Revealing exhumation of the central Alps during the Early Oligocene by detrital zircon U–Pb age and fission-track double dating in the Taveyannaz Formation
Gang LuMaria Giuditta FellinWilfried WinklerMeinert RahnMarcel GuillongAlbrecht von QuadtSean D. Willett
9
Citation
87
Reference
10
Related Paper
Citation Trend
Abstract:
Abstract The late Eocene-to-early Oligocene Taveyannaz Formation is a turbidite series deposited in the Northern Alpine Foreland Basin (close to the Alpine orogenic front). Double dating of zircons with the fission-track and the U–Pb methods is applied on samples from the Taveyannaz Formation to reconstruct the exhumation history of the Central-Western Alps and to understand the syn-collisional magmatism along the Periadriatic lineament. Three samples from this unit show similar detrital zircon fission-track age populations that center at: 33–40 Ma (20%); 69–92 Ma (30–40%); and 138–239 Ma (40–50%). The youngest population contains both syn-volcanic and basement grains. Combined with zircon U–Pb data, it suggests that the basement rocks of Apulian-affinity nappes (Margna Sesia, Austroalpine) were the major sources of detritus, together with the Ivrea Zone and recycled Prealpine flysch, that contributed debris to the Northern Alpine Foreland Basin. Furthermore, the rocks of the Sesia–Lanzo Zone or of equivalent units exposed at that time presumably provided the youngest basement zircon fission-track ages to the basin. The Biella volcanic suite was the source of volcanogenic zircons. Oligocene sediment pathways from source to sink crossed further crystalline basement units and sedimentary covers before entering the basin from the southeast. The lag times of the youngest basement age populations (volcanic zircons excluded) are about 11 Myr. This constrains average moderate-to-high exhumation rate of 0.5–0.6 km/Myr in the pro-side of the orogenic wedge of the Central Alps during the late Eocene to early Oligocene.Keywords:
Basement
Fission track dating
Massif
Detritus
Foreland basins are important areas of exploration for petroleum in China.According to the basin construction and evolution,the foreland basins in central and western China can be divided into four types of assemblages including the presenile,the reconstructed,the regenerated and the superimposed.This paper discusses the geological conditions of accumulation,such as the assemblages of source rock,reservoir and seal,in different foreland basins based on the examples of northwestern Junggar foreland basin(the presenile),western Sichuan foreland basin(the reconstructed),northern Chaidamu foreland thrust(the regenerated) and southern Junggar foreland basin(the superimposed).The thermal evolutions of main source rocks are stated in the four types of foreland basins.The foreland development in the late period of Himalayan movement has an obvious control on the thermal evolution of source rocks in the Chaidamu foreland thrust(the regenerated) and southern Junggar foreland basin(the superimposed).
Hydrocarbon exploration
Cite
Citations (2)
Abstract Over the past few decades, Toarcian (Early Jurassic) black shale deposits of NW Europe have been extensively studied, and the possible global and regional mechanisms for their regional variation have been discussed. In this context, the black shales of the Northwest German Basin are still sparsely studied with regard to their palaeo-depositional history. This study aims to understand the connection between regional and global influences on the widespread Early Toarcian oceanic anoxic event by examining two wells covering the Upper Pliensbachian to Upper Toarcian sediments in the Northwestern German Basin. The core intervals were analysed using a multidisciplinary approach, including geochemistry, biostratigraphy and organic petrography. Marine palaeoenvironmental changes were reconstructed, and sediment sequences were stratigraphically classified to allow a supra-regional stratigraphic correlation. The results reveal complex interactions between sea level changes, climate warming, basin confinement, and Tethys–Arctic connectivity resulting in the Toarcian black shale deposition. Upper Pliensbachian sediments were deposited under terrigenous influence, shallow water depths, and predominantly oxic bottom water conditions. The deposition of black shale is characterized by algal organic material input and anoxic bottom water conditions. Strong correlations between water stratification, anoxia, and bioproductivity suggest that global warming and intensification of monsoonal rainfall, continental weathering, and increasing freshwater and nutrient inputs were the main factors controlling the formation of black shales. Prolonged deposition of OM-rich sediments in the NWGB may be related to intensified monsoonal precipitation in northern Europe and enhanced Tethys–Arctic connectivity at the serpentinum–bifrons transition. Graphical Abstract
Syncline
Mineral resource classification
Cite
Citations (8)
There are abundant oil and gas resources in the foreland basins in central and western China.Many outstanding successes of petroleum exploration have been obtained recently in that region.However,the exploration activity is rare because of the complex geology in the foreland basins.A classical foreland basin overseas is a linear depression located between the active orogen and stable craton.Nevertheless,in central and western China,there are mainly rejuvenated foreland basins resulting from convergence within the craton,related to the reactivation of old Tethys tectonic domains during the new Tethys stage.Therefore,there are many differences in comparison with the classical foreland basin abroad.The difference,due to the superimposition of foreland structures of two periods,is responsible for differences in basin geometry,in plate flexure and subsidence,in sedimentation,and in structural deformation.According to these differences,we have classified the foreland basins in central and western China into four types,i.e.,alteration foreland basin,palingenetic foreland basin,superposition foreland basin and caduceus foreland basin.They have different structural characteristics that determine the different reservoir features and the variable exploration potential for these three types of foreland basin.
Tectonic subsidence
Cite
Citations (18)
Thermochronology
Fission track dating
Cite
Citations (0)
Mineral resource classification
Historical geology
Cite
Citations (4)
Mineral resource classification
Cite
Citations (0)
Historical geology
Cite
Citations (1)
Tufa
Historical geology
Mineral resource classification
Cite
Citations (11)
Historical geology
Cite
Citations (0)
Abstract Modes in the frequency of distribution of fission track ages obtained from detrital zircon grains may prove characteristic of individual sandstone bodies, supporting the identification of the sources from which a particular flow of sedimentary detritus was derived and thus allowing new inferences to be made concerning palaeogeography. A computer program has been written and used to identify modes in the zircon fission track age distribution within two Lower Cretaceous sandstone samples from the Weald of southern England. Pronounced modes appear in one rock around 119 Ma, 160 Ma, 243 Ma and 309 Ma and in the other around 141 Ma, 175 Ma, 257 to 277 Ma and 394 to 453 Ma. The geological implications of these quite dissimilar zircon age spectra are discussed. It is concluded that they support the palaeogeographical models of Allen (1981) and indicate that the provenance of the first sample, from the Top Ashdown Sandstone member at Dallington in East Sussex, was almost entirely southerly, while that of the second, from the Netherside Sand member at Northchapel in West Sussex, was more varied, but predominantly westerly and northerly.
Fission track dating
Detritus
Cite
Citations (161)