THE PROTEROZOIC SUPERCONTINENT RODINIA - PALEOMAGNETICALLY DERIVED RECONSTRUCTIONS FOR 1100 TO 800 MA

Citation
Ab. Weil et al., THE PROTEROZOIC SUPERCONTINENT RODINIA - PALEOMAGNETICALLY DERIVED RECONSTRUCTIONS FOR 1100 TO 800 MA, Earth and planetary science letters, 154(1-4), 1998, pp. 13-24
Citations number
82
Categorie Soggetti
Geochemitry & Geophysics
ISSN journal
0012821X
Volume
154
Issue
1-4
Year of publication
1998
Pages
13 - 24
Database
ISI
SICI code
0012-821X(1998)154:1-4<13:TPSR-P>2.0.ZU;2-B
Abstract
Well-dated paleomagnetic poles for the interval 1100-800 Ma have been compiled for the Laurentia, Baltica, S (a) over tilde o Francisco, Con go and Kalahari cratons in order to construct apparent polar wander pa ths (APWPs) for this interval, Laurentia's APWP consists of a well-det ermined Keweenawan track for 1100-1000 Ma and a 1000-800 Ma Grenville loop. We use a counterclockwise APW loop for the Grenville poles based on ages for post-metamorphic cooling through similar to 500 degrees C for the Grenville Province between 1000 and 950 Ma, and the temporal and spatial similarities with Proterozoic counterclockwise APWP's for other cratons. Baltica's APWP is comprised of seven dated poles that d efine a similar loop, counterclockwise and hinged at 950 Ma, that can be superimposed on the Laurentian Grenville loop. This loop is also se en in the seven poles of the APWP for the combined S (a) over tilde o Francisco-Congo craton; superposition of these loops leads to a recons truction in which the S (a) over tilde o Francisco-Congo craton is to the south-southeast of Laurentia in present-day coordinates. A long 10 90-985 Ma APWP track for the Kalahari is in reasonable agreement with the roughly coeval Keweenawan track when the Kalahari craton is rotate d similar to 40 degrees counterclockwise away from the Congo craton wh ile remaining hinged at the Zambezi belt. The resulting Rodinia recons truction resembles those previously proposed on geological grounds for Laurentia, East Gondwana, Baltica, S (a) over tilde o Francisco-Congo , and the Kalahari craton. (C) 1998 Elsevier Science B.V.