Abstract

Professor R. Stoneley commented that the rocks seen approximately 100 km NW of Neyriz in Iran supported Dr. Hall's thesis.

In an analogous regional position along the same geotectonic zone, sedimentary ‘mélanges’, which represent at least 2 olistostrornal slumps and locally contain pillow lavas, are overlain by a sheet of highly serpentinized peridotite. There are no intervening ‘flysch’ deposits in this area, but the serpentinites enclose masses of marble and variably metamorphosed schists. It is beyond doubt that these rocks were emplaced from a north-easterly direction above a deep water trough within the Arabian continental margin in the late Senonian.

A further mélange zone passing some 30–40 km to the NE marks the separation of the Arabian–Zagros continental shelf from the central Iranian continental block: large masses of Maestrichtian to Lower Miocene limestones of varying facies lie in a contemporaneous argillaceous and arenaceous matrix and basic igneous rocks are also present. This further mélange was mobilised in the early Neogene, probably at the time of collision between the continental blocks.

In reply, the Author thanked Professor Stoneley for his comments. It would be interesting to know more of the age and nature of the metamorphic rocks in the Neyriz region; so far, high-pressure metamorphism is unrecorded in the Zagros. ‘Paired’ mélanges, often ophiolitic, appear to be a feature of this geotectonic zone. The structurally lower mélanges and associated rocks were emplaced on the Arabian continental margin in the late Cretaceous, at the same time as ophiolite obduction elsewhere along the

First Page Preview

First page PDF preview
You do not currently have access to this article.