Rodinia refined or obscured: palaeomagnetism of the Malani igneous suite (NW India)

New palaeomagnetic data from the Neoproterozoic felsic volcanic rocks of th e Malani igneous suite (MIS) in NW India, combined with data from an earlie r study, yield a palaeomagnetic pole with latitude = 74.5 degreesN, longitu de = 71.2 degreesE (dp/dm = 7.4/9.7 degrees). A statistically positive fold test and remanences carried by typical high-temperature oxidation (deuteri c) minerals support a primary magnetic signature. U/Pb ages from MIS (771-7 51 Ma) overlap with those for granitoids and dolerite dykes from the Seyche lles microcontinent (mainly 748-755 Ma), and palaeomagnetic data for both e ntities can be matched with a tight reconstruction fit (Seychelles --> Indi a: Euler latitude = 25.8 degreesN, longitude = 330 degreesE, rotation angle = 28 degrees). In this Neoproterozoic time interval, MIS and the Seychelle s must have been located at intermediate northerly latitudes along the west ern margin of Rodinia, with magmatism that probably originated in a contine ntal are. The most reliable, dated palaeomagnetic data (+/- 756 Ma) from MIS, Seychel les and Australia require a crucial reappraisal of the timing and plate dyn amics of Rodinia break-up and Gondwana assemblage. These new data necessita te an entirely different fit of East Gondwana elements than previously prop osed, and also call to question the validity of the Southwest US-East Antar ctic and Australia-Southwest US models. The palaeomagnetic data mandate tha t Greater India was located west of Australia rather than forming a conjuga te margin with East Antarctica in the hlid-Neoptroterozoic. Break-up of Rod inia along western Laurentia may therefore have taken place along two major Neoproterozoic rifts: one leading to separation of Laurentia and Australia -East Antarctica, and the second between Australia and India. (C) 2001 Else vier Science B.V. Ah rights reserved.