Results 121 to 130 of about 42,838 (280)

Determining impact angle from the spatial distribution of shock metamorphism: A case study of the Gosses Bluff (Tnorala) impact structure, Australia

Meteoritics &Planetary Science, EarlyView.
Abstract The majority of planetary impacts occur at oblique angles. Impact structures on Earth are commonly eroded or buried, rendering the identification of the direction and angle of impact—using methods such as asymmetries in ejecta distribution, surface topographic expression, central uplift structure, and geophysical anomalies—challenging. In this
Eloise E. Matthews, Auriol S. P. Rae, Thomas Kenkmann, Nicholas E. Timms, Aaron J. Cavosie, Marian B. Holness   +5 more
wiley   +1 more source

Vertical profiling of shock attenuation at the Rochechouart impact structure, France

Meteoritics &Planetary Science, EarlyView.
Abstract Rochechouart, south‐west France, is a complex impact structure. Here, we present the first report of shock barometry of quartz from what are likely parautochthonous basement units at depth, based on samples from the 2017 C.I.R.I.R drilling campaign. The crystallographic orientations of 725 sets of PDFs in 512 quartz grains in samples from four
P. Struzynska, S. Alwmark, C. Alwmark, M. H. Poelchau, P. Lambert   +4 more
wiley   +1 more source

Empirical evidence for multi-decadal transients affecting geodetic velocity fields and derived seismicity forecasts in Italy

Scientific Reports
This study critically examines the use of geodetic strain rates for forecasting long-term earthquake rates in a slow-deforming region such as Italy, challenging the prevailing assumption of their temporal stationarity in interseismic stages for seismic ...
Michele M. C. Carafa, Peter Bird, Alessandro Verdecchia, Matteo Taroni, Carlo Doglioni   +4 more
doaj   +1 more source

Chondrule olivine: Relationship between structure and composition using synchrotron X-ray Laue microdiffraction [PDF]

, 2006
Published ...
Benedix, GK, Bland, PA, Butterworth, AL, Menzies, ON, Tamura, N   +4 more
core  

A geophysical investigation of the Roter Kamm impact crater, Namibia

Meteoritics &Planetary Science, EarlyView.
Abstract The Roter Kamm impact crater is located in the southern Namib Desert. The crater has a diameter of 2.5 km and belongs to the category of simple, bowl‐shaped impact craters, with an elevated rim of fractured target rock. The crater's interior is completely buried beneath sediments, preventing extensive surface investigations of the bedrock ...
Hannah Nienhaus, Pritam Yogeshwar, Wiebke Mörbe, Bülent Tezkan, Yajun Liu, Bufelo Lushetile, Martin Melles   +6 more
wiley   +1 more source

The Branched GDGT Isomer Ratio Refines Lacustrine Paleotemperature Estimates

Geochemistry, Geophysics, Geosystems
Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are membrane‐spanning lipids synthesized by bacteria in numerous substrates. The degree of methylation of the five methyl brGDGTs in both soils and lake sediments, described by the MBT′5Me index ...
Joseph B. Novak, James M. Russell, Emma R. Lindemuth, Alexander A. Prokopenko, Lina Pérez‐Angel, Boyang Zhao, George E. A. Swann, Pratigya J. Polissar   +7 more
doaj   +1 more source

Mineral Surface and Fluid Chemistry in Nakhlite Analog Water-Rock Reactions [PDF]

, 2018
We report on experiments with Mars analog materials under diagenetic conditions and find characteristic chemical surface changes in correspondence with the fluid ...
Bridges, J. C., Bullock, M. A., Chavez, C., Filiberto, J., Hicks, L. J., Kelley, S. P., McIntosh, R. A., Miller, M. A., Moore, J. M., Ott, U., Schwenzer, S. P., Smith, H., Swindle, T. D., Treiman, A. H.   +13 more
core  

Apatite in Bennu samples indicates multiple stages of aqueous alteration

Meteoritics &Planetary Science, EarlyView.
Abstract Calcium phosphates are ubiquitous in planetary materials, including samples returned from asteroid Bennu by the OSIRIS‐REx mission. We characterized apatite [Ca5(PO4)3(F,Cl,OH)] grains in Bennu samples by scanning electron microscopy, electron microprobe analysis, and transmission electron microscopy to investigate their compositions, mineral ...
Laura B. Seifert, T. M. Erickson, L. P. Keller, J. J. Barnes, K. Thomas‐Keprta, L. Le, J. Gorce, Z. Rahman, T. J. Zega, H. C. Connolly Jr, D. S. Lauretta   +10 more
wiley   +1 more source

Geochemical and petrographic re‐evaluation of ungrouped iron meteorites from Western Australia

Meteoritics &Planetary Science, EarlyView.
Abstract Under the current classification scheme, ungrouped irons make up ~11% of all recognized iron meteorites. A further ~7% of iron meteorites are currently classified as simply “irons” and are yet to be fully classified. To potentially classify these meteorites, newer approaches, including either statistical modeling or advanced geochemical ...
Ashley Rogers, Lucy Forman, Kai Rankenburg, Rachel Kirby, Martin Danišík, Victoria Cousins, Gretchen K. Benedix   +6 more
wiley   +1 more source

Remote Compositional Analyses of Space-weathered Lunar Maria

The Planetary Science Journal
Visible-to-shortwave infrared (VSWIR) reflectance spectroscopy has revolutionized our understanding of planetary surface compositions. However, space-weathering processes on airless bodies complicate quantitative compositional analyses.
Ji-In Jung, Mathieu G. A. Lapôtre, Ralph E. Milliken, Sarah E. Minson   +3 more
doaj   +1 more source