Chiemgau impact: A new carbon impactite

Presentation: 43. Lunar and Planetary Science Conference (LPSC), March 19–23, 2012, The Woodlands, Texas, USA: http://www.lpi.usra.edu/meetings/lpsc2012/programAbstracts/view/

Shumilova T. G.1   Isaenko S. I.1   Makeev B. A.1   Ernstson K.2   Neumair A.3 Rappenglück M. A.3: Enigmatic Poorly Structured Carbon Substances from the Alpine Foreland, Southeast Germany:  Evidence of a Cosmic Relation [Abstract #1430]

1Institute of Geology, Komi SC, Russian Academy of Sciences, Pervomayskaya st. 54, Syktyvkar, 167982 Russia, 2Faculty of Philosophy I, University of Würzburg, D-97074 Würzburg, Germany,  3Institute for Interdisciplinary Studies, D-82205 Gilching, Germany.

Abstract download:

http://www.lpi.usra.edu/meetings/lpsc2012/pdf/1430.pdf

Poster download:

Poster LPSC

The study deals with a so far unknown impactite from the Chiemgau meteorite crater strewn field incorporating a high pressure/high temperature carbon allotrop.

 

Shatter cones from the Lake Tüttensee crater (Chiemgau impact)

Shatter cones are conical fractures in rocks exhibiting typical fracture markings that are produced by shock waves and that belong to the well-known and reliable macroscopic shock features in rocks from meteorite craters (impact structures).

So far, shatter cones have never been found in the crater strewn field of the Chiemgau impact as a positive impact evidence, which we explained by the predominant uncemented loose sediments of the impact target. In this regard, a change of thinking is necessary since only recently clear shatter cone structures were detected in a rock sample from the Lake Tüttensee ring wall (Fig. 1).

shatter cones from the tüttensee crater, chiemgau impact meteorite crater strewn field

Fig. 1. Shatter cones with counter orientation from the Lake Tüttensee crater. Continue reading “Shatter cones from the Lake Tüttensee crater (Chiemgau impact)”

The Chiemgau meteorite impact event – also in the Saarland (West Germany) region?

by CIRT – Chiemgau Impact Research Team
The abstracts for the 74th Annual Meeting of the Meteoritical Society, August 8-12, in Greenwich, England, UK, have now been published in the Internet. With regard to the Holocene Chiemgau large meteorite strewn field three contributions are especially interesting because of their immediate relation to this impact event. The abstract pdfs can be downloaded:

[1] A POSSIBLE NEW IMPACT SITE NEAR NALBACH (SAARLAND, GERMANY)
E. Buchner, W. Müller and M. Schmieder
www.lpi.usra.edu/meetings/metsoc2011/pdf/5048.pdf
[2] NALBACH (SAARLAND, GERMANY) AND WABAR (SAUDI ARABIA) GLASS – TWO OF A KIND?
M. Schmieder, W. Müller and E. Buchner
www.lpi.usra.edu/meetings/metsoc2011/pdf/5059.pdf
[3] IMPACTITES AND RELATED LITHOLOGIES IN GERMANY – CURRENT STATE OF KNOWLEDGE
M. Schmieder, W. Müller, L. Förster and E. Buchner
www.lpi.usra.edu/meetings/metsoc2011/pdf/5060.pdf

Among the authors W(erner) Müller is particularly singled out who has only recently performed meticulous field work near the town of Nalbach in the Saarland region near the French border. He sampled a large amount of peculiar rocks and natural glasses as well as suspected iron meteorites. From these finds he concludes the possible existence of a meteorite impact only in younger times, and as the discoverer of the phenomenon he has published an article in the Scribd scientific internet forum:

Prims: a possible Holocene meteorite impact in the Saarland region, West Germany
which may be clicked HERE

This postulated meteorite impact is shortly attended by the other authors in the above-mentioned abstracts where the original Scribd article is referred to only in abstract [2], but strangely not in abstract [1] obviously standing more to reason thematically.

Amazingly similar: Finds from the Saarland suspected impact and the Chiemgau impact.

The close relation to the Chiemgau impact arises from Werner Müller’s Scribd article and, hence, comprises the abstract articles of Buchner et al. and Schmieder et al. As can be read in the article of Müller and especially pointed out by him, many striking parallels to finds in the Chiemgau meteorite crater strewn field are obvious:

— pebbles and cobbles showing mechanical load and high-temperature signature in the form of glass coating and interspersing the in most cases sandstone samples
— polymictic breccias
— slag-like melt rocks
— glass as matrix of melt rocks with various rock fragments
— glass-like carbon
— spherules
— probably shock-induced spallation effects in melt rocks

The reader is encouraged to take a look at the images in Werner Müller’s Scribd article and to compare them with the Chiemgau samples. Images are to be found on the website http://www.chiemgau-impact.com/petrographie.html and in the Ernstson et al., 2010 article or, as originals, in the Grabenstätt impact museum

Although there is so far no definite age for the postulated Saarland impact, W. Müller, because of first-sight field impressions and considering the in most cases very fresh glasses, clearly favors a Holocene age. Hence, with regard to the Chiemgau impact Holocene age the obvious question arises whether the Chiemgau and Saarland impacts may belong to the very same cosmic event. This can be imagined given the cosmic projectile was already in disintegration when approaching Earth (like, e.g. in the 1994 Shoemaker-Levi-9 comet crash with Jupiter) and in the end leaving impact scars in an even much larger strewn field than hitherto assumed for the Chiemgau impact.

From this viewpoint of a relation of both phenomena it is rather remarkable if the CIRT research project on the Chiemgau meteorite impact achieves considerable support by two of the abstract authors (E. Buchner, M. Schmieder) as is well known confirmed opponents of the CIRT research and of the Chiemgau impact at all. Notably the hint of Buchner et al. [1] to a possible meteoritic airburst to have produced the Saarland impact signature raises attention because such a possibility has already been discussed for the Chiemgau impact event in the context of the formation of some peculiar craters there (e.g. Ernstson et al., 2010, S. 92-93).

A comment on the abstract article of Schmieder et al. [3] is being added. The authors refer to several structures in Germany for which a meteoritic origin has been postulated, “[cit.] however, all of these geologic features currently lack evidence for shock metamorphism and/or meteoritic matter as proof for impact”. Among these structures, the Chiemgau impact has been classified, thereby referring to the 30 pages article ‘Ernstson K. et al. 2010. J. Siberian Fed. Univ. Engin. Technol. 1:72–103 (HERE to be downloaded)‘ Either have Schmieder and Buchner never read this basic and comprehensive article about the Chiemgau impact or they calculatedly conceal that on p. 82-83 under the heading 8. Shock metamorphism generally accepted impact shock effects in rocks from the Chiemgau craters together with several photomicrographs are reported. The shock effects include multiple sets of planar deformation features (PDFs) with up to five sets in one quartz grain, and diaplectic glass requiring even higher shock pressures of formation than do PDFs.

This keeping silence about proofs for the Chiemgau impact and at the same time claiming the Chiemgau impact is not confirmed [3], is rather odd with regard to the fact that comparably unambiguous impact proofs for the Saarland phenomenon could so far not be presented [1].

Owing to the promising similarities between Chiemgau impact material and material from the Saarland area we can but encourage the colleagues to perform continuing research. We are glad to see that the research of Buchner and Schmieder on the Saarland impact contributes to a better understanding of the Chiemgau impact, even though their work features some deficits and oddness.

 

Gupeiite, xifengite, Fe2Si ? hapkeite: Strange iron silicide matter from the Chiemgau meteorite impact

The strange iron silicide matter from the Chiemgau meteorite impact strewn field at the 42nd Lunar and Planetary Science Conference (LPSC), March 7-11, 2011, The Woodlands, Texas, USA:

iron silicides xifengite gupeiite hapkeite ? moissanite micro-craters chiemgau impact
SEM and TEM analyses of minerals xifengite, gupeiite, Fe2Si (hapkeite ?), titanium carbide (TiC) and cubic moissanite (SiC) from the subsoil in the Alpine Foreland: Are they cosmochemical?

M. Hiltl1, F. Bauer2, K. Ernstson3, W. Mayer4, A. Neumair4, and M.A. Rappenglück4
1Carl Zeiss Nano Technology Systems GmbH, Oberkochen, Germany, 2Oxford Instruments GmbH NanoScience, Wiesbaden, Germany, 3University of Würzburg, Germany, 4Institute for Interdisciplinary Studies, Gilching, Germany

Abstract: Click here..

Click here the enlarged images > Continue reading “Gupeiite, xifengite, Fe2Si ? hapkeite: Strange iron silicide matter from the Chiemgau meteorite impact”

Highlighting a controversy:

Highlighting a controversy: “The fall of Phaethon”, discussion and reply in “Antiquity” journal

In summer 2010 the historian Barbara Rappenglück and other scientists of the Chiemgau Impact Research Team have published an article in the prestigious international journal “Antiquity”. The article having been peer-reviewed by independent international experts is entitled “The fall of Phaethon: a Greco-Roman geomyth preserves the memory of a meteorite impact in Bavaria (south-east Germany)“ (Antiquity 84, 2010, 428-439; http://antiquity.ac.uk/ant/084/ant0840428.htm). In the actual issue of “Antiquity” officials of the Bavarian State Office for Environment (LfU) give a (not peer-reviewed) “Response” to the article of Rappenglück et al., trying to basically question the existence of a meteorite impact in the Chiemgau area (Bavaria, Germany), the so-called Chiemgau impact (Doppler et al., Antiquity 85, 2011, 274-277). Rappenglück et al. reply in the same issue of „Antiquity“ and reject the objections of the LfU (Antiquity 85, 2011, 278-280; http://antiquity.ac.uk/ant/085/ant0850278.htm). The copyright guidelines of “Antiquity” do not allow for making the text available on this website. Hence we here give an overview of our rejection.

Doppler et al.’s argumentation relies on studies that are based on approaches inappropriate for impact research. This is illustrated by the following example: Doppler et al. (2011: 276) reject our proposed 900×400 m double-crater (Ernstson et al. 2010: 21; Rappenglück et al. 2010: 430) in Lake Chiemsee with the argument that “over 200 km of seismic profiles” and four piston cores had not shown any “major disturbance in the sedimentary sequence”. Let us first look at the “200 km of seismic profiles”. This seemingly remarkable length, being projected on the expanse of Lake Chiemsee with its 80 km2 as an orthogonal net, turns out to produce a big mesh size of about 800 m. This means that even a big structure like the double-crater could easily have escaped detection. In comparison, our detection of the double-crater happened by spider-web-like sonar measurements of a small section of the lake. Let us additionally look on Doppler et al.’s four piston cores. With respect to impact research four cores in relation to an expanse of 80 km2 are comparable to a needle in a haystack. Additionally, Doppler et al. are taken in by the misapprehension that in case of secondary impacts into Lake Chiemsee its total lakebed would have been completely disturbed (Doppler et al. 2011: 276: “They [the cores] produced undisturbed sections and show no indication of a major disturbance in the sedimentary sequence which would be expected from an impact.”) This idea shows an amateur-like understanding of impact processes and a total ignorance of the geophysics involved in a meteorite impact, as will be shown in the next paragraph dealing with their drilling at Lake Tüttensee.

The central argument of Doppler et al. is based on a drilling at the edge of Lake Tüttensee, where they encountered “an undisturbed sequence ranging from 4800 years ago near the surface to 12 500 years ago from the lake deposits at the base” (Doppler et al. 2011: 274). From this observation they conclude that neither the Tüttensee basin is a meteorite crater nor has it been formed in very recent Holocene times (as claimed by us), but owes its existence to the last ice age. Doppler et al.’s conclusion is based on the (false) assumption that the location of their drilling is inside the crater. The question whether the location is inside or outside the crater is essential with respect to the intensity of the impact forces, their propagation and their effects. The nowadays visible rests of the rim wall suggests that the location of the drilling should be inside the original crater. But as it is illustrated in the graphics, this is not true. The location of the drilling is outside the original cavity of the crater, where according to impact cratering shock intensities are already lowered to such a degree (a few kbars maximum pressure) that minor deformations are not possibly to be seen in a few-centimeter diameter sized drill core, not to mention the absence of any detectable enhanced temperature signature. Hence, Doppler et al.’s central argument proofs to be invalid.

Kraterbildung1 3

Simplified impact cratering process and the position of the LfU drill hole. First published in ‘Antiquity’ 85, 2011, 279.

Here we point out our decisive argument for a meteorite impact, which has been consequently ignored by Doppler et al. Planar deformation features (PDFs) in quartz, a manifestation of shock metamorphism of rocks, is internationally accepted as proof of an impact (Stöffler & Langenhorst 1994: 165). PDFs are the result of very short-term but extreme forces (minimum pressures for the formation of PDFs in quartz are about 5-10 GPa [50-100 kbar]) and can only be caused by the impact of a meteorite. Neither tectonic processes nor the pressure of rock or ice overburden produce effects attributed to shock metamorphism. We have found PDFs in rocks from the Tüttensee ring wall and in the surrounding ejecta layer (as well as in other parts of our crater strewn field) (Ernstson et al. 2010: 82). These rocks were shocked in the very beginning of the impact in the center of the expanding cavity, excavated from the crater and deposited outside of it. A photomicrograph of such PDFs was published in our article (Rappenglück et al. 2010: fig. 3); PDFs from several locations in our crater field can be seen in Ernstson et al. (2010: 82). For that reason alone the Chiemgau meteorite impact is confirmed.

Instead of facing up this evidence of shock metamorphism and respecting the internationally accepted cogency of shock metamorphism for the proof of a meteorite impact, Doppler et al. try to persuade their readers that their (untenable) criticism of secondary aspects (be it the question of the dating, of the carbonaceous spherules, the strongly corroded cobbles, the vitrified stones, the so-called groove stones, the iron silicides etc.) brings discredit on the impact event as a whole. With this tactics our critics for one thing apply an unscientific practice, for another thing they thereby give proof of their fundamental lack of knowledge concerning impact research and the accepted criterions in this field of research. Doppler et al. by themselves provide an almost absurd evidence of this ignorance by mentioning „astronomical conditions required as a criteria for an impact“ (Doppler et al. 2011: 277, with reference to Heinlein). Such “astronomical conditions required as criteria for an impact” simply do not exist. The reference to Heinlein (Der so genannte „Kelten-Killer-Komet“ – Gab es einen Kometeneinschlag im Chiemgau? Journal für Astronomie, III/2009, Nr. 30, Zeitschrift der Vereinigung der Sternfreunde e.V., p. 84-86.) shows that a confusion of „criteria“ and „model calculations“ is obviously given. Model calculations are characterized by a number of variables that have to be adapted in accordance to the progress of science. Hence they cannot serve as criteria for the proof of anything, and our critics are taken in by a misapprehension. At http://www.chiemgau-impact.com/neu_disk.html more detailed information concerning the internationally accepted criteria for meteorite impacts are available as well as an overview how the Chiemgau impact matches these criteria.

In addition:

Here we present some examples of Doppler et al.’s false handling of our text in “Antiquity” (Rappenglück et al. 2010: 428-439) that show that Doppler et al.’s text even lacks the fundamental formal demands of a scientific debate.

Doppler et al. (2011: 274) contend that we would date the Chiemgau impact to “some 2500 years ago” in “the Iron Age”. In actual fact we have dated the event to a period of 4200-2800 years ago (2200-800 BC), this means the Bronze Age (Rappenglück et al. 2010: 436).

Doppler et al. (2011: 274) contend that we would date the impact by the myth. This is false: We have dated the impact and the myth independently from each other and then compared the dates (Rappenglück et al. 2010: 435-37).

Doppler et al. contend (2011: 276) that we would claim that once the Lake Chiemsee included the Lake Tüttensee. This is simply not true, and of course they fail to mention the passage in our “Antiquity” article, where this assertion should allegedly be made. This kind of handling our text can at least be called slipshod, if it is not willful distortion.

Remarkably, this kind of handling texts continues even with studies that they use to underpin their statements: Doppler et al. (2011: 277) contend that Möslein identified the disputed deposit at Stöttham “as anthropogenic”. Of course they do not give a reference, because in his excavation report (Möslein, S., 2009. Grabungsbericht. Chieming TS, Stöttham-Dorfäcker 2007/08. Technical report, Bad-Tölz, unpubl.; available at the administrative district office of Traunstein) Möslein does not at all classify the process of deposition of the layer in question (Möslein 2009: 14f.).

Doppler et al. (2011: 276) also cite Gareis (Gareis, J. 1978. Die Toteisfluren des bayerischen Alpenvorlandes als Zeugnis für die Art des spätwürmzeitlichen Eisschwundes [Würzburger Geographische Arbeiten 46]. Würzburg) as a key witness for the glacial formation of the Tüttensee landscape. But Gareis (1978: 68) several times explicitly excludes a glacial origin of parts of the Tüttensee rim wall.

These examples cast a poor light even on the formal solidity of Doppler et al.’s text.

Recommended for further reading:

Ernstson, K., Mayer, W., Neumair, A., Rappenglück, B., Rappenglück, M.A., Sudhaus, D., Zeller, K.W. (2010), The Chiemgau Crater Strewn Field: Evidence of a Holocene Large Impact Event in Southeast Bavaria, Germany: Journal of Siberian Federal University, Engineering & Technologies 3 (1), 72-103. (http://elib.sfu-kras.ru/bitstream/2311/1631/1/04_.pdf)

Hiltl, M., F. Bauer, K. Ernstson, W. Mayer, A. Neumair, M.A. Rappenglück (2011), SEM and TEM analysis of minerals xifengite, gupeiite, Fe2Si (hapkeite?), titanium carbide (TIC) and cubic moissanite (SiC) from the subsoil in the Alpine Foreland: Are they cosmochemical?: 42nd Lunar and Planetary Science Conference, 1391.pdf. (http://www.lpi.usra.edu/meetings/lpsc2011/pdf/1391.pdf)

Liritzis, I., N. Zacharias, G.S. Polymeris, G. Kitis, K. Ernstson, D. Sudhaus, A. Neumair, W. Mayer, M.A. Rappenglück, B. Rappenglück (2010), The Chiemgau Meteorite Impact and Tsunami Event (Southeast Germany): First OSL Dating: Mediterranean Archaeology & Archaeometry, Vol.10, No. 4 (in press).

Rappenglück B., K. Ernstson, W. Mayer, A. Neumair, M.A. Rappenglück, D. Sudhaus, K.W. Zeller (2009), The Chiemgau impact: an extraordinary case study for the question of Holocene meteorite impacts and their cultural implications, Proceedings, Cosmology across cultures, ASP Conference Series 409, San Francisco, Astronomical Society of the Pacific, 338-343. (http://www.aspbooks.org/a/volumes/article_details/?paper_id=30130)

Rappenglück, B., M.A. Rappenglück, K. Ernstson, W. Mayer, A. Neumair, D. Sudhaus, I. Liritzis (2010), The fall of Phaethon: a Greco-Roman geomyth preserves the memory of a meteorite impact in Bavaria (south-east Germany), Antiquity 84, 2010, 428-439. (http://antiquity.ac.uk/ant/084/ant0840428.htm)

Schüssler, U., M. Rappenglück, K. Ernstson, W. Mayer, B. Rappenglück (2005), Das Impakt-Kraterstreufeld im Chiemgau: European Journal of Mineralogy 17, Bh. 1, 124.

The fall of Phaethon

The fall of Phaethon: a Greco-Roman geomyth preserves the memory of a meteorite impact in Bavaria (south-east Germany)

Barbara Rappenglück1, Michael A. Rappenglück1, Kord Ernstson2, Werner Mayer1, Andreas Neumair1, Dirk Sudhaus3 & Ioannis Liritzis4

Phaeton
Arguing from a critical reading of the text, and scientific evidence on the ground, the authors show that the myth of Phaethon – the delinquent celestial charioteer – remembers the impact of a massive meteorite that hit the Chiemgau region in Bavaria between 2000 and 428 BC. (Editor’s abstract)
1 Institute for Interdisciplinary Studies, Bahnhofstrasse 1, 82205 Gilching, Germany (Email: Barbara.Rappenglueck@evtheol.uni-muenchen.de)
2 Julius-Maximilians-Universität Würzburg, Am Judengarten 23, 97204 Höchberg, Germany (Email: kernstson@ernstson.de)
3 Albert-Ludwigs-Universität Freiburg, Institut für Physische Geographie, 79085 Freiburg, Germany (Email: dirk.sudhaus@gmx.net)
4 University of the Aegean, Department of Mediterranean Studies, Dimokratias 1, 85100 Rhodes, Greece (Email: liritzis@rhodes.aegean.gr)
Received: 20 July 2009; Accepted: 18 August 2009; Revised: 21 September 2009
ANTIQUITY 84 (2010): 428–439 http://antiquity.ac.uk/ant/084/ant0840428.htm

Chiemgau Crater Strewn Field

The Chiemgau Crater Strewn Field: Evidence of a Holocene Large Impact Event in Southeast Bavaria, Germany
Kord Ernstson, Werner Mayer, Andreas Neumair, Barbara Rappenglück, Michael A. Rappenglück, Dirk Sudhaus and Kurt W. Zeller

Kord Ernstson*a, Werner Mayerb, Andreas Neumairb, Barbara Rappenglückb, Michael A. Rappenglückb, Dirk Sudhausc and Kurt W. Zeller✝d

a University of Würzburg, Am Judengarten 23, 97204 Höchberg, Germany
b Institute for Interdisciplinary Studies, Bahnhofstraße 1, 82205 Gilching, Germany
c Institute of Geography, University of Augsburg, Universitätsstraße 10, 86135 Augsburg, Germany
d Österreichisches Forschungszentrum Dürrnberg, Pflegerplatz 5, 5400 Hallein, Austria

Received 30.01.2009, received in revised form 27.02.2010, accepted 9.03.2010

Abstract. – The Chiemgau strewn field in the Alpine Foreland discovered in the early new millennium comprises more than 80 mostly rimmed craters in a roughly elliptically shaped area with axes of about 60 km and 30 km. The crater diameters range between a few meters and a few hundred meters. Geologically, the craters occur in Pleistocene moraine and fluvio-glacial sediments. The craters and surrounding areas so far investigated in more detail are featuring heavy deformations of the Quaternary cobbles and boulders, abundant fused rock material (impact melt rocks and various glasses), shock-metamorphic effects, and geophysical anomalies. The impact is substantiated by the abundant occurrence of metallic, glass and carbon spherules, accretionary lapilli, and of strange matter in the form of iron silicides like gupeiite and xifengite, and various carbides like, e.g., moissanite SiC. The hitherto established largest crater of the strewn field is Lake Tüttensee exhibiting an 8 m-height rim wall, a rim-to-rim diameter of about 600 m, a depth of roughly 30 m and an extensive ejecta blanket. Physical and archeological dating confine the impact event to have happened most probably between 1300 and 300 B.C. The impactor is suggested to have been a low-density disintegrated, loosely bound asteroid or adisintegrated comet in order to account for the extensive strewn field.

full article http://elib.sfu-kras.ru/bitstream/2311/1631/1/04_.pdf

 

* Corresponding author E-mail address: kernstson@ernstson.de
© Siberian Federal University. All rights reserved

Comment on the mantra-like arguments of critics

With regard to the mantra-like arguments of critics

— that according to computer simulations the Chiemgau impact crater strewn field is far too extensive (Reimold et. al. 2006, Wünnemann et al. 2007),

— that it is impossible that meteorites other than iron meteorites can produce small craters on the ground (Reimold et. al. 2006),

— that it is utterly out of the question that comet fragments are able to produce a crater strewn field at the Earth’s surface,

— that we are anyhow knowing all about comets [“Cometary matter is unchanged since the formation of our solar system 4,500 Ma” (Jessberger 2005), and “Comets don’t carry >> unknown matter<<” (Jessberger 2006)]

we in the following present some new results (Main Belt Comets, MBC; large impact crater strewn field in Argentina; Carancas, Peru, stony meteorite impact crater) referring to this group of themes.

Exotic objects in the solar system: Comet-like asteroids (main belt comets – MBC)

Between 1979 and 2010 five objects having diameters from 150 m to 5 km have been discovered in the asteroid main belt between the orbits of Mars and Jupiter that show comet-like properties. Without significant deviations their orbit corresponds to the asteroid belt. Different from the rest of the asteroids they exhibit the following peculiarities:

Loss of mass indicated by a tail (dust, gas, debris) and, like with comets, depending on the exposition to the sun.

This points to a distinct content of volatiles in the form of ice under diverse cover. A time span of thousands of years for the comet-like behavior is assumed. Since the hydrogen isotopic ration of the terrestrial water is not compatible with the ratio so far measured for comets, it is internationally discussed whether the MBCs may have contributed to the delivery of water to Earth. A formation of the MBCs by collisions in the asteroid belt resulting in a release of ice to the surface is also being discussed.

The most recently discovered object (in January 2010) has a diameter of c. 150 m (light spot at lower left), and a photo was taken by the Hubble telescope:

Ch Neu

Source: http://science.nasa.gov/headlines/y2010/02feb_asteroidcollision.htm?list1316228

Additional links:

http://www8.nationalacademies.org/astro2010/DetailFileDisplay.aspx?id=250

http://www2.ess.ucla.edu/~jewitt/mbc.html

http://star.pst.qub.ac.uk/~hhh/mbcs.shtml

Bajada del Diablo, Argentina: a newly discovered large meteorite crater strewn field.

Critics from Berlin (Museum of Natural History, Reimold et al. 2006) claim that according to computer simulations the strewn field of a fragmented meteorite can be very small only, not much more than 1 km wide. Indeed, the crater strewn fields of Kaalijarvi (Estonia), Ilumetsa (Estonia), Morasko (Poland), Sikhote-Alin (Russia), Henbury (Australia), Wabar (Saudi Arabia) are small the half axes being 0,5 – 2 km and up to 1 km, respectively.

Perhaps the computer has not heard of this, but the strewn field of Campo del Cielo (Gran Chaco Gualamba, Chaco, Argentina) comprises 22 small craters at least (diameters from 5 to 103 m, up to 5 m deep) which are distributed over an area of minimum 19 km x 3 km. The recently discovered crater strewn field of Bajada del Diablo (Provincia de Chubut, Patagonia, Argentina) is even larger and measures 27 km x 15 km at least. The c. 100 craters have diameters between 60 m and 500 m and are up to 50 m deep.

These data strongly remind of the Chiemgau meteorite crater strewn field, and the Argentine researchers explicitly refer to the Chiemgau impact and suggest – as does the CIRT – the projectile to have been a loosely bound asteroid (like the 253 Mathilde “rubble pile”) or a fragmented comet nucleus.

The link to the article (abstract) in Geomorphology, 110, 58-67, 2009: http://www.sciencedirect.com/science…

Produced by the impact of a stony meteorite: the 13.5 m-diameter Carancas, Peru, impact crater:

Referring to the Chiemgau impact Reimold et al. (2006) declare the impossibility that small craters on the Earth’s surface can be produced by meteorites other than iron meteorites. Only one year later, object lesson was given when in Peru a stony meteorite produced a 13 m-diameter impact crater.

Correspondingly, we read in a first publication of scientists (2008):

“Unlike what it is generally expected, a few tons stony meteorite did not disintegrate in its passage through the atmosphere, but rather it reached the ground with a velocity high enough to produce an impact crater. This event challenges our present view of the fate of meteoroids striking the Earth. The presence of small craters on Earth as well as Mars has to be re-analyzed on the basis of the Carancas event.” [http://www.lpi.usra.edu/meetings/acm2008/pdf/8260.pdf]

A comprehensive article on the Carancas impact has been printed in Meteoritics and Planetary Science (MAPS):

G. Tancredi, J. Ishitsuka, P. H. Schultz, R. S. Harris, P. Brown, D. O. Revelle, K. Antier, A. Le Pichon, D. Rosales, E. Vidal, M. E. Varela, L. Sánchez, S. Benavente, J. Bojorquez, D. Cabezas and A. Dalmau (2009):

A meteorite crater on Earth formed on September 15, 2007: The Carancas hypervelocity impact

The link to the abstract:

http://www3.interscience.wiley.com/journal/123285061/abstract

IMPACT CRITERIA for the Chiemgau impact event and meteorite crater strewn field

When is a meteorite crater a meteorite crater?

macha
Image courtesy Google Earth

There are people believing this to be the case when a crater under discussion is accepted by a committee to be included in an official database like the Earth impact database of the New Brunswick university in Canada. There are other people being convinced a meteorite crater is a meteorite crater when there is clear scientific evidence for such an origin and who doubt that acommittee is qualified to decide on results of scientific research. This is the reason why different impact databases are revealing quite different numbers of established terrestrial meteorite craters (impact structures). Disregarding this fine distinction, there are quite a few criteria (e.g., morphological, geological, geophysical, mineralogic-petrographical, geochemical) as a base for the evaluation of a meteorite crater, and some of them are regarded as in proof of impact. In other words and to say it simpler: Having mapped basaltic rocks in the field, one will be convinced there is volcanism, and having mapped rocks displaying shock-metamorphic effects, one will be convinced there is a nearby impact site.

 

Impact criteria – compelling and less compelling – as compiled by Norton, O.R. (2002): The Cambridge Encyclopedia of Meteorites. – Cambridge University Press, pp. 291-299, and French, B.M. (1998): Traces of Catastrophe. A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures. Lunar and Planetary Institute, pp. 97-99 (download as a pdf file here), and others, are:

1. Morphology

Circular structures in general; depressions with raised rims or/and central uplifts; multi-ring structures: less meaningful because many other geological structures may show circular symmetries, and true impact structures may strongly deviate from such a shape.

2. Geophysical anomalies

Many impact structures  are closely related with characteristic gravity and magnetic anomalies, but reversely, measured anomalies in general don’t allow to deduce an impact event. Seismic reflection surveys may reveal the characteristic layering of buried impact structures.

3. Geologic evidence

Regularly found in and around impact structures: strong deformations, folding, faulting, fracturing; polymictic and monomictic breccias and dike breccias, megabreccias; high-pressure/short-term deformations of clasts in a soft matrix; rocks looking like volcanic or magmatic rocks; layers of exotic material.

4. High-temperature evidence

Melt rocks, natural glasses, breccias with melt rock fragments and glasses

5. High-pressure evidence – shock metamorphism

Planar deformation features (PDFs) in quartz, feldspar and other minerals, planar fractures (PFs) in quartz, diaplectic quartz and feldspar crystals, diaplectic glass; multiple sets of intense kink banding in mica, multiple sets of microtwinning in calcite. Kink banding in mica and PFs in quartz are also known from very strong tectonic deformation.

6. Shatter cones

 

Steinheim shatter cone Sudbury shatter cone

Shatter cones, here in limestone from the Steinheim Basin impact structure and in an quartz-arenite from the Sudbury impact structure, are characteristic shock-induced conical fracture planes in all types of hard rocks. Shatter-cone fracture planes show typical “horse-tail” fracture markings.

7. Special evidence

Occurrence of micro and/or nano-diamonds; accretionary lapilli, various kinds of spherules. – Spherules may be anthropogenic.

8. Meteorite fragments

In larger meteorite craters in most cases completely absent because of vaporization of the projectile upon impact. Microscopic geochemical signature of the impactor is possible. Meteorite fragments are in general found in and around young small craters. In the Macha crater strewn field (Yacutia), however, the largest particles assumed to be meteoritic are 1.2 mm-sized only.

9. Direct observation (historical record)

Apart from the observation of meteorite showers (e.g., Sikhote Alin) impacts to have formed a meteorite crater have not been passed on. Geomyths may be interpreted as document of observed impacts.

 

According to current understanding, points 5. shock metamorphism, 6. shatter cones, 8. meteorite fragments, and 9. direct observation are each one by itself accepted as a confirmation of an impact event.

The criteria 1. – 9. applied to
the Chiemgau crater strewn field

1. Morphology – yes

Numerous circularly shaped craters with raised rims

rimmed crater no. 004

The 11 m-diameter crater no. 004 in the Chiemgau impact strewn field. Note the distinct raised rim.

2. Geophysical anomalies – yes

– Gravity negative anomaly of the Lake Tüttensee crater surrounded by a conspicuous zone of relatively positive anomalies

– A distinct horizon of strongly enhanced soil magnetic susceptibility in the strewn field.

Tüttensee gravity anomaly

Gravity survey (Bouguer residual anomaly) of the Lake Tüttensee cratersoil magnetic susceptibility

Anomalous soil magnetic susceptibility profile near the Lake Tüttensee crater

3. Geologic evidence – yes, multiple

Tüttensee breccia

Multicolored polymictic impact breccia from the Lake Tüttensee crater ejecta layer.coherent clasts

Highly fractured however coherent carbonate and silicate clasts from the Lake Tüttensee crater ejecta layer: evidence of high-pressure/short-term deformation.squeezed cobble

Highly fractured and squeezed however coherent quartzite cobble from the Lake Tüttensee crater rim wall: evidence of high-pressure/short-term deformationStöttham exotic layer

The Stöttham exotic impact layer (arrow)

4. High-temperature evidence – yes

Tüttensee impact melt rock

Pumice-like impact melt rock from the Lake Tüttensee crater.welded cobbles

Two glass-coated cobbles welded by cindery glass from crater no. 004melt rock

Sawed surface of a silicate cobble from crater no. 004. Extremely vesicular and fissured rock where, except for quartz, all minerals are more or less transformed to glass giving the dark color to the rock. The widely open fissures may result from shock spallation.

5. Shock metamorphism – yes

PDFs, Tüttensee PDFs, Popigai

“Toasted” quartz with multiple sets of PDFs in quartz; photomicrograph, crossed polarizers, quartzite clast from the Lake Tüttensee crater rim wall. “Toasted” quartz is a common feature in shocked grains and is explained by tiny fluid inclusions. – For comparison to the right: toasted quartz with PDFs from the Popigai impact structure, Russia

.PDFs, crater 004

Two sets of planar deformation features (PDFs) in quartz; photomicrograph, crossed polarizers, 1.5 mm field width; quartzite clast from the Chiemgau impact 004 crater. The slightly curved PDFs must not irritate: Although there are authors, e.g. Reimold & Koeberl (2000), who claim bent PDFs are of non-impact origin, the example of the Popigai bent PDFs in the above image and many other examples from various impact structures show the verdict of Reimold & Koeberl is not tenable

.shocked plagioclase

Twin lamellae and multiple sets of PDFs in feldspar. Photomicrograph, crossed polarizers; impact melt rock from the Lake Tüttensee crater.

6. Shatter cones – yes

shatter cone Tüttensee

Two shatter cones in counter position in a fine-grained sandstone from the Lake Tüttensee crater.

7. Special evidence  – yes

Nanodiamonds – yes  

Article

Rösler W., Hoffmann V., Raeymaekers, B., Schryvers, D. and Popp, J. (2005) Diamonds in carbon spherules –evidence for a cosmic impact? (http://www.lpi.usra.edu/meetings/metsoc2005/pdf/5114.pdf; 7.5.2006).

Accretionary lapilli – yes

Lapillo Chiemgau Lapillo Chiemgau2

Accretionary lapilli (to the right with a fragmental metallic core) from the Chiemgau impact strewn field. Lapilli diameters about 4 – 5 mm. Accretionary lapilli are normally known from volcanism but have been shown to occur also in impact structures where they have been formed in the impact explosion cloud.

Spherules – yes

glass spherule

2 mm-diameter broken vesicular glass spherule; Stöttham impact layer.carbon spherules

Carbon spherules from various sites in the Chiemgau impact strewn field. Also see Yang, Z.Q. et al., 2008: TEM and Raman characterization of diamond micro- and nanostructures in carbon spherules from upper soils. – Diamond and Related Materials 17/6: 937-943.

8. Meteorite fragments – probably yes

Exotic material like iron silicides gupeiite and xifengite, carbides like titanium carbide and silicon carbide moissanite strongly point to extraterrestrial origin.

SEM image of moissanite crystals in iron silicide matrix. Sample from the Chiemgau meteorite crater strewn field.

gupeiite suessite

Comparison of analyses of Chiemgau gupeiite and meteoritic suessite

9. Direct observation (historical record) – possibly yes

Rubens_Fall_of_Phaeton

Peter Paul Rubens: The fall of Phaeton, National Gallery of Art, Washington.

 

Article

Rappenglück, B. and Rappenglück, M., 2006: Does the myth of Phaethon reflect an impact? – Revising the fall of Phaethon and considering a possible relation to the Chiemgau Impact. – Mediterranean Archaeology and Archaeometry 6/3 (2006), 101-109.

The following contributions (oral, poster) of the Chiemgau Impact Research Team (CIRT) were presented:

 

Michael A. Rappenglück & Kord Ernstson: The Chiemgau crater strewn field (Southeast Bavaria, Germany): Evidence of a Holocene large impact event

International Conference “100 years since Tunguska phenomenon: Past, present and future”. – June 26 – 28, 2008, Moscow (Russia)

Kord Ernstson & Michael A. Rappenglück: The Chiemgau crater strewn field: Evidence of a Holocene large impact event in Southeast Bavaria, Germany

International Scientific Conference “100 years of the Tunguska event”. – June 30 – July 6, 2008, Krasnoyarsk (Russia)

Barbara Rappenglück & Michael A. Rappenglück (for the Chiemgau Impact Research Team): The fall of Phaethon:  Is this a geomyth reflecting an impact in Bavaria during the Celtic period?

33rd International Geological Congress. Session: Myth and Geology. – August 5 – 14, 2008, Oslo (Norway)

 

The following contributions (oral, poster) of the Chiemgau Impact Research Team (CIRT) submitted and has been accepted for presentation:

Chiemgau Impact Research Team (CIRT): The Chiemgau Impact: An extraordinary case-study for the question of Holocene impacts and their cultural implications

SEAC (Société Européenne pour l’astronomie dans la culture) meeting (XVIth). – September 8-12, 2008, Granada (Spain)