Revision of the Stratigraphy

The U-Pb dates of detrital zircons in samples of the Goldie Formation collected from outcrops closer to the present coast near Mt. Markham in the Queen Elizabeth Range and in the Commonwealth Range along the south side of the Beardmore Glacier have a completely different distribution. Although the U-Pb dates of these zircons also have a polymodal distribution, they are strongly clustered between 645 and 520 Ma 

In addition, the U-Pb date of zircons in the gabbro of the Cotton Plateau (668 1 Ma) implies that Rodinia broke up somewhat later and that the rift valley between Laurentia and the East Antarctic craton began to trap sediment later than the previous interpretation of the evidence had indicated. The reassignment of the bulk of the Goldie Formation to the Starshot Formation of the Byrd Group also means that the contact between the inboard part of the Goldie Formation and the over-lying Shackleton Limestone is now presumed to be an unconformity. 

According to Myrow et al. (2002), the transition from the carbonate rocks of the Shackleton Limestone to the clastic rocks of the uppCT Byrd Group in the Holyoake-Cotton Plateau area (i.e., the Douglas, Dick, and Starshot formations) records the change from sedimentation along a passive continental margin to 

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