Abstract: Siliceous sponge reefs have been revealed in the upper Triassic Ma’antang Formation in western Sichuan.
The lithology， fossils， distribution and controlling factors of those reefs have been researched， but can be studied
in a deep-going way. Comparing those reefs and the upper Jurassic siliceous reefs in Europe， it is considered that a
series of sponge and coral may exist in the western Sichuan， according to the evolution of the global siliceous reefs
andthecolliculusupliftintheseismicprofiles. Thesiliceousreefsdevelopedintherelativelydeepwaterandthelow
energy environment， which had been exposed by late tectonic movements. While the predicted reefs may develop
in the shallow water and relatively high energy environment， which have been deeply buried in the depression of the
western Sichuan Basin. And the distribution of the siliceous reefs is obviously influenced by the Qinlin Old land，
whose size turned smaller northwardly. This is of significant for understanding the transfer process frome the marine
carbonate to the marine clastic rock and the oil exploration direction in the Ma’antang Formation.

Key words: Sichuan Basin, siliceous sponge reef, Tethys, reef evolution, oil exploration