Imperial College London

Professor Gareth Collins

Faculty of EngineeringDepartment of Earth Science & Engineering

Professor of Planetary Science



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




4.83Royal School of MinesSouth Kensington Campus






BibTex format

author = {Timms, NE and Pearce, MA and Erickson, TM and Cavosie, AJ and Rae, ASP and Wheeler, J and Wittmann, A and Ferriere, L and Poelchau, MH and Tomioka, N and Collins, GS and Gulick, SPS and Rasmussen, C and Morgan, JV and Gulick, SPS and Morgan, JV and Chenot, E and Christeson, GL and Claeys, P and Cockell, CS and Coolen, MJL and Ferriere, L and Gebhardt, C and Goto, K and Green, S and Jones, H and Kring, DA and Lofi, J and Lowery, CM and Ocampo-Torres, R and Perez-Cruz, L and Pickersgill, AE and Poelchau, MH and Rae, ASP and Rasmussen, C and Rebolledo-Vieyra, M and Riller, U and Sato, H and Smit, J and Tikoo, SM and Tomioka, N and Urrutia-Fucugauchi, J and Whalen, MT and Wittmann, A and Xiao, L and Yamaguchi, KE},
doi = {10.1007/s00410-019-1565-7},
journal = {Contributions to Mineralogy and Petrology},
title = {New shock microstructures in titanite (CaTiSiO5) from the peak ring of the Chicxulub impact structure, Mexico},
url = {},
volume = {174},
year = {2019}

RIS format (EndNote, RefMan)

AB - Accessory mineral geochronometers such as apatite, baddeleyite, monazite, xenotime and zircon are increasingly being recognized for their ability to preserve diagnostic microstructural evidence of hypervelocity-impact processes. To date, little is known about the response of titanite to shock metamorphism, even though it is a widespread accessory phase and a U–Pb geochronometer. Here we report two new mechanical twin modes in titanite within shocked granitoid from the Chicxulub impact structure, Mexico. Titanite grains in the newly acquired core from the International Ocean Discovery Program Hole M0077A preserve multiple sets of polysynthetic twins, most commonly with composition planes (K1) = ~  {1¯11} , and shear direction (η1) = < 110 > , and less commonly with the mode K1 = {130}, η1 = ~ <522 > . In some grains, {130} deformation bands have formed concurrently with the deformation twins, indicating dislocation slip with Burgers vector b = < 341 > can be active during impact metamorphism. Titanite twins in the modes described here have not been reported from endogenically deformed rocks; we, therefore, propose this newly identified twin form as a result of shock deformation. Formation conditions of the twins have not been experimentally calibrated, and are here empirically constrained by the presence of planar deformation features in quartz (12 ± 5 and ~ 17 ± 5 GPa) and the absence of shock twins in zircon (< 20 GPa). While the lower threshold of titanite twin formation remains poorly constrained, identification of these twins highlight the utility of titanite as a shock indicator over the pressure range between 12 and 17 GPa. Given the challenges to find diagnostic indicators of shock metamorphism to identify both ancient
AU - Timms,NE
AU - Pearce,MA
AU - Erickson,TM
AU - Cavosie,AJ
AU - Rae,ASP
AU - Wheeler,J
AU - Wittmann,A
AU - Ferriere,L
AU - Poelchau,MH
AU - Tomioka,N
AU - Collins,GS
AU - Gulick,SPS
AU - Rasmussen,C
AU - Morgan,JV
AU - Gulick,SPS
AU - Morgan,JV
AU - Chenot,E
AU - Christeson,GL
AU - Claeys,P
AU - Cockell,CS
AU - Coolen,MJL
AU - Ferriere,L
AU - Gebhardt,C
AU - Goto,K
AU - Green,S
AU - Jones,H
AU - Kring,DA
AU - Lofi,J
AU - Lowery,CM
AU - Ocampo-Torres,R
AU - Perez-Cruz,L
AU - Pickersgill,AE
AU - Poelchau,MH
AU - Rae,ASP
AU - Rasmussen,C
AU - Rebolledo-Vieyra,M
AU - Riller,U
AU - Sato,H
AU - Smit,J
AU - Tikoo,SM
AU - Tomioka,N
AU - Urrutia-Fucugauchi,J
AU - Whalen,MT
AU - Wittmann,A
AU - Xiao,L
AU - Yamaguchi,KE
DO - 10.1007/s00410-019-1565-7
PY - 2019///
SN - 0010-7999
TI - New shock microstructures in titanite (CaTiSiO5) from the peak ring of the Chicxulub impact structure, Mexico
T2 - Contributions to Mineralogy and Petrology
UR -
UR -
UR -
VL - 174
ER -