Discussion on the Lower Palaeozoic of Oman and its context in the evolution of a Gondwanan continental margin

Abstract

R. C. Buckley & N. A. Harbury write: We agree with the continental setting proposed for the ‘Lower Haima’ Group and Amin Formation as defined in Millson et al. 1996, and this review of Lower Palaeozoicstratigraphy is a valuable contribution to regional correlation in the Arabian Peninsula. Whilst we support the broad lithostratigraphic succession for the Haima Group presented in Millson et al. 1996, we have recently conducted extensive fieldwork in the Huqf region, and wish in particular to focus on the nature of the ‘Lower Haima’–Amin boundary and the palaeocurrents and provenance recorded within these sedimentary rocks. We believe that the basal sandstones (‘Lower Haima’ of Millson et al. 1996 ) should not be correlated with the Lower Haima of South Oman ( Hughes-Clarke 1988 ; Boserio et al. 1994 ) but should be included in the Upper Haima Group. In this discussion the ‘Buah Anticline’ area is as described in all previous publications (e.g. Ries & Shackleton 1990; Dubreuilh et al. 1992 ), and not as it appears on fig. 3 of Millson et al. 1996. Nature of the ‘Lower Haima’-Amin boundary. Millson et al. 1996 document prominent irregular unconformity surface between the sandstones and conglomerates of the ‘Lower Haima’ Group and the claystones and siltstones of the Amin Unit 1 (Upper Haima Group). We have been able to measure continuous sections across this boundary at three localities in the area (10 km SSW of L; 2 km south of K; and immediately south of locality N of Millson et al. 1996 , fig