Sequence stratigraphy of the Palaeoproterozoic Nabberu Province of Western Australia

Abstract

Sequence‐stratigraphic analysis of the Nabberu Province, on the northern margin of the Yilgarn Craton, shows that it evolved during two megacycles and contrasting tectonic settings. Megasequence VIIIL is interpreted to record the north‐south opening and closing of a southern Andean‐type marginal sea. Four supersequences are rift, thermal‐subsidence and foreland‐basin stages of the megasequence. During Megacycle VIIIU, a major change in regional tectonics is implied by interpreted long‐lived sinistral strike‐slip faulting. The origin of that faulting is believed to be collision with the Pilbara Craton along an east‐southeast‐trending boundary transform fault. A strike‐slip basin, which is recorded by a composite supersequence, developed parallel to the boundary transform during the last stage of collision. Orthogonal collision between the Yilgarn and Gawler Cratons, and indentation of a northeast‐trending Pilbara‐Gawler continental margin, is implied by strike‐slip faulting and basin formation in the Nabberu Province. The strike‐slip basin was probably linked to a foreland basin to the southeast and south, parts of which may be preserved in the Albany or Fraser Provinces of the southern Yilgarn Craton.