Storm-dominated shallow marine deposits: the Fernie–Kootenay (Jurassic) transition, southern Rocky Mountains

1979 ◽  
Vol 16 (9) ◽  
pp. 1673-1690 ◽  
Author(s):  
Anthony P. Hamblin ◽  
Roger G. Walker
Keyword(s):  
Rocky Mountains ◽  
Tidal Current ◽  
Density Current ◽  
Sedimentary Structure ◽  
Fair Weather ◽  
Shallow Marine ◽  
Southern Rocky Mountains ◽  
Marine Deposits ◽  
Storm Waves ◽  
Lowermost Part

The transition from the Passage Beds of the Fernie into the lowermost part of the Kootenay Formation is exposed in 11 sections in the Crowsnest Pass to Banff area. Six distinct facies can be defined. Facies A (thin bedded turbidites) and facies B (thicker bedded turbidites) both have sole marks indicating north-northwestward flow. Facies C is the most important and consists of interbedded sandstones and shales, with sole marks indicating north-northwestward flow, and "hummocky cross stratification" as the characteristic internal sedimentary structure. It is interpreted to be formed by storm waves in depths below fair-weather wave base. Facies D contains low angle intersecting sets of parallel lamination (beach) and facies E is characterized by trough cross bedding (fluvial). Facies F consists of lenticular sandstones and shales, with coals. The facies occur in the sequence listed and indicate a northward prograding beach complex. Following intense storms, water driven toward the beach surges back seaward, entraining sand and developing into a density current. If deposition from the density current takes place in depths stirred by the storm waves, hummocky cross stratification is formed. In slightly deeper, quieter water the density current deposits a classical turbidite. Thus, the eastward-prograding Kootenay "delta" of previous interpretations now appears to be a northward-prograding beach complex fed by rivers, but with sand transported alongshore by waves. There is no evidence of tidal current activity, and shallow marine deposition is dominated by storms.

scholarly journals Sedimentology and ichnology of the mid-Cretaceous succession of Ouled Nail Mounts (Eastern Saharan Atlas, Algeria)

2021 ◽  
Vol 74 (3) ◽  
pp. 209-223
Author(s):  
Mohammed Nadir Naimi ◽  
◽  
Amine Cherif ◽  
Keyword(s):  
Trace Fossils ◽  
Decapod Crustaceans ◽  
Shallow Marine ◽  
Marine Deposits ◽  
Northern Algeria ◽  
Continental Intercalaire ◽  
Lowermost Part ◽  
Maximum Flooding Surface ◽  
Glossifungites Ichnofacies

Shallow marine deposits characterize the upper Albian – lower Cenomanian deposits of Northern Algeria. In Djebel Azzeddine (Ouled Nail Mounts), the corresponding sediments have been subdivided into three distinctive units A to C. The first discovered ammonite fauna from the Bou Saada area allowed the attribution of a part of the mid-Cretaceous post-Continental Intercalaire deposits to the upper Albian. The ammonite-bearing level indicates a maximum flooding surface and could be correlated with similar levels from Northern Algeria. The studied succession is characterized by a low ichnodiversity containing eight ichnotaxa with abundant Thalassinoides, common Skolithos, and rare Gyrolithes, Oichnus, Planolites and cf. Tisoa. This ichnoassemblage is dominated by domichnion, fodinichnion and praedichnion trace fossils, and is attributed to the Skolithos and Glossifungites ichnofacies. These traces are produced mainly by decapod crustaceans, polychaetes and naticid gastropods. The sedimentological and ichnological data suggest shoreface to backshore environments with mixed tide/storm energy, and long subaerial exposures indicated by Lofer cyclothems in the lowermost part and dinosaur footprints in the upper part of the section.

Cardium Formation (U. Cretaceous) at Seebe, Alberta—storm-transported sandstones and conglomerates in shallow marine depositional environments below fair-weather wave base

1981 ◽  
Vol 18 (4) ◽  
pp. 795-809 ◽  
Author(s):  
Marsha E. Wright ◽  
Roger G. Walker
Keyword(s):  
Depositional Environments ◽  
Density Currents ◽  
Fair Weather ◽  
Sand Waves ◽  
Shallow Marine ◽  
Medium Scale ◽  
Total Absence ◽  
Long Period ◽  
Storm Waves ◽  
Cardium Formation

As a result of detailed mapping at Seebe, Alberta, we have defined five coarsening-upward sequences in the Turanian Cardium Formation. The sequences begin with bioturbated mudstones and coarsen into sandstones, commonly with conglomeratic veneers on top. In sequence 2, the conglomerate is up to 20 cm thick, and has been molded into sand waves a few centimetres high and with wavelengths of about 1 m.The sandstones are dominated by hummocky cross-stratification (HCS), a broad, low-angle undulating stratification now believed to be formed below fair-weather wave base by long-period storm waves. Sandstones with HCS occur in the upper parts of sequences 1, 2, 3, and 5, suggesting that all of these sequences terminate in water deeper than fair-weather wave base (10–15 m). The trace fossil assemblage of abundant Zoophycos and long, horizontal Rhizocorallium suggests similar depths. Foraminifera in sequences 3 and 4 show a high diveristy of agglutinated species, also suggesting deposition below fair-weather wave base.In view of the physical and biological evidence for deposition in a few tens of metres of water, and the total absence of medium-scale cross-bedding, we suggest that the entire Cardium Formation at Seebe was deposited below fair-weather wave base. The sandstones were emplaced by storm-generated density currents, the same storm both generating the flow and imprinting HCS on the deposit. Finally, we suggest that the conglomerates were also moved rapidly out to sea by density currents, there being no evidence for the traditional beach or transgressive lag interpretation of these rocks.

Storm-dominated shallow marine sediments of the Arisaig Group (Silurian–Devonian) of Nova Scotia

1980 ◽  
Vol 17 (1) ◽  
pp. 120-131 ◽  
Author(s):  
Douglas J. Cant
Keyword(s):  
Nova Scotia ◽  
Marine Sediments ◽  
Fair Weather ◽  
Silty Mudstone ◽  
Shallow Marine ◽  
Bottom Currents ◽  
Marine Deposits ◽  
Shallow Marine Sediments

Shallow marine deposits of the Arisaig Group (Silurian–Devonian) of Nova Scotia consist of shaly sediments with varying proportions of coarser interbeds. Brachiopods, graptolites, crinoids, corals, and bivalves are present in parts of the group.One end-member lithology consists of black, fissile shale with few fossils. This grades into grayer, less fissile, more fossiliferous shale with coarse siltstone interbeds up to 5 cm thick. Higher in the group, nearer nonmarine beds, the background sediments consist of mottled, nonfissile silty mudstone with many large in situ brachiopods and lenses of coarse siltstone. The interbeds are composed of coarse siltstone or fine sandstone and, in some cases, have lenses of coquina within them. They range from 5–50 cm in thickness, but in places have amalgamated by scouring and locally comprise almost 100% of the section. Most of the coarse interbeds have sharp bases with horizontal or low angle laminations, but some thicker beds show sets of low angle, curving laminations which truncate other sets, termed “hummocky cross-stratification," The top surfaces of these beds are covered by interference ripples and burrows.The coarse interbeds were laid down rapidly by fractional seaward-flowing bottom currents during storms. Some of the coarse beds were later modified by bioturbation during fair weather periods when settling of sediment from suspension and faunal activity were the dominant processes. The Arisaig Group represents the deposits of a storm-dominated shelf and illustrates the range in variation which can occur in the sediments of this type of environment.

A new, large acteonid gastropod (Mollusca) from the latest Cretaceous of Antarctica

2002 ◽  
Vol 76 (6) ◽  
pp. 1102-1105 ◽  
Author(s):  
Jeffrey D. Stilwell ◽  
William J. Zinsmeister
Keyword(s):  
Antarctic Peninsula ◽  
First Record ◽  
Shallow Marine ◽  
Marine Deposits ◽  
Island Species ◽  
Southern Half ◽  
Lowermost Part ◽  
Seymour Island

Opisthobranch Gastropods are rare in Mesozoic deposits of Antarctica. The first documented occurrence of opisthobranchs from this continent is from Cretaceous shallow-marine deposits of the James Ross Basin, Antarctic Peninsula, where Wilckens (1910, p. 95–96, pl. 4, fig. 19) described the minute ringiculid Cinulia sp., based on five specimens from two localities on Snow Hill Island. No further work has been done on the Snow Hill Island species. The next mention of Antarctic Cretaceous opisthobranchs was by Zinsmeister et al. (1989, p. 733, fig. 2, p. 734, fig. 3), who cited the occurrence of the ringiculid “Oligoptycha cf. O. concinna Meek and Hayden, 1858,” in the lowermost part of Unit 8 of the López de Bertodano Formation (Maastrichtian) on the southern half of Seymour Island (Fig. 1). We report the first record of Acteonidae from the Mesozoic of Antarctica, Acteon (Tenuiactaeon) antarctihadrum n. sp., discovered in shallowmarine Maastrichtian deposits.

Pruning to manage white pine blister rust in the southern Rocky Mountains

2011 ◽  
Author(s):  
Amanda Crump ◽  
William R. Jacobi ◽  
Kelly S. Burns ◽  
Brian E. Howell
Keyword(s):  
Rocky Mountains ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Southern Rocky Mountains ◽  
Blister Rust
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