Middle Permian Faunas Research Articles

Late Pennsylvanian to Middle Permian revised algal and foraminiferan biostratigraphy and palaeobiogeography of the Lycian Nappes (SW Turkey): Palaeogeographic implications

Shallow-marine limestones associated to a Palaeotethyan seamount in the Teke Dere unit of the Tavas Nappe (Lycian Nappes, SW Turkey) are essentially latest Moscovian-Kasimovian in age. The wide range of microfauna and -flora of the series show biogeographic affinities comparable to those from the northern Palaeotethyan borders (especially to assemblages from the Carnic Alps, Urals, Donbass and Darvaz). These biogeographic affinities seem to persist until the end of the Early Permian (Artinskian). The Middle Permian fauna is represented by the typical warm, tropical assemblages known at the same time in the Palaeotethys (NW Caucasus, Darvaz, south China, Primorie and Japan), and in the Neotethys (Transcaucasia, central Iran, southern Afghanistan and Sibumasu). The new Kasimovian algae and incertae sedis Novantiellopsis elliottii n. gen. n. sp., Uvanellopsis fluegelii n. gen. n. sp., Tubiphytes rauzerae n. sp. and Asselodiscus davydovi n. sp. are described.

Origin and assembly of south-east Asian continental terranes

Abstract The pre-Tertiary continental core of south-east Asia is a composite of at least four tectonostratigraphic terranes; Sibumasu (Shan States of Burma, north-west Thailand, Peninsular Burma and Thailand, Western Malaya, and north-western Sumatra), Indo-China (east Thailand, Laos, Vietnam south-west of the Song Ma-Song Da zone and Kapuchea), East Malaya (including south-east Sumatra and Natuna) and south-west Borneo. These terranes are separated from each other by sutures, and are now joined to South China along the Song Ma-Song Da zone. Stratigraphic, palaeontological, and palaeomagnetic evidence suggests that all of these crustal blocks probably had their origin on the north-eastern margin of Gondwanaland where they formed part of a complex continental margin. The Indo-China and East Malaya terranes both have typical late Palaeozoic Cathaysian floras, which indicate that they were close to South China in the Permian. Stratigraphic studies in northeast Vietnam suggest that Indo-China and South China may well have sutured as early as the late Devonian to early Carboniferous. Carboniferous and Permian faunas and floras of these blocks do not appear to be related to those of north-eastern Gondwanaland, indicating that they rifted away at some earlier time. The Sibumasu block remained on the north-western Australian margin of Gondwanaland until the late Lower Permian, and was in continuity with the Tibetan Lhasa and Changtang blocks (south of the Langcangjiang Fracture Zone) and the proto-Kreios microcontinent further to the west. Late Carboniferous and Lower Permian sediments of the Sibumasu, Lhasa, and Changtang blocks, and the Iranian and Afghan portions of proto-Kreios include extensive glacial-marine deposits. Early Permian shallow-marine faunas were of cold-water type until a major change occurred in late Lower Permian times, with Middle Permian faunas becoming typically warm-water Tethyan in aspect. It seems most likely that Sibumasu (still attached to the Lhasa and Changtang blocks and proto-Kreios) rifted from Gondwanaland in the late Lower Permian. Amalgamation of the south-east Asian blocks was probably completed by the end of the Triassic. This is indicated by terrestrial vertebrate biogeography and palaeomagnetism. It is still a matter of debate whether Indo-China sutured to South China in the Devonian-Carboniferous along the Song Ma line, or in the late Triassic along the Song Da zone. Evidence seems stronger for a late Triassic suturing of Sibumasu to the other ‘Cathaysian’ southeast Asian blocks, although a Permian closure of ‘palaeo-Tethys’ has recently been proposed for the Shan-Thai-Indo-China region. The south-west Borneo block probably rifted from the margin of Indo-China in the Cretaceous, and travelled south to its present position during the opening of the proto-South China Sea.