Tracing Alpine sediment sources through laser ablation U–Pb dating and Hf‐isotopes of detrital zircons

Abstract

Alpine provenance studies based on conventional methods such as sandstone framework grain and heavy mineral analyses are now enhanced by improved techniques in laser ablation inductively coupled plasma mass spectrometry detrital zircon analysis. Although the conventional methods appear to have reached their limits of resolution in palaeogeographic problems, laser ablation inductively coupled plasma mass spectrometry U–Pb dating of detrital zircons adds the time dimension to the provenance analysis. Hafnium‐isotope ratios measured on dated zircons give further information on the origin of the magmas in which the detrital zircons have grown. This study reports detrital zircon U–Pb dating and Hf‐isotope results from sandstone formations related to rifting, drifting and subduction settings at different stages of the Alpine Tethys development. This study is a first evaluation of the correlation between U–Pb age and isotopic features of detrital zircons aimed at describing source terranes in different palaeogeographic domains in the Alpine Tethys area. Pan‐African/Cadomian (Ediacaran–Ordovician), Variscan (Middle Devonian–Carboniferous) and Post‐Variscan (Permian) detrital zircon populations are present in nearly all palaeogeographic settings, but in varying amounts. Single Mesoproterozoic and Palaeoproterozoic detrital zircons are found as minor populations. When comparing the northern and southern margins of the Alpine Tethys, the southern margin detrital sources are characterized mostly by a decreased occurrence or by the absence of Silurian–Devonian zircons. A major distinction between northern (Helvetic, North and Middle Penninic domains) and southern (Austro‐Alpine and South Alpine domains) detrital sources is the occurrence of Triassic zircons at the southern Alpine Tethys margin during rifting and subduction stage sedimentation. Hafnium‐isotope ratios measured on uppermost Permian–Triassic zircons from the South Alpine domain suggest a continental crust derivation of the hosting magmas, as expected in a continental rift environment. In the late stage of Alpine convergence (Late Cretaceous–Palaeogene), the Permian–Triassic zircons are reworked into basins situated on the northern Alpine Tethys margin.

Detrital zircon age patterns from turbidites of the Balagne and Piedmont nappes of Alpine Corsica (France): Evidence for an European margin source

“…Thus, an integration of the different analytical datasets applied to detrital zircons in sedimentary basins offers the possibility to assess the tectonic evolution history of the orogen from which the sediments were derived in terms of ages, rock types and source materials (Wysoczanski et al, 1997;Carter and Moss, 1999;Bruguier et al, 1997;Cawood et al, 2012). Detrital zircon age patterns and Lu-Hf isotopic analysis were recently used to unravel the origin of terrigenous sediments and the growth of the crusts in the Western Alps in a situation close to Alpine Corsica environment (Bütler et al, 2011;Beltrán-Triviño et al, 2013;Malusà et al, 2013Malusà et al, , 2016aManzotti et al, 2015Manzotti et al, , 2016Chu et al, 2016 and references therein; Anfinson et al, 2016).…”

Late Miocene provenance change on the eastern margin of the Yinggehai-Song Hong Basin, South China Sea: Evidence from U–Pb dating and Hf isotope analyses of detrital zircons

“…Therefore, the provenance of the sandstones in the Lingtou gas field remains unclear. Although conventional methods of determining provenance appear to reach their limits and cannot meet the needs of further hydrocarbon exploration, UePb ages add the time dimension to the provenance analysis (Beltran-Triviño et al, 2013). UePb dating of detrital zircon is one of the most widely used methods in provenance studies, especially combined with Hf isotopes (e.g.…”

Provenance of Upper Miocene to Quaternary sediments in the Yinggehai-Song Hong Basin, South China Sea: Evidence from detrital zircon U–Pb ages

“…Traditional petrography, heavy mineral analysis and sequence stratigraphic methods cannot distinguish the source area effectively, especially in the source complex regions. In recent years, sedimentary provenance technology has been improved by single grain radiometric dating of grain populations, for example detrital zircon U-Pb dating (Cawood and Nemchin, 2000;Fonneland et al, 2004;Morton et al, 2008;Beltrán-Triviño et al, 2013). Zircon as a kind of stable mineral can withstand the effects of weathering, erosion and thermal alteration (Cherniak and Watson, 2001;Košler and Sylvester, 2003), and possess a stable U-Pb isotopic system over a wide range of pressures, temperatures and fluid composition (Moecher and Samson, 2006;Zhao et al, 2013).…”