Results 111 to 120 of about 1,985 (228)

Evaluating maturity of organic matter in hydrated C1 and CM‐like clasts and a dehydrated clast within a polymict eucrite and a howardite

Meteoritics &Planetary Science, EarlyView.
Abstract Volatile‐rich xenolithic clasts in different types of brecciated meteorites represent unique pristine solar system material. This study investigates the maturity and thermal history of organic matter using Raman spectroscopy and aqueous alteration effects using infrared spectroscopy in the matrix of 15 volatile‐rich clasts (C1 and CM‐like ...
Swarna Prava Das, Alessandro Maturilli, Aurélie Van den Neucker, Markus Patzek, Dipak Kumar Panda, Gopal K. Pradhan, Guneshwar Thangjam, Surya Snata Rout   +7 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

The Ames impact structure, Oklahoma: New radioisotopic constraints and implications for North American impact chronology

Meteoritics &Planetary Science, EarlyView.
Abstract The Ames impact structure (Oklahoma) is thought to have formed during the Ordovician Meteor Event, based on conodont biostratigraphy of its crater fill. Here, U–Pb zircon dates from its impact‐melt portion, conducted using secondary ion mass spectrometry and laser ablation–inductively coupled plasma–mass spectrometry (n = 37 spots), yield a ...
Elizabeth J. Catlos, Andrew F. Parisi, Michael E. Brookfield, Timmons Erickson, Sean P.S. Gulick, Axel K. Schmitt, Daniel F. Stockli, Daniel P. Miggins, Ben Ruchte, Mark Cloos   +9 more
wiley   +1 more source

Morpho‐structural analysis of impact craters on Pluto: Implications for the study of complex craters

Meteoritics &Planetary Science, EarlyView.
Abstract We used Pluto's global digital elevation model to automatically perform a morphometric analysis of impact craters. Triangular irregular networks (TINs) were generated for each crater, providing a detailed representation of crater topography and enabling more accurate morpho‐structural analysis. A dedicated toolkit generated radial profiles for
N. de Campos, A. P. Crósta
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

Origin and formation of a chondritic xenolith in Krymka (LL3.2, breccia): Indications for a late formation of the accretionary breccia

Meteoritics &Planetary Science, EarlyView.
Abstract An unusual chondritic xenolith was found in two sequentially prepared thin sections of a sample from the Krymka (LL3.2) chondrite. The xenolith has a rounded, slightly deformed shape of about 5 mm in apparent diameter and is partially surrounded by a double rim made of an inner fine‐grained silicate‐rich rim and an outer sulfide‐rich rim.
Aelita Girich, Addi Bischoff, Samuel Ebert, Kazuhide Nagashima, Andreas Morlok, Harald Hiesinger, Jasper Berndt   +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

Nanoscale space weathering features in mature lunar soil revealed by TEM and APT

Meteoritics &Planetary Science, EarlyView.
Abstract Space weathering significantly alters the optical, chemical, and structural properties of lunar regolith at micro‐ and nanoscales; yet detailed nanoscale variability within individual soils remains underexplored. Here we apply transmission electron microscopy (TEM) and atom probe tomography to four mineral grains (olivine, ilmenite, and two ...
Jennika Greer, Alexander M. Kling, Luke Daly, Dieter Isheim, David N. Seidman, Michelle S. Thompson, Philipp R. Heck   +6 more
wiley   +1 more source

Supercooling, Glass Formation, and Mineral Assemblages upon Freezing of Salty Ice Grains from Enceladus’s Ocean

The Planetary Science Journal
The analysis of micrometer-sized ice grains emitted into space by Saturn’s moon Enceladus suggests that the moon’s subsurface ocean may be habitable. However, the formation conditions of these ice grains are largely unknown.
Fabian Klenner, Lucas M. Fifer, Baptiste Journaux, Ardith D. Bravenec, Allan M. M. Leal, Steven D. Vance, David C. Catling   +6 more
doaj   +1 more source

Potassium isotopic compositions and exposure ages of evolved and silica‐rich achondrites

Meteoritics &Planetary Science, EarlyView.
Abstract Some of the oldest igneous rocks in the Solar System include evolved and silica‐rich achondrites that originate from parent bodies less than 1000 km in diameter, referred to as planetesimals. While Earth was initially in a molten state and required continental crust formation and plate tectonics to generate andesite bulk compositions, evolved ...
Z. Vaci, Z. Tian, P. Koefoed, M. Habermann, M. Humayun, K. Ziegler, H. Busemann, D. Krietsch, J. M. D. Day, K. Wang   +9 more
wiley   +1 more source