Dataset for: Variably Shock-Compacted Chondrites: Deformation-Thermal Histories, Large Differences in Mineral Deformation Response, and Implications for Lithification
Sponsor
Research was supported by the National Aeronautics and Space Administration (Grant 80NSSC19K05170).
Document Type
Dataset
Publication Date
2026
Abstract
Eight different H, L, and LL chondrites that contain eleven different lithologies were studied with optical and electron microscopy (OM, SEM, EBSD), microtomography (µCT), and physical property techniques to elucidate their deformation-thermal histories and to infer how the chondrites were lithified. These lithologies span a large range in shock stage, metal fabric, and porosity, and there is good evidence that progressive shock compaction decreased porosity and increased metal fabrics to help lithify the chondrites. A large difference occurs in the response of minerals to shock. In weakly shocked chondrites (Baszkówka, Bjurböle, Saratov, NWA 7298 Lithology A and C), silicates were dominantly fractured, whereas troilite and especially metal show more plastic deformation and were fluidized. These chondrites were formed with estimated shear stresses of ~4-7 GPa. In strongly shocked chondrites (NWA 7298 Lithology B, NWA 11315 Lithology A and B, Alfianello, NWA 8709, NWA 4860), olivine grains display more plastic deformation and were ultimately recrystallized, and troilite and some metal grains were melted; bulk melting to different extents also occurred. These chondrites were formed with estimated shear stresses of >7 GPa. Three settings for lithification are inferred: (A) Lithification began by the accretion of warm chondrule aggregates. (B) Later lithification occurred in warm parent bodies undergoing thermal metamorphism that were being affected by mainly low-velocity collisions; fluidized metal and troilite together with metamorphic heat may have played an important role. (C) Final lithification occurred in cool parent bodies, after the waning of metamorphic heat, that were being affected by higher-velocity collisions; shock compression and heating (including melting) could have been important for lithification. Thus, collisions together with heat of different types (accretionary, metamorphic, and shock-related) were probably the main ways in which rocky planetesimals were lithified. Ordinary chondrite parent bodies likely experienced repeated impacts with cycles of fragmentation and lithification to produce both lithified rocks that could be sampled as meteorites as well as unconsolidated regolith.
Rights
This work is marked with CC0 1.0 Universal
DOI
10.15760/geology-data.09
Persistent Identifier
https://archives.pdx.edu/ds/psu/44633
Recommended Citation
Ruzicka, Alexander M.; Friedrich, Jon M.; Hugo, Richard C.; Macke, Robert J.; Sheikh, Daniel; and Hutson, Melinda, "Dataset for: Variably Shock-Compacted Chondrites: Deformation-Thermal Histories, Large Differences in Mineral Deformation Response, and Implications for Lithification" (2026). Geology Faculty Datasets. 9. https://doi.org/10.15760/geology-data.09
(csv utf-8)
Description
This data supports an article being published in Geochimica et Cosmochimica Acta.
Data include information about the samples that were studied, bulk properties including density, porosity and metal fabric, shock stage and deformation parameters, a summary of deformation styles and characteristics, and information about EBSD data files.
The file contains five tables.
File: Dataset for Geochimica et Cosmochimica Acta (csv utf-8)