Abstract The Ordovician–Silurian (~485–419 Ma) was a time of considerable evolutionary upheaval, encompassing both great diversification and one the first major mass extinctions. Ordovician coincided with global climatic cooling paleocontinental collision, ecological impacts which were mediated by region-specific processes including substrate changes, biotic invasions, tectonic movements. From ...

The tail of the earliest known articulated fully skeletonized vertebrate, the arandaspid Sacabambaspis from the Ordovician of Bolivia, is redescribed on the basis of further preparation of the only specimen in which it is most extensively preserved. The first, but soon discarded, reconstruction, which assumed the presence of a long horizontal notochordal lobe separating equal sized dorsal and v...

Brett, C. E. and Brookfield, M. E., 1984. Morphology, faunas and genesis of Ordovician hardgrounds from southern Ontario, Canada. Palaeogeogr., PaIaeoclirnatol., PalaeoecoI., 46: 233-290. We have used associations of different rnicrofacies to define facies (or microfaties associations) which fom reasonably welldefined sequences, which we infer, from amlogies with recent and ancient carbonate en...

Regional tectonic synthesis suggests that a segment of the bipartite eastern Gondwana-type Carpathian-Balkan nappe-stacked Getic/Kučaj/Supragetic basement (eastern Serbia) experienced Cambro-Ordovician Cenerian (Sardic) accretionary-type deformation. The Ordovician Alpine Getic/Kučaj nappe exposes an earlier-mapped shallow-marine transgressive-type Fe-silicate-rich ironstone sequence. is used a...

19 The Fishguard Volcanic Group represents an excellently preserved example of a volcanic 20 sequence linked to the closure of the Iapetus Ocean. This study re-examines the petrogenesis 21 and proposed tectonic setting for the Llanvirn (467-458 Ma) Fishguard Volcanic Group, 22 South Wales, UK. New major and trace element geochemical data and petrographic 23 observations are used to re-evaluate ...

All the stops for this trip are within the Crown Point Reservation State Historic Site. From the west, take NY Route 22 north from Ticonderoga, continuing north through the Village of Crown Point. Turn east approximately five miles north of the Village of Crown Point, following signs to the 'Bridge to Vermont'. From the east, take VT Route 22A north from Fairhaven, or south from Burlington area...