Upper Ordovician conodont biostratigraphy and the age of the Collingwood Member, southern Ontario, Canada1Earth Science Sector (ESS) Contribution 20100302.

2011 ◽  
Vol 48 (11) ◽  
pp. 1497-1522 ◽  
Author(s):  
Shunxin Zhang ◽  
Glen A. Tarrant ◽  
Christopher R. Barnes

The Upper Ordovician stratigraphy in southern Ontario represents the clastic foredeep associated with the Appalachian Taconic Orogeny transitioning northwest into coeval carbonate platform facies. Ten measured and sampled sections in both the Collingwood area and on Manitoulin Island, Lake Huron, provide two relatively complete composite sections (277 and 95 m, respectively) through the marine part of the sequence. A total of 100 2 kg samples collected for a conodont biostratigraphic study yielded 77 215 well-preserved specimens. Taxonomic study of the fauna, illustrated herein, identified 34 species representing 22 genera and three taxa in open nomenclature. Taxonomic revisions are made to five species of Pseudobelodina and one of Rhipidognathus ; a new species, Pseudobelodina microdentata , is established. The fauna primarily represents the Midcontinent Province with incursions from the North Atlantic Province primarily in the Collingwood area. Four conodont zones are recognized that help refine the ages for the Upper Ordovician upper Lindsay (Collingwood Member), Blue Mountain, Georgian Bay, and Queenston formations. In particular, the Collingwood Member of the Lindsay Formation, a regionally distributed organic-rich shale of hydrocarbon source rock potential, is demonstrated to lie within the Amorphognathus ordovicicus Zone of North Atlantic Province and the Oulodus robustus Zone of Midcontinent Province and to be early Richmondian age.

Author(s):  
Julio Parapar ◽  
Juan MOREIRA ◽  
Ruth BARNICH

Ampharete oculicirrata sp. nov. (Annelida: Ampharetidae) is described from samples collected by the Joint Nature Conservation Committee and Marine Scotland Science, in the West Shetland Shelf NCMPA in the NE Atlantic. This species is characterised by a very small body size, thin and slender paleae, twelve thoracic and eleven abdominal uncinigers, presence of eyes both in the prostomium and the pygidium, the latter provided with a pair of long lateral cirri. The external micro-morphology of the new taxon was studied using scanning electron microscopy and compared with species described or reported from the North Atlantic. Two complementary keys to all species of Ampharete in the area are also provided.


Zootaxa ◽  
2011 ◽  
Vol 2791 (1) ◽  
pp. 63 ◽  
Author(s):  
KEREM BAKIR ◽  
MURAT SEZGIN ◽  
ALAN A. MYERS

A new species of amphipod, Megamphopus katagani sp. nov., is described from the sea of Marmara (Turkey). A key to the species of Megamphopus known from the North-East Atlantic, Mediterranean and associated seas is provided.


Zootaxa ◽  
2005 ◽  
Vol 821 (1) ◽  
pp. 1 ◽  
Author(s):  
BRUNO DELL’ANGELO ◽  
ANTONIO BONFITTO

A new species of Polyplacophora (Mollusca) has been found in the Salice outcrop, in the Peloritain Mountains (Sicily, Italy), is attributed to the early Pleistocene. Lepidopleurus (Leptochiton) salicensis n.sp. is characterized by its uniformly sculptured tegmentum, with (well) raised, randomly distributed, neatly separated rounded/polygonal granules. The new species is compared with Lepidopleurus (Leptochiton) alveolus (M.Sars MS, Lovén, 1846), from the North Atlantic, and Lepidopleurus (Leptochiton) tavianii Dell’Angelo, Landau & Marquet, 2004, from the Pliocene of Estepona (Málaga, Spain).


Author(s):  
Eve C. Southward

A description is given of Siboglinum holmei sp.nov., a shallow-water Atlantic species. It is compared with S. caulleryi, a related species from the Pacific.


1973 ◽  
Vol 10 (12) ◽  
pp. 1790-1804 ◽  
Author(s):  
K. Czurda ◽  
C. G. Winder ◽  
R. M. Quigley

The Meaford–Dundas Formation in southern Ontario is a medium gray shale with good fissility and resistant interbeds of gray fossiliferous limestones and siltstones. The hard layers are up to 20 cm in thickness and comprise 10 to 20% of the formation. The shale layers vary in thickness from 50 cm to 2 m.The clay minerals are principally illite, iron-chlorite, and small amounts of vermiculite and mixed-layer types. The carbonate content seems constant across the area at about 4 to 5% of the formation, except for the southwestern area where the carbonate increases to 20 or 25%. This increase is chiefly in dolomite content, a feature which reflects such factors as original conditions of deposition and possibly diagenesis subsequent to burial. The quartz content in the shale beds, and especially in the hard interbeds, increases towards the north to an average of 35 to 40% compared with 10 to 15% in the south. Framboids (aggregates of pyrite grains in spheroidal clusters) are a striking feature of the shale beds of the Meaford–Dundas Formation in the Meaford area.Fabric studies by means of X-ray diffraction patterns and scanning electron photomicrographs reveal, in most cases, high parallelism of clay platelets in the bedding planes, resulting in the good fissility of the shale.The principal source rock areas are the Appalachian orogen in the east (Taconic Mountains), which probably supplied most of the clay minerals and some quartz, and the Canadian Shield in the north, which provided the basin of sedimentation in the south with heavy minerals and additional quartz.


1983 ◽  
Vol 20 (4) ◽  
pp. 651-671 ◽  
Author(s):  
Godfrey S. Nowlan

Diverse conodont faunas recovered from the Grog Brook Group in northwestern New Brunswick indicate a Late Ordovician, probably Gamachian, age. The conodonts are of mixed provincial affinity including components of the North Atlantic Province (e.g., Hamarodus, Icriodella, Periodon, and Protopanderodus) and taxa representing shallow (e.g., Rhipidognathus) to deeper water environments (e.g., Phragmodus) in the Midcontinent Province. Elements of Amorphognathus ordovicicus Branson and Mehl numerically dominate the faunas that together with sparse representatives of Gamachignathus ensifer McCracken, Nowlan and Barnes suggest a latest Ordovician age. The beds from which the conodont faunas have been recovered are interpreted as distal debris flows that originated at the basin margin and brought Midcontinent Province conodonts down the slope to mix with indigenous North Atlantic Province faunas. The faunas are correlative with those from the Matapedia Group (previously thought to overlie the Grog Brook Group) and their occurrence suggests at least partial lateral equivalence of the two units.The conodonts recovered are only slightly thermally altered. Two alternative hypotheses are proposed to explain the juxtaposition of relatively unaltered conodonts of the Grog Brook Group and highly altered forms from the Matapedia Group. The first suggests that thrust faulting took place in the Late Ordovician – Early Silurian and that this process and later normal faulting account for the unusual distribution of conodont colour alteration. The second possibility is that the strata of the Grog Brook Group in the section examined were deposited on a structural high and overlain by little or no sediment of the Matapedia Group; however, such a structural high must have had access to a source of Midcontinent Province conodonts. Acadian thrusting then brought higher grade Matapedia Group strata into contact with this part of the Grog Brook Group.


Author(s):  
Eve C. Southward

The first species ofLamellisabella to be described from the Atlantic Ocean has rows of small teeth on the tentacles. It occurs at about 4000 m depth in the Bay of Biscay, and its range probably extends along the continental rise at least as far south as the Gulf of Guinea.


Author(s):  
C.M. Howson ◽  
S.J. Chambers

A new species of Ophlitaspongia (Porifera: Microcionidae) from wave-exposed sublittoral rock in the north-east Atlantic is described and compared to the two other species recorded from the genus in the north-east Atlantic. The species known as Ophlitaspongia seriata is considered to be a junior synonym of Halichondria panicea. Consequently, the name O. papilla has been reinstated. The other recorded species O. basifixa, is from deep water. Ophlitaspongia basifixa has characters which differentiate it from Ophlitaspongia sp. nov. The genus Ophlitaspongia has been separated from related genera and reinstated for species in the North Atlantic.


Sarsia ◽  
1993 ◽  
Vol 78 (3-4) ◽  
pp. 255-264 ◽  
Author(s):  
Hans J. Flügel ◽  
Peter Callsen-Cencic

1974 ◽  
Vol 111 (6) ◽  
pp. 549-564 ◽  
Author(s):  
A. M. McCann ◽  
M. J. Kennedy

SummaryConglomerate beds occur in an Upper Ordovician—Lower Silurian clastic sequence on the northeastern side of the Newfoundland Central Paleozoic Mobile Belt. They contain scattered pebbles and cobbles dispersed in a finely laminated sandstone and siltstone matrix. Laminations are generally 5–20 mm thick and the clasts 10–300 mm across. The laminations are locally disrupted by the clasts. These laminations have subsequently been tectonically flattened into augen around the clasts and locally disrupted by boudinage. It is concluded that these conglomerate beds represent icerafted glacio-marine deposits interbedded with turbidites which were probably deposited in a locally restricted marine environment. The deposits are interpreted on the basis of scattered fossil localities as being of Late Ordovician–Early Silurian age. They are compared with deposits of similar age elsewhere in the North Atlantic region.


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