scholarly journals Investigating Fracture Network Deformation Using Noble Gas Release

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
W. Payton Gardner ◽  
Stephen J. Bauer ◽  
Scott Broome
Keyword(s):  
Isotopic Composition ◽  
Noble Gas ◽  
Gas Release ◽  
Fracture Networks ◽  
Discrete Sampling ◽  
Well Completion ◽  
Before And After ◽  
Sampling Intervals ◽  
Deformation Mechanics ◽  
Gas Measurements

We investigate deformation mechanics of fracture networks in unsaturated fractured rocks from subsurface conventional detonation using dynamic noble gas measurements and changes in air permeability. We dynamically measured the noble gas isotopic composition and helium exhalation of downhole gas before and after a large subsurface conventional detonation. These noble gas measurements were combined with measurements of the subsurface permeability field from 64 discrete sampling intervals before and after the detonation and subsurface mapping of fractures in borehole walls before well completion. We saw no observable increase in radiogenic noble gas release from either an isotopic composition or a helium exhalation point of view. Large increases in permeability were observed in 13 of 64 discrete sampling intervals. Of the sampling intervals which saw large increases in flow, only two locations did not have preexisting fractures mapped at the site. Given the lack of noble gas release and a clear increase in permeability, we infer that most of the strain accommodation of the fractured media occurred along previously existing fractures, rather than the creation of new fractures, even for a high strain rate event. These results have significant implications for how we conceptualize the deformation of rocks with fracture networks above the percolation threshold, with application to a variety of geologic and geological engineering problems.

Reproducibility and accuracy of noble gas measurements on water samples in the microlitre range

2013 ◽  
Vol 28 (1) ◽  
pp. 42-48
Author(s):  
Tim Sander ◽  
Thomas Marx ◽  
Jürgen Engel ◽  
Werner Aeschbach-Hertig
Keyword(s):  
Water Samples ◽  
Noble Gas ◽  
Gas Measurements

Tracing the Origins of the Ice Giants through Noble Gas Isotopic Composition

2021 ◽  
Author(s):  
Kathleen Mandt ◽  
Olivier Mousis ◽  
Jonathan Lunine ◽  
Bernard Marty ◽  
Thomas Smith ◽  
...  
Keyword(s):  
Solar System ◽  
Isotopic Composition ◽  
Heavy Element ◽  
Noble Gas ◽  
Giant Planet ◽  
Isotope Ratios ◽  
Building Blocks ◽  
Giant Planets ◽  
Element Abundances ◽  
Current State

<p>The current composition of giant planet atmospheres provides information on how such planets formed, and on the origin of the solid building blocks that contributed to their formation. Noble gas abundances and their isotope ratios are among the most valuable pieces of evidence for tracing the origin of the materials from which the giant planets formed. In this review we first outline the current state of knowledge for heavy element abundances in the giant planets and explain what is currently understood about the reservoirs of icy building blocks that could have contributed to the formation of the Ice Giants. We then outline how noble gas isotope ratios have provided details on the original sources of noble gases in various materials throughout the solar system. We follow this with a discussion on how noble gases are trapped in ice and rock that later became the building blocks for the giant planets and how the heavy element abundances could have been locally enriched in the protosolar nebula. We then provide a review of the current state of knowledge of noble gas abundances and isotope ratios in various solar system reservoirs, and discuss measurements needed to understand the origin of the ice giants. Finally, we outline how formation and interior evolution will influence the noble gas abundances and isotope ratios observed in the ice giants today. Measurements that a future atmospheric probe will need to make include (1) the <sup>3</sup>He/<sup>4</sup>He isotope ratio to help constrain the protosolar D/H and <sup>3</sup>He/<sup>4</sup>He; (2) the <sup>20</sup>Ne/<sup>22</sup>Ne and <sup>21</sup>Ne/<sup>22</sup>Ne to separate primordial noble gas reservoirs similar to the approach used in studying meteorites; (3) the Kr/Ar and Xe/Ar to determine if the building blocks were Jupiter-like or similar to 67P/C-G and Chondrites; (4) the krypton isotope ratios for the first giant planet observations of these isotopes; and (5) the xenon isotopes for comparison with the wide range of values represented by solar system reservoirs.</p><p>Mandt, K. E., Mousis, O., Lunine, J., Marty, B., Smith, T., Luspay-Kuti, A., & Aguichine, A. (2020). Tracing the origins of the ice giants through noble gas isotopic composition. Space Science Reviews, 216(5), 1-37.</p>

A preliminary assessment of the application of Sr, Nd, Pb, He and N isotope analysis to fluid inclusions in kimberlite olivine: A new approach to trace deep-mantle sources

2020 ◽  
Author(s):  
Andrea Giuliani ◽  
Janne M. Koornneef ◽  
Peter Barry ◽  
Patrizia Will ◽  
Henner Busemann ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Trace Element ◽  
Mass Spectrometer ◽  
Fluid Inclusions ◽  
Noble Gas ◽  
Isotope Analysis ◽  
Helium Isotope ◽  
New Approach ◽  
Deep Mantle ◽  
Mantle Sources

<p>Kimberlites are the deepest melts that reach Earth’s surface and, therefore, can provide unique insights into the composition and evolution of the convective mantle through time. Application of isotope geochemistry to trace the composition of kimberlite sources has thus far been hindered by the ubiquitous alteration and incorporation of xenocrystic material in kimberlite rocks. Bulk-kimberlite analyses are typically considered reliable for Nd and Hf isotopes due to their overwhelmingly higher concentrations in kimberlite melts compared to common mantle and crustal contaminants. Conversely, Sr and Pb isotope compositions of bulk kimberlite samples are seldom considered representative of their parental melts thus requiring analysis of robust magmatic phases, primarily perovskite. Addressing the primary (i.e. magmatic) isotopic composition of volatile elements, such as N and noble gases, requires analyses of volatile-rich phases, and fluid inclusions in olivine represent a typical primary target in mantle-derived magmas. However, fluid inclusions in kimberlitic olivine are dominantly secondary in origin. Secondary inclusions can form at any time after crystallisation of their mineral host, which requires assessment of the origin of trapped fluids (i.e. pristine magmatic fluids, crustal fluids of external derivation, or combination thereof) before their isotopic composition can be used to make inferences about kimberlite mantle sources.</p><p>Here we present trace-element and Sr-Nd-Pb-He-N isotopic compositions of multiple olivine aliquots representing two different magmatic units of the ~88 Ma Wesselton kimberlite (Kimberley, South Africa). The Sr and Nd isotopic composition of olivine analysed by isotope-dilution (ID) TIMS are within the narrow range of perovskite <sup>87</sup>Sr/<sup>86</sup>Sr (0.7043-0.7046) and whole-rock <sup>143</sup>Nd/<sup>144</sup>Nd (eNd<sub>i</sub> = 0.4–2.2) for the Kimberley kimberlites. These results indicate that the secondary fluid inclusions, which dominate the incompatible trace-element budget of olivine separates, have a pristine magmatic origin devoid of crustal contribution.</p><p>Helium isotope compositions were measured by laser heating of 1.6 to 9.8 mg of olivine using an ultrahigh-sensitivity compressor-source noble gas mass spectrometer. <sup>3</sup>He/<sup>4</sup>He ratios are between 1.6 R<sub>A</sub> and 3.7 R<sub>A</sub> (where R<sub>A</sub> indicates the atmospheric <sup>3</sup>He/<sup>4</sup>He ratio), values more radiogenic than MORBs but comparable to HIMU OIBs. These results indicate a high time-integrated (U+Th)/He ratio in the source of the Kimberley kimberlites, which is consistent with the moderately high (i.e. HIMU-like) time-integrated U/Pb ratio implied by elevated initial <sup>206</sup>Pb/<sup>204</sup>Pb in Wesselton olivine (19.1-19.5), Kimberley kimberlites (up to 19.9) and megacrysts in southern African Cretaceous kimberlites (up to 20.5). The combination of low <sup>3</sup>He/<sup>4</sup>He, moderately radiogenic <sup>87</sup>Sr/<sup>86</sup>Sr, and negative d<sup>34</sup>S values (-2.6‰ to -5.7‰) require a contribution from subducted recycled material in the source of the Kimberley kimberlites. Conversely, a preliminary N isotope analysis of Wesselton olivine by in-vacuo crushing using a noble gas mass spectrometer returned a mantle-like d<sup>15</sup>N of -2.9‰, which might suggest limited recycling of surface N (d<sup>15</sup>N >0‰) in the source of these kimberlites. We conclude that the combination of Sr-Nd-Pb and He-N isotope tracing of fluid inclusions in olivine can provide a robust new approach to address the composition of kimberlite sources and, therefore, the evolution of the deep mantle through time.</p>

scholarly journals Lung Function before and after a Large Chlorine Gas Release in Graniteville, South Carolina

2016 ◽  
Vol 13 (3) ◽  
pp. 356-363 ◽  
Author(s):  
Kathleen A. Clark ◽  
Wilfried J. J. Karmaus ◽  
Lawrence C. Mohr ◽  
Bo Cai ◽  
Pallavi Balte ◽  
...  
Keyword(s):  
South Carolina ◽  
Lung Function ◽  
Gas Release ◽  
Chlorine Gas ◽  
Before And After

Low level noble gas measurements in the field and laboratory in support of the Comprehensive Nuclear-Test-Ban Treaty

2004 ◽  
Vol 61 (2-3) ◽  
pp. 231-235 ◽  
Author(s):  
Trevor J Stocki ◽  
Marc Bean ◽  
R Kurt Ungar ◽  
Harri Toivonen ◽  
Weihua Zhang ◽  
...  
Keyword(s):  
Noble Gas ◽  
Nuclear Test ◽  
Low Level ◽  
Gas Measurements ◽  
Test Ban ◽  
Nuclear Test Ban ◽  
Test Ban Treaty

What CO 2 well gases tell us about the origin of noble gases in the mantle and their relationship to the atmosphere

2008 ◽  
Vol 366 (1883) ◽  
pp. 4183-4203 ◽  
Author(s):  
Chris J Ballentine ◽  
Greg Holland
Keyword(s):  
Solar Wind ◽  
Isotopic Composition ◽  
Solar Nebula ◽  
Noble Gases ◽  
Noble Gas ◽  
Isotopic Fractionation ◽  
Elemental Abundance ◽  
Published Data ◽  
Abundance Pattern ◽  
New Information

Study of commercially produced volcanic CO 2 gas associated with the Colorado Plateau, USA, has revealed substantial new information about the noble gas isotopic composition and elemental abundance pattern of the mantle. Combined with published data from mid-ocean ridge basalts, it is now clear that the convecting mantle has a maximum 20 Ne/ 22 Ne isotopic composition, indistinguishable from that attributed to solar wind-implanted (SWI) neon in meteorites. This is distinct from the higher 20 Ne/ 22 Ne isotopic value expected for solar nebula gases. The non-radiogenic xenon isotopic composition of the well gases shows that 20 per cent of the mantle Xe is ‘solar-like’ in origin, but cannot resolve the small isotopic difference between the trapped meteorite ‘Q’-component and solar Xe. The mantle primordial 20 Ne/ 132 Xe is approximately 1400 and is comparable with the upper end of that observed in meteorites. Previous work using the terrestrial 129 I– 129 Xe mass balance demands that almost 99 per cent of the Xe (and therefore other noble gases) has been lost from the accreting solids and that Pu–I closure age models have shown this to have occurred in the first ca 100 Ma of the Earth's history. The highest concentrations of Q-Xe and solar wind-implanted (SWI)-Ne measured in meteorites allow for this loss and these high-abundance samples have a Ne/Xe ratio range compatible with the ‘recycled-air-corrected’ terrestrial mantle. These observations do not support models in which the terrestrial mantle acquired its volatiles from the primary capture of solar nebula gases and, in turn, strongly suggest that the primary terrestrial atmosphere, before isotopic fractionation, is most probably derived from degassed trapped volatiles in accreting material. By contrast, the non-radiogenic argon, krypton and 80 per cent of the xenon in the convecting mantle have the same isotopic composition and elemental abundance pattern as that found in seawater with a small sedimentary Kr and Xe admix. These mantle heavy noble gases are dominated by recycling of air dissolved in seawater back into the mantle. Numerical simulations suggest that plumes sampling the core–mantle boundary would be enriched in seawater-derived noble gases compared with the convecting mantle, and therefore have substantially lower 40 Ar/ 36 Ar. This is compatible with observation. The subduction process is not a complete barrier to volatile return to the mantle.

On Noble Gas Anomalies in the Great Namaqualand Troilite

1968 ◽  
Vol 23 (9) ◽  
pp. 1266-1271 ◽  
Author(s):  
E. C. Alexander ◽  
J. H. Bennett ◽  
O. K. Manuel
Keyword(s):  
Neutron Activation ◽  
Isotopic Composition ◽  
Neutron Capture ◽  
Noble Gases ◽  
Noble Gas ◽  
Helium Neon

The abundances and isotopic composition of the stable noble gases were measured in a troilite nodule from the Great Namaqualand fine octahedrite. Helium, neon and argon show a significant spallation component. The major anomalies in krypton and xenon are from neutron capture on selenium and tellurium and from the decay of extinct I129. The abundances of tellurium, iodine and uranium in the troilite were determined by neutron activation analyses and compared with the xenon anomalies. The results indicate that part of the excess Xe129 is from neutron capture on tellurium and the remainder is due to the retention of radiogenic Xe129 from the decay of extinct I129, about 200 million years after an initial I129/I127 = 3 × 10-3.

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