Sedimentary fades, depositional environments, and faunal associations of the lower Llandovery (Silurian) Beechill Cove Formation, Arisaig, Nova Scotia

1983 ◽  
Vol 20 (12) ◽  
pp. 1761-1779 ◽  
Author(s):  
R. K. Pickerill ◽  
J. M. Hurst
Keyword(s):  
Depositional Environments ◽  
Low Energy ◽  
Sedimentation Rates ◽  
Storm Activity ◽  
Distributional Patterns ◽  
Low Diversity ◽  
Energy Environment ◽  
Shallow Subtidal ◽  
Oxygen Minimum ◽  
Mudstone Facies

Six facies are recognised in the Beechill Cove Formation. These are: (1) conglomerate facies deposited as a transgressive beach lag; (2) red shale facies deposited in shoreface environments; (3) mottled mudstone facies; extensively bioturbated sediments indicative of shallow subtidal areas influenced by low sedimentation rates; (4) regular layered facies; shelf turbidites generated by storm activity and superimposed on quiescent subtidal environments; (5) lenticular facies, including a thinner bedded more persistent and a thicker bedded lenticular subfacies, induced by storm activity and deposited in shallow subtidal environments; and (6) laminated shale facies produced by sediment fallout from suspension in a low-energy environment where the oxygen, minimum layer intersected the sediment–water interface. Three faunal associations occur, which have distinct distributional patterns. The Lingula clintoni association, which is characterized by L. clintoni in life position and a moderately diverse but abundant trace-fossil assemblage, is restricted to the mottled mudstone facies. The Leptostrophia beechillensis association, a transported residue, is dominated by brachiopods and restricted to the regular layered facies. The low-diversity Dalmanella primitiva association is transported and restricted to the lenticular facies. No faunas are known from the conglomerate or laminated shale facies, and only rare trace fossils occur in the red shale facies.

Vertebrate microremains from the upper Silurian Winnica Formation of the Holy Cross Mountains, Poland

2017 ◽  
Vol 155 (7) ◽  
pp. 1523-1541 ◽  
Author(s):  
OSKAR BREMER ◽  
GRZEGORZ NIEDŹWIEDZKI ◽  
HENNING BLOM ◽  
MAREK DEC ◽  
WOJCIECH KOZŁOWSKI
Keyword(s):  
Deep Water ◽  
High Energy ◽  
Depositional Environments ◽  
Low Energy ◽  
Environmental Distribution ◽  
Holy Cross Mountains ◽  
Lower Abundance ◽  
Energy Environment ◽  
Upper Silurian

AbstractVertebrate microremains from the upper Silurian Winnica Formation in the Holy Cross Mountains, Poland are described from the Winnica and Rzepin sections. Both sites record the uppermost part of the Słupianka Member, but represent different depositional environments. The Winnica samples come from a low-energy environment, while the Rzepin sample was taken from a high-energy, oolitic facies. Both sites contain thelodontsThelodus parvidens,Thelodus trilobatus, an anaspid cf.Liivilepisand a number of acanthodian scales of ‘nostolepid’, poracanthodid and ‘gomphonchid’ types. Notable differences between the sites are the addition of the osteostracanTahulaspiscf.ordinata, the thelodontParalogania ludlowiensisand acanthodian scales identified asNostolepis gracilisin the Rzepin section. Placing the vertebrate faunas within the vertebrate biozonation established for the Silurian proved difficult. The suggested late Ludlow age for the Słupianka Member based on sequence stratigraphical and chemostratigraphical correlations cannot be definitely confirmed or refuted, but a late Ludfordian age seems the most plausible based on invertebrate and vertebrate faunas. The much lower abundance of poracanthodid acanthodians in the Rzepin sample supports the notion ofPoracanthodes porosusZone as a deep-water equivalent to a number of vertebrate biozones. The presence ofP. ludlowiensisonly in the oolitic sample confirms a long temporal range, but restricted environmental distribution for this taxon.

Longshore variability of beach states and bar types in a microtidal, storm-influenced, low-energy environment

Geomorphology ◽  
2015 ◽  
Vol 241 ◽  
pp. 175-191 ◽  
Author(s):  
N. Aleman ◽  
N. Robin ◽  
R. Certain ◽  
E.J. Anthony ◽  
J.-P. Barusseau
Keyword(s):  
Low Energy ◽  
Energy Environment

Global correlation of the radiolarian faunal change across the Triassic–Jurassic boundary

2005 ◽  
Vol 42 (5) ◽  
pp. 777-790 ◽  
Author(s):  
Elizabeth S Carter ◽  
Rie S Hori
Keyword(s):  
Global Changes ◽  
Sedimentation Rates ◽  
Sedimentary Environments ◽  
Faunal Change ◽  
Queen Charlotte Islands ◽  
Global Correlation ◽  
Compensation Depth ◽  
Low Diversity ◽  
Upper Slope ◽  
Carbonate Compensation Depth

Precise comparison of the change in radiolarian faunas 3.5 m above a U–Pb zircon dated 199.6 ± 0.3 Ma tuff and approximately coincident with a negative δ13C anomaly in the Queen Charlotte Islands, B.C. (Canada) with Inuyama (Japan) sequences indicates that major global changes occurred across the Triassic–Jurassic (T–J) boundary. Nearly 20 genera and over 130 Rhaetian species disappeared at the end of the Triassic. The index genera Betraccium and Risella disappear and the final appearance of Globolaxtorum tozeri, Livarella valida, and Pseudohagiastrum giganteum sp. nov. are also diagnostic for the end of the Triassic. The low-diversity Hettangian survival fauna immediately above the boundary is composed mainly of small, primitive spumellarians with spongy or irregularly latticed meshwork and rod-like spines, and new genera Charlottea, Udalia, and Parahsuum s.l. first appear in the lowest Hettangian in both localities. Irrespective of different sedimentation rates and sedimentary environments, such as shelf to upper slope (Queen Charlotte Islands) and deep sea below carbonate compensation depth (CCD; Inuyama), radiolarians show a similar turnover pattern at the T–J boundary.

Smithian shoreline migrations and depositional settings in Timpoweap Canyon (Early Triassic, Utah, USA)

2014 ◽  
Vol 151 (5) ◽  
pp. 938-955 ◽  
Author(s):  
NICOLAS OLIVIER ◽  
ARNAUD BRAYARD ◽  
EMMANUEL FARA ◽  
KEVIN G. BYLUND ◽  
JAMES F. JENKS ◽  
...  
Keyword(s):  
Sea Level ◽  
High Frequency ◽  
Depositional Environments ◽  
Small Scale ◽  
Early Triassic ◽  
Relative Sea Level ◽  
Depositional Sequence ◽  
Sea Level Fluctuations ◽  
Stacking Pattern ◽  
Shallow Subtidal

AbstractIn Timpoweap Canyon near Hurricane (Utah, USA), spectacular outcrop conditions of Early Triassic rocks document the geometric relationships between a massive Smithian fenestral-microbial unit and underlying, lateral and overlying sedimentary units. This allows us to reconstruct the evolution of depositional environments and high-frequency relative sea-level fluctuations in the studied area. Depositional environments evolved from a coastal plain with continental deposits to peritidal settings with fenestral-microbial limestones, which are overlain by intertidal to shallow subtidal marine bioclastic limestones. This transgressive trend of a large-scale depositional sequence marks a long-term sea-level rise that is identified worldwide after the Permian–Triassic boundary. The fenestral-microbial sediments were deposited at the transition between continental settings (with terrigenous deposits) and shallow subtidal marine environments (with bioturbated and bioclastic limestones). Such a lateral zonation questions the interpretation of microbial deposits as anachronistic and disaster facies in the western USA basin. The depositional setting may have triggered the distribution of microbial deposits and contemporaneous marine biota. The fenestral-microbial unit is truncated by an erosional surface reflecting a drop in relative sea level at the scale of a medium depositional sequence. The local inherited topography allowed the recording of small-scale sequences characterized by clinoforms and short-distance lateral facies changes. Stratal stacking pattern and surface geometries allow the reconstruction of relative sea-level fluctuations and tracking of shoreline migrations. The stacking pattern of these small-scale sequences and the amplitude of corresponding high-frequency sea-level fluctuations are consistent with climatic control. Large- and medium-scale sequences suggest a regional tectonic control.

Oxygen minimum zones harbour novel viral communities with low diversity

2012 ◽  
Vol 14 (11) ◽  
pp. 3043-3065 ◽  
Author(s):  
Noriko Cassman ◽  
Alejandra Prieto-Davó ◽  
Kevin Walsh ◽  
Genivaldo G. Z. Silva ◽  
Florent Angly ◽  
...  
Keyword(s):  
Oxygen Minimum Zones ◽  
Low Diversity ◽  
Viral Communities ◽  
Oxygen Minimum

Data Transmission Method using Broadcasting in Bluetooth Low Energy Environment

2018 ◽  
Vol 19 (5) ◽  
pp. 963-969
Author(s):  
Rae-Young Jang ◽  
Jae-Ung Lee ◽  
Sung-Jae Jung ◽  
Woo-Young Soh
Keyword(s):  
Data Transmission ◽  
Low Energy ◽  
Transmission Method ◽  
Bluetooth Low Energy ◽  
Energy Environment

Global wave resource classification and application to marine energy deployments

2020 ◽  
Author(s):  
Iain Fairley ◽  
Matthew Lewis ◽  
Bryson Robertson ◽  
Mark Hemer ◽  
Ian Masters ◽  
...  
Keyword(s):  
Wave Height ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Low Energy ◽  
Energy Extraction ◽  
Energy Converter ◽  
Storm Activity ◽  
Moderate Energy ◽  
Roll Out

<p>Understanding and classification of the global wave energy resource is vital to facilitate wave energy converter technology development and global roll-out of this promising renewable energy technology. To date, many wave energy converters have been developed based on Northern European wave climates; these are not representative of wave climates worldwide and may not be the best for large scale energy extraction. Classification of resources will highlight alternative wave resource types that may prove fruitful for deployment of future technologies; equally it will enable existing technology to define regions worthy of site exploration. Therefore k-means clustering is used here to classify the global resource from a data-driven, device agnostic perspective.</p><p>Parameters relevant to energy extraction (significant wave height, peak wave period, extreme wave height, spectral and directional properties) were extracted from the ECMWF ERA5 reanalysis dataset and used to split the global resource into 6 classes. Only areas within 3 degrees of land (feasible energy transport to user) were considered. The 6 classes returned by the analysis consisted of: 1) low energy high variability areas in enclosed seas; 2) low energy moderate variability areas in semi-enclosed seas and sheltered ocean coasts; 3) moderate energy areas, largely on eastern oceanic coastlines and influenced by local storm activity; 4) moderate energy areas primarily influenced by long period swell and largely on western oceanic coastlines; 5) higher energy areas, with variable conditions, primarily in the northern hemisphere; 6) highest energy areas, primarily on the tips of continents in the southern hemisphere. Consideration of device power matrices show that existing devices only perform well in classes 5 and 6, despite these areas having limited global coverage, which suggests devices should be developed for lower energy classes.</p><p>To refine global roll-out planning for existing devices, based on a request from a wave energy converter developer, a second classification is currently being developed with two additional constraints on the areas tested. These constraints are excluding any areas with a mean wave power of less than 15 kW/m (an often-used value for the lower power limit for commercial viability) and a maintenance constraint whereby wave heights must drop below 3m for a minimum of 48hrs per month. These newer results will be presented at the annual assembly and contrasted with our more device agnostic classification.</p>

Settlement down again patterns of a carbonated platform following up a sedimentary crisis : example of the middle-late Jurassic boundary in the southeastern part of the Paris Basin

2004 ◽  
Vol 175 (3) ◽  
pp. 289-302 ◽  
Author(s):  
Sébastien Lorin ◽  
Philippe Courville ◽  
Pierre-Yves Collin ◽  
Jacques Thierry ◽  
Anthony Tort
Keyword(s):  
Late Jurassic ◽  
Regional Scale ◽  
High Energy ◽  
Depositional Environments ◽  
Low Energy ◽  
Tectonic Activity ◽  
Paris Basin ◽  
Marine Waters ◽  
Carbonate Production ◽  
Lithostratigraphic Units

Abstract Following a sedimentary crisis which begins in the late Lower Callovian and spans all the early Oxfordian, the settlement down patterns of a platform with carbonated sedimentation are analysed in a southeastern area of the Paris Basin (fig. 1). Ten lithostratigraphic units (reefal formations, associated bioclastic facies and marly distal lateral facies ; fig. 2) are defined (fig. 3). New ammonite and brachiopod faunas, collected in situ, allow to date accurately the sedimentary units with a precision matching an ammonite subzone of the standard bio-chronostratigraphic scale (fig. 4) of the middle-late Oxfordian (from the Parandieri Subzone, at the base of the Transversarium Zone, to the Planula Subzone, at the top of the Planula Zone). The sedimentologic analysis coupled with the study of the benthic and pelagic faunal communities allow to define twelve type-facies (tabl. I and II). Regrouped into three associations, these characterise depositional environments which occur in succession, following three platform models (fig. 5). As witnesses of the evolution of the accomodation/sedimentation ratio, the resulting time succession of sedimentary bodies shows a depositional dynamics organised into three sequence tracks (fig. 5 and 6) : – a retrogradation phase is characterised by a moderately deep and open platform, dominated by low energy and marly sedimentation, which ranges from the Middle Oxfordian (Plicatilis Zone and Transversarium Zone) to the lowermost late Oxfordian (Bifurcatus Zone) ; – during the late Oxfordian (Bimammatum Zone, from the Semimammatum Subzone to the Bimammatum Subzone) an aggradation phase corresponds to the installation of three successive shallow platforms with contrasted morphology. Indicating the re-initiation of carbonated production, these platforms are well limited and represent high energy shallows with reef buildings, which lateraly grade into dismantling bioclastic faciès, then secondly and more laterally again into low energy and medium deep marly facies ; – the upper part of the late Oxfordian (Hauffianum Subzone, in the uppermost Bimammatum Zone, and Planula Zone) shows the wide extent of a low energy and morphologically very little contrasted distal platform. This one has a high potential of carbonated production characterised by bioclastic, oolitic and micritic facies which illustrate a progradation phase ; such a phase proceeds in the early Kimmeridgian. The collected data and the corresponding phenomenons pointed out on this area of the southeastern border of the Paris Basin are discussed and replaced in the general framework of the sedimentary, biologic, palaeogeographic and palaeoclimatic events henceforth recognised at the middle-late Jurassic boundary on the peri-Tethyan intracratonic domains of western Europe. The demise of the carbonate production seems to be correlated with a global cooling of both marine waters and atmosphere, which is considered as a limiting factor. During the Middle Oxfordian, the re-initiation of carbonate production with the developement of reef buildings should correspond to a large scale warming of the marine waters still observed elswhere on the Russian Platform, in the North Sea and in the Paris Basin. However, the geographic distribution and the chronologic succession of the facies and deduced palaeoenvironments is probably equally related to a synsedimentary tectonic activity which operates as a favorable factor at both a local and regional scale.

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