Imperial College London

Professor Gareth Collins

Faculty of EngineeringDepartment of Earth Science & Engineering

Professor of Planetary Science
 
 
 
//

Contact

 

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

 
 
//

Location

 

4.83Royal School of MinesSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Timms:2020:10.1016/j.gca.2020.04.031,
author = {Timms, NE and Kirkland, CL and Cavosie, AJ and Rae, ASP and Rickard, WDA and Evans, NJ and Erickson, TM and Wittmann, A and Ferrière, L and Collins, GS and Gulick, SPS},
doi = {10.1016/j.gca.2020.04.031},
journal = {Geochimica et Cosmochimica Acta},
pages = {12--30},
title = {Shocked titanite records Chicxulub hydrothermal alteration and impact age},
url = {http://dx.doi.org/10.1016/j.gca.2020.04.031},
volume = {281},
year = {2020}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - Hydrothermal activity is a common phenomenon in the wake of impact events, yet identifying and dating impact hydrothermal systems can be challenging. This study provides the first detailed assessment of the effects of shock microstructures and impact-related alteration on the U-Pb systematics and trace elements of titanite (CaTiSiO5), focusing on shocked granite target rocks from the peak ring of the Chicxulub impact structure, Mexico. A >1 mm long, shock-twinned titanite grain preserves a dense network of irregular microcracks, some of which exploit shock twin interfaces. Secondary microcrystalline anatase and pyrite are heterogeneously distributed along some microcracks. In situ laser ablation multi-collector inductively-coupled plasma mass spectrometry (LA-MC-ICPMS) analysis reveals a mixture of three end-member Pb components. The Pb components are: 1) common Pb, consistent with the Pb isotopic signature of adjacent alkali feldspar; 2) radiogenic Pb accumulated since magmatic crystallization; and 3) a secondary, younger Pb signature due to impact-related complete radiogenic Pb loss. The youngest derived ages define a regression from common Pb that intersects Concordia at 67 ± 4 Ma, in agreement with the established age of 66.04 ± 0.05 Ma for the Chicxulub impact event. Contour maps of LA-MC-ICPMS data reveal that the young ages are spatially restricted to microstructurally-complex domains that correlate with significant depletion in trace elements (REE-Y-Zr-Nb-Mo-Sn-Th) and reduction in magnitude of the Eu/Eu anomaly. Mapping by time-of-flight secondary ion mass spectrometry (ToF-SIMS) show that patterns of localised element depletion in titanite are spatially related to microcracks, which are enriched in Al. The spatial correlation of ages and trace element abundance is consistent with localised removal of Pb and other trace elements from a pervasive network of fast fluid pathways in fractured domains via a fluid-mediated element transport proc
AU - Timms,NE
AU - Kirkland,CL
AU - Cavosie,AJ
AU - Rae,ASP
AU - Rickard,WDA
AU - Evans,NJ
AU - Erickson,TM
AU - Wittmann,A
AU - Ferrière,L
AU - Collins,GS
AU - Gulick,SPS
DO - 10.1016/j.gca.2020.04.031
EP - 30
PY - 2020///
SN - 0016-7037
SP - 12
TI - Shocked titanite records Chicxulub hydrothermal alteration and impact age
T2 - Geochimica et Cosmochimica Acta
UR - http://dx.doi.org/10.1016/j.gca.2020.04.031
UR - https://www.sciencedirect.com/science/article/pii/S0016703720302982?via%3Dihub
UR - http://hdl.handle.net/10044/1/79097
VL - 281
ER -