Nature of magmatism and sedimentation at a Columbia active margin: Insights from combined U-Pb and Lu-Hf isotope data of detrital zircons from NW India

作者：Kaur Parampreet^*; Zeh Armin; Chaudhri Naveen; Gerdes Axel; Okrusch Martin

来源：Gondwana Research, 2013, 23(3): 1040-1052.

DOI：10.1016/j.gr.2012.07.008

• Aravalli orogen
• Detrital zircons
• U-Pb-Hf isotopes
• Late Palaeoproterozoic crustal evolution
• Columbia supercontinent

Detrital zircons from a Palaeoproterozoic quartzite, deposited between 1.85 and 1.82 Ga in the northern Aravalli orogen of NW India, show a distinctive age peak of ca. 1.85 Ga and variable, but largely subchondritic epsilon Hf-1.85 Ga between -1.3 and -21.0 corresponding to hafnium model ages of 2.5 to 3.6 Ga. These data indicate an important period of reworking of ancient (Eo- to Neoarchaean), strongly heterogeneous continental crust at this time. Prevalence of ca. 1.85 Ga subduction-related granitoids, almost identical U-Pb age spectra and epsilon Hf-t of detrital zircons in ca. 1.85 Ga metasedimentary rocks in the Aravalli orogen and the inner Lesser Himalaya indicate similar sediment provenances and thus a geological connection between these two terranes during late Palaeoproterozoic. All together, the data constrain a rapid succession of sedimentation, metamorphism and subduction-related magmatic activity and support the interpretation of an active geodynamic realm along the entire north Indian margin at ca. 1.85 Ga. Comparison of detrital zircon data in conjunction with published paleomagnetic data from north India and other crustal blocks of the Columbia supercontinent, additionally, suggest a close affinity of north India with Madagascar, the Cathaysia block of South China and South Korea during Columbia times.

• 出版日期2013-4