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Meteorite impact on a micrometer scale: iron silicide, carbide and CAI minerals from the
Chiemgau impact event (Germany)
Michael A. Rappenglück1, Frank Bauer2, Kord Ernstson3, Michael Hiltl4
1Institute for Interdisciplinary Studies, Gilching, Germany; mr@infis.org; 2Oxford Instruments GmbH NanoScience, Wiesbaden, Germany; frank.bauer@oxinst.com 3Faculty of Philosophy I, University of
Würzburg, Germany; kernstson@ernstson.de 4Carl Zeiss Microscopy GmbH, Oberkochen, Germany; mhiltl@online.de
Introduction
Iron silicides
!"#$%&''$()$*+(,$'*-*.*/#'$01*23$4$56$'($)&+$'&%7-#/$*,$&$+#2*(,$()$+(82"-9$:;$<%$=$>;$<%$?(?&-'$&@(8?$4$<23$!"#$'*A#$()$?"#$7&+?*.-#'$+&,2#'$
@#?B##,$?"#$(+/#+$()$&$%*--*%#?#+$&,/$)#B$.#,?*%#?#+'3$!"#$-&+2#'?$7*#.#$*'$:$.%$-(,2$&,/$"&'$&$%&''$()$C:4$23$!"#$'8+)&.#'$'"(B$%#?&--*.$
-8'?#+$&,/$-&.<$7+&.?*.&--9$&,9$.(++('*(,3$D,$%&,9$.&'#'E$&$+#2%&2-97?*.$'8+)&.#$+#'#%@-*,2$&@-&?*(,$)#&?8+#'$()$%#?#(+*?#'$*'$'?+*<*,2$01*23$4$
F6E$&,/$'7-&'"$)(+%'$&,/$'7"#+8-#'$&+#$.(%%(,$01*23$4$GE$563$1+#H8#,?-9E$'7&+<-*,2$.+9'?&-'$.&,$@#$'##,$B*?"$?"#$,&<#/$#9#$?($'?*.<$(8?$)+(%$
?"#$%#?&--*.$%&?+*=$01*23$4$I63
Carbides (silicon carbide - moissanite, titanium carbide, khamrabaevite)
CJ$K."L''-#+$M3$#?$&-3$04;;N6E$O8+3$P3$Q*,#+&-3$4;;NE$CRE$F#*"3$CE$C4S3$T4J$U&77#,2-L.<E$Q3$#?$&-3$04;;N6$O8+(7#&,$P3$()$Q*,#+&-(29E$CRE$F"$CE$C;V3$T>J$ O+,'?'(,E$
W3$#?$ &-3$ 04;C;6E$ P3$K*@#+*&,$1#/#+&-$M,*X3E$O,2*,##+*,2$Y$!#.",(-(29E$ 4;C;E$ >ZCE$R4[C;>3$TSJ$\*-?-E$Q3$#?$&-3$ 4;CC3$5@'?+&.?$]C>^C3$S4,/$_8,&+$Y$ `-&,#?&+9$
K.*#,.#$G(,)#+#,.#3$TNJ$ O+,'?'(,E$W3$Y$U&77#,2-L.<E$Q353$04;;V6E$D,?#+,&?*(,&-$K.*#,?*)*.$G(,)#+#,.#$aC;;$9#&+'$()$ ?"#$!8,28'<&$#X#,?b3$ P8,#$ >;[P8-9$ :E$
4;;VE$W+&',(9&+'<$0U8''*&63$T:J$O+,'?'(,E$W3$#?$&-3$04;CC6E$G#,?3$O8+3$P3$c#('.*3E$>0S6E$>VN[>^R3$TRJ$D'&#,<(E$K3$#?$&-3$04;C46E$O8+3$Q*,3$G(,)3E$d(-$CE$OQG$4;C4[
4CR3$ TVJ$ O+,'?'(,E$ W3$ #?$ &-3$ 04;C>6E$e8'"<*,$ Q#%(+*&-$ K#%*,&+$ 4;C>E$ `+(.##/*,2'E$ K9<?9X<&+f$ Dc$ W(%*$ KG$ MF$ U5KE$ NS:$ 73$ T^J$ _*+*?A*'E$ D3$ #?$ &-3$ 04;C;6E$
Q#/*?#++&,#&,$5+."&#(-(29$&,/$5+."&#(%#?+9E$C;E$CR[>>3$TC;J$U&77#,2-L.<E$Q353$Y$O+,'?'(,E$W3$04;;V6E$D,?#+,&?*(,&-$G(,)#+#,.#$aC;;$9#&+'$'*,.#$!8,28'<&$
7"#,(%#,(,f$P8,#$4:g4VE$4;;VE$Q('.(B$0U8''*&63$ TCCJ$K"8%*-(X&$!3$c3$ #?$&-3$04;C46E$ S>,/$_8,&+$ &,/$`-&,#?&+9$ K.*#,.#$G(,)#+#,.#$ 04;C46E$CS>;37/)3$ TC4J$
U&77#,2-L.<E$ F3$ #?$ &-3$ 04;C46E$ >S?"$ D,?#+,&?*(,&-$ c#(-(2*.&-$ G(,2+#''E$ N[C;$5828'?$ 4;C4E$ F+*'@&,#3TC>J$ h#8%&*+E$53$ Y$ O+,'?'(,E$ W3$ 04;CC6E$ 1&--$ Q##?*,2E$
5cME$K&,$1+&,.*'.(E$G&-*)3E$N[^$I#.3E$c`CC5[C;4>3$TCSJ$O+,'?'(,E$W3$#?$&-3$04;CS6E$SN?"$_8,&+$&,/$`-&,#?&+9$'.*#,.#$G(,)#+#,.#$04;CS6E$C4;;37/)3$TCNJ$hDK!$
K?+8.?8+&-$I&?&@&'#3$TC:J$W8/*#-<&E$\3$0C^RR6E$i3$W+*'?&--(2+3E$CSNE$CRR3$TCRJ$U&77#,2-L.<E$Q353$#?$&-3E$4;C>E$5@'?+&.?$]N;NN3$R:?"$5,,8&-$Q#?#(+*?*.&-$K(.*#?9$
Q##?*,23$TCVJ$DX&,(X&E$Q353$#?$&-3$04;;C6E$5@'?+&.?$]C^NR3$>4,/$_8,&+$Y$`-&,#?&+9$K.*#,.#$G(,)#+#,.#3$TC^J$G"*$Q&$#?$&-3$04;CC6E$5%#+*.&,$Q*,#+&-(2*'?E$^:E$
R;^[RCN3$ T4;J$ KB##,#9$ K%*?"E$ K353$ #?$ &-3$ 4;C;3$5@'?+&.?$ ]CVRR$ SC'?$ _8,&+$ Y$ `-&,#?&+9$ K.*#,.#$ G(,)#+#,.#3$ T4CJ$ W&"-#,@#+2E$ d3$ #?$ &-3$ 4;;;3$ 5%#+*.&,$
Q*,#+&-(2*'?$VNE$C;:C[C;:N3$T44J$I#-(8-#E$O3$#?$&-3$04;;C6E$c#(."*%*.&$#?$G('%(."*%*.&$5.?&E$:NE$CV>>[CV>V3$T4>J$W&%(E$K3_3$#?$&-3$04;CC6E$O&+?"$`-&,#?3$K.*3$
_#??#+'E$>C;E$S;C[S;V3$T4SJ$1#"+E$W3!3$#?$&-3$04;;S6E$58)."-8''E$NNE$4^R[>;>3
Conclusions
References
Deformation features
CAIs - calcium aluminum inclusions
5$ '*2,*)*.&,?$ )#&?8+#$ ()$ &--$ &,&-9A#/$ *+(,$ '*-*.*/#$ 7&+?*.-#'$ *'$ ?"#*+$ .(,?#,?$ ()$ ?*?&,*8%$ &,/$ '*-*.(,$ .&+@*/#'3$!"#9$ (..8+$ &'$ #=?+#%#-9$ 78+#$
.+9'?&-'$01*23$4E$1*23$N6$&,/$%(+#$)*,#-9$/*'7#+'#/$*,$?"#$%&?+*=$01*23$>63$!"#$K*G$"&'$@##,$&,&-9A#/$?($@#$?"#$.8@*.$%(*''&,*?#$%*,#+&-$g$0b6>G[
K*G3$!"#$?*?&,*8%$.&+@*/#$*,$2#,#+&-$(..8+'$&'$?"#$0!*EdE1#6G$%*,#+&-$<"&%+&@&#X*?#E$&,/$&-'($?"#$())['?(*."*(%#?+*.$)(+%$()$!*G;3:>$"&'$@##,$
'"(B,$?($#=*'?$01*23$>63
B
U#.#,?$ &,&-9'#'$ TCRJ$ "&X#$ '"(B,$ ?"&?$ ?"#$ ?"#$ *+(,$ '*-*.*/#'$ )+(%$ ?"#$ G"*#%2&8$ *%7&.?$ '?+#B,$ )*#-/$ .(,?&*,$ G5D'$ B*?"$ %*,#+&-'$ G&5-4jSE$
.&-.*8%$ %(,(&-8%*,&?#E$ &,/$ G&45-4jNE$ /*.&-.*8%$ /*&-8%*,&?#3$ !"#$ %(,(.-*,*.$ "*2"[?#%7#+&?8+#$ 0kCEN;;lG6E$ -(B[7+#''8+#$ /*%(+7"$ ()$
G&5-4jSE$%*,#+&-$<+(?*?#E$B&'$)*+'?$*/#,?*)*#/$*,$&$G5D$)+(%$?"#$G\$."(,/+*?#$hm5$SR;$TCVJ$&,/$-&?#+$+#7(+?#/$TC^E$4;J$?($#=*'?$*,$&$G5D$*,$?"#$
.&+@(,&.#(8'$."(,/+*?#$%#?#(+*?#$hm5$C^>S3$
Fig. 6. Iron silicide matrix (light gray) with inclusions of TiC/(Ti,V,Fe)C and moissanite SiC (dark gray),
and black spots of C (graphite, diamond, amorphous carbon?) film and light edging CAIs. Images: Carl
Zeiss microscopy and Oxford Instruments.
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*,$'(8?"#&'?$F&X&+*&E$c#+%&,9$0TC[CSJE$1*23$C63$!"#$*%7&.?$*'$/(.8%#,?#/$@9$&@8,/&,?$*%7&.?$%#-?$+(.<'$
&,/$ X&+*(8'$ 2-&''#'E$ '"(.<[%#?&%(+7"*.$ #))#.?'$ -*<#$ 7-&,&+$ /#)(+%&?*(,$ )#&?8+#'$ 0`I1'6$ &,/$ /*&7-#.?*.$
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2-&''$ &,/$ .&+@(,$ '7"#+8-#'3$ Q*.+(?#<?*?#'$ TCSJ$ &,/$ &..+#?*(,&+9$ -&7*--*$ &//$ ?($ ?"#$ *%7&.?$ '*2,&?8+#3$$ $
O,*2%&?*.$.&+@(,$%&??#+$.(,?&*,*,2$.&+@9,#'$&,/$ /*&%(,/[-*<#Z.&+@9,#[-*<#$.&+@(,$ &--(?+(7#'$&-'($?#'?*)9$
#=?+#%#$ ?#%7#+&?8+#'$ &,/$ 7+#''8+#'$ TRE$ CCJ3$ 1+(%$ /&?*,2$ &+."#(-(2*.&-$ (@n#.?'$ ?"#$ *%7&.?$ %8'?$ "&X#$
"&77#,#/$%(+#$?"&,$4N;;$9#&+'$F`$*,$?"#$F+(,A#$52#ZG#-?*.$#+&3$1+(%$?"#$@#2*,,*,2$()$?"#$/*'.(X#+9$&,/$
*,X#'?*2&?*(,$()$?"#$'?+#B,$)*#-/$.(%7+*'*,2$.+&?#+'$'*A#/$@#?B##,$&$)#B$%#?#+'$&,/$&$)#B$"8,/+#/$%#?#+'E$
#=?#,/#/$ )*,/'$ ()$ *+(,$ '*-*.*/#$ 7&+?*.-#'$ *,$ ?"#$ '8@'(*-$ %&*,-9$ .(%7('#/$ ()$ =*)#,2*?#$ &,/$ 287#**?#$ &,/$
(@X*(8'-9$&''(.*&?#/$B*?"$?"#$.+&?#+'$7-&9#/$&$'*2,*)*.&,?$+(-#$&'$7(''*@-#$%#?#(+*?*.$%&??#+3$h#B$&,&-9?*.&-$
KOQE$!OQ$&,/$OFKI$"&X#$'"(B,$?"&?$?"#$*+(,$'*-*.*/#'$B"#,$2(*,2$/(B,$?($%*.+(%#?#+$'.&-#'$&+#$"('?*,2$
&$+#&-$oA((o$()$%(+#$?"&,$>;$."#%*.&-$#-#%#,?'E$#=?+#%#-9$+&+#$%*,#+&-'$&,/$7#.8-*&+$?#=?8+&-$)#&?8+#'3$
Fig. 1. Location map for the Chiemgau meteorite crater strewn field.
100
µm
2 cm
millimeter
scales
A
B
A
C
1 cm
D
Matrix
K($ )&+$ ?"#$ *+(,$ '*-*.*/#$ %*,#+&-'$ 287#**?#$ 01#>K*6E$ =*)#,2*?#$ 01#NK*>6E$ )#+'*-*.*?#$ 01#K*6E$ )#+/*'*-*.*?#$ 01#K*46$ &,/$ "&7<#*?#$ 01#4K*6$ "&X#$ @##,$
&,&-9A#/$B"*-#$287#**?#E$=*)#,2*?#$&,/$)#+'*-*.*?#$&+#$.(,'?*?8?*,2$?"#$%&*,$%&''$()$?"#$7&+?*.-#$%&?+*=3
C
20 µm
1+(%$ ?"#$ ,#B$ KOQE$ !OQ$ &,/$ OFKI$ *,X#'?*2&?*(,'$ ?"#$ #=*'?#,.#$ ()$ ?"#$ *+(,$ '*-*.*/#$ 1#4K*E$ %*,#+&-$ "&7<#*?#$ @#.&%#$ #X*/#,?$ &'$ &$ X#+9$
*%7(+?&,?$%*,#+&-$.(,?+*@8?*,2$?($?"#$G"*#%2&8$*+(,$'*-*.*/#'3$D,$1*23$4$0%*//-#6$"&7<#*?#$'"(B'$*,?#+2+(B,$B*?"$287#**?#$&,/$=*)#,2*?#$?($
)(+%$?"#$*+(,$'*-*.*/#$%&?+*=$?"&?$*'$"('?*,2$&$?*?&,*8%$.&+@*/#$0!*G6$.+9'?&-3$D,$1*23$4$0+*2"?6$?"#$1#4K*$7"&'#$*'$&-'($.-#&+-9$/(.8%#,?#/$&,/$
*,$ 7&+?$ &77#&+'$ -*<#$ ?"#$ 9(-<$ ()$ )+*#/$ #22'$ B*?"*,$ &$ '($ )&+$ 8,*/#,?*)*#/$ .&-.*8%$ '*-*.&?#$ 7"&'#E$ 7(''*@-9$ &$ B(--&'?(,*?#$ 7(-9%(+7"3$ D,$ ?"#$
-*?#+&?8+#$?B($"&7<#*?#$ 7(-9%(+7"'E$&$ .8@*.$&,/$&$?+*2(,&-$%(/*)*.&?*(,E$"&X#$@##,$+#7(+?#/E$&,/$ "#+#$?"#$?+*2(,&-$7(-9%(+7"$ 0K3c3$`>mCE$
h(3$C:S$TCN$EC:J6$"&'$@##,$#'?&@-*'"#/3
Internal structure and composition
Fig. 2. Various aspects of the the iron silicide particles from the Chiemgau impact strewn field (see text). Images: CIRT
Fig. 4. Selected SEM images of multi-variant composition of the iron
silicide particles. In fact, the aspects shown here are giving only a
strongly limited insight into the immense diversity of textures and
components. A, B: Amoebae-like and pyramidal-shaped iron silicide in
widely unstructured iron silicide. C: Iron silicide possibly with beginning
(and then stopped) secession of spheroidal melt particles. D: Spheroidal
iron silicide particle with strange crystal form. E: Peculiar ornate
structures in the iron silicide matrix lacking a conclusive explanation.
Possibly spotty melting of the matrix. F: Zirconium (zircon or/and
baddeleyite) possible exsolution lamellae in iron silicide. G: Zircon
crystals in iron silicide matrix. The white tips on the crystals have been
shown to be uranium. H: More uranium, here forming the whitish rim of
zirconium inclusions I: Iron silicide with significant uranium peak in
spectrum #1. Spectrum #2 shows uranium and mostly zirconium (similar
to H), spectrum 3 more or less pure iron silicide. J: Zircon crystals
obviously having impacted a plastic or liquid iron silicide matrix that
seems to have been frozen during the disturbance. Images: Carl Zeiss
microscopy.
2
c
m
20 µm
20 µm
10µm10µm10µm10µm
F
57&+?$)+(%$?"#$%&,9$7#.8-*&+$7+(7#+?*#'$0?"#$=*)#,2*?#E$287#**?#E$"&7<#*?#E$)#+'*-*.*?#E$)#+/*'*-*.*?#$*,?#+2+(B?"E$#=?+#%#-9$78+#E$*,$
7&+?$ -&+2#+$ .+9'?&-'$ ()$ .8@*.$ %(*''&,*?#$ &,/$ <"&%+&@&#X*?#E$ X&+*(8'$ *,/*.&?*(,'$ ()$ 7+(@&@-#$ '"(.<$ #))#.?'6$ )#&?8+#/$ @9$ ?"#$ *+(,$
'*-*.*/#'$ )+(%$ ?"#$ G"*#%2&8$ %#?#(+*?#$ *%7&.?$ '?+#B,$ )*#-/E$ ?"#$ *,?*%&?#$ G5D$ .(#=*'?#,.#$ ()$ ?"#$ "*2"[?#%7#+&?8+#Z-(B[7+#''8+#$
G&5-4jS$ <+(?*?#$ &,/$ ?"#$ "*2"[7+#''8+#$ G&45-4jN$7"&'#$ *,$ 7&+?*.8-&+$ '8@'?&,?*&?#$ &,$ #=?+&?#++#'?+*&-$ (+*2*,$ ()$ ?"#'#$ %#?&--*.$
7&+?*.-#'$7(*,?*,2$&?$?"#$'&%#$?*%#$?($&$7(''*@-9$'?+&,2#$*%7&.?(+$?($"&X#$7+(/8.#/$?"#$G"*#%2&8$'?+#B,$)*#-/3$\#,.#E$B#$'"(8-/$
2#?$+*/$())$?"#$'*%7-#$*/#&$?"&?$*%7&.?'$(,$#&+?"$&+#$+#-&?#/$B*?"$#*?"#+$'?(,9$(+$*+(,$%#?#(+*?#'3$
1(+$?"#$ ?*%#$@#*,2$?"#$2#,#+&-$H8#'?*(,$ +#%&*,'$8,&,'B#+#/$B"#?"#+$?"#$ 7+(7('#/$'"(.<$ B&'$#=7#+*#,.#/$/8+*,2$ &$.('%*.$
7&''&2#$()$?"#$*+(,$'*-*.*/#'$(+$*,$?"#$?#++#'?+*&-$#X#,?$()$?"#$G"*#%2&8$*%7&.?3$
10µm
!"#$ (+?"(+"(%@*.$
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/*&-8%*&?#$ "*2"$
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,&?8+&-$ .(8,?#+7&+?3$
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CAIs
Fig. 7. Iron silicide particles from the Chiemgau strewn field show in
general a strong mechanical overprint. We observe open fractures in
irregular patterns (Fig. 7 A) and as multiple sets of subparallel open
fissures pointing to tensile deformation (B). These deformations and
also the strongly fractured TiC crystal (C) suggest dynamic
fracturing by shock spallation.
Moissanite crystals in part show multiple sets of closely spaced planar features (D) reminding of shock-produced planar
deformation features (PDFs) known from various minerals. E, F: The occurrence of the many micrometer-sized rimmed craters on
the surface of an iron silicide particle may point to a highly energetic cosmic bombardment, and the supposed open imprints of lost
zircon crystals could possibly be witness of a shock collision in space. Images: Carl Zeiss microscopy. $$
ACD
E
Observations and analyses
Fig. 3. EBSD: various aspects of the iron silicide matrix exhibiting a complex texture. To
the left: red = fersilicite, green = ferdisilicite, yellow = gupeiite, margenta = xifengite as the
principal phases. To the right: Suessite is represented by only few counts. The black areas
seem to be a calcium silicate near to wollastonite-1T. For the carbide mineral inclusion see
the the extra chapter. Images: Carl Zeiss microscopy and Oxford Instruments.
10 µm
20 µm
A B C
D
E
F
GHI
J
