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.

Characterization of organic content, brittleness index and geomechanical properties of the Eocene Cambay Shales – Insights from the Ankleshwar oil field in Western India

2020 ◽  
pp. 1-67
Author(s):  
Shib Sankar Ganguli ◽  
Souvik Sen ◽  
Sumit Verma
Keyword(s):  
Mineralogical Composition ◽  
Resource Assessment ◽  
Organic Content ◽  
Oil Field ◽  
Brittleness Index ◽  
Western India ◽  
Reservoir Properties ◽  
Geomechanical Properties ◽  
Brittle Zone

Shale resource assessment involves a detailed characterization of organic and geomechanical parameters for better insights on the reservoir properties and classifying areas of economic yield. In order to assess the Eocene Younger Cambay Shale (YCS) Group of the Ankleshwar field, western India for feasible shale resource play, we have applied a multistage screening methodology that combines estimation of organic richness, brittleness index, and geomechanical analyses. The estimated thermal maturity (Ro) and average total organic carbon (TOC) contents are within the range of 0.8-1.0 and 1.8 wt%, respectively. These estimates are comparable to the reported core-based measurements. Brittleness index (BI) based on the mineralogical composition reveals that the YCS intervals of marine origin fall into the ‘less ductile’ to ‘brittle’ zone, whereas the elastic property based estimated BI falls into the ‘less brittle’ to ‘high brittle’ zone. We established a field relationship between BI and shale volume and also deciphered the effect of TOC content on the rock elastic properties. Pore pressure in the shales is slightly above the hydrostatic gradient (10.5-11.5 MPa/km). The estimated average fracture pressure of 18.5 MPa/km, together with the BI of moderately ductile to less brittle behavior suggests that the studied shales are capable of withstanding substantial strain while hydrofracturing for effective production. We demonstrate an expedient example to characterize a potential shale unit within a producing hydrocarbon field utilizing the drilled wells with limited or no core data.

Studies in the geology and mineralogy of soils: II. Soils of South-East Scotland

1929 ◽  
Vol 19 (4) ◽  
pp. 802-813 ◽  
Author(s):  
R. Hart
Keyword(s):  
Mineral Content ◽  
Mineralogical Composition ◽  
Fine Sand ◽  
Parent Material ◽  
The South ◽  
Sand Fraction ◽  
Silicate Minerals ◽  
Fresh State ◽  
The Matrix

(1) The mineralogical composition of the fine sand fraction of certain soils from the south-east of Scotland is described.(2) The soils are shown to possess a fairly high content of silicate minerals in a comparatively fresh state.(3) The distribution and amount of potash, phosphate and lime-bearing minerals in the soils is discussed.(4) The soils can be grouped according to their mineral content and this grouping is found to depend on the geology of the parent material.(5) All the soils are formed on glacial drift and the results suggest that the local rocks have a preponderating influence on the composition of the matrix of the drift.

CASE STUDY OF THE CONVERGENCY OF NONLINEAR PERTURBATION SERIES: MORSE–FESHBACH NONLINEAR SERIES

1999 ◽  
Vol 14 (13) ◽  
pp. 2103-2115 ◽  
Author(s):  
BISWANATH RATH
Keyword(s):  
New York ◽  
Energy Levels ◽  
Perturbation Series ◽  
Nonlinear Perturbation ◽  
Theoretical Physics ◽  
The Matrix ◽  
Diagonalization Method ◽  
Matrix Diagonalization ◽  
Divergent Behavior

We study the divergent behavior of the Morse–Feshbach nonlinear perturbation series (MFNS) [P. M. Morse and H. Feshbach, Methods of Theoretical Physics, Part II (McGraw-Hill, New York, 1953)] for producing convergent energy levels using the ground state of a quartic anharmonic oscillator (AHO) in the strong coupling limit. Numerical calculations have been done up to tenth order. Further comparison of the MFNS convergent result has been made with the matrix diagonalization method.

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.

Factors affecting the nanopore structure and methane adsorption capacity of organic-rich marine shales in Zhaotong area, Southern Sichuan Basin

2020 ◽  
Vol 8 (2) ◽  
pp. T403-T419
Author(s):  
Panke Sun ◽  
Hanqing Zhu ◽  
Huaimin Xu ◽  
Xiaoni Hu ◽  
Linfeng Tian
Keyword(s):  
Adsorption Capacity ◽  
Sichuan Basin ◽  
Clay Content ◽  
Mineralogical Composition ◽  
Methane Adsorption ◽  
Gas Content ◽  
Quartz Content ◽  
Structure Characteristics ◽  
Longmaxi Shale ◽  
Nanopore Structure

As a national shale-gas demonstration zone in China, the Zhaotong area has great gas resource potential. However, the nanopore structure characteristics, methane adsorption capacity, and their affecting factors of the Lower Silurian Longmaxi Shale in this area remain unclear. To address these puzzles, we conducted a series of experiments, such as X-ray diffraction, field emission scanning electron microscopy, low-pressure [Formula: see text] adsorption, and high-pressure methane adsorption, and we calculated the relevant characteristic parameters, such as pore volume (PV), specific surface area (SSA), fractal dimension, and Langmuir parameters by using the nonlocal density functional theory method, Frenkel-Halsey-Hill theory, and Langmuir model, respectively. The results indicate that the nanopores of the Lower Longmaxi Shale in the Zhaotong area are composed of micropores and mesopores, which mainly exist as organic matter (OM) pores. The pore surface exhibits a high degree of heterogeneity as indicated by the fractal dimensions ranging from 2.845 to 2.866. The nanopore structure characteristics (i.e., SSA and PV) and methane adsorption capacity are mainly controlled by the total organic carbon (TOC) content. In addition, the mineralogical composition (i.e., the quartz and clay content) also contributes significantly to the micropore PV and gas content. The external provenance has a significant effect on the mineralogical composition, TOC content, and methane adsorption capacity. With the increasing influence of the external provenance, the biogenic quartz content decreases and the relationship between the quartz content and TOC content becomes more discrete, which indicates the change of depositional environment, and the clay content increases, which can dilute the OM concentration during the deposition and enhance the compaction potential, and it can eventually result in less gas content. The results of this study reveal the nanopore system characteristics of the Longmaxi Shale in the Zhaotong area and provide further insight into the influence of external provenance on reservoir characteristics and gas content variability of the Lower Longmaxi Shale in the southern Sichuan Basin.

scholarly journals Identification of early Llandovery (Silurian) anoxic palaeo-depressions at the western margin of the Murzuq Basin (southwest Libya), based on gamma-ray spectrometry in surface exposures

GeoArabia ◽  
2006 ◽  
Vol 11 (3) ◽  
pp. 101-118 ◽  
Author(s):  
Nuri Fello ◽  
Sebastian Lüning ◽  
Petr Štorch ◽  
Jonathan Redfern
Keyword(s):  
Black Shale ◽  
Gamma Ray ◽  
Regional Distribution ◽  
Uranium Content ◽  
Organic Content ◽  
Black Shales ◽  
Gamma Ray Spectrometry ◽  
Hydrocarbon Source Rock ◽  
Western Margin ◽  
Anoxic Event

ABSTRACT Following the melting of the Gondwanan icecap and the resulting postglacial sea-level rise, organic-rich shales were deposited in shelfal palaeo-depressions across North Africa and Arabia during the latest Ordovician to earliest Silurian. The unit is absent on palaeohighs that were flooded only later when the anoxic event had already ended. The regional distribution of the Silurian black shale is now well-known for the subsurface of the central parts of the Murzuq Basin, in Libya, where many exploration wells have been drilled and where the shale represents the main hydrocarbon source rock. On well logs, the Silurian black shale is easily recognisable due to increased uranium concentrations and, therefore, elevated gamma-ray values. The uranium in the shales “precipitated” under oxygen-reduced conditions and generally a linear relationship between uranium and organic content is developed. The distribution of the Silurian organic-rich shales in the outcrop belts surrounding the Murzuq Basin has been long unknown because Saharan surface weathering has commonly destroyed the organic matter and black colour of the shales, making it complicated to identify the previously organic-rich unit in the field. In an attempt to distinguish (previously) organic-rich from organically lean shales at outcrop, seven sections that straddle the Ordovician-Silurian boundary were measured by portable gamma-ray spectrometer along the outcrops of the western margin of the Murzuq Basin. It was found that the uranium content of the shales remained largely unaltered by the weathering processes and could therefore be used as a valid proxy parameter to distinguish between pre-weathering organically rich and lean shales. It is now possible to identify and map-out the thickness and approximate organic richness of the black shale using measurement of uranium radiation. Five of the newly measured sections are characterised by uranium-enriched intervals, representing areas of earliest Silurian palaeo-depressions. Major uranium peaks are absent in the spectral gamma-ray curves of two other sections, which are interpreted to mark earliest Silurian palaeo-highs. The new data on the distribution of Silurian black shales from the outcrop belt was integrated with subsurface data from the Murzuq Basin. The resulting map of the distribution of black shales may help with predictions of the occurrence of this unit in less well-explored areas of the basin. Graptolite biostratigraphic data suggests that the anoxic event centred on the middle Rhuddanian, with more oxygenated conditions and onset of deposition of organically leaner shales having commenced sometime during the late Rhuddanian. The presence of anoxic palaeo-depressions during the earliest Silurian within the Ghat outcrop belt indicates that the Tihemboka High at the western margin of the Murzuq Basin could not have been a positive structure during this time.

scholarly journals Tensile Characteristics of Bio-Composite Material Reinforced with Corn Skin

2021 ◽  
Vol 53 (5) ◽  
pp. 210513
Author(s):  
Jefri Bale ◽  
Yeremias Pell ◽  
Kristomus Boimau ◽  
Boy Bistolen ◽  
Dion Rihi
Keyword(s):  
Tensile Tests ◽  
Point Of View ◽  
Matrix Cracking ◽  
Specimen Thickness ◽  
Brittle Behavior ◽  
Pull Out ◽  
Calculated Stress ◽  
Chip Fracture ◽  
Final Failure ◽  
The Matrix

The main focus of the present work was to study corn skin as reinforcement of polyester bio-composite (CSPCs). The effect of reinforcement type, i.e. short fibers and discontinuous chips, on the tensile properties was studied. The corn skin materials were chemically treated with NaOH and added as reinforcement of polyester bio-composite using the hand lay-up fabrication method. Tensile tests were carried out according to ASTM D3039. The tensile strength characteristics of stress and modulus showed a different behavior between the two types of reinforcement due to a slight difference in specimen thickness, which affected the calculated stress and modulus values. Furthermore, from a physical properties point of view, the larger surface area of CSC compared to CSF, which still contains a lignin layer after the treatment with NaOH, could decrease the interfacial bonding between polyester as the matrix and CSC as the reinforcement. The tensile damage characteristics showed brittle behavior, propagataing perpendicular to the loading direction. Matrix cracking and interfacial debonding were identified as the main two damage modes of the CSF bio-composite and the CSC bio-composite, where the final failure was dominated by fiber pull out and chip fracture.

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

Comment Clauses and mood choice in New York City Spanish

2019 ◽  
Vol 10 (5) ◽  
pp. 728-744
Author(s):  
Kevin Martillo Viner
Keyword(s):  
New York ◽  
New York City ◽  
York City ◽  
Generational Differences ◽  
First Generation ◽  
Matrix Clause ◽  
Conditioning Factors ◽  
Two Generations ◽  
The Matrix ◽  
Grammatical Mood

Abstract This paper focuses on Spanish grammatical mood variation in Comment Clauses (e.g., es mejor que no vayas (subjunctive) / vas (indicative) ‘it’s better you not go’) in the speech of two generations in New York City. The data come from 36 participants, 18 from each of two generational cohorts. Carried out within the variationist-sociolinguistic research paradigm, we test grammatical mood against eight variables, four external (generation, region, speaker sex, language skill) and four internal (grammatical tense, clause type, lexical identity, negation). Statistical findings reveal that generation significantly conditions subjunctive use (the first generation has a significantly higher rate of use of subjunctive forms than does the second generation); English skill conditions first-generation subjunctive use (those with ‘good or excellent’ English skills have a higher subjunctive rate than those with ‘fair or poor’ English skills); clause type conditions both generations’ subjunctive use (impersonal constructions yield a higher subjunctive rate than personal constructions); lexical identity and negation in the matrix clause both condition first-generation use of mood (gustar ‘to like’ favors the indicative; importar ‘to be important’ and ser + impersonal expression ‘to be’ both favor the subjunctive). Generational differences are thus observed with respect to both social and linguistic conditioning factors.

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