Provenance and rift basin architecture of the Neoproterozoic Hedmark Basin, South Norway inferred from U–Pb ages and Lu–Hf isotopes of conglomerate clasts and detrital zircons

Abstract

The Neoproterozoic Hedmark Basin in the Caledonides of South Norway was formed at the western margin of the continent Baltica by rifting 750-600 Ma ago. The margin was destroyed in the Caledonian Orogeny and sedimentary basins translated eastwards. This study uses provenance analysis to map the crustal architecture of the pre-Caledonian SW Baltican margin. Conglomerate clasts and sandstones were sampled from submarine fan, alluvial fan and terrestrial glacigenic sedimentary rocks. Samples were analysed for U-Pb isotopes and clast samples additionally for Lu-Hf isotopes. The clasts are mainly granites c. 960 Ma and 1680 Ma old, coeval with the Sveconorwegian Orogeny and formation of the Palaeoproterozoic Transscandinavian Igneous Belt (TIB). Mesoproterozoic (Sveconorwegian) ages are abundant in the western part of the basin, whereas Palaeoproterozoic ages are common in the east. Lu-Hf isotopes support crustally contaminated source for all clasts linking them to Fennoscandia. Detrital zircon ages of the sandstones can be matched with those from the granitic clasts except for ages within the range 1200-1500 Ma. These ages are typically found in the present-day Telemark, SW Norway. The sandstones and conglomerate clasts in the western part of the Hedmark Basin were sourced from the Sveconorwegian domain in the present SW Norway or its continuation to the present-day NW. The conglomerate clasts in the eastern part of the Hedmark Basin were sourced mainly from the TIB domain or its northwesterly continuation. The Hedmark Basin was initiated within the boundary of two domains in the basement: the TIB and the Sveconorwegian domains.

Evolution of drainage, sediment‐flux and fluvio‐deltaic sedimentary systems response in hanging wall depocentres in evolving non‐marine rift basins: Paleogene of Raoyang Sag, Bohai Bay Basin, China

“…For details on quantitative methodologies see Bridge and Tye (2000), Leclair and Bridge (2001), Bridge (2003), Bhattacharya and Tye (2004), Bhattacharya and Maceachern (2009 & Zhang, 1996;Wu, 2001), as well as our analysis of drainages, suggest that there were no paleo drainages from the northern NCC feeding the Raoyang Sag during the Es2 and Es1 intervals (Figures 4 and 8a). Abundant quartz arenite clasts in the sandstone units associated in this interval support the interpretation of significant sedimentary recycling of deposits within this interval (Lamminen, Andersen, & Nystuen, 2015; Figure 6c). Nearly 67% of the Paleozoic zircons (251-410 Ma) found in samples from this study appear to have a short columnar form, with a xenomorphic granular shape, showing apparent fragmentation, deformation and grinding characteristics with weak ring structures (Figure 6e).…”

“…Bishop (1995) and Mather (2000) both discuss the expansion of the hinterland drainage areas of disgorging streams resulting in sudden increases of sediments, versus stream-capture events resulting in sudden decreases of sediments. Lamminen et al (2015) suggest that changes of zircon age suites are all related to one another, with any decrease/increases in one age suite inducing a corresponding increase/decrease in other age suites. Comparing the paleo-drainage map with a modern drainage map in the NCC leads us to propose herein that the paleo-Daqing River captured a branch of the paleo-Yongding River.…”

Root zone of a continental rift: the Neoproterozoic Kebnekaise Intrusive Complex, northern Swedish Caledonides

“…from syn-rift sedimentary rocks occurring as xenoliths in the KIC. Detrital zircons from other late Neoproterozoic sedimentary rocks deposited in Iapetus-related rift basins along the margin of Baltica have yielded ages as young as 600 Ma (Bingen et al, 2005;Smit et al, 2011;Lamminen et al, 2015). Thus, even zircons with ages around 600 Ma may be inherited, and represent an earlier phase of rift-related magmatic activity.…”

The Sub-Cambrian Peneplain in southern Norway: its geological significance and its implications for post-Caledonian faulting, uplift and denudation

“…The infill of these basins is characterized by dominantly immature sandstones and conglomerates, probably derived from footwall uplift mountains, with additional fluvial sand that has been transported long distances (Bjørlykke et al 1976;Nystuen 1976aNystuen , 1987Lamminen et al 2011Lamminen et al , 2014. Shelf basins, such as the Engerdalen and Tåssåsfjället basins (Kumpulainen & Nystuen 1985), appear to have received sediments by extensive reworking from a much wider Baltic drainage region (Be'eri-Shlevin et al 2011;Bingen et al 2011).…”

“…Shelf basins, such as the Engerdalen and Tåssåsfjället basins (Kumpulainen & Nystuen 1985), appear to have received sediments by extensive reworking from a much wider Baltic drainage region (Be'eri-Shlevin et al 2011;Bingen et al 2011). Clastic zircons may even have been derived from 600-700 Ma granites bordering Baltica to the south and SW, transported during repeated cycles of deposition and reworking in the continental fluvial plains of Baltica before the supercontinent broke up (Lamminen et al 2014).…”