Some Ordovician Rocks
Thetford Mines Ophiolite Complex - Ordovician serpentinite from Thetford Mines,
Quebec, Canada.
Glover Bluff Impact Breccia, Oneota Formation - Lower Ordovician impact breccia from the Glover
Bluff Impact Crater, Wisconsin, USA.
Bendigonian Formation - fossiliferous clayshale with carbonized Tetragraptus
fossil graptolites from the Lower Ordovician at Spring Gully, Bendigo,
Victoria, Australia.
Sandamap Pegmatite - ~470 Ma purpurite (~Early-Middle Ordovician
boundary times) from the Southern Tin Belt, Namibia.
Fazenda Mem—ria Stock (ÒAlaskan White GraniteÓ) - porphyritic
garnetiferous leucogranite from the Middle Ordovician (~466 Ma) at Fazenda Mem—ria, Cear‡
State, Brazil.
Mynydd Preselii Dolerite Suite - spotted metadolerite (early Middle Ordovician) from
the Preseli Hills of Wales in Britain.
St. Peter Sandstone - white, clean, quartz arenite (quartzose sandstone)
(Middle Ordovician) from Kentland Dome Impact Structure, Indiana, USA.
Blakely Sandstone - quartzose sandstone from the Middle Ordovician at
Coleman Quartz Mine, Arkansas, USA.
Cloridorme Formation - silty mudrock with flute casts in a turbidite
succession from the Middle Ordovician (Caradocian) at St. Yvon, Quebec, Canada.
Lower Hartfell Shales - fossiliferous black shale with Climacograptus
wilsoni graptolites (~mid-Caradocian, upper Middle Ordovician) from Dob's
Linn, Southern Uplands, Scotland, northern Britain.
Galena Formation - fossiliferous limestone with Hormotoma
fossil snail (upper Middle Ordovician to lower Upper Ordovician) from eastern
Iowa, USA.
Lockne Breccia - impact resurge breccia from the Upper Ordovician
(~455-458 Ma) at Lockne Impact Crater, Sweden.
Kope Formation - fossiliferous packstone (lower Upper Ordovician)
with abundant crinoid stem columnals plus tentaculites, bryozoans, and
trilobite fragments (= chocolate brown-colored pieces) from near Cincinnati,
northern Kentucky, USA.
Collingwood Member of the Lindsay Formation (Cobourg
Formation/Whitby Formation) -
black shale (Upper Ordovician) with Pseudogygites latimarginatus and Triarthrus
eatoni trilobite sclerites from St. Mary's Cement Company Quarry at
Bowmanville, Ontario, Canada.
Bellevue Limestone - fossiliferous limestones with Streptaster
vorticellatus edrioasteroid (left) and Carneyella ulrichi
edrioasteroid (right) (middle Upper Ordovician) from near Maysville,
Kentucky, USA.
Arnheim Formation - fossiliferous shale with Isotelus maximus
trilobite (upper Upper Ordovician) from Flat Run, Mt. Orab, Ohio, USA.
Liberty Formation - fossiliferous wackestone with hexaradial mutant of Promopalaeaster
fossil starfish (upper Upper Ordovician) from Caesar Creek Lake's emergency
spillway, Warren County, Ohio, USA.
Whitewater Formation - fossiliferous packstone with Xenocrinus
crinoids (upper Upper Ordovician) from Flat Fork, Warren County, Ohio, USA.