scholarly journals Diagenesis of Upper Jurassic sandstones of the Blokelv-1 core in the Jameson Land Basin, East Greenland

2018 ◽  
pp. 65-84
Author(s):  
Mette Olivarius ◽  
Rikke Weibel ◽  
Niels H. Schovsbo ◽  
Dan Olsen ◽  
Claus Kjøller
Keyword(s):  
Upper Jurassic ◽  
Late Eocene ◽  
Petrographic Analysis ◽  
Burial Depth ◽  
Early Eocene ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lower Porosity ◽  
Porosity And Permeability ◽  
Calcite Cement

Petrographic analysis combined with X-ray diffraction are used to identify the diagenetic changes that have affected the porosity and permeability of gravity-flow sandstones of the Oxfordian–Volgian Hareelv Formation in the cored Blokelv-1 borehole in Jameson Land. Kaolinite replacement of albite grains probably occurred early after deposition and microquartz coatings formed under shallow burial. At deeper burial, illite and quartz formed from kaolinite and K-feldspar. Pervasive ankerite cement formed in the finest grained sandstones and may have formed at the expense of early calcite cement. Quartz overgrowths are volumetrically small, partly due to inhibition by microquartz coatings and partly due to limited residence time during deep burial. The succession reached the maximum burial depth of c. 2.8 km during the late Eocene. Basaltic material was intruded into the sediments during the early Eocene and the enhanced heat flow accelerated diagenesis in the close vicinity of the intrusions, which have thicknesses of up to 2 m. Most of the sandstones have porosities between 14.4 and 25.7% and permeabilities between 0.4 and 411.9 mD; this variation resulted from a combination of microquartz coatings and clay minerals. However, the intrusion-influenced sandstones and the ankerite-cemented sandstones have lower porosity and permeability.

scholarly journals First Report on the Geologic Occurrence of Natural Na–A Zeolite and Associated Minerals in Cretaceous Mudstones of the Paja Formation of Vélez (Santander), Colombia

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Carlos Alberto Ríos-Reyes ◽  
German Alfonso Reyes-Mendoza ◽  
José Antonio Henao-Martínez ◽  
Craig Williams ◽  
Alan Dyer
Keyword(s):  
Natural Zeolite ◽  
Scanning Electron Micrographs ◽  
Total Sulfur ◽  
Zeolite A ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Phases ◽  
The World ◽  
Porosity And Permeability ◽  
First Time

This study reports for the first time the geologic occurrence of natural zeolite A and associated minerals in mudstones from the Cretaceous Paja Formation in the urban area of the municipality of Vélez (Santander), Colombia. These rocks are mainly composed of quartz, muscovite, pyrophyllite, kaolinite and chlorite group minerals, framboidal and cubic pyrite, as well as marcasite, with minor feldspar, sulphates, and phosphates. Total organic carbon (TOC), total sulfur (TS), and millimeter fragments of algae are high, whereas few centimeters and not biodiverse small ammonite fossils, and other allochemical components are subordinated. Na–A zeolite and associated mineral phases as sodalite occur just beside the interparticle micropores (honeycomb from framboidal, cube molds, and amorphous cavities). It is facilitated by petrophysical properties alterations, due to processes of high diagenesis, temperatures up to 80–100 °C, with weathering contributions, which increase the porosity and permeability, as well as the transmissivity (fluid flow), allowing the geochemistry remobilization and/or recrystallization of pre-existing silica, muscovite, kaolinite minerals group, salts, carbonates, oxides and peroxides. X-ray diffraction analyses reveal the mineral composition of the mudstones and scanning electron micrographs show the typical cubic morphology of Na–A zeolite of approximately 0.45 mμ in particle size. Our data show that the sequence of the transformation of phases is: Poorly crystalline aluminosilicate → sodalite → Na–A zeolite. A literature review shows that this is an unusual example of the occurrence of natural zeolites in sedimentary marine rocks recognized around the world.

Effect of P2O5 on the Properties of Alite-Calcium Strontium Sulphoaluminate Cement

2011 ◽  
Vol 306-307 ◽  
pp. 961-965
Author(s):  
Chao Nan Yin ◽  
Ling Chao Lu ◽  
Shou De Wang
Keyword(s):  
Compressive Strength ◽  
Electron Microscope ◽  
Heat Evolution ◽  
Petrographic Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sulphoaluminate Cement ◽  
Suitable Amount ◽  
Acceleration Period ◽  
Scanning Electron

The influence of P2O5on the properties of alite-calcium strontium sulphoaluminate cement was researched by means of X-ray diffraction, scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) and petrographic analysis. The results show that the optimal content of P2O5is 0.3% and the compressive strength of the cement at 1, 3, 28d are 27.0, 59.1, 110.9MPa when the calcining temperature is 1350°C. P2O5mainly exists in the belite and a suitable amount of P2O5can promote the formation of C1.5Sr2.5A3and alite. When the content of P2O5is higher than 0.3%, the formation of C1.5Sr2.5A3and alite can be hindered. P2O5can enhance the hydration heat evolution rate in the acceleration period and the hydrate heat of cement containing P2O5increases slightly.

scholarly journals 14C Dating and Material Analysis of the Lime Burial of Cova de Na Dent (Mallorca, Spain)

Radiocarbon ◽  
2014 ◽  
Vol 56 (2) ◽  
pp. 387-398 ◽  
Author(s):  
Guy De Mulder ◽  
Roald Hayen ◽  
Mathieu Boudin ◽  
Tess Van den Brande ◽  
Louise Decq ◽  
...  
Keyword(s):  
Bronze Age ◽  
Simultaneous Thermal Analysis ◽  
Balearic Islands ◽  
Crushed Rock ◽  
Petrographic Analysis ◽  
X Ray Diffraction ◽  
14C Dating ◽  
X Ray ◽  
Bone Fragments ◽  
The Bronze Age

Lime burials are a characteristic phenomenon of the protohistoric funerary tradition on the Balearic Islands. At Cova de Na Dent, a lime burial has been sampled for analysis. The lime burial was made up of lime and fragmented bones. Six layers were sampled and described in the laboratory according to their color, the consistency of the deposition, and the aspect and quantity of the bone fragments. Bone samples and lime were dated. The lime was analyzed by using petrographic analysis, X-ray diffraction, FTIR spectroscopy, and simultaneous thermal analysis. The results show that the bones were cremated in the presence of crushed rock carbonate. The14C dates on the lime suggest an earlier chronology for this ritual, starting in the Bronze Age, as generally is accepted.

scholarly journals Mineralogical Study of Levels with Magnesian Clay Minerals in the Santos Basin, Aptian Pre-Salt Brazil

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 970
Author(s):  
Maurício Dias da Silva ◽  
Márcia Elisa Boscato Gomes ◽  
André Sampaio Mexias ◽  
Manuel Pozo ◽  
Susan Martins Drago ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Clay Fraction ◽  
Total Sample ◽  
Petrographic Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineralogical Study ◽  
Original Rock ◽  
Mixed Layers

The object of this study is magnesian clay minerals present in carbonate rocks of the post-rift phase of the pre-salt in the Santos Basin. These rocks developed in an Aptian-age alkaline lacustrine environment. This study summarizes the formation of clay minerals associated with different lithotypes in a range of 19 m and a depth of more than 5100 m. They were characterized from petrographic analysis by optical microscopy, X-ray diffraction (total sample and clay fraction), and modeling by Newmod®; and examined and analyzed by scanning electron microscopy. An approach based on identifying lithotypes and characterization of microsites allowed us to understand the occurrence of different clay minerals. Kerolite was the most abundant mineral in the sampled range. It occurs in lamellar aggregates under greater preservation of the original rock lamination and in association with spherulites and shrubs. The Stv/Ker mixed layers occurs in the same association, and formed finer unlaminated aggregates associated with the more intense dolomitization and silicification processes. Saponite occurs associated with detrital minerals forming clayey levels intercalated with microcrystalline carbonates. Fluids with a high Mg/Si and pH < 9 favor the precipitation of kerolite. The increase in pH during diagenesis may be responsible for the formation of Stv/Ker mixed layers.

scholarly journals Reservoir Quality of Upper Jurassic Corallian Sandstones, Weald Basin, UK

Geosciences ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 446
Author(s):  
Dinfa Vincent Barshep ◽  
Richard Henry Worden
Keyword(s):  
Carbon Capture ◽  
Carbon Capture And Storage ◽  
Upper Jurassic ◽  
Reservoir Quality ◽  
Main Process ◽  
Shallow Marine ◽  
Porosity And Permeability ◽  
Calcite Cement ◽  
Diagenetic Evolution

The Upper Jurassic, shallow marine Corallian sandstones of the Weald Basin, UK, are significant onshore reservoirs due to their future potential for carbon capture and storage (CCS) and hydrogen storage. These reservoir rocks, buried to no deeper than 1700 m before uplift to 850 to 900 m at the present time, also provide an opportunity to study the pivotal role of shallow marine sandstone eodiagenesis. With little evidence of compaction, these rocks show low to moderate porosity for their relatively shallow burial depths. Their porosity ranges from 0.8 to 30% with an average of 12.6% and permeability range from 0.01 to 887 mD with an average of 31 mD. The Corallian sandstones of the Weald Basin are relatively poorly studied; consequently, there is a paucity of data on their reservoir quality which limits any ability to predict porosity and permeability away from wells. This study presents a potential first in the examination of diagenetic controls of reservoir quality of the Corallian sandstones, of the Weald Basin’s Palmers Wood and Bletchingley oil fields, using a combination of core analysis, sedimentary core logs, petrography, wireline analysis, SEM-EDS analysis and geochemical analysis to understand the extent of diagenetic evolution of the sandstones and its effects on reservoir quality. The analyses show a dominant quartz arenite lithology with minor feldspars, bioclasts, Fe-ooids and extra-basinal lithic grains. We conclude that little compactional porosity-loss occurred with cementation being the main process that caused porosity-loss. Early calcite cement, from neomorphism of contemporaneously deposited bioclasts, represents the majority of the early cement, which subsequently prevented mechanical compaction. Calcite cement is also interpreted to have formed during burial from decarboxylation-derived CO2 during source rock maturation. Other cements include the Fe-clay berthierine, apatite, pyrite, dolomite, siderite, quartz, illite and kaolinite. Reservoir quality in the Corallian sandstones show no significant depositional textural controls; it was reduced by dominant calcite cementation, locally preserved by berthierine grain coats that inhibited quartz cement and enhanced by detrital grain dissolution as well as cement dissolution. Reservoir quality in the Corallian sandstones can therefore be predicted by considering abundance of calcite cement from bioclasts, organically derived CO2 and Fe-clay coats.

Influence of High-silicon Limestone on Mineral Structure and Performance of Belite-Barium Calcium Sulphoaluminate Clinker

2010 ◽  
Vol 168-170 ◽  
pp. 460-465 ◽  
Author(s):  
Pi Qi Zhao ◽  
Ling Chao Lu ◽  
Shou De Wang
Keyword(s):  
Raw Materials ◽  
Decomposition Temperature ◽  
Cement Clinker ◽  
Petrographic Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Structure ◽  
Calcium Sulphoaluminate ◽  
High Silicon ◽  
And Performance

The mineral structure and performance of belite-barium calcium sulphoaluminate cement clinker were investigated by petrographic analysis, X-ray diffraction and scanning electron microscopy, while raw materials were studied by differential thermal analysis, thermogravimetric analysis and X-ray diffraction. The results show that high-silicon limestone has low decomposition temperature which can promote the development of alite by adding small quantity. The formation and development of C3S is hindered in α-quartz while C3S is formed easily by mixing magnesite and dolomite in the low temperature. The proper proportions of high-silicon limestone and ordinary limestone is 1:5, and the compressive of this cement at 3, 7, 28 d are 37.9, 60.3, 87.9 MPa, which shows excellent mechanical properties.

Catagenesis in shales and occurrence of authigenic clays in sandstones, North Sabine H-49 well, Canadian Arctic Islands

1979 ◽  
Vol 16 (6) ◽  
pp. 1309-1314 ◽  
Author(s):  
A. E. Foscolos ◽  
T. G. Powell
Keyword(s):  
Electron Microscopy ◽  
Canadian Arctic ◽  
Burial Depth ◽  
X Ray Diffraction ◽  
X Ray ◽  
The North ◽  
Physico Chemical ◽  
Sverdrup Basin ◽  
Chemical Conditions ◽  
Scanning Electron

Authigenic clays in eight sandstone samples from the North Sabine H-49 well in the Sverdrup Basin, N.W.T., have been studied by X-ray diffraction and scanning electron microscopy. The following sequence of authigenic minerals was observed with increasing burial depth: quartz–kaolinite, illitic 2:1 layer silicates, and chlorite. It is suggested that the formation of authigenic clays in sandstones can be considered in the context and as a product of catagenesis of adjacent shales. Upon burial, water is released from the shales by compaction, clay dehydration, and clay destruction. Continuing compaction carries the products of clay transformation to the sandstones where they precipitate to form authigenic clays. The nature of the authigenic clay is directly related to the physico-chemical conditions existing at various depths.

Microstructural and Microanalytical Study on Cementitious Materials Subjected to the Cyclic Sulfate Environment

2014 ◽  
Vol 898 ◽  
pp. 371-374
Author(s):  
Xiao Lu Yuan
Keyword(s):  
Electron Microscope ◽  
Mercury Intrusion Porosimetry ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mercury Intrusion ◽  
Lower Porosity ◽  
Scanning Electron

Microstructural properties have been studied in cementitious materials, which were subjected to cyclic sulfate exposure, through x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and mercury intrusion porosimetry (MIP). Results indicate that portlandite in OPC concrete and OPC-FA concrete is mainly converted to gypsum. Portlandite in OPC-GBFS concrete is mainly converted to gypsum and ettringite. Concrete subjected to the cyclic sulfate attack has a lower porosity and the higher amount of macro-pores than that before exposure. Concretes incorporating FA or GBFS had lower porosity and higher amount of micro-pores than OPC concrete.

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