Abstract:In the present paper we apply a multi-technique approach (shale compaction data, seismic stratigraphy, isopach maps, moisture content of lignite, fission track data) to assess timing and amount of uplift and erosion of the Alpine Foreland Basin. The combination of the different techniques allows us to discriminate the effects of two different erosion events during the Neogene: (1) Seismic stratigraphy and isopach maps indicate a Karpatian (Early Miocene) regional tilting of the basin to the west (slope of about 0.5 %) and a minor erosion phase. (2) Moisture content of lignite combined with fission track data provides evidence for extensive regional uplift after deposition of Late Miocene fluvial deposits. It is estimated that sediments, 500 to 900 m thick, have been eroded. Shale compaction data derived from sonic logs indicates additional uplift of the eastern part of the basin (near the river Enns). Here, 300 to 1000 m of sediments were additionally eroded (giving a total erosion of about 1000 to 1900 m!), with a general increase of erosion thickness towards the northeast. While the regional uplift is probably related to isostatic rebound of the Alps after termination of thrusting, the local uplift in the east could be affected by Late Neogene E-W compressional events within the Alpine-Pannonian system. Both, tilting and erosion influence the hydrocarbon habitat in the Molasse Basin (tilting of oil-water contacts, PVT conditions, biodegradation).

The Molasse Basin represents the northern foreland basin of the Alps. After decades of exploration, it is considered to be mature in terms of hydrocarbon exploration. However, geological evolution and hydrocarbon potential of its imbricated southernmost part (Molasse fold and thrust belt) are still poorly understood. In this study, structural and petroleum systems models are integrated to explore the hydrocarbon potential of the Perwang imbricates in the western part of the Austrian Molasse Basin.The structural model shows that total tectonic shortening in the modeled north-south section is at least 32.3 km (20.1 mi) and provides a realistic input for the petroleum systems model. Formation temperatures show present-day heat flows decreasing toward the south from 60 to 41 mW/m 2 . Maturity data indicate very low paleoheat flows decreasing southward from 43 to 28 mW/m 2 . The higher present-day heat flow probably indicates an increase in heat flow during the Pliocene and Pleistocene.Apart from oil generated below the imbricated zone and captured in autochthonous Molasse rocks in the foreland area, oil stains in the Perwang imbricates and oil-source rock correlations argue for a second migration system based on hydrocarbon generation inside the imbricates. This assumption is supported by the models presented in this study. However, the model-derived low transformation ratios (<20%) indicate a charge risk. In

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The Greater McArthur Basin in northern Australia forms the world's oldest potential unconventional gas play. It comprises Paleoto Mid-Proterozoic sedimentary successions (i.e., the McArthur and Limbunya Groups) dominated by carbonate rocks (i.e., dolostones) deposited in various shallow marine to more restricted lagoonal and sabkha/playa evaporitic environments, while the associated organic-rich shales (i.e., the Barney Creek and Fraynes Formations) likely formed in relatively deeper and/or redox stratified depositional settings. Here we use a multi-proxy approach based on the isotope tracers of carbon ( 13 C) and strontium (87 Sr/ 86 Sr), and selected paleo-redox proxies (cerium anomalies: Ce/Ce*) to further constrain (i) temporal and spatial changes in the paleo-depositional environments and redox-structure of the basin, and also (ii) to test the applicability of the above isotope proxies for intra-basin correlations in the Greater McArthur Basin. This study presents the first continuous high-resolution  13 C and 87 Sr/ 86 Sr isotope records acquired from two drill cores: LV09001 and Manbulloo-S1 (located more than 400 km from each other), which intersected the above Proterozoic carbonate and organic-rich sedimentary sequences (i.e., the Barney Creek and Fraynes Formations, dated at ~1640 ± 5 million years) deposited in the central and western parts of the basin, respectively. Importantly, our composite isotope trends from the Greater McArthur Basin (based on data from LV09001 and Manbulloo-S1) show consistent and systematic variations in the carbonate-based  13 C, 87 Sr/ 86 Sr and Ce/Ce* proxy records that are tightly coupled to changes in the local depositional environments, the latter interpreted as oscillations between relatively open marine (suboxic to anoxic) and more restricted (anoxic to euxinic) conditions. Overall, our results indicate coherent basin-wide isotope patterns with characteristic isotope anomalies during the purported basin restriction (i.e., the deposition of organic-rich shales) the measured  13 C and 87 Sr/ 86 Sr trends shift to isotopically lighter and more radiogenic values, respectively. These coherent isotope trends acquired from LV09001 and Manbulloo-S1 cores thus supports the proposed connectivity of the central and western parts of the basin, and the suitability of our multi-proxy isotope approach for future intra-basin correlation studies in the Greater McArthur Basin.

The Neoproterozoic to Late Paleozoic-aged Amadeus Basin is a large (~170 000 km2) east–west-trending basin, bounded to the south by the Musgrave Province and to the north by the Arunta Block of the Northern Territory. Commercial oil and gas production is established in the northern part of the basin but the southern part is still a frontier exploration area. Vintage and new seismic reflection data have been used with well data along the south-eastern Amadeus Basin to construct a new structural and depositional model. Three major phases of deformation controlling deposition have been identified. The first phase is characterised by a SW–NE trending structural fabric and is thought to be older than the deposition of the first sediments identified above basement (Heavitree and Bitter Springs formations). The second phase corresponds to the Petermann Orogeny (580–540 Ma) and trends in a NW–SE orientation. The third phase is the Alice Springs Orogeny (450–300 Ma) and is oriented W–E to WNW–ESE in this part of the basin. This tectono-stratigraphic model involving three distinct phases of deformation potentially explains several critical observations: the lack of Heavitree reservoir at Mt Kitty-1, limited salt movements before the Petermann Orogeny (~300 Ma after its deposition) and salt-involved structures that can be either capped by the Petermann Unconformity and overlying Cambrian to Devonian sediments, or can reach the present day surface. Finally, this model, along with availability of good quality seismic data, opens new perspectives for the hydrocarbon exploration of the Amadeus Basin. Each of the tectonic phases impacts the primary petroleum system and underpins play-based exploration.