Imperial College London

Professor Gareth Collins

Faculty of EngineeringDepartment of Earth Science & Engineering

Professor of Planetary Science
 
 
 
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Contact

 

+44 (0)20 7594 1518g.collins Website

 
 
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Location

 

4.83Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Davison:2016:1/68,
author = {Davison, TM and Collins, G and Bland, P},
doi = {1/68},
journal = {Astrophysical Journal},
title = {Mesoscale Modeling Of Impact Compaction Of Primitive Solar System Solids},
url = {http://dx.doi.org/10.3847/0004-637X/821/1/68},
volume = {821},
year = {2016}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - We have developed a method for simulating the mesoscale compaction of early solar system solids in low velocity impact events, using the iSALE shock physics code. Chondrules are represented by nonporous disks, placed within a porous matrix. By simulating impacts into bimodal mixtures over a wide range of parameter space (including the chondrule-to-matrix ratio, the matrix porosity and composition and the impact velocity), we have shown how each of these parameters influences the shock processing of heterogeneous materials. The temperature after shock processing shows a strong dichotomy: matrix temperatures are elevated much higher than the chondrules, which remain largely cold. Chondrules can protect some matrix from shock compaction, with shadow regions in the lee side of chondrules exhibiting higher porosity that elsewhere in the matrix. Using the results from this mesoscale modelling, we show how the ε − α porous compaction model parameters depend on initial bulk porosity. We also show that the timescale for the temperature dichotomy to equilibrate is highly dependent on the porosity of the matrix after the shock, and will be on the order of seconds for matrix porosities of less than 0.1, and on the order of 10’s to 100’s seconds for matrix porosities of ~ 0.3–0.5. Finally, we have shown that the composition of the post-shock material is able to match the bulk porosity and chondrule-to-matrix ratios of meteorite groups such as carbonaceous chondrites and unequilibrated ordinary chondrites.
AU - Davison,TM
AU - Collins,G
AU - Bland,P
DO - 1/68
PY - 2016///
SN - 1538-4357
TI - Mesoscale Modeling Of Impact Compaction Of Primitive Solar System Solids
T2 - Astrophysical Journal
UR - http://dx.doi.org/10.3847/0004-637X/821/1/68
UR - http://arxiv.org/abs/1603.00376
UR - http://hdl.handle.net/10044/1/30734
VL - 821
ER -