, and there is mineral potential associated with Cambrian volcanics and Delamerian intrusives. Late Palaeozoic sediments are preserved in basins controlled by northeast and northwest-trending structures, in glacially deepened valleys, and as thin mantles overlying the bedrock. Australia was still a part of Gondwana, and lay near the South Pole. Widespread glaciation affected virtually all of SA during the Late Carboniferous and Early Permian. Ice moved north-northwestwards across the State, scouring bedrock, overdeepening valleys and structural troughs, and plastering lodgement till over parts of the land surface. Deglaciation, commencing during the Asselian and complete by the Sakmarian, was accompanied by marine transgression into tectonic basins and isostatically depressed lowlands marginal to the icesheet. Meltwaters deposited considerable thicknesses of complex ice-contact, fluvioglacial and glaciolacustrine clastics. Glaciomarine sediments are preserved in the Denman, Arckaringa, Troubridge and Nadda Basins, and on the Padthaway Ridge. Regression, probably due to isostatic recovery, terminated deposition in the southern basins, but non-marine sedimentation continued in the north. With continuing climatic amelioration during the Early Permian, extensive peat swamps drained by rivers developed in the Arckaringa, Pedirka and Cooper Basins. In the latter they formed coally source rocks for a major oil and gas resource. Late Permian fluvial and flood-basin lake deposits are also gas-bearing in the Cooper Basin, but are unknown elsewhere. During the Mesozoic, an era of profound palaeogeographic change, global sea-level rise brought the last great marine transgression onto the Australian continent from the north. To the south, crustal extension and plate divergence created the Australian Southern Rift System, the separation of Australia from Antarctica, and the concomitant seaway south of the Australian continent. During the Triassic, subaerial weathering and pedogenesis were widespread. Low-energy terrigenous clastics were deposited locally, including coal swamp deposits, of which Leigh Creek Coalfield provides a major energy resource. During the Jurassic, crustal instability increased. Epeirogenic downwarp in the north was accompanied by deposition of a very widespread fluvial and lacustrine clastic blanket. This forms the aquifer for the huge Great Artesian Basin water resource, and is a major hydrocarbon reservoir. In the south, the early stages of extension and rifting caused the extrusion of basalt and emplacement of kimberlitic rocks, the latter a target for diamond exploration. Thick terrigenous (including coal swamp) deposits also began accumulating in local rift valleys. A major Early Cretaceous epicontinental marine transgression flooded the downwarped region in the north, depositing a blanket of fossiliferous mudstone and sandstone over the older non-marine clastics. The mudstones form the regional artesian aquiclude and locally host precious opal. In the south, conditions were still non-marine; thick terrigenous and volcanogenic sediments accumulated along the continental rift. By the mid- to late Cretaceous, the retreating sea, and resumption of terrestrial conditions with low-energy fluvial to lacustrine sediments, marked the end of widespread deposition in the north. To the south, a marginal marine influence appeared in the developing rift system, where thick, fine to coarse clastics continued to accumulate as Australia and Antarctica separated. In the South-East these sediments, together with the older rift deposits, are now commercial gas producers. Tertiary strata are widespread in SA, in gently downwarped cratonic basins, palaeochannels, and as thin sheets in the interior. Thicker successions accumulated in passive continental margin basins, where they unconformably overlie the Mesozoic rift basins. Relatively thin, fluvial and lacustrine, carbonaceous and arenaceous sediments characterise Palaeogene inland depocentres, whereas thin argillaceous and carbonate mudstones formed in Neogene lakes. These continental sediments were deposited on a subdued landsurface, with uplands as presently located. With continental separation, Eocene marine transgressions into the southern basins deposited marginal marine clastics and extensive, temperate-water, platform to deep water carbonates. The Tertiary climate changed from high-rainfall temperate to cool temperate during the Early Paleocene, to warmer during the Late Paleocene and Early Eocene, but still with rainforest. Aridity increased during the late Tertiary, with open woodland and minor forest pockets. Prolonged weathering of a generally subdued landscape which began in the Mesozoic continued into the Tertiary. Ferricrete formed during the Early Mesozoic-Middle Eocene, mid-Tertiary and late Tertiary, and silcrete during the Late Eocene-Middle Miocene and Late Miocene-Pleistocene. Tertiary sediments and weathered rocks contain important groundwater, coal, construction material, sedimentary mineral and opal resources. The Quaternary was characterised by marked climatic and sea-level oscillations, impacting on many geomorphological features. Barrier shorelines in the South-East represent successive Pleistocene sea-level highstands preserved by coastal plain uplift occurring over the past 800,000 years. In the interior, cold arid phases (times of dune building and evaporative playa deposition) alternated with periods of moister climate, increased stream discharge and greatly extended lake systems. Subaerial weathering has formed carbonate palaeosols and a variety of karst features. The Holocene sea transgressed the continental shelf, reaching its present level about 7000 years ago. The rising sea was followed by variable coastal neotectonic warping, resulting in geographically variable apparent sea-level regression over the past 6000 years. Holocene and Pleistocene shoreline deposits are used as datums from which neotectonic deformation is calculated. In the Port Adelaide estuary, significant land subsidence has been recognised as a result of human modification of the local environment. Geological hazards in SA are minor. Quaternary volcanism was restricted (to the lower South-East), and seismic activity is relatively low.