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An eight kilogram chunk and more: evidence for a new class of iron silicide meteorites from the Chiemgau impact strewn field (SE Germany)

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Frank Bauer at Andor Technology
Frank Bauer
M. Hiltl
M. Hiltl
M. Hiltl
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Michael A. Rappenglück at vhs Gilching and Observatory Gilching
Michael A. Rappenglück
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Kord Ernstson at University of Wuerzburg
Kord Ernstson
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359
X. Минералогия астроблем и метеоритов
использовалось оборудование ЦКП «Геонаука»,
финансируемого из средств темы НИР #
AAAA-A17-117121270036-7.
Литература
1. Shumilova T. G., Isaenko S. I., Makeev B. A.,
Zubov A. A., Shanina S. N., Tropnikov Ye. M., Askhabov
A. M. Ultrahighpressure liquation of an impact melt //
Doklady Earth Sciences. 2018. 480(1): 595—598.
2. Shumilova T. G., Zubov A. A., Isaenko S. I., Karateev
I. A. & Vasiliev A. L. Mysterious longliving ultrahigh
pressure or secondary impact crisis // Sci Rep 10. 2591
(2020).
3. Shumilova T. G., Lutoev V. P., Isaenko S. I.,
Kovalchuk N. S., Makeev B. A., Lysiuk A. Yu., Zubov A. A.,
Ernstson K. Spectroscopic features of ultrahighpres
sure impact glasses of the Kara astrobleme // Scientific
Reports. V. 8. № 6923 (2018). doi:10.1038/s41598018
25037z.
An eight kilogram chunk and more: evidence for a new class of iron silicide
meteorites from the Chiemgau impact strewn field (SE Germany)
F. Bauer1, M. Hiltl2, M. A. Rappenglück3, K. Ernstson4
1 Oxford Instruments GmbH NanoScience, Wiesbaden, Germany; frank.bauer @oxinst.com
2 Carl Zeiss Microscopy GmbH, D73447 Oberkochen, Germany; mhiltl@online.de
3 Institute for Interdisciplinary Studies, D82205 Gilching, Germany; mr@infis.org
4 University of Würzburg, D97074 Würzburg, Germany; kernstson@ernstson.de
Introduction
The find of a big 8 kg weighting iron silicide
chunk (Fig. 1) found about 30 years ago in the
Chiemgau meteorite impact strewn field (Fig. 1)
[1—3 and references therein] has strongly sup
ported the earlier formulated hypothesis [1—3
and references therein] of an extraterrestrial or
igin for the abundant occurrences of iron silicides
(Fig. 2) in connection with the craters in the ellip
tically formed strewn field sized about 60 × 30 km
[1]. Up to now some thousands of iron silicide parti
cles have been sampled, mostly by metal detectors,
roughly amounting to a mass of a few kilograms
(apart from the 8 kg chunk). Here we report on new
analyses, which establish an obviously common for
mation and origin.
Fig. 1. Location map for the Chiemgau impact crater strewn field. Middle, right: Iron silicide finds addressed analytically
in this paper
Fig. 2. Various aspects (apart from Fig. 1) of the iron silicide finds from the Chiemgau impact strewn field
360
Юшкинские чтения — 2020
Methods and results
Optical microscopy, SEM, TEM and EBSD analy
ses, Raman spectroscopy.
Elements: Apart from the main constituents Fe,
Si more than 30 other chemical elements have been
evidenced so far like uranium, the REE cerium, yt
trium und ytterbium, or gallium. No decay products
of uranium like thorium or lead have been mea
sured.
Iron silicide minerals of the matrix: gupei
ite, xifengite, hapkeite, naquite and linzhite; hap
keite Fe2Si in its cubic polymorph and in its trigo
nal polymorph (the most stable iron silicide up to
255 GPa).
Identified minerals: Carbides — silicon carbide
moissanite SiC (cubic and hexagonal polymorphs),
titanium carbide TiC, khamrabaevite (Ti,V,Fe)C,
probably zirconium carbide ZrC (Fig. 4) — Graphite
C, zircon ZrSiO4; Carbon and TiC/(Ti,V,Fe)C in a ma
trix of cubic hapkeite and cubic gupeiite; SiC and
TiC/(Ti,V,Fe)C as superpure crystals in the iron sili
cide matrix (Fig. 2). — Calciumaluminum inclusion
(CAI) minerals CaAl2O4, calcium monoaluminate,
krotite, and Ca2Al2O5, dicalcium dialuminate.
Shock metamorphism and micro-impacts: pla
nar deformation features (PDF) in moissanite; open,
tensile spallation fractures in titanium carbide crys
tals; cosmic particle impacts (Fig. 3).
Conclusion
Enigmatic internal structures and exotic com
position for all sizes of iron silicide samples from
Fig. 3. Internal structure of iron silicides from the Chiemgau strewn field under the SEM
Fig. 4. SEMEDS micrographs and analyses; samples from Fig. 1, right. Quite comparable analyses have been made in the
8 kg iron silicide chunk (Fig. 1) [3] and in earlier analyses of various finds
the Chiemgau impact crater strewn field establish a
common formation process and a common source.
Artificial production, geogenic formation (and
e.g. fulgurite formation) can be excluded, which is
basically also supported by the find situations in the
field [1, 2]. The iron silicides are of extraterrestri
al origin.
The iron silicides in their entity belong to the
Chiemgau meteorite impact strewn field.
They should constitute a new class of meteor
ites. For reasons of definiteness we suggest to name
the trigonal Fe2Si polymorph hapkeite — 2T possi
bly rating a new mineral name [2].
References
1. Rappenglück, M. A., Rappenglück, B. & Ernstson.
K. Kosmische Kollision in der Frühgeschichte. Der
ChiemgauImpakt: Die Erforschung eines bayerischen
MeteoritenkraterStreufelds // Zeitschrift für Anomalistik.
2017. V. 17. P. 235—260 (English translation in [2]).
2. Rappenglück, M. A., Rappenglück, B. & Ernstson.
K. Cosmic collision in prehistory. — The Chiemgau
Impact: research in a Bavarian meteorite crater strewn
field // Zeitschrift für Anomalistik. 2017. V 17. P. 235—
260. http://www.impaktstrukturen.de/wpcontent/up
loads/2018/11/Anomalistentranslation.pdf.
3. Bauer, F., Hiltl, M., Rappenglück, M. A., Ernstson,
K. Trigonal and cubic Fe2Si polymorphs (hapkeite) in
the eight kilograms find of natural iron silicide from
Grabenstätt (Chiemgau, Southeast Germany)// 50th
Lunar and Planetary Science Conference. The Woodlands,
LPI. 2019, abstract 1520.pdf.
... In addition to the finds of the local researchers, contributions came from the population, which had become aware of the peculiar material through lectures and publications. The extensive mineralogical-petrographic-geochemical investigation of the impact-associated materials was accompanied in particular by a thorough analysis of the iron silicides with optical microscopy, SEM, TEM and EBSD at the institutes of Oxford Instruments and Zeiss [17,18]. Figure 2 shows the maps of the areas where the local researchers have extended their search for iron silicides. ...
... Recent analyses [17] have shown that the iron silicides from the Chiemgau impact strewn field contain CAIs with minerals CaAl 2 O 4 , calcium monoaluminate, and Ca 2 Al 2 O 5 , dicalcium dialuminate ( Figure 27). The monoclinic high-temperature (>1,500°C), low-pressure dimorph of CaAl 2 O 4 , mineral krotite, was first identified in a CAI from the CH chondrite NWA 470 [25] and later reported [26,27] to exist in a CAI in the carbonaceous chondrite meteorite NWA 1934. ...
A Prominent Iron Silicides Strewn Field and Its Relation to the Bronze Age/Iron Age Chiemgau Meteorite Impact Event (Germany)
Article
Full-text available
  • Feb 2023
About 20 years ago, amateur archeologists and local history researchers discovered the iron silicide (FESI) strewn field measuring about 60 km x 30 km in the districts of the Chiemgau and the Inn-Salzach region in southeast Germany. They evidenced the connection between the FESi distribution and the pervasive rim wall craters and suggested a meteorite impact event, now widely recognized under the name of the Chiemgau impact. Widespread in the strewn field and in individual finds far beyond it they recovered and documented thousands of FESI particles of millimeter to centimeter size with a total mass of more than 2 kg, whereby a large lump of 8 kg stands out as a single find. The find layer is largely uniformly located at a depth of 30 - 40 cm in a glacial loose sediment soil. Microprobe, SEM-EDS, TEM and EBSD analyses determined as main minerals gupeiite and xifengite, subordinately hapkeite, naquite and linzhite. Besides the main elements Fe and Si of the matrix, more than 30 other chemical elements have been addressed so far, including uranium and various REE. Incorporated into the FESI matrix are the carbide minerals moissanite and titanium carbide as superpure crystals, and khamrabaevite, zirconium carbide, and uranium carbide, furthermore CAIs. SEM images indicate shock metamorphism. The present article describes the discovery history of this worldwide unique FESI occurrence with the exact find situations, as well as the very varied morphologies of the find particles with the macroscopically recognizable components and SEM EDS examples.
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... In addition to the finds of the local researchers, contributions came from the population, which had become aware of the peculiar material through lectures and publications. The extensive mineralogical-petrographic-geochemical investigation of the impact-associated materials was accompanied in particular by a thorough analysis of the iron silicides with optical microscopy, SEM, TEM and EBSD at the institutes of Oxford Instruments and Zeiss [17,18]. Figure 2 shows the maps of the areas where the local researchers have extended their search for iron silicides. ...
... Recent analyses [17] have shown that the iron silicides from the Chiemgau impact strewn field contain CAIs with minerals CaAl 2 O 4 , calcium monoaluminate, and Ca 2 Al 2 O 5 , dicalcium dialuminate ( Figure 27). The monoclinic high-temperature (>1,500°C), low-pressure dimorph of CaAl 2 O 4 , mineral krotite, was first identified in a CAI from the CH chondrite NWA 470 [25] and later reported [26,27] to exist in a CAI in the carbonaceous chondrite meteorite NWA 1934. ...
Enigmatic Glass‐Like Carbon from the Alpine Foreland, Southeast Germany: A Natural Carbonization Process
Article
  • Dec 2018
  • ACTA GEOL SIN-ENGL
Unusual carbonaceous matter, termed here chiemite, composed of more than 90% C from the Alpine Foreland at Lake Chiemsee in Bavaria, southeastern Germany has been investigated using optical and atomic force microscopy, X‐ray fluorescence spectroscopy, scanning and transmission electron microscopy, high‐resolution Raman spectroscopy, X‐ray diffraction and differential thermal analysis, as well as by δ13C and 14C radiocarbon isotopic data analysis. In the pumice‐like fragments, poorly ordered carbon matter co‐exists with high‐ordering monocrystalline α‐carbyne, and contains submicrometer‐sized inclusions of complex composition. Diamond and carbyne add to the peculiar mix of matter. The required very high temperatures and pressures for carbyne formation point to a shock event probably from the recently proposed Holocene Chiemgau meteorite impact. The carbon material is suggested to have largely formed from heavily shocked coal, vegetation like wood, and peat from the impact target area. The carbonization/coalification high PT process may be attributed to a strong shock that instantaneously caused the complete evaporation and loss of volatile matter and water, which nevertheless preserved the original cellular structure seen fossilized in many fragments. Relatively fresh wood encapsulated in the purported strongly shocked matter point to quenched carbon melt components possibly important for the discussion of survival of organic matter in meteorite impacts, implying an astrobiological relationship.
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The Chiemgau Impact (Germany) meteorite crater strewn field. Model craters, Part 1: the small #004 Emmerting, Kaltenbach and Mauerkirchen craters, and the role of Digital Terrain Models
Preprint
Full-text available
  • Sep 2024
The article is the first part of a treatise on the large impact crater strewn field of the Holocene Chiemgau impact with a focus on the now huge number of craters, and a model description of typical examples, for which the craters #004 Emmerting, Kaltenbach and Mauerkirchen were selected here in the first part of addressing the small craters. The selection is justified by the fact that they were already at the beginning of research into the remarkable impact event with geological, geophysical, geochemical, and mineralogical-petrographic investigations and today, some 20 years later, demonstrate how the application of extremely high-resolution digital terrain models down to the decimeter and centimeter range has changed impact research almost in a paradigm shift. This is also a key aspect of this article, which will be followed by two more for the medium-sized and larger craters. Keywords: Chiemgau impact, impact crater strewn field, Digital Terrain Model, impact rocks, shock metamorphism,
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"Earth's Impact Events Through Geologic Times": Comment on Schmieder & Kring article in Astrobiology
Article
Full-text available
  • Jan 2021
We use Schmieder and Kring's article to show how science still works within the so-called "impact community" and how scienti c data are manipulated and "rubber-stamped" by reviewers (here, e.g., C. Koeberl and G. Osinski). We accuse the authors of continuing to list the Azuara and Rubielos de la Cérida impact structures and one of the world's most prominent ejecta occurrences of the Pelarda Fm. in Spain 1 2 as non-existent in the compilation. The same applies to the spectacular Chiemgau impact in Germany, which has been proven by all impact criteria for several years. For the authors' dating list, we propose that the multiple impact of Azuara is included together with the crater chain of the Rubielos de la Cérida impact basin as a dated candidate for the third, so far undated impact markers in the Massignano outcrop in Italy.
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Kollision in der Frühgeschichte
  • K Kosmische
K. Kosmische Kollision in der Frühgeschichte. Der ChiemgauImpakt: Die Erforschung eines bayerischen MeteoritenkraterStreufelds // Zeitschrift für Anomalistik.