Shallow-water onlap model for the deposition of Devonian black shales in New York, USA

Geology ◽  
2019 ◽  
Vol 47 (3) ◽  
pp. 279-283 ◽  
Author(s):  
Langhorne B. Smith ◽  
Juergen Schieber ◽  
Ryan D. Wilson
Keyword(s):  
New York ◽  
Shallow Water ◽  
Black Shales

scholarly journals Shallow-water onlap model for the deposition of Devonian black shales in New York, USA: COMMENT

Geology ◽  
2019 ◽  
Vol 47 (12) ◽  
pp. e495-e495 ◽  
Author(s):  
Charles Ver Straeten ◽  
Carlton Brett ◽  
Gordon Baird ◽  
Diana Boyer ◽  
Richard Lindemann ◽  
...  
Keyword(s):  
New York ◽  
Shallow Water ◽  
Black Shales

scholarly journals Shallow-water onlap model for the deposition of Devonian black shales in New York, USA: REPLY

Geology ◽  
2019 ◽  
Vol 47 (12) ◽  
pp. e496-e496
Author(s):  
Langhorne B. Smith ◽  
Juergen Schieber ◽  
Ryan Wilson
Keyword(s):  
New York ◽  
Shallow Water ◽  
Black Shales

scholarly journals Trans-border (east Serbia/west Bulgaria) correlation of the Jurassic sediments: Main Jurassic paleogeographic units

2006 ◽  
pp. 13-17 ◽  
Author(s):  
Platon Tchoumatchenco ◽  
Dragoman Rabrenovic ◽  
Barbara Radulovic ◽  
Vladan Radulovic
Keyword(s):  
Shallow Water ◽  
Marine Sediments ◽  
Deep Water ◽  
Carbonate Platform ◽  
Lower Jurassic ◽  
Black Shales ◽  
Upper Kimmeridgian ◽  
Middle Callovian

In the region across the Serbian/Bulgarian state border, there are individualized 5 Jurassic paleogeographic units (from West to East): (1) the Thracian Massif Unit without Jurassic sediments; (2) the Luznica-Koniavo Unit - partially with Liassic in Grsten facies and with deep water Middle Callovian-Kimmeridgian (p. p) sediments of the type "ammonitico rosso", and Upper Kimmeridgian-Tithonian siliciclastics flysch; (3) The Getic Unit subdivided into two subunits - the Western Getic Sub-Uni - without Lower Jurassic sediments and the Eastern Getic Sub-Unit with Lower Jurassic continental and marine sediments, which are followed in both sub-units by carbonate platform limestones (type Stramberk); (4) the Infra (Sub)-Getic Unit - with relatively deep water Liassic and Dogger sediments (the Dogger of type "black shales with Bossitra alpine") and Middle Callovian-Tithonian of type "ammonitico rosso"; (5) the Danubian Unit - with shallow water Liassic, Dogger and Malm (Miroc-Vrska Cuka Zone, deep water Dogger and Malm (Donjomilanovacko-Novokoritska Zone).

scholarly journals Thermally-controlled color gradient for fossils and associated sediments: implications for paleoecology

1992 ◽  
Vol 6 ◽  
pp. 14-14
Author(s):  
Gordon C. Baird ◽  
Timothy W. Lyons ◽  
Carlton E. Brett
Keyword(s):  
New York ◽  
New York State ◽  
Foreland Basin ◽  
Field Work ◽  
Black Shales ◽  
Foreland Basins ◽  
Regional Study ◽  
Southern Ontario ◽  
Color Gradient ◽  
Appalachian Foreland

Regional study of Middle-Late Ordovician and Middle-Late Devonian carbonate and siliciclastic deposits in the northern Appalachian foreland basin reveals a prominent pattern of eastward-darkening of marine mudrocks and associated fossils. Exoskeletons of certain trilobite genera transform from a saddle brown coloration in southern Ontario exposures to black and near-black in central and eastern New York. Similar eastward darkening of mudstones and argillaceous carbonate units is observed to be covariant with conodont color alteration (C.A.I.) values across this same region. This pattern is coupled with other lines of evidence for eastward increases in heat-of-burial for strata across New York State, indicating that the darkening is linked to this control. Laboratory heating of thermally “cold”, light-colored samples shows that this process can be simulated under controlled conditions. The darkening of fossils and mudrocks probably occurs due to thermal maturation of organic matter within these materials.Darkening of certain fossiliferous mudrock facies from color values as high as N 7.5 at a C.A.I. of 1.0 to those of N 2.5 at C.A.I. of 3.5 has important implications for paleoecological interpretations. Where obvious fossil-rich beds are absent and field work cursory, it might be tempting to infer a shelf-to-basin transition in the uprank direction where none exists. Where skeletal packstone and grainstone beds are common in thermally mature deposits it is possible that intervening dark-colored shales may be erroneously interpreted as basinal, organicrich (black) shales and the grain-supported beds as turbidites, when, in fact, such beds are shallow-shelf tempestites. We believe that similar value gradients should be present wherever local or regional heat-flow anomalies or differential burial patterns are developed. Foreland basins bordering orogens should contain such gradients and workers must be alert to this illusory color effect when working on complex facies in such settings. It is probable that many paleoenvironmental judgments may have been colored by misinterpretations of this type.

scholarly journals Depositional Heterogeneities and Brittleness of Mudstone Lithofacies in the Marcellus Subgroup, Appalachian Basin, New York, U.S.A.

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6620
Author(s):  
Izhar Ul Haq ◽  
Eswaran Padmanabhan ◽  
Omer Iqbal
Keyword(s):  
New York ◽  
Mineralogical Composition ◽  
Organic Content ◽  
Black Shales ◽  
Quartz Content ◽  
Brittle Behavior ◽  
Depositional System ◽  
The Matrix ◽  
Load Transport ◽  
Brittle Zone

Organic-rich rocks of the Marcellus subgroup in the study area consist of a diverse suite of mudstone lithofacies that were deposited in distinct facies belts. Lithofacies in the succession range in composition from argillaceous to siliceous, calcareous, and carbonaceous mudstone. Heterogeneities in the succession occurs in the form of varying mineralogical composition, slightly bioturbated to highly bioturbated chaotic matrix, organic-rich and organic-lean laminae, scattered fossil shells in the matrix, and fossils acting as lamination planes. Lithofacies were deposited in three facies belts from the proximal to the distal zone of the depositional system. Bedded siliceous mudstone (BSM) facies occur in the proximal facies belt and consists of a high quartz content in addition to clay minerals and pyrite. In the medial part of the facies belt lies the laminated argillaceous mudstone (LAM), bedded calcareous mudstone (BCaM), and bedded carbonaceous mudstone (BCM). The size of detrital mineral grains in the lithofacies of the medial facies belt is larger than bedded argillaceous mudstone (BAM) of the distal facies belt, characterized by clay-rich matrix with occasional fossil shells and horizontally aligned fossils. Two types of horizontal traces and one type of fecal string characterize the proximal mud-stone facies, whereas only single horizontal trace fossil is found in the mudstones of the medial and distal facies belt. Parallel alignment of fossil shells and fossil lags in lithofacies indicate that bed-load transport was active periodically from the proximal source of the depositional system. Bioturbation has heavily affected all of the lithofacies and presence of mottled burrows as well as Devonian fauna indicate that oxic to dysoxic conditions prevailed during deposition. The deposition of this organic-rich mudstone succession through dynamic processes in an overall oxic to dysoxic environment is different from conventional anoxic depositional models interpreted for most of the organic rich black shales worldwide. Total organic content (TOC) varies from top to bottom in the succession and is highest in BCM facies. The brittleness index, calculated on the basis of mineralogy, allowed classification of the lithofacies into three distinct zones, i.e., a brittle zone, a less brittle zone, and a ductile zone with a general proximal to distal decrease in the brittle behavior due to a decrease in the size of the sediments.

Organic facies in Devonian and Mississippian strata of Western Canada Sedimentary Basin: relation to kerogen type, paleoenvironment, and paleogeography

2004 ◽  
Vol 52 (3) ◽  
pp. 234-255 ◽  
Author(s):  
L.D. Stasiuk ◽  
M.G. Fowler
Keyword(s):  
Shallow Water ◽  
Sedimentary Basin ◽  
Black Shales ◽  
Upper Devonian ◽  
Source Rocks ◽  
Western Canada ◽  
Western Canada Sedimentary Basin ◽  
Organic Facies ◽  
Kerogen Type ◽  
Canada Sedimentary Basin

Abstract Petrographic analyses of dispersed organic matter (including macerals and palynomorphs), siliceous and calcareous microfossil assemblages and microtextures (e.g. stromatolitic) have been used to define and interpret five organic facies and regionally map their distribution for the following informal groupings of potential hydrocarbon source rocks in the Western Canada Sedimentary Basin: Upper Devonian Woodbend group, Upper Devonian Winterburn group and Upper Devonian to Lower Mississippian black shales of the Exshaw and Bakken formations. Five petrographic organic facies (A–E) are defined for the potential source rocks based on assemblages of alginites, acritarchs, sporinites, siliceous microfossils and algal mat microtextures. Organic facies A, B (prasinophyte alginites and acritarchs) and C (coccoidal alginite), represent accumulation in relatively deep (basin), intermediate (shelf-platform), and shallow water depths (bank-reef margin to lagoonal). Organic facies D is defined by siliceous microfossils (e.g. Radiolaria) and accumulated in deep basinal to outer shelf settings immediately east of an ancient Pacific Ocean, or south of an ancient Arctic Ocean. This facies may reflect regions of upwelling which extended into intracratonic and epicontinental settings. Organic facies E, characterized by stromatolitic microtextures with or without coccoidal alginite, only occur within Upper Devonian Winterburn Group shallow water, restricted shelf to lagoonal dolostones associated with evaporites. As a whole, the regional distribution of organic facies is related to paleogeography, paleobathymetry or paleostructure in the source rocks. Surprisingly, petrographic organic facies do not show strong positive correlation with kerogen type as defined by Hydrogen-Oxygen indices or TOC-S2 plots.

Redescription, paleogeography, and experimental paleoecology of the Silurian phyllocarid Gonatocaris

2020 ◽  
Vol 94 (5) ◽  
pp. 906-921
Author(s):  
Joseph H. Collette ◽  
Roy E. Plotnick
Keyword(s):  
New York ◽  
Shallow Water ◽  
South China ◽  
Experimental Work ◽  
Fine Sand ◽  
Acute Angle ◽  
Grain Sizes ◽  
The Past ◽  
Work Done ◽  
Original Type

AbstractGonatocaris decora (Clarke, 1901) is an unusual, highly ornamented Silurian phyllocarid from the Pittsford Shale Member of the Vernon Formation, Salina Group of New York, that has been allied with Emmelezoe in the past due to the possession of an ‘optic tubercle.’ The systematic positions of Gonatocaris and Emmelezoe have been difficult to assess due to the lack of complete remains, attributions based on spurious characters, and missing and unfigured specimens. Relatively recent collections of Gonatocaris decora, along with a relocation of the original type material of Emmelezoe, have allowed a reexamination of all relevant genera and a more robust systematic placement for G. decora. Characters of generic importance for Gonatocaris include a greatly elongated abdomen; an acute angle of the ventral carapace margin separating distinct anteroventral and posteroventral margins from each other; and distinctive, multiscale horizontal ridge-like ornament of the carapace valves. Growth was found to be isometric. Experimental work done using a model of the scale-like ornament and multiple grain sizes of substrate indicates that cuticle ornament may have served to increase friction between the animal and a fine sand substrate, although resistance to predation is the currently favored hypothesis. Because Gonatocaris species are currently known only from the eastern margin of Laurentia and northern South China, it is likely that this genus was nektonic. Accumulations of similarly sized carapaces and other disarticulated sclerites in shallow-water settings may indicate spawning events following molting en masse.

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