Journal of Geophysical Research: Planets最新文献

{"title":"Evolution of Convective Stresses in Stagnant-Lid Planets","authors":"C. Grigné","doi":"10.1029/2024JE008817","DOIUrl":"https://doi.org/10.1029/2024JE008817","url":null,"abstract":"<p>Stresses generated by convection in the mantle of rocky planets depend on the convective velocity and on the viscosity of the layer. When planets cool down, their convective motion slows down and the heat transfer becomes less efficient. The evolution of convective stresses as a function of this declining convective vigor has been described in contradictory ways, with either a decrease or an increase of stresses over time being invoked to explain some change of tectonic style when a planet cools down. In this study, 2-D Cartesian numerical simulations for a bottom-heated Newtonian fluid and scaling laws are used to show that, with a strongly temperature-dependent viscosity, convective stresses always increase, even if moderately, when the system gets colder. The stagnant-lid regime of convection for statistical steady-state is studied. The thickness of the stagnant lid and the viscous stress at its base are analyzed as a function of the temperature at the base of the model. Additional simulations with transient cooling are conducted and also exhibit an increase of convective stresses over time. The tectonic style of a planet (stagnant-lid mode or plate tectonics) is generally thought to be controlled by a fixed yield strength, with a transition from one mode to the other when the convective stresses cross this fixed limit. In this study, the evolution of convective stresses does not point to a clear temperature limit that would trigger a change of regime, and thermal evolution alone is not sufficient to explain transitions between tectonic styles.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008817","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence of Combined Erosive and Constructional Formation Mechanisms for a Lunar Sinuous Rille","authors":"O. Ro Hon,&nbsp;L. M. Carter,&nbsp;S. S. Sutton","doi":"10.1029/2024JE008536","DOIUrl":"https://doi.org/10.1029/2024JE008536","url":null,"abstract":"<p>We have identified a sinuous rille in the northern Aristarchus region that displays an evolution of erosional to constructional formation mechanisms through multiple proposed flow regimes. The first flow regime, down the side of the Plateau, is interpreted to be erosional and contains characteristic features such as plunge pools at the base of lava cascades. The rille moves off of the Plateau in the second regime and into the flat, low-lying mare, where it becomes a constructional channel. At its distal end, the rille is interpreted to spread into an inflated sheet flow, becoming indistinct within the mare. These interpretations were made using morphological comparisons between this sinuous rille, referred to as the northern Aristarchus Rimae (NAR), and terrestrial analogs from Kīlauea volcano in Hawai'i. Morphologic zones within the NAR were identified and correlated to flow regimes observed in the formation of the Fissure 8 lava channel during Kīlauea's 2018 eruption. The comparison between the terrestrial analog and NAR was done using cross-sectional and profile comparisons along the channel as well as the evolution of channel morphology and specific features within it. The interpretations of erosional features were based on previously published work on terrestrial lava tube formation and observations from erosional features within the Kazumura lava tube. The strong similarities between actively observed volcanic processes on Earth and ancient volcanic features on the Moon, as identified in this paper, provide insight into the emplacement behavior of lunar lavas.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solar Wind—Venus Interaction During the Solar Maximum and Solar Minimum Periods: A Newly Developed Multi-Fluid MHD Model","authors":"Nihan Chen,&nbsp;Haoyu Lu,&nbsp;Jinbin Cao,&nbsp;Shibang Li,&nbsp;Lihui Chai,&nbsp;Tielong Zhang,&nbsp;Xiaoxin Zhang,&nbsp;Jianing Zhao,&nbsp;Yihui Song,&nbsp;Jianxuan Wang,&nbsp;Yuchen Cao,&nbsp;Bingzhao Li","doi":"10.1029/2024JE008401","DOIUrl":"https://doi.org/10.1029/2024JE008401","url":null,"abstract":"<p>To investigate the individual behavior of ion species, a three-dimensional multi-fluid magnetohydrodynamic model was developed to simulate the global interaction between the solar wind and Venus under different solar conditions. The model includes H⁺, O₂⁺, O⁺, and CO₂⁺, resolving their continuity, momentum, and energy conservation for plasma flow. The differences between the solar maximum and minimum cases are reflected in the variations of solar EUV flux, solar wind dynamic pressure, and corresponding changes in atmospheric distributions. Simulation results show that the bow shock shifts inward during the solar minimum. The model incorporates motional, Hall, and ambipolar electric fields. The results reveal that the electron pressure gradient force acts to decelerate the solar wind at the bow shock. During solar minimum, enhanced solar wind dynamic pressure steepens the electron pressure gradient at the bow shock, strengthening the outward electron pressure gradient force, which counteracts the solar wind more efficiently at a distance closer to Venus. Additionally, during solar minimum, increased transport of O⁺ and CO₂⁺ from the dayside to the magnetotail leads to a higher ion escape rate, consistent with enhanced solar wind energy transfer. In contrast, O₂⁺ exhibits greater transport to the nightside during solar maximum due to its distinct production mechanism, which relies on ion-neutral reactions rather than direct photoionization. These findings highlight that this model could serve as an efficient tool for studying ion-scale processes and may have applications in investigating the impact of individual upstream conditions on the induced magnetic field and ion dynamics.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Jupiter's UV Auroral Response to a Magnetospheric Compression Event","authors":"R. S. Giles,&nbsp;T. K. Greathouse,&nbsp;R. W. Ebert,&nbsp;W. S. Kurth,&nbsp;C. K. Louis,&nbsp;M. F. Vogt,&nbsp;B. Bonfond,&nbsp;D. Grodent,&nbsp;J.-C. Gérard,&nbsp;G. R. Gladstone,&nbsp;J. A. Kammer,&nbsp;V. Hue,&nbsp;R. J. Wilson,&nbsp;S. J. Bolton,&nbsp;J. E. P. Connerney","doi":"10.1029/2025JE009012","DOIUrl":"https://doi.org/10.1029/2025JE009012","url":null,"abstract":"<p>The highly elliptical polar orbit of the Juno mission provides a unique opportunity to simultaneously measure the compression state of Jupiter's magnetosphere and the total power emitted by the planet's ultraviolet aurora, using a single spacecraft. This allows us to study how Jupiter's aurora respond to a compression event. In this paper, we present a case study of an extreme compression event that occurred on December 6–7 2022 when Juno was a distance of 70 <i>R</i>_J from Jupiter. This extreme compression was accompanied by a very large increase in the ultraviolet auroral emissions to 12 TW, a factor of six higher than the baseline level. This event coincided with the predicted arrival of a powerful interplanetary shock, which was expected to cause the largest increase in the solar wind dynamic pressure seen thus far during the Juno mission. The simultaneous occurrence of the interplanetary shock, the extreme compression and the bright ultraviolet aurora suggests that in this case, the auroral brightening was caused by the solar wind shock compressing the magnetosphere.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring Mercury's Tidal Stresses Through Time: Effects of Orbital Eccentricity, Rotational Dynamics, and Their Implications for Tectonics","authors":"Liliane M. L. Burkhard,&nbsp;Nicolas Thomas","doi":"10.1029/2024JE008736","DOIUrl":"https://doi.org/10.1029/2024JE008736","url":null,"abstract":"<p>Mercury's tectonics are assumed to have originated mainly from the planet's cooling and contraction processes, but tidal stresses are hypothesized to have influenced the orientations of scarp features and faults, potentially imparting a preferred orientation during their formation. Global cooling typically leads to isotropic contraction with minimal shear deformation. However, some shear kinematics have been identified in the form of oblique-slip deformation along lobate scarps and high-relief ridges through mapping fault patterns and structural morphologies. In this study, we explore the present and possible past tidal stress values through potential evolutions for the spin and eccentricity of Mercury, in particular the suggested spin/orbit configurations of 5/2, 2/1, and 3/2 before final capture and their progressions through the past 2 billion years. Our findings indicate that Mercury currently experiences tidal stresses of up to ∼±15 kPa, while in the past, increased eccentricity and spin rates could have elevated these stresses to ∼±40 kPa. Although shear failure was not observed in the modeled scenarios, we analyzed the effects of lowering the crust's shear strength to identify the preferred shear direction. Our results show that tidal stresses influenced by Mercury's orbital eccentricity and spin rate may have played a role in determining the shear direction of inferred strike-slip kinematics on a spinning Mercury. The observed alignment between the timing of shear failure during orbit and the increase in compressional normal stress suggests a possible correlation to the structural interpretation that Mercury's shear deformation is transpressional in nature.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008736","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated Seismic Refraction, Reflection, and Rayleigh Wave Imaging at Kilbourne Hole, New Mexico: Implications for Lunar Subsurface Exploration","authors":"Jingchuan Wang,&nbsp;Nicholas C. Schmerr,&nbsp;Ernest R. Bell Jr.,&nbsp;Naoma McCall,&nbsp;Vedran Lekić,&nbsp;Mong-Han Huang,&nbsp;Jacob A. Richardson,&nbsp;Kelsey E. Young,&nbsp;Patrick L. Whelley,&nbsp;Stephen P. Scheidt,&nbsp;Molly L. Wasser,&nbsp;Caela Barry,&nbsp;Casey Braccia,&nbsp;Linden Wike,&nbsp;Jacob Giles,&nbsp;Shannon Rees,&nbsp;John D. West,&nbsp;Jose M. Hurtado,&nbsp;Tara Sweeney,&nbsp;Nohemi Valenzuela","doi":"10.1029/2025JE008950","DOIUrl":"https://doi.org/10.1029/2025JE008950","url":null,"abstract":"<p>Maars are volcanoes with a central crater surrounded by an ejecta ring formed through surface explosive processes from underlying magma interacting with fluids. The study of terrestrial maar volcanoes, as analogs to explosive volcanic vents on the Moon and other planets, can improve our understanding of planetary volcanism and evolution. In this study, we conducted a series of geophysical experiments at Kilbourne Hole Maar, New Mexico, a well-preserved crater used for both science and crewed exploration lunar analog studies. The surveys included multiple active source seismic lines that sampled the geological units of both the crater rim and floor. We demonstrate the effectiveness of shallow seismic reflection methods integrated with <i>P</i> wave refraction and surface wave analysis to determine the elastic properties and create detailed near-surface structural models in a terrestrial volcanic setting. The reflection profiles capture the top-down strata of the crater rim. The velocity changes derived from independent inversions of refraction travel times and surface wave dispersions indicate varying (6–15 m) ash thickness around the rim and reveal the presence of high-velocity anomalies in possible connection with crater collapse beneath the crater floor. Additionally, we estimate a base surge volume of approximately <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>6.4</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mn>6</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> $6.4times {10}^{6}$</annotation>\u0000 </semantics></math> <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>m</mi>\u0000 <mn>3</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${mathrm{m}}^{3}$</annotation>\u0000 </semantics></math> present on the rim. The integrated results highlight the potential for characterizing the subsurface of planetary bodies in greater detail and provide high-fidelity data simulations for astronaut training. The operational insights serve as a valuable guideline for future crewed lunar missions and contribute to the development of strategies for optimizing planetary exploration.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JE008950","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144237298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ionospheric Analysis With Martian Mutual Radio Occultation","authors":"Jacob Parrott,&nbsp;Håkan Svedhem,&nbsp;Beatriz Sánchez-Cano,&nbsp;Olivier Witasse,&nbsp;Colin Wilson,&nbsp;Ingo Müller-Wodarg","doi":"10.1029/2024JE008854","DOIUrl":"https://doi.org/10.1029/2024JE008854","url":null,"abstract":"<p>This study presents a comprehensive analysis of the Martian ionosphere using Mutual Radio Occultation (RO) observations between Mars Express and Trace Gas Orbiter, featuring 71 full vertical profiles out of a total of 124 measurements. Among these, 35 measurements were taken from regions with Solar Zenith Angles lower than 40°. The profiles also represent the largest data set for the lower M1 ionospheric layer during the midday ever measured. This paper has also been submitted with a comprehensive data set, which marks the first time MEX-TGO RO data has been made available to the community. Additionally, neutral temperature profiles have been extracted from the measurements. We find unexpected features in the lower thermosphere temperature behavior which we conclude is likely due to the effects of local circulation and associated dynamical heating rather than solar-controlled.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008854","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electron Structures in Titan's Induced Magnetosphere and Low-Frequency Wave Activity","authors":"Konstantin Kim,&nbsp;Niklas J. T. Edberg,&nbsp;Ronan Modolo,&nbsp;Michiko Morooka,&nbsp;R. J. Wilson,&nbsp;Andrew J. Coates,&nbsp;Anne Wellbrock,&nbsp;Jan-Erik Wahlund,&nbsp;Erik Vigren,&nbsp;Ali Sulaiman,&nbsp;Cesar Bertucci,&nbsp;Ravindra Desai,&nbsp;Leonardo Regoli","doi":"10.1029/2024JE008802","DOIUrl":"https://doi.org/10.1029/2024JE008802","url":null,"abstract":"<p>The interaction of Titan's ionosphere with Saturn's magnetosphere leads to a mix of perturbed electromagnetic fields and accelerated and thermalized plasma in the induced magnetosphere. The complexity of this region has been noted in previous studies. However, many local structures and processes have not been studied and addressed in detail before. In this case study, we examine the origin of quasi-periodic plasma structures in Titan's induced magnetosphere observed during the T36 flyby. We use data from the electron and ion spectrometers CAPS/ELS and IMS, the RPWS Langmuir probe and electric antenna, and the fluxgate magnetometer (MAG) to analyze plasma parameters, for example, density and temperature and magnetic field fluctuations, to characterize the processes involved. The observed plasma structures are quasi-periodic on a scale of about 20 s (or local ion gyroperiod) and possess acceleration signatures from a few eV up to 700 eV. A burst of low-frequency (around the ion-cyclotron and lower-hybrid frequency) and low-amplitude (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mrow>\u0000 <msub>\u0000 <mi>B</mi>\u0000 <mrow>\u0000 <mi>b</mi>\u0000 <mi>g</mi>\u0000 </mrow>\u0000 </msub>\u0000 <mo>≈</mo>\u0000 <mn>7</mn>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${B}_{bg}approx 7$</annotation>\u0000 </semantics></math> nT, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mrow>\u0000 <mi>δ</mi>\u0000 <mi>B</mi>\u0000 <mo>/</mo>\u0000 <msub>\u0000 <mi>B</mi>\u0000 <mrow>\u0000 <mi>b</mi>\u0000 <mi>g</mi>\u0000 </mrow>\u0000 </msub>\u0000 <mo>≈</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $delta B/{B}_{bg}approx $</annotation>\u0000 </semantics></math> 0.14) waves are observed in the proximity of the plasma structures. We discuss possible mechanisms leading to the development of the observed plasma structures, for example, magnetohydrodynamics instabilities and the contribution of the local electric fields.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008802","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multispectral Observations of Float Rocks Used to Investigate the Origin of Boulders on the Western Jezero Fan Front, Mars","authors":"B. S. Kathir,&nbsp;M. S. Rice,&nbsp;B. H. N. Horgan,&nbsp;L. Mandon,&nbsp;J. R. Johnson,&nbsp;K. M. Stack,&nbsp;A. P. Broz,&nbsp;N. Williams,&nbsp;N. Mangold,&nbsp;R. C. Wiens,&nbsp;J. I. Simon,&nbsp;C. C. Bedford,&nbsp;A. Bechtold,&nbsp;B. J. Garczynski,&nbsp;A. Vaughan,&nbsp;N. Randazzo,&nbsp;R. A. Yingst,&nbsp;S. A. Theuer,&nbsp;G. Paar,&nbsp;J. Martínez-Frías,&nbsp;J. I. Núñez,&nbsp;T. Fouchet","doi":"10.1029/2024JE008702","DOIUrl":"https://doi.org/10.1029/2024JE008702","url":null,"abstract":"<p>In Jezero crater, Mars, the Perseverance rover has explored the western fan and encountered loose pieces of rock separated from outcrops or “float” rocks. Comparing float rocks to in-place outcrops can provide key insights into the crater's erosional history and the diversity of units in the Jezero watershed that Perseverance cannot visit in situ. Here, we used multispectral observations from Perseverance's Mastcam-Z instrument to investigate the lithology and origin of float rocks found on the western Jezero fan front (sols 415–707). We identified four textural classes of float rocks (conglomerates, layered, massive, and light-toned) and investigated their physical characteristics, spectral properties, and distribution to interpret their source and mode of transport. Likely derived from local sedimentary fan outcrops, conglomerate and layered float rocks are highly spectrally variable and altered with differing ferric and ferrous signatures. Massive float rocks are the least altered with ferrous signatures and likely derived from local outcrop sources or more distal sources (∼50–250 km) in the Jezero watershed. Massive float rocks separate into two subclasses: massive olivine and massive pyroxene, which are likely derived from the regional olivine-carbonate-bearing watershed unit and the crustal Noachian basement unit, respectively. The unique light-toned float rocks have variable hydration and low Fe-abundance, but there is no local outcrop equivalent of these rocks on the crater floor or fan front, suggesting transport into the basin from a source region outside Jezero. Perseverance found no meteorites at the western fan, implying that fan sediments may be in the youngest ages estimated from crater counts (Hesperian).</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008702","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-Ti Melts From the Taurus-Littrow Valley (TLV). A Product of Volcanism or Impact? An ANGSA Investigation Using the Station 3 Double Drive Tube 73001/73002","authors":"C. K. Shearer,&nbsp;S. B. Simon,&nbsp;T. M. Erickson,&nbsp;C. R. Neal,&nbsp;J. L. Valenciano,&nbsp;J. I. Simon,&nbsp;S. Eckley,&nbsp;B. L. Jolliff,&nbsp;D. P. Moriarty,&nbsp;the ANGSA science team","doi":"10.1029/2024JE008437","DOIUrl":"https://doi.org/10.1029/2024JE008437","url":null,"abstract":"<p>The ANGSA initiative examined an unopened Apollo 17 double drive tube that penetrated a “light mantle” surface feature that represents a landslide deposit originating from the South Massif in the Taurus Littrow Valley. Within this double drive tube are several lunar lithologies not identified in the Apollo, Luna, Chang'e 5 or lunar meteorite collections. One such lithology is lithic fragment 73002, 27G. It consists of a fine-grained, high-Ti melt lithology which hosts lithic clasts and mineral fragments derived from a variety of high-Ti basalts. This lithology represents either a quickly cooled mare basalt with xenocrysts produced by thermal erosion of older crystalline high-Ti basalts, or a high-Ti impact melt with remnants of the target lithologies. Both types of lithologies are rare to non-existent, so this new sample has the potential to shed light on either the dynamical near-surface interactions between erupting magmas and previously erupted flows, or impact processes involving high-Ti mare basalt targets. Although not entirely unambiguous, numerous lines of evidence support an impact origin for this rock type. Based on crystal size distribution, the interclast melt experienced rapid cooling, exceeding rates documented in most high-Ti mare basalts. Mineral and bulk chemistry and preferred orientations of matrix grains indicate that the rapidly cooled portion of this lithology contains remnants of a variety of mare basalts. It seems unlikely that basalt flow would contain such a variety of xenoliths at its chilled surface. Although the interclast melt falls on an appropriate liquid-line-of-descent, its composition has characteristics distinct from other high-Ti basalts.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 6","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}