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Devonian Reef Complexes of the Canning Basin Devonian reef complexes are well exposed on the Lennard shelf, the northernmost structural subdivision of the Canning basin, forming a series of limestone ranges some 350 km long (Fig. 1). The reef complexes were constructed as shallow reef-fringed limestone platforms, fronted by steeply dipping marginal-slope deposits, which descended into flat-lying basin deposits in water up to several hundred meters deep (

A diverse assemblage of algal stromatolites occurs in Devonian reef complexes of the Canning Basin, Western Australia. Some forms grew on fore-reef depositional slopes down to at least 45 meters below sea level and are believed to be products of deepwater nonskeletal algae. It is concluded that algal stromatolites in the stratigraphic record are not to be regarded as diagnostic evidence for deposition in very shallow water.

Rachel Wood (2000) discussed changes in the Devonian reefbuilding biota across the Frasnian-Famennian (F-F) boundary in the Canning basin. This boundary coincides with a major mass extinction of metazoans, yet Wood concluded that the Famennian reef-building community shows ''no noteworthy changes in biodiversity'' (p. 990) when compared with its Frasnian precursor. We are unable to agree with that conclusion or with many others in Wood's paper. Reefal platforms in the Canning basin were built by calcimicrobes during the Famennian and by calcimicrobes and metazoans (stromatoporoids and corals) in the Givetian and Frasnian. The reef-building REFERENCES CITED