. Bulletin of the British Museum (Natural History), Geology. 184 A. H. M. VANDENBERG & B. D. WEBBY. J ORDOVICIAN REGIONAL MET AMORPHICS BASS Fig. 1 Distribution of Ordovician and Silurian rocks in central and eastern Victoria. Localities mentioned in text and Fig. 2 are: 1, Darraweit Guim; 2, Mount Easton region; 3, Yalmy River; 4, Delegate (southeast ). The Bolinda Shale is composed of 800 m or more of thin-bedded coarse-grained black shale and fine sandstone with a rich Bolindian graptolite fauna, comprising mostly cosmopolitan species. The assemblage consists of very abundant Clim
. Bulletin of the British Museum (Natural History), Geology. 184 A. H. M. VANDENBERG & B. D. WEBBY. J ORDOVICIAN REGIONAL MET AMORPHICS BASS Fig. 1 Distribution of Ordovician and Silurian rocks in central and eastern Victoria. Localities mentioned in text and Fig. 2 are: 1, Darraweit Guim; 2, Mount Easton region; 3, Yalmy River; 4, Delegate (southeast ). The Bolinda Shale is composed of 800 m or more of thin-bedded coarse-grained black shale and fine sandstone with a rich Bolindian graptolite fauna, comprising mostly cosmopolitan species. The assemblage consists of very abundant Climacograptus latus, C. longispinus supernus and Orthograptus amplexicaulis (sensu lato), somewhat less abundant C. hastatus, C. cf. tubuli- ferus, Paraorthograptus pacificus pacificus and Dicellograptus ornatus, and rare specimens of Orthograptus fastigatus, Orthoretiograptus denticulatus and Pleurograptus linearis (sensu lato). This assemblage constitutes the Zone of D. ornatus and C. latus of VandenBerg (in Webby et al. 1981) and is virtually identical to that of the Paraorthograptus pacificus Subzone at Dob's Linn (Williams 1982). The overlying Darraweit Guim Mudstone consists of 20 to 45 m of sparsely fossiliferous black calcareous mudstone and slump-folded mudstone of partly evaporitic origin, and may be the only unit in Australia to show the effects of the late Ordovician glaciation (VandenBerg, in prep.). The impoverished shelly fauna consists of small bivalves, hyolithids, straight nautiloids, and a single trilobite, Songxites darraweitensis. More important, however, is the occurrence of Climacograptusl extraordinarius which is associated with C. angustus and C. cf. acceptus (VandenBerg et al. 1984). This assemblage represents the upper Bolindian Zone of extraor- dinarius and is considered to correlate with the C? extraor dinar ius Zone at Dob's Linn (Williams 1983). Contacts between the Darraweit Guim Mudstone and the overlying Deep Creek Siltstone are usually poorly
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