Determination of Tectonic Setting of Sandstone-Mudstone Suites Using SiO2 Content and K2O/Na2O Ratio

Abstract. Aside from many well-known sources, the greenhouse gas methane (CH4) was recently discovered entrapped in the sediments of Swiss Alpine glacier forefields derived from calcareous bedrock. A first study performed in one glacial catchment indicated that CH4 was ubiquitous in sediments and rocks and was largely of thermogenic origin. Here, we present the results of a follow-up study that aimed at (1) determining the occurrence and origin of sediment-entrapped CH4 in other calcareous glacier forefields across Switzerland and (2) providing an inventory of this sediment-entrapped CH4, i.e., determining the contents and total mass of CH4 present, and its spatial distribution within and between five different Swiss glacier forefields situated on calcareous formations of the Helvetic nappes in the Central Alps. Sediment and bedrock samples were collected at high spatial resolution from the forefields of Im Griess, Griessfirn, Griessen, Wildstrubel, and Tsanfleuron glaciers, representing different geographic and geologic regions of the Helvetic nappes. We performed geochemical analyses on gas extracted from sediments and rocks, including the determination of CH4 contents, stable carbon-isotope analyses (δ13CCH4), and the determination of gas-wetness ratios (ratio of CH4 to ethane and propane contents). To estimate the total mass of CH4 entrapped in glacier-forefield sediments, the total volume of sediment was determined based on the measured forefield area and either literature values of mean sediment thickness or direct depth measurements using electrical resistivity tomography. Methane was found in all sediments (0.08–73.81 µg CH4 g−1 dry weight) and most rocks (0.06–108.58 µg CH4 g−1) collected from the five glacier forefields, confirming that entrapped CH4 is ubiquitous in these calcareous formations. Geochemical analyses further confirmed a thermogenic origin of the entrapped CH4 (average δ13CCH4 of sediment of −28.23 (± 3.42) ‰; average gas-wetness ratio of 75.2 (± 48.4)). Whereas sediment-entrapped CH4 contents varied moderately within individual forefields, we noted a large, significant difference in the CH4 content and total CH4 mass (range of 200–3881 t CH4) between glacier forefields at the regional scale. The lithology and tectonic setting within the Helvetic nappes appeared to be dominant factors determining rock and sediment CH4 contents. Overall, a substantial quantity of CH4 was found to be entrapped in Swiss calcareous glacier forefields. Its potential release and subsequent fate in this environment is the subject of ongoing studies.

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Determination of SiO2 Content in Boron-Containing Silica Refractories by Hydrofluoric Acid Gravimetry

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.177.478 ◽

2010 ◽

Vol 177 ◽

pp. 478-480

Author(s):

Jian Ping Xu

Keyword(s):

Conventional Method ◽

Hydrofluoric Acid ◽

Sio2 Content ◽

Positive Interference

The co-volatilization of boron and silicon has been studied for determination of SiO2 content in boron-containing silica refractories. The co-volatilization of boron may cause positive interference for determining of SiO2 content. The interference can be eliminated by the volatilization of boron with 5mL and 2mL of ethanol by separately volatizing, before volatilization of SiO2 with hydrofluoric acid. The method for determination of SiO2 content in boron-containing silica refractories has been established. The scope and precision of this method are equaled to that of the conventional method by hydrofluoric acid gravimetry.

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Quantity and distribution of methane entrapped in sediments of calcareous, Alpine glacier forefields

10.5194/bg-2019-490 ◽

2020 ◽

Author(s):

Biqing Zhu ◽

Manuel Kübler ◽

Melanie Ridoli ◽

Daniel Breitenstein ◽

Martin H. Schroth

Keyword(s):

Total Mass ◽

Tectonic Setting ◽

Regional Scale ◽

Stable Carbon Isotope ◽

Alpine Glacier ◽

Helvetic Nappes ◽

Glacier Forefield ◽

Significant Difference ◽

Geochemical Analyses

Abstract. Aside from many well-known sources, the greenhouse gas methane (CH4) was recently discovered entrapped in sediments of Swiss Alpine glacier forefields derived from calcareous bedrock. A first study performed in one glacial catchment indicated that CH4 was ubiquitous in sediments and rocks, and was largely of thermogenic origin. Here we present results of a follow-up study, which aimed at (1) determining occurrence and origin of sediment-entrapped CH4 in other calcareous glacier forefields across Switzerland, and (2) providing an inventory for this sediment-entrapped CH4, i.e., determining contents and total mass of CH4 present, and its spatial distribution within and between five different Swiss glacier forefields situated on calcareous formations of the Helvetic Nappes of the Central Alps. Sediment and bedrock samples were collected at high spatial resolution from the forefields of Im Griess, Griessfirn, Griessen, Wildstrubel, and Tsanfleuron glaciers, representing different geographic and geologic regions of the Helvetic Nappes. We performed geochemical analyses on gas extracted from sediments and rocks, including determination of CH4 contents, stable carbon-isotope analyses (δ13CCH4), and determination of gas-wetness ratios (ratio of CH4 to ethane and propane contents). To estimate the total mass of CH4 entrapped in glacier-forefield sediments, the total volume of sediment was determined based on measured forefield area and either literature values of mean sediment depth or direct depth measurements using electrical-resistivity tomography. Methane was found in all sediments (0.08–73.81 μg CH4 g−1 dry weight) and most rocks (0.06–108.58 µg CH4 g−1) collected from the five glacier forefields, confirming that entrapped CH4 is ubiquitous in these calcareous formations. Geochemical analyses further confirmed a thermogenic origin of the entrapped CH4 (average δ13C-CH4 of sediment: −28.23 (± 3.42) ‰; average gas-wetness ratio: 75.2 (± 48.4)). Whereas sediment-entrapped CH4 contents varied moderately within individual forefields, we noted a large, significant difference in CH4 content and total CH4 mass (range: 200–3881 t CH4) between glacier forefields at the regional scale. Lithology and tectonic setting within the Helvetic Nappes appeared to be dominant factors determining rock and sediment CH4 contents. Overall, a substantial quantity of CH4 was found to be entrapped in Swiss calcareous glacier forefields. Its potential release and subsequent fate in this environment is the subject of ongoing studies.

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Determination of CaCO3 and SiO2 content in the binders of historic lime mortars

Materials and Structures ◽

10.1617/s11527-011-9802-1 ◽

2011 ◽

Vol 45 (6) ◽

pp. 841-849 ◽

Cited By ~ 10

Author(s):

Elif Uğurlu Sağın ◽

Hasan Böke ◽

Nadir Aras ◽

Şerife Yalçın

Keyword(s):

Sio2 Content ◽

Lime Mortars

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Determination of the seismicity and peak ground acceleration for Lombok island: an evaluation on tectonic setting

MATEC Web of Conferences ◽

10.1051/matecconf/201819503018 ◽

2018 ◽

Vol 195 ◽

pp. 03018 ◽

Cited By ~ 4

Author(s):

Didi S. Agustawijaya ◽

Heri Sulistiyono ◽

Ikhwan Elhuda

Keyword(s):

Tectonic Setting ◽

Small Island ◽

Benioff Zone ◽

Ground Acceleration ◽

North West ◽

The North ◽

Tectonic Forces ◽

Back Arc ◽

Lombok Island

Lombok Island is located in the Nusatenggara region, which is considered as one of the most active seismic parts of Indonesia. The determination of seismicity is crucial to the island, since Lombok Island is a relatively dense populated small island. Earthquakes that occurred around the island were generated by southern subduction mega-thrust and northern back-arc thrust. Mostly, distributions are concentrated on the north-west and south-east parts of Lombok Island. Probabilistic data analysis of 309 earthquake events during the period of 1973 - 2017 results in the Gutenberg-Richter parameters (a and b) of 3.62 and-0.53 indicating medium to high seismic activities. The Joyner-Boore attenuation relation seems to be suitable for seismic characteristics of the island. The reconstruction of tectonic setting indicates that the Benioff zone may develop at the depths of 150 km beneath the island causing horizontal tectonic forces working within the direction of N 171 °E - N 351 °E. This could create a strike-slip fault on the crustal basement within the NE - SW direction.

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Tectonic interpretation of large scale geodetic measurements (VLBI, SLR) in the Central Mediterranean region: constraints and uncertainties

Annals of Geophysics ◽

10.4401/ag-4133 ◽

1995 ◽

Vol 38 (1) ◽

Author(s):

E. Mantovani ◽

D. Albarello ◽

C. Tarnburelli ◽

M. Viti

Keyword(s):

Mediterranean Region ◽

Large Scale ◽

Tectonic Setting ◽

Geodetic Data ◽

Central Mediterranean ◽

Geodetic Measurements ◽

The Mediterranean ◽

Tectonic Interpretation ◽

Relative Motions

Some considerations are reported on the tectonic setting and microplate mosaic in the Mediterranean zones where VLBI and SLR stations are located. In particular, the possible sources of ambiguity in the determination of the Africa-Eurasia and Adriatic-Eurasia relative motions from geodetic data are discussed. Possible alternative kinematic interpretations, with respect to those reported in the literature, are then proposed.

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Galactic orbits of stars

Symposium - International Astronomical Union ◽

10.1017/s0074180900105340 ◽

1966 ◽

Vol 25 ◽

pp. 93-97

Author(s):

Richard Woolley

Keyword(s):

Globular Cluster ◽

Potential Field ◽

High Velocity ◽

Velocity Vector ◽

Variable Stars ◽

The Sun ◽

Proper Motions ◽

Rr Lyrae ◽

The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

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Distance to SN 1987A and the LMC

Symposium - International Astronomical Union ◽

10.1017/s0074180900118959 ◽

1999 ◽

Vol 190 ◽

pp. 549-554

Author(s):

Nino Panagia

Keyword(s):

Angular Size ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Light Curves ◽

Distance Modulus ◽

Absolute Size ◽

Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

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