The Lower Palaeozoic Haima Group of the Sultanate of Oman comprises a sequence dominated by siliciclastic rocks up to several kilometres thick and broadly divisible into two groups. The sequence is known in outline from subsurface exploration, but recent field work on outcrops in the isolated Huqf area in east-central Oman has allowed a more detailed environmental interpretation of the succession. At the base coarse continental deposits of the Lower Haima Group rest unconformably on Precambrian–Lower Cambrian Huqf Group sediments (mainly carbonates and evaporites). The overlying Upper Haima Group comprises from base to top the aeolian dominated Amin Formation, the non-marine (coastal plain) to shallow marine (intertidal–subtidal) sediments of the Andam Formation, the non-marine to marginally marine Ghudun Formation, and the complex cyclical deep to shallow water deposits of the Safiq Formation.

Correlation of the Haima Group of Oman with the Lower Palaeozoic of the Arabian Peninsula, North Africa and Iran allows the evolution of the Gondwanan margin to be modelled. A widespread Lower Cambrian sequence of coarse alluvium, resting on peneplained Upper Precambrian–Infracambrian Huqf Group strata, represents the final stage of uplift and basin fill associated with the Late Proterozoic suturing of Arabia and adjacent plates which resulted in the formation of the Gondwanan continent. The overlying thick sequence of continental (fluvial and aeolian) sediments was deposited in a series of stable intracratonic basins across the Gondwanan landmass.

In the Mid- and Late Cambrian an overall sea-level rise led to the repeated development of shallow marine shelf carbonates across the margin. The subsequent replacement of this marginal carbonate sequence with a thick marginal to non-marine, sand dominated sequence may reflect the interplay of several events: the drift of Gondwana towards more southerly latitudes, a phase of strong tectonic rejuvenation during the latest Cambrian–Early Ordovician, and/or a eustatic fall in sea-level. Organic-rich marine mudrocks were deposited over much of the Gondwanan platform during a series of marked eustatic sea-level rises during the Mid–Late Ordovician and Early Silurian. In Oman no evidence has yet been found for the significant Late Ordovician glacial event recorded from North Africa and Saudi Arabia.

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