Abstract We report erosion rates determined from in situ produced cosmogenic 10 Be across a spectrum of Australian climatic zones, from the soil-mantled SE Australian escarpment through semi-arid bedrock ranges of southern and central Australia, to soil-mantled ridges at a monsoonal tropical site near the Arnhem escarpment. Climate has a major effect on the balance between erosion and transport and also on erosion rate: the highest rates, averaging 35 m Ma −1 , were from soil-mantled, transport-limited spurs in the humid temperate region around the base of the SE escarpment; the lowest, averaging about 1.5 m Ma −1 , were from the steep, weathering-limited, rocky slopes of Kings Canyon and Mt Sonder in semi-arid central Australia. Between these extremes, other factors come into play including rock-type, slope, and recruitment of vegetation. We measured intermediate average erosion rates from rocky slopes in the semi-arid Flinders and MacDonnell ranges, and from soil-mantled sites at both semi-arid Tyler Pass in central Australia and the tropical monsoonal site. At soil-mantled sites in both the SE and tropical north, soil production generally declines exponentially with increasing soil thickness, although at the tropical site this relationship does not persist under thin soil thicknesses and the relationship here is ‘humped’. Results from Tyler Pass show uniform soil thicknesses and soil production rates of about 6.5 m Ma −1 , supporting a longstanding hypothesis that equilibrium, soil-mantled hillslopes erode in concert with stream incision and form convex-up spurs of constant curvature. Moreover, weathering-limited slopes and spurs also occur in the same region: the average erosion rate for rocky sandstone spurs at Glen Helen is 7 m Ma −1 , similar to the Tyler Pass soil-mantled slopes, whereas the average rate for high, quartzite spurs at Mount Sonder is 1.8 m Ma −1 . The extremely low rates measured across bedrock-dominated landscapes suggest that the ridge–valley topography observed today is likely to have been shaped as long ago as the Late Miocene. These rates and processes quantified across different, undisturbed landscapes provide critical data for landscape evolution models.

ABSTRACT The Petermann and Alice Springs orogens are late Neoproterozoic to early Cambrian and middle Paleozoic intracratonic fold-and-thrust belts that shaped the Amadeus Basin in Central Australia. Displacements during both orogenies were accommodated in the footwalls of crustal-scale fault systems. The deformational style is characterized by basement-involved triangle zones in which displacement is partitioned into two mechanical units. A lower succession is characterized by basinward thrusting and an upper succession with hinterland-directed displacement. The interleaving of basement and cover units within the basin-directed wedges is a reflection of the relatively low mechanical contrast between cover successions and basement. North-vergent shortening during the Petermann orogeny exceeded 100 km, the bulk of which was accommodated by dramatic thickening, which led to burial of the Amadeus Basin sequences deeper than 20 km. Despite the thickening, there was little foreland-basin development, suggesting that the lithosphere may have been too weak to form a long-wavelength flexure. Along the northern margin of the Amadeus Basin, the Alice Springs orogeny was associated with as much as 50 km of shortening that can be resolved into two phases: (1) south-directed, basinward overthrusting of a basement wedge and (2) underthrusting that led to the development of a large-displacement north-vergent passive back thrust within the northern Amadeus Basin. This back thrusting led to the formation of structural hydrocarbon traps that developed along the southern flank of a progressively narrowing and deepening foreland flexure. Our study provides a kinematic framework for basin-shaping deformation along the margins of the Amadeus Basin and suggests that future hydrocarbon exploration in the Central Australian basins should assess the implications of the style of basement-cover interaction, as highlighted by the structural styles of both the Petermann and Alice Springs orogenies.