IGA Lecture: Ian Somerville (UCD) – Coral reefs and biostromes from Carboniferous limestones of Morocco: faunal composition, palaeoecology and palaeobiogeographic domains

Ian Somerville will be giving the next IGA talk on Wednesday March 4th at 18:30 in the GSI – after the EGM at 18:15, of course

Abstract

Over the last decade, field work in Morocco investigating Lower Carboniferous (Mississippian) limestones has led to some significant faunal discoveries. In the Tiouinine area of north central Morocco a well exposed Upper Viséan coral framework reef has been identified, which is a first for the Lower Carboniferous in North Africa and possibly the world. It contains a rich assemblage of rugose and tabulate corals with support provided by calcareous algae. Its development comes at a time when reefs were slowly recovering from the mass extinction event in the Late Devonian. Rugose corals also formed laterally extensive biostromes in the Tindouf Basin in southern Morocco. A lower horizon is dominated by several species of Siphonodendron, however an upper biostrome at the top of the marine sequence contains a rich and diverse assemblage with several new species recorded. Interestingly, the age of this biostrome according to the foraminiferal dating is Bashkirian (Early Pennsylvanian) when many rugose genera and species were supposed to have become extinct. Clearly in Saharan basins they were able to survive in refugia. Another remarkable aspect of this younger biostrome is that it has been recognised in other Saharan basins in Algeria and Mali several hundred kilometres to the east and south, highlighting the widespread nature of shallow water platform carbonates on the northern margin of Gondwana.

IDS BIOGRAPHY

Graduated with BSc from The Queen’s University of Belfast in 1973 and PhD in 1977.

Lecturer in University of Ulster (Jordanstown) 1977-1979.

Joined Geology Department in UCD in 1979 as Lecturer in Palaeontology and Stratigraphy;

Senior Lecturer in 1996 and Associate Professor in 2007.

Research interests in corals, forams, conodonts, algae; carbonate sediments; coral reefs and mudmounds; Carboniferous basins in Europe, China and North Africa.