Volatile release from intrusive magma bodies of terrestrial planets

2020 ◽  
Author(s):  
Sara Vulpius ◽  
Lena Noack ◽  
Frank Sohl ◽  
Gianluigi Ortenzi ◽  
Elis Jörg Hoffmann

<p>Besides the accretion from the solar nebular and the degassing from magma oceans, the main source of the atmospheres of terrestrial planets is magmatic volatile release from the interior. The atmosphere on early Earth is crucial for the emergence and evolution of life. It´s build-up and composition is largely influenced by magmatic outgassing. This outgassing process includes the well-studied extrusive as well as the often neglected intrusive volatile release. However, it is assumed that the intrusive magma production rates - at least on Earth - are significantly higher compared to extrusive rates, which makes the investigation and quantification of possible volatile exsolution processes even more important.</p> <p>We simulate the crystallization of an intrusive magma body emplaced at different depths within the lithosphere. As the solubility of volatiles like H<sub>2</sub>O and CO<sub>2</sub> increases with pressure, they usually do not exsolve from the melt. However, through the precipitation of nominally dry minerals, the remaining melt is enriched in incompatible elements and volatiles. They accumulate until a saturation level is reached and the volatiles exsolve. The composition of the resulting volatile phase depends on the solubility of the volatile species, the pressure and temperature, the initial composition of the melt, the partition coefficient and the oxygen fugacity. We consider these parameters in our model and benchmark our results with literature values. Additionally, we investigate the likelihood of reactions with the surrounding mantle, to form water-bearing minerals, during the ascent of volatiles. Finally, we quantify the impact of intrusive degassing on the build-up and composition of the atmosphere.</p>

2021 ◽  
Author(s):  
Sara Vulpius ◽  
Lena Noack

<p>The process of fractional crystallization within a magma body has an influence on the solubility and thus on the associated release of volatiles. Nevertheless, this mechanism is widely neglected in the literature. Due to cooling of an intrusion, nominally anhydrous minerals precipitate from the melt. These minerals mainly incorporate elements that are compatible with their crystal lattice. Since volatiles such as H<sub>2</sub>O and CO<sub>2</sub> behave like incompatible elements, they accumulate in the remaining melt. At a certain point, the melt is saturated and the exsolution of the volatiles initiates. The solubility is determined by several parameters like the lithostatic and the partial pressure, the temperature and the melt composition. <br>In this study, we investigate the effect of these parameters as well as the impact of fractional crystallization on the solubility and the related volatile release. We focus on the exsolution of H<sub>2</sub>O and CO<sub>2</sub> from basaltic magma bodies within the lithosphere. To determine the fate of the accumulating volatiles, we compare the density of the developing liquid phase (volatiles and residual melt) with the density of the host rock. If the host rock has a higher density, the liquid phase will ascent either directly to the surface or to shallower levels of the crust. Furthermore, we take into account the possibility that hydrous minerals (e.g., amphibole) are precipitated during fractional crystallization or due to a reaction with the surrounding rock. </p>


Elements ◽  
2017 ◽  
Vol 13 (4) ◽  
pp. 231-236 ◽  
Author(s):  
Charles K. Shearer ◽  
Steven B. Simon

The behavior of boron during the early evolution of the Solar System provides the foundation for how boron reservoirs become established in terrestrial planets. The abundance of boron in the Sun is depleted relative to adjacent light elements, a result of thermal nuclear reactions that destroy boron atoms. Extant boron was primarily generated by spallation reactions. In the initial materials condensing from the solar nebula, boron was predominantly incorporated into plagioclase. Boron abundances in the terrestrial planets exhibit variability, as illustrated by B/Be. During planetary formation and differentiation, boron is redistributed by fluids at low temperature and during crystallization of magma oceans at high temperature.


2021 ◽  
Vol 91 (5) ◽  
pp. 507-519
Author(s):  
Małgorzata Bronikowska ◽  
Małgorzata Pisarska-Jamroży ◽  
A.J. (Tom) van Loon

ABSTRACT Dropstones in lacustrine and marine sediments show a wide range of sizes: from less than a millimeter to many meters. Their size and shape determine the velocity and the acceleration when they settle through the water column, and this, in turn, determines in principle the imprint that they make in the bottom sediment. Although these parameters are crucial for dropstone deposition, the unknown material (sediment) properties (like strength, porosity, pore-water content, viscosity, etc.) of the bottom sediment play a just as important role in this process as the water depth, which can physically be understood as the length of the pathway traveled vertically through a dense medium before the impact. Reconstruction of the principal environmental conditions at the time of dropstone fall and deposition consequently requires considering the variety of factors affecting the final imprint depth of a dropstone, the combination of several numerical methods. Here, we show the results of numerical modeling of dropstones with different sizes that settle through water columns with different depths. Our results show how environmental factors control the deformation structures formed at the sedimentary surface during the impact of a dropstone, and how deep the imprint caused by the settling dropstone will be.


1989 ◽  
Vol 116 (1) ◽  
pp. 429-437
Author(s):  
Tobias Owen ◽  
Akiva Bar-Nun ◽  
Idit Kleinfeld

AbstractThe possible role of comets in bringing volatiles to the inner planets is investigated by means of laboratory studies of the ability of ice to trap gases at low temperatures. The pattern of the heavy noble gases formed in the atmosphere of Venus can be explained by the impact of a planetesimal composed of ices formed in the range of 20 to 30 K. The noble gas patterns on Mars and Earth are less explicable by cometary bombardment alone.


2021 ◽  
Vol 8 ◽  
Author(s):  
Miriam Christina Reiss ◽  
James D. Muirhead ◽  
Amani S. Laizer ◽  
Frederik Link ◽  
Emmanuel O. Kazimoto ◽  
...  

Constraining the architecture of complex 3D volcanic plumbing systems within active rifts, and their impact on rift processes, is critical for examining the interplay between faulting, magmatism and magmatic fluids in developing rift segments. The Natron basin of the East African Rift System provides an ideal location to study these processes, owing to its recent magmatic-tectonic activity and ongoing active carbonatite volcanism at Oldoinyo Lengai. Here, we report seismicity and fault plane solutions from a 10 month-long temporary seismic network spanning Oldoinyo Lengai, Naibor Soito volcanic field and Gelai volcano. We locate 6,827 earthquakes with ML −0.85 to 3.6, which are related to previous and ongoing magmatic and volcanic activity in the region, as well as regional tectonic extension. We observe seismicity down to ∼17 km depth north and south of Oldoinyo Lengai and shallow seismicity (3–10 km) beneath Gelai, including two swarms. The deepest seismicity (∼down to 20 km) occurs above a previously imaged magma body below Naibor Soito. These seismicity patterns reveal a detailed image of a complex volcanic plumbing system, supporting potential lateral and vertical connections between shallow- and deep-seated magmas, where fluid and melt transport to the surface is facilitated by intrusion of dikes and sills. Focal mechanisms vary spatially. T-axis trends reveal dominantly WNW-ESE extension near Gelai, while strike-slip mechanisms and a radial trend in P-axes are observed in the vicinity of Oldoinyo Lengai. These data support local variations in the state of stress, resulting from a combination of volcanic edifice loading and magma-driven stress changes imposed on a regional extensional stress field. Our results indicate that the southern Natron basin is a segmented rift system, in which fluids preferentially percolate vertically and laterally in a region where strain transfers from a border fault to a developing magmatic rift segment.


2009 ◽  
Vol 57 (12) ◽  
pp. 1338-1345 ◽  
Author(s):  
J. Horner ◽  
O. Mousis ◽  
J.-M. Petit ◽  
B.W. Jones

Author(s):  
Keiko Hamano

A magma ocean is a global layer of partially or fully molten rocks. Significant melting of terrestrial planets likely occurs due to heat release during planetary accretion, such as decay heat of short-lived radionuclides, impact energy released by continuous planetesimal accretion, and energetic impacts among planetary-sized bodies (giant impacts). Over a magma ocean, all water, which is released upon impact or degassed from the interior, exists as superheated vapor, forming a water-dominated, steam atmosphere. A magma ocean extending to the surface is expected to interact with the overlying steam atmosphere through material and heat exchange. Impact degassing of water starts when the size of a planetary body becomes larger than Earth’s moon or Mars. The degassed water could build up and form a steam atmosphere on protoplanets growing by planetesimal accretion. The atmosphere has a role in preventing accretion energy supplied by planetesimals from escaping, leading to the formation of a magma ocean. Once a magma ocean forms, part of the steam atmosphere would start to dissolve into the surface magma due to the high solubility of water into silicate melt. Theoretical studies indicated that as long as the magma ocean is present, a negative feedback loop can operate to regulate the amount of the steam atmosphere and to stabilize the surface temperature so that a radiative energy balance is achieved. Protoplanets can also accrete the surrounding H2-rich disk gas. Water could be produced by oxidation of H2 by ferrous iron in the magma. The atmosphere and water on protoplanets could be a mixture of outgassed and disk-gas components. Planets formed by giant impact would experience a global melting on a short timescale. A steam atmosphere could grow by later outgassing from the interior. Its thermal blanketing and greenhouse effects are of great importance in controlling the cooling rate of the magma ocean. Due to the presence of a runaway greenhouse threshold, the crystallization timescale and water budget of terrestrial planets can depend on the orbital distance from the host star. The terrestrial planets in our solar system essentially have no direct record of their earliest history, whereas observations of young terrestrial exoplanets may provide us some insight into what early terrestrial planets and their atmosphere are like. Evolution of protoplanets in the framework of pebble accretion remains unexplored.


Author(s):  
Hodjat Shiri ◽  
Mark Randolph

The significant influence of the riser-seabed interaction on the fatigue performance of steel catenary risers is now widely accepted. Most design, however, is still carried out using linear seabed springs, and assuming a flat seabed. Improved nonlinear hysteretic seabed models have recently been proposed, which automatically simulate the different stiffness in the seabed response through the touchdown zone. A further consideration, however, is the influence of the trench that forms at the seabed. ROV surveys have shown that trenches several diameters deep can develop beneath the riser in the early stages of the SCR life, and a critical question is how this affects the fatigue life. A non-linear soil hysteretic model has been used to model gradual trench development in the touchdown zone. Initially, the seabed model parameters are adjusted to allow trenches of varying depth to be developed over a moderate number of displacement cycles of the SCR. Design wave spectra are then applied, simulating a generic Spar system, after correcting the model parameters to more typical values normal range. The paper presents results that show the impact of trenches of different depths on the fatigue performance of SCRs in the touchdown zone.


2020 ◽  
Author(s):  
Dan J. Bower ◽  
Daniel Kitzmann ◽  
Aaron Wolf ◽  
Patrick Sanan ◽  
Caroline Dorn ◽  
...  

<div> <div> <div> <p>The earliest secondary atmosphere of a rocky planet originates from extensive volatile release during one or more magma ocean epochs that occur during and after the assembly of the planet. Magma oceans set the stage for the long-term evolution of terrestrial planets by establishing the major chemical reservoirs of the iron core and silicate mantle, chemical stratification within the mantle, and outgassed atmosphere. Furthermore, current and future exoplanet observations will favour the detection and characterisation of hot and warm planets, potentially with large outgassed atmospheres. In this study, we highlight the potential to combine models of coupled interior–atmosphere evolution with static structure calculations and modelled atmospheric spectra (transmission and emission). By combining these components in a common modelling framework, we acknowledge planets as dynamic entities and leverage their evolution to bridge planet formation, interior-atmosphere interaction, and observations.</p> <p>An interior–atmosphere model is combined with static structure calculations to track the evolving radius of a hot rocky mantle that is outgassing volatiles. We consider oxidised species CO2 and H2O and generate synthetic emission and transmission spectra for CO2 and H2O dominated atmospheres. Atmospheres dominated by CO2 suppress the outgassing of H2O to a greater extent than previously realised, since previous studies have applied an erroneous relationship between volatile mass and partial pressure. Furthermore, formation of a lid at the surface can tie the outgassing of H2O to the efficiency of heat transport through the lid, rather than the radiative timescale of the atmosphere. We extend this work to explore the speciation of a primary atmosphere that is constrained using meteoritic materials as proxies for the planetary building blocks, and find that a range of reducing and oxidising atmospheres are possible.</p> </div> </div> </div><div> <div> <div> <p>Our results demonstrate that a hot molten planet can have a radius several percent larger (about 5%, assuming Earth-like core size) than its equivalent solid counterpart, which may explain the larger radii of some close-in exoplanets. Outgassing of a low molar mass species (such as H2O, compared to CO2) can combat the continual contraction of a planetary mantle and even marginally increase the planetary radius. We further use our models to generate synthetic transmission and emission data to aid in the detection and characterisation of rocky planets via transits and secondary eclipses. Atmospheres of terrestrial planets around M-stars that are dominated by CO2 versus H2O could be distinguished by future observing facilities that have extended wavelength coverage (e.g., JWST). Incomplete magma ocean crystallisation, as may be the case for close-in terrestrial planets, or full or part retention of an early outgassed atmosphere, should be considered in the interpretation of observational data from current and future observing facilities.</p> </div> </div> </div>


2021 ◽  
Vol 87 (1) ◽  
pp. 57-67
Author(s):  
Celina Luízar Obregón ◽  
Daniel L’hermite

In this work, laser-induced plasma spectroscopy was used to identify the elemental composition, at different depths, of a commercial Peruvian ceramic. The IVEA MobiLIBS system and IUMTEK TX1000 system were used, under environmental conditions and 5.6 mJ of energy, forming craters of approximately 60 μm in diameter. To improve accuracy, repetitions of the impact points were performed, accumulating the signals at the same depth. The blue and white pigments that covered it, as well as the matrix paste, were characterized, making different levels of penetration in the material, obtaining their respective elemental composition. This allowed finding the difference between stratigraphic layers, based mainly on the variation of the intensities of Copper, Titanium, Carbon and other characteristic elements of the clays that make up the matrix paste. Contemporary pottery was found to have sequential layers of decoration, engobe and matrix paste.


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