scholarly journals Petrograpic and material observations of basaltic lapilli tuff, 1979 and 2017 Surtsey drill cores, Iceland

2020 ◽  
Vol 14 ◽  
pp. 47-62
Author(s):  
Marie D. Jackson
Keyword(s):  
Water Absorption ◽  
Time Lapse ◽  
Dry Density ◽  
High Porosity ◽  
Thin Sections ◽  
Depositional Processes ◽  
Alteration Processes ◽  
Lapilli Tuff ◽  
Microtubular Structures ◽  
Drill Cores

Petrographic studies of thin sections from the 1979 and 2017 Surtsey drill cores provide new insights into microstructural features in basaltic lapilli tuff sampled from the principal structural and hydrothermal zones of the volcano. These describe narrow rims of fine ash on altered glass pyroclasts in thin sections of the 2017 cores, characteristics of granular and microtubular structures in the original thin sections of the 1979 core, and glass alteration in diverse environments. The narrow ash rims follow the outlines of glass pyroclasts in the subaerial tuff cone and in submarine and sub-seafloor deposits; they suggest complex eruptive and depositional processes. The tubular microstructures resemble endolithic microborings in older oceanic basalt; they suggest possible microbial activity. Tubule lengths indicate rapid growth rates, up to 30 µm in ~15 years. Comparisons of glass alteration in thin sections prepared immediately after drilling in 1979 and 2017 indicate differential time-lapse alteration processes in the structural and hydrothermal zones of the volcano. In contrast, thin sections of the 1979 core prepared after 38 years in the repository reveal labile glass alteration during archival storage. The oven-dry density of the sub-seafloor lapilli tuff decreases in 2017 samples with high porosity and water absorption and increases in 2017 samples with a compact ash matrix and lower water absorption. The petrographic descriptions and material measurements provide a foundational reference for further investigations of explosive eruption and deposition of basaltic tephra at Surtsey and the subsequent alteration of these deposits in the volcanic environment and, potentially, the curatorial environment.

Observations on the Structure of Surtsey, Iceland, and its Basaltic Lapilli Tuff

2020 ◽  
Author(s):  
James G. Moore ◽  
Marie D. Jackson
Keyword(s):  
Thermal Anomaly ◽  
High Water ◽  
Unit Weight ◽  
High Porosity ◽  
The South ◽  
Dynamic Surface ◽  
Near Surface ◽  
Thin Sections ◽  
Lapilli Tuff ◽  
Comparison Of The Results

<p>Comparison of the results of new investigations of the 1979 and 2017 cored boreholes coupled with observations of the dynamic surface of Surtsey have modified our concepts of the subsurface structure of the volcano, an oceanic island erupted from 1963–1967 on the insular shelf of the south coast of Iceland. The temperature anomalies in the 2017 vertical and inclined boreholes closely resembled each other in shape and magnitude even though they are 80 m apart horizontally. The peak temperature of the vertical hole anomaly immediately after drilling was 124 °C at 105 m below surface (m.b.s.) and the inclined hole anomaly 127 °C at 115 m.b.s. This temperature anomaly and the paucity of coherent basalt in the 2017 cores casts doubt on a previous concept — that the heat anomaly in the 1979 borehole, 141 °C at 100–106 m.b.s., was due to nearby intrusions. The new observations suggest instead that top-down heating from the subaerial lava shield may have contributed to the Surtsey thermal anomaly.  In August 1966–June 1967, lava flows rapidly filled the Surtur vent crater to 80 m.b.s. and overflowed to the south and east. The conduction of heat from the cooling shield into the water-saturated substrate would have been influenced by the material characteristics of the underlying lapilli tuff, but the mechanisms of downwards heat transfer are not clear. In the zone of tidal flux centred at ~58 m.b.s., for example, the tuff was highly porous in 1979 and it remains porous and permeable 50 years after eruptions terminated. Boiling of interstitial water below sea level could have produced steam that rose and warmed the porous and permeable tephra adjacent to the lava shield, where it produced broad areas of palagonitized tuff.  Other sources of heat are also under consideration. At 107 m.b.s., fresh glass in the lapilli tuff of the original 1979 thin sections contains abundant granular and microtubular structures. These resemble endolithic microborings, and they are perhaps indicative of an early, short-lived episode of cooler temperatures and functional microbial activity at <120 °C. A geometrical analysis of layering in unrolled digital scans of the 2017 cores indicates that the relation of the apparent dip to the true dip of layering in the core inclined 55° from horizontal is such that steep dips are more common in westerly true dips, and gentle dips are more common in easterly true dips. The measurements indicate that near-surface layering in both the vertical and inclined cores dips westerly, suggesting that the boreholes are located inside the Surtur crater.  In this proximal setting, the section of lapilli tuff may be almost entirely composed of facies re-sedimented from unstable depositional sites and/or recycled through the vent perhaps multiple times. Sub-seafloor lapilli tuff samples with high porosity, high water absorption and low unit weight may reflect these complex eruptive processes. The new observations support the hypothesis that broad conduit and vent filling deposits underlie the Surtur crater.</p>

scholarly journals Lithofacies from the 1963-1967 Surtsey eruption in SUSTAIN drill cores SE-2a, SE-2b and SE-03

2020 ◽  
Vol 14 ◽  
pp. 19-32
Author(s):  
Jocelyn McPhie ◽  
James D.L. White ◽  
Carolyn Gorny ◽  
Marie D. Jackson ◽  
Magnús Tumi Gudmundsson ◽  
...  
Keyword(s):  
Hydrothermal Alteration ◽  
Sedimentary Facies ◽  
Drill Hole ◽  
Explosive Eruptions ◽  
Volcanic System ◽  
Sea Floor ◽  
Alteration Processes ◽  
Lapilli Tuff ◽  
Drill Holes ◽  
Drill Cores

Surtsey was drilled in 2017 in the context of the Surtsey Underwater volcanic System for Thermophiles, Alteration processes and INnovative Concretes (SUSTAIN) project. Vertical drill holes, SE-02a and SE02b (drilled to 191.64 m), and angled drill SE-03 (drilled to 354.05 m), intersected armoured lapilli tuff and lapilli tuff generated mainly by explosive eruptions at Surtur from November 1963 to January 1964. The top ~20 m of lapilli tuff was erupted from Surtungur. Intervals of coherent basalt in SE-02b (15.7 to 17 m and <15 cm at the end) and in SE-03 (<1 m at ~60 m and ~238 m, and 10 m near the base) are probably intrusions that may have fed the small lavas erupted at Surtur ~2.5 years later. Although collared only a few m from the 1979 drill hole, neither SE-02a nor SE-02b intersected the 13-m-thick interval of basalt found in the 1979 drill hole. The 2017 drill cores are entirely lithified and variably altered, reflecting the effects of hydrothermal alteration and cement deposition on the originally fresh, unconsolidated ash and lapilli. Drill hole SE-03 was drilled on an azimuth of 264o and at 55o from horizontal, obliquely crossing the crater- and conduit-fill of Surtur. Although the exact trajectory of SE-03 is unknown (the drill hole was not surveyed), the drill hole ended at a vertical depth of ~100 m below the pre-eruption sea floor, however, sedimentary facies known to underlie the sea floor nearby were not intersected. Surtur eruptions therefore excavated the pre-eruption sea floor to a depth of several tens of m.

Permeability-porosity transforms from small sandstone fragments

Geophysics ◽  
2006 ◽  
Vol 71 (1) ◽  
pp. N11-N19 ◽  
Author(s):  
Ayako Kameda ◽  
Jack Dvorkin ◽  
Youngseuk Keehm ◽  
Amos Nur ◽  
William Bosl
Keyword(s):  
Pore Space ◽  
Petroleum Industry ◽  
Rock Physics ◽  
Three Dimensions ◽  
Absolute Permeability ◽  
High Porosity ◽  
Drill Cuttings ◽  
Thin Sections ◽  
Numerical Experimentation ◽  
The Absolute

Numerical simulation of laboratory experiments on rocks, or digital rock physics, is an emerging field that may eventually benefit the petroleum industry. For numerical experimentation to find its way into the mainstream, it must be practical and easily repeatable — i.e., implemented on standard hardware and in real time. This condition reduces the size of a digital sample to just a few grains across. Also, small physical fragments of rock, such as cuttings, may be the only material available to produce digital images. Will the results be meaningful for a larger rock volume? To address this question, we use a number of natural and artificial medium- to high-porosity, well-sorted sandstones. The 3D microtomography volumes are obtained from each physical sample. Then, analogous to making thin sections of drill cuttings, we select a large number of small 2D slices from a 3D scan. As a result, a single physical sample produces hundreds of 2D virtual-drill-cuttings images. Corresponding 3D pore-space realizations are generated statistically from these 2D images; fluid flow is simulated in three dimensions, and the absolute permeability is computed. The results show that small fragments of medium– to high-porosity sandstones that are statistically subrepresentative of a larger sample will not yield the exact porosity and permeability of the sample. However, a significant number of small fragments will yield a site-specific permeability-porosity trend that can then be used to estimate the absolute permeability from independent porosity data obtained in the well or inferred from seismic techniques.

Comprehensive Characterization of Agricultural By-Products for Bio-Aggregate Based Concrete

2022 ◽  
Author(s):  
Herinjaka Haga Ratsimbazafy ◽  
Aurélie Laborel-Préneron ◽  
Camille Magniont ◽  
Philippe Evon
Keyword(s):  
Water Absorption ◽  
Building Materials ◽  
Complete Characterization ◽  
Water Soluble ◽  
Dry Density ◽  
Characterization Methods ◽  
Manufacturing Method ◽  
West Part ◽  
Hemp Shiv ◽  
By Products

The valorization of available agricultural by-products is important for the development of bio-aggregate based concretes as eco-friendly solutions for building materials. However, their diversity requires to assess their potential of use in vegetal concretes. This study aims to propose simple and relevant multi-physical characterization methods for plant aggregates. Basic and complementary characterizations were carried out on hemp shiv as a reference plant aggregate, and nine by-products available in the South-West part of France, i.e., oleaginous flax shiv, sunflower pith and bark, coriander straw, wheat straw, wheat chaff, corn shuck, miscanthus stem and vine shoot. The basic characterizations performed were those recommended by the TC-RILEM 236 BBM, i.e., particle size distribution, bulk density, water absorption and thermal conductivity. Complementary characterizations have also been proposed, taking into account the possible environment of the binder and the vegetal concrete manufacturing method. The additional tests developed or adapted from previous research assess the following properties: the content of water-soluble compounds at pH 7 and 12, the dry density of plant aggregates compacted in wet state, the real water absorption after compaction and the compression behavior of these compacted aggregates. This complete characterization highlights the distinct behavior of the different agroresources and allows to correlate these characteristics to the use properties of hardened composites.

scholarly journals Preparation and characteristics of gelatin sponges crosslinked by microbial transglutaminase

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3665 ◽  
Author(s):  
Haiyan Long ◽  
Kunlong Ma ◽  
Zhenghua Xiao ◽  
Xiaomei Ren ◽  
Gang Yang
Keyword(s):  
Cell Proliferation ◽  
Water Absorption ◽  
Crosslinking Agent ◽  
Microbial Transglutaminase ◽  
High Porosity ◽  
Cell Compatibility ◽  
High Viability ◽  
Good Biocompatibility ◽  
The Stability

Microbial transglutaminase (mTG) was used as a crosslinking agent in the preparation of gelatin sponges. The physical properties of the materials were evaluated by measuring their material porosity, water absorption, and elastic modulus. The stability of the sponges were assessed via hydrolysis and enzymolysis. To study the material degradation in vivo, subcutaneous implantations of sponges were performed on rats for 1–3 months, and the implanted sponges were analyzed. To evaluate the cell compatibility of the mTG crosslinked gelatin sponges (mTG sponges), adipose-derived stromal stem cells were cultured and inoculated into the scaffold. Cell proliferation and viability were measured using alamarBlue assay and LIVE/DEAD fluorescence staining, respectively. Cell adhesion on the sponges was observed by scanning electron microscopy (SEM). Results show that mTG sponges have uniform pore size, high porosity and water absorption, and good mechanical properties. In subcutaneous implantation, the material was partially degraded in the first month and completely absorbed in the third month. Cell experiments showed evident cell proliferation and high viability. Results also showed that the cells grew vigorously and adhered tightly to the sponge. In conclusion, mTG sponge has good biocompatibility and can be used in tissue engineering and regenerative medicine.

scholarly journals Partial Replacement of Cement with Waste Paper Sludge Ash

2021 ◽  
Vol 9 (11) ◽  
pp. 1975-1983
Author(s):  
Shahid Bashir
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Cement Industry ◽  
Waste Paper ◽  
Partial Replacement ◽  
Dry Density ◽  
Paper Sludge ◽  
Paper Sludge Ash ◽  
Sludge Ash

Abstract: Cement production is one of the sources that emit carbon dioxide, in addition to deforestation and combustion of fossil fuels also leads to ill effects on environment. The global cement industry accounts for 7% of earth’s greenhouse gas emission. To enhance the environmental effects associated with cement manufacturing and to constantly deplore natural resources, we need to develop other binders to make the concrete industry sustainable. This work offers the option to use waste paper sludge ash as a partial replacement of cement for new concrete. In this study cement in partially replaced as 5%, 10%, 15% and 20% by waste paper sludge ash in concrete for M25 mix and tested for compressive strength, tensile strength, water absorption and dry density up to the age of 28days and compared it with conventional concrete, based on the results obtained, it is found that waste paper ash may be used as a cement replacement up to 5% by weight and the particle size is less the 90µm to prevent reduction in workability. Keywords: slump test, Compressive strength, split tensile strength, water absorption test, Waste Paper Sludge Ash Concrete, Workability.

The Cambrian Basal Sandstone Unit in central Alberta — an investigation of temperature distribution, petrography, and hydraulic and geomechanical properties of a deep saline aquifer

2014 ◽  
Vol 51 (8) ◽  
pp. 783-796 ◽  
Author(s):  
Simon Weides ◽  
Inga Moeck ◽  
Jacek Majorowicz ◽  
Matthias Grobe
Keyword(s):  
Geothermal Gradient ◽  
High Porosity ◽  
Reservoir Properties ◽  
Geothermal Heat ◽  
Hydraulic Stimulation ◽  
Deep Saline Aquifer ◽  
Thin Sections ◽  
Geomechanical Properties ◽  
Western Canada Sedimentary Basin ◽  
Porosity And Permeability

Recent geothermal exploration indicated that the Cambrian Basal Sandstone Unit (BSU) in central Alberta could be a potential target formation for geothermal heat production, due to its depth and extent. Although several studies showed that the BSU in the shallower Western Canada Sedimentary Basin (WCSB) has good reservoir properties, almost no information exists from the deeper WCSB. This study investigated the petrography of the BSU in central Alberta with help of drill cores and thin sections from six wells. Porosity and permeability as important reservoir parameters for geothermal utilization were determined by core testing. The average porosity and permeability of the BSU is 10% and <1 × 10−14 m2, respectively. A zone of high porosity and permeability was identified in a well located in the northern part of the study area. This study presents the first published geomechanical tests of the BSU, which were obtained as input parameters for the simulation of hydraulic stimulation treatments. The BSU has a relatively high unconfined compressive strength (up to 97.7 MPa), high cohesion (up to 69.8 MPa), and a remarkably high friction coefficient (up to 1.22), despite a rather low tensile strength (<5 MPa). An average geothermal gradient of 35.6 °C/km was calculated from about 2000 temperature values. The temperature in the BSU ranges from 65 to 120 °C. Results of this study confirm that the BSU is a potential geothermal target formation, though hydraulic stimulation treatments are required to increase the permeability of the reservoir.

The Heritage Stone of Nossa Senhora de Guadalupe Church, Mouçós, North of Portugal: Characterisation and Glyptography

2021 ◽  
Author(s):  
David Freire-Lista ◽  
Bruno Campos ◽  
Patricia Moreira da Costa
Keyword(s):  
Water Absorption ◽  
Bulk Density ◽  
Wave Velocity ◽  
Effective Porosity ◽  
P Wave ◽  
Building Stones ◽  
Thin Sections ◽  
P Wave Velocity ◽  
The Mean ◽  
The Church

&lt;p&gt;Granite is the most important building stone in the north of Portugal. The importance of the stones in this region is evidenced by the pre-Roman roots Mor (r), Mur (r) and Mour of place names such as Montemuro, Moreiras, Mou&amp;#231;&amp;#243;s, and Mourelhe. These roots indicate the existence of building stones used since ancient times in these places.&lt;/p&gt;&lt;p&gt;The quarries of the main building stones of historical buildings were generally in the vicinity of the buildings. Formerly, stonemasons carved mason's marks on ashlars. The mason's marks are lapidary signs to indicate the work carried out by each one. The mason's marks are generally symbolised by the initial of the stonemason's name. They are often found on dressed stones in buildings and in other public structures.&lt;/p&gt;&lt;p&gt;Nossa Senhora de Guadalupe church of Mou&amp;#231;&amp;#243;s (possibly 16&lt;sup&gt;th&lt;/sup&gt; century) has typical characteristics from the late Romanesque. It is located in Vila Real (North of Portugal). It is made up of three volumes: a single nave, a lower rectangular apse, and a sacristy attached to the apse. The exterior of this church is preserved almost unaltered in its original state. Each of the granite ashlars that make up this church has a mason's mark in the center of its face.&lt;/p&gt;&lt;p&gt;The mason's marks of the church have been identified; all the ashlars with visible mason's marks have been mapped, and a glyptographic study has been carried out. This has made it possible to calculate the number of stonemasons that worked in the construction of the church and the number of ashlars that were transported in each carriage, and to determine the construction phases of the church.&lt;/p&gt;&lt;p&gt;Eight cubic samples have been cut to calculate the granite&amp;#8217;s hydric properties (effective porosity, water absorption and bulk density) according to UNE-EN:1936. Ultrasound wave velocity was measured according to UNE-EN:14579. Furthermore, three thin sections have been made to characterise the granite petrographically under a polarisation microscope Leica DM-4500-P. A mosaic of photomicrographs has been made to evaluate the petrographic properties.&lt;/p&gt;&lt;p&gt;There are six main types of mason's marks in Nossa Senhora de Guadalupe Church. All quarrymen extracted the stones from the same quarry, or from nearby quarries. The mean effective porosity of the building granite is 3.2%&amp;#177;0.3, and the mean water absorption is 1.2%&amp;#177;0.1. Its mean bulk density is 2566 kg/m&lt;sup&gt;3&lt;/sup&gt;&amp;#177;61.0 and its ultrasound P wave velocity is 2920 m/s&amp;#177;98.3.&lt;/p&gt;&lt;p&gt;The mason's marks are preserved because of the excellent petrographic and petrophysical properties of Mou&amp;#231;&amp;#243;s granite. Further, Nossa Senhora de Guadalupe church was protected with lime plaster during the past centuries, and the plaster was not removed with the projection of abrasive particles.&lt;/p&gt;&lt;p&gt;The use of analytical techniques such as petrography, ultrasonic P wave velocity and the determination of hydric properties will guarantee the quality and durability of a sustainable restoration.&lt;/p&gt;&lt;p&gt;The historical quarries, forms of traditional stone extraction and uses of Mou&amp;#231;&amp;#243;s granite constitute a heritage that must be safeguarded.&lt;/p&gt;&lt;p&gt;Acknowledgements: The Funda&amp;#231;&amp;#227;o para a Ci&amp;#234;ncia e a Tecnologia (FCT) of Portugal. CEECIND/03568/2017.&lt;/p&gt;

Biodiversity of the Silurian osteostracans of the East Baltic

2014 ◽  
Vol 105 (2) ◽  
pp. 73-148 ◽  
Author(s):  
T. Märss ◽  
O. Afanassieva ◽  
H. Blom
Keyword(s):  
New Taxa ◽  
Thin Sections ◽  
Histological Characteristics ◽  
First Time ◽  
Drill Cores

ABSTRACTThe sculpture and histology of osteostracan head shields and trunk squamations from the Silurian of Estonia are described, illustrated and used for the identification of disarticulated microremains collected from outcrop sections and numerous drill cores in Estonia and Latvia over the last 40 years. The scattered osteostracan material contains thousands of specimens of scales and shield fragments. The sculpture and histology of species of the previously identified eight genera in the region (Tremataspis, Dartmuthia, Saaremaaspis, Oeselaspis, Aestiaspis, Thyestes, Procephalaspis, Witaaspis) are redescribed, together with Ateleaspis, found in Estonia for the first time. The sculpture on the cornua of several taxa is described for the first time. The new taxa Tremataspis perforata sp. nov., Dartmuthia procera sp. nov., Eldaaspis miklii gen. et sp. nov., Tahulaspis ordinata gen. et sp. nov., Tahulaspis praevia gen. et sp. nov., Meelaidaspis gennadii gen. et sp. nov. and Ohesaareaspis ponticulata gen. et sp. nov. are established, based upon sculpture and histological characteristics of the exoskeleton. The supraoral field with denticles of that field are described for the first time in Oeselaspis pustulata, as is the supraoral plate with buccal denticles in Meelaidaspis gennadii gen. et sp. nov. Thin sections of all taxa (except of Witaaspis) have been studied. This work sheds light on East Baltic osteostracan biodiversity from the Maasi Beds of the Jaagarahu Stage, Sheinwoodian, lower Wenlock up to the Ohesaare Stage, upper Přidoli, Silurian.

A Comparative Study of Granular Agglomeration between 3D Printed Hydroxyapatite and Commercial Bone Graft Granules

2019 ◽  
Vol 798 ◽  
pp. 83-87
Author(s):  
Faungchat Thammarakcharoen ◽  
Ariya Yampakdee ◽  
Bovornwut Buranawat ◽  
Jintamai Suwanprateeb
Keyword(s):  
Phase Composition ◽  
Comparative Study ◽  
Bone Graft ◽  
Water Absorption ◽  
Tricalcium Phosphate ◽  
Water Film ◽  
Xrd Analysis ◽  
High Porosity ◽  
Capillary Action ◽  
3D Printed

Granule characteristics and the agglomeration ability of 3D printed hydroxyapatite granules (3DP HA) when contacting water were compared to those of commercial bone graft granules based on hydroxyapatite/β-tricalcium phosphate/collagen mixture (Sunmax). Microstructure, phase composition, water absorption and granular agglomeration of the granules were characterized. SEM showed that the granule sizes of Sunmax were in the range of 0.8-1.5 mm whereas that of 3DP HA was relatively more uniform at about 1 mm. 3DP HA granules comprised the weaving of numerous minute crystals containing large pores and having high porosity while Sunmax granules were crushed granules and having low porosity. XRD analysis confirmed that Sunmax granules were biphasic hydroxyapatite and β-tricalcium phosphate while 3DP HA granules were monophasic hydroxyapatite. Sunmax granules exhibited greater agglomeration volume than that of 3DP HA granules. However, the water absorption of 3DP HA granules was greater than that of Sunmax granules. The greater agglomeration ability of Sunmax granules was likely due to the collagen constituent of the granules which could act as adhesive to bind granules together in addition to water capillary action. In contrast, 3DP HA granules formed the agglomeration by the water film due to the capillary action only so the efficiency was lower although the water absorption was greater.

Sign in / Sign up

Export Citation Format

Share Document