New article: Jiloca graben and Rubielos de la Cérida impact basin (NE Spain)

When modeling ignores observations: The Jiloca graben (NE Spain) and the Rubielos de la Cérida impact basin

by Kord Ernstson1 and Ferran Claudin2

June 2020


Abstract. – The Iberian System in NE Spain is characterized by a distinctive graben/basin system (Calatayud, Jiloca, Alfambra/Teruel), among others, which has received much attention and discussion in earlier and very recent geological literature. A completely different approach to the formation of this graben/basin system is provided by the impact crater chain of the Rubielos de la Cérida impact basin as part of the important Middle Tertiary Azuara impact event, which has been published for about 20 years. Although the Rubielos de la Cérida impact basin is characterized by all the geological, mineralogical and petrographical impact findings recognized in international impact research, it has completely been hushed up in the Spanish geological literature to this day. The article presented here uses the example of the Jiloca graben to show the absolute incompatibility of the previous geological concepts with the impact structures that can be observed in the Jiloca graben without much effort. Digital terrain modeling and aerial photography together with structural and stratigraphic alien geology define a new lateral Singra-Jiloca complex impact structure with central uplift and an inner ring, which is positioned exactly in the middle of the Jiloca graben. Unusual topographic structures at the rim and in the area of the inner ring are interpreted as strike-slip transpression and transtension. Geological literature that still sticks to the old ideas and develops new models and concepts for the graben/basin structures, but ignores the huge meteorite impact and does not even enter into a discussion, must at best cause incomprehension.

Key words: Meteorite impact, Azuara impact event, Alfambra-Teruel graben, Calatayud basin, strike-slip transgression, transtension, Singra-Jiloca impact


1 University of Würzburg, 97074 Würzburg (Germany),                                                 

2 Associate Geological Museum Barcelona (Spain);

The full article can be clicked HERE.

An article pdf for download can be clicked HERE.


Daroca thrust (Iberian Chain, Spain) and the Azuara impact structure – the controversy continues

Comment on

Sanchez, M.A. ; Gil, A. y Simón, J.L. (2017): Las rocas de falla del cabalgamiento de Daroca (sector central de la Cordillera Ibérica): Interpretación reológica y cinemática. Geogaceta, 61: 75-78. (

Casas-Sainz, A.M., Gil-Imaz, A., Simón, J.L., Izquierdo Llavall, Aldega, E.L., Román-Berdiel, T., Osácar, M.C., Pueyo-Anchuela, O., Ansón, M., García-Lasanta, C., Corrado, S., Invernizzi, C., Caricchi, C. (2018): Strain indicators and magnetic fabric in intraplate fault zones: Case study of Daroca thrust, Iberian Chain, Spain. Tectonophysics, 730: 29-47 (10.1016/j.tecto.2018.02.013) (

Gutierrez, F, Carbonela, D., Sevil, J., Moreno, D., Linares, R, Comas, X., Zarroca, M., Roqué,C., McCalpin, J.P. (2020): Neotectonics and late Holocene paleoseismic evidence in the Plio-Quaternary Daroca Half-graben, Iberian Chain, NE Spain. Implications for fault sorce characterization. Journal of Structural Geology, 131: 1-17 (

by Ferran Claudin & Kord Ernstson (March 2020)

The town of Daroca in the Spanish Province of Zaragoza hides a peculiar geologic scenario – an enigma for geologists from time out of mind. Being enthroned above the town the geologic stratigraphy shows with a very sharp cut Cambrian dolomite (Ribota dolomite) over Tertiary young sediments (Fig. A). Older layers over younger ones are not uncommon in geology, and overthrust and thrust faulting are related processes. But Daroca is different. The Cambrian plate is kilometer-sized and fragmented into larger blocks, and a Tertiary 180° overtrust can reasonably be excluded. Early geologists confronted with the situation in sheer desperation thought of a preexisting Cambrian autochthonous plate and a vast undercutting by the Tertiary. Today this explanation is left out of consideration and simple thrust faulting is being favored. But the case is all but simple. There is no root zone and not any relief from where the giant plate could have started to override the Tertiary around Daroca. Nevertheless, the thrust kinematics are developed further by geologists (e.g., Capote et al. 2002), and tens of kilometers long faults are drawn within models of syn-tectonic sedimentation (Casas et al. 2000; Fig. 3).

The Daroca (Spain) thrust and the Azuara impact structure

Fig. A. The prominent Daroca exposure.

In 2012 we published an extended article (Claudin and Ernstson 2012) under the title “Azuara impact structure: The Daroca thrust geologic enigma – solved? A Ries impact structure analog“.. which proposes a new and in our opinion reasonable model of formation and a physically plausible solution of the enigma. To cut the story short, the Daroca thrust originated in the meanwhile generally established Azuara impact event, when according to the spall plate model of Melosh (1989) the Daroca Ribota dolomite plate started from the developing excavation crater and the near-surface interference zone with extreme velocity (Fig. B), supported by enormous volumes of rock melt, water and gases (water vapor and carbon dioxide from the shocked target) as a kind of hovercraft. This is no speculation but has much earlier been discussed for the so-called role-and-glide mode in the excavation process of the Ries impact crater (Germany). In our paper on the Daroca thrust we write about the affinity of both events and point to Ries giant megablocks having been excavated and transported over enormous distances.

In the case of the Daroca thrust this impressive way of transport can so nicely and conclusively be observed on the geological general map 1 : 200 000, sheet Daroca, which we show in simplified manner below (Fig. B) and in a copy of the geological map in Fig. 11 of the Spanish complete version).

simplified geological map for the Daroca thrust origin The spall plate model of impact excavation

Fig. B. The impact cratering model for the Daroca thrust – no intraplate fault zone (see text).

We do not know with certainty whether the authors of the three papers have read our paper and whether they have understood the herein presented simple explanation, but strangely enough since the publication of our paper on the Daroca thrust with the close relation to the Azuara impact structure, practically “overnight” a series of publications has appeared to demonstrate that the Daroca thrust has a normal tectonic fault origin, after not any geologist from Spain or elsewhere had paid attention to the enigma for decades (apart from the Casas et al. (2000) and Capote et al. (2002) papers, only seeing a tectonic fault despite all non-tectonic field evidence).

Of course, science thrives on controversy on certain topics and especially on new discoveries and models, but one principle is that the different views should be on a scientific level and that both views should be carefully discussed and balanced.

In all three papers we miss the observance of this basic scientific constitution. Not a single word is used to mention the Daroca article and the Azuara impact structure in general, and not a single one of the abundant publications on one of the most spectacular geological scenarios in Spain is found in their works. Today the Internet is a common medium and broadly used to get information about serious scientific publications (ResearchGate e.g.), and on preparing their papers a few clicks by the authors of the three papers had of course opened a host of literature about the Azuara impact event and the Daroca thrust.

In principle our Comment article could therefore end here. But we do not want to make the same omission ignoring the papers under discussion here. In the main part of our Comment paper following below, F. Claudin has compiled an exhaustive analysis of the three Daroca “tectonic” papers confronting their in many respects rather questionable claims with standard geologic literature and with the impressive meteorite impact-related features, once more described here point by point with a host of figures that do not exist for the authors.

Exemplarily, one point of importance is addressed already here, the Casas-Sainz et. al. paper about magnetic fabric from AMS (anisotropy of magnetic susceptibility) and strain indicators. From the text we learn that magnetic AMS analyses were performed at 6 sites, but only a single one (no.16) is located in Daroca at the thrust exposure (their Fig. 2A). Since the site is navigated at fractures of a second, we have to proceed from a spot analysis (their Table. 1), and the rock for 12 specimen measurements is described as a fault microbreccia (their Table 3). The rest of the 5 AMS sites is located roughly 1 km southeast of Daroca (their Fig. 2A).

We imagine: For the Daroca thrust as described in very detail in our paper (Claudin & Ernstson 2012), a spot few meters sized at best served for an AMS analysis of a microbreccia (we assume of Ribota dolomite) for which it is obviously not known when it acquired the brecciation and a resulting AMS texture.

Considering now the Daroca thrust impact model of an enormously dislocated spall plate, which Casas-Sainz et al. completely ignore, what will a point AMS tell us about old in situ tectonics and intraplate fault zones? Nothing. The Daroca plate may have transported magnetic textures from its original place more than 10 km to the east, intense brecciation and other deformation (which can be seen in Daroca outcrops) in the excavation, ejection, transport and emplacement processes should have produced a completely new texture, not to forget possible strong temperature overprint in the impact cratering process.

The same holds true for the five other sites of AMS analyses. Since the aim and outcome of the paper is basically the AMS of the thrust zone, more than a little methodological insight into the authors’ working cannot be recognized. The paper of Gutierrez et al. (2020) does not differ in any way in this respect. Their ground penetrating radar (GPR) and resistivity measurements at Daroca are good to look at, but for the topic under discussion they are absolutely meaningless. The idea arises that the visual impression of scientific evidence for the so-called Daroca Half-graben is to be created by the pure application of a few geophysical measurements on a very small area.

The complete article (in Spanish) may be clicked here.

Chiemite: addition to the article below

Chiemite and Muschelkalk, sandstone facies, breccia-like interleaved - Saarland impact, cut face

Chiemite and Muschelkalk cobble are breccia-like interleaved. Saarland impact, cut face, centimeter scale.

The most recent find of chiemite in the Saarland impact region (Nalbach, Saarlouis craters) concerns a cobble in which a larger piece of chiemite is breccia-like interleaved with a cobble (probably Muschelkalk in predominantly sandy facies) (photos). This supports the idea that during the impact the chiemite was mainly formed from a carbon melt (vaporized and condensed carbon from the heavily shocked vegetation) and that when it hit the rock it created a vesicular texture in it (partially carbonate melt, decarbonization).

This find should at least make the self-appointed great impact experts on the Internet think about how the Muschelkalk limestone got into the coal cellar and intimately aggregated with the coke.

chiemite on Muschelkalk cobble, Saarland meteorite impact siteFrom the Saarland impact region: chiemite interleaved with Muschelkalk limestone/Muschelkalk sandstone (cut face in the entrance photo). Picture width 10 cm.

chiemite on vesicular Muschelkalk cobble, Saarland meteorite impact site

Chiemite remains on the blistered cobble surface.

Wikipedia: Chiemite impactite and the EGU poster deception with the Wikipedia name

SEM images chiemite and chiemite pseudomorphic after woodChiemite, which is described in international, renowned peer-reviewed publication organs as high pressure/high temperature impactite with the contents of diamond and carbines (T = 2500 – 4000 K, P = several GPa), is of terrestrial origin and has originated from a spontaneous shock coalification/carbonization of the vegetation (wood, peat) of the Chiemgau impact area. The published methods of the chiemite investigation were: 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.

The most comprehensive article on the chiemite impactite so far is published here:

Enigmatic Glass-like Carbon from the Alpine Foreland, Southeast Germany: A Natural Carbonization Process. – Acta Geologica Sinica (English Edition), 92, 2179-2200, 2018.


About the first author (from the Journal Editor). – Tatyana Shumilova, born in Vorkuta, Russian Federation, in December 1967. She received her PhD at the Institute of Geology UB Komi SC UB RAS in 1995. She was habilitated at the Saint-Petersburg Mining University (Leningrad Mining Institute) in 2003. At present she is a head of the Laboratory of Diamond Mineralogy and main scientist at the Institute of Geology UB Komi SC UB RAS and Affiliated Researcher at the University of Hawaii. She published over 50 papers in peer-reviewed journals such as Scientific Reports, Carbon, European Journal of Mineralogy, Mineralogy and Petrology, Doklady Earth Sciences, and others.

The background for these additions to the article is the following contrast:

At the this year’s (2019) meeting of the European Geosciences Union (EGU) in Vienna in April, Dr. Robert Huber (marine geologist at Marum, Center for Marine Environmental Sciences, University of Bremen) and Dr. Robert Darga (ice age geologist, director of the Mammut Museum in Siegsdorf, Chiemgau, Oberbayern) obviously succeeded in persuading some other scientists to present a joint poster, on which their crude ideas were presented: “If You Wish Upon A Star. Chiemite: An Anthropocene Pseudo-Impactite. “

Placing the poster in Wikipedia and Wikimedia Commons does not enhance the value of this poor attempt.

The three coauthors of the poster are from Australia – Mineral Resources, CSIRO, Federal Agency for the improvement of the economic and social performance of industry -, shedding some light on their relevant scientific competence. Scientifically the poster presentation of these impact critics, in which not a single reference is brought to the Chiemgau impact and not a single reference to the chiemite is absolutely worthless, far from any scientific seriousness, and should cause mockery at most in a respectable science scene. One wonders why the poster could be shown at all on the Vienna conference.

In the meantime, the chiemite impactite has been found widely in the Saarland impact region as well as in numerous specimens in the impact area of the Czech Republic Abstract Poster. In both cases the chiemites show identical formation and occur in both areas together with strongly shocked impact rocks.

chiemite impactite from the Saarland and Czech Republic impacts

Chiemite from the Saarland impact ………………………..and the Czech impact

Pelarda Fm. Impact Ejecta – Azuara Impact Structure (Spain)

Pelarda Fm. – Azuara Impact Structure (Spain) – comprehensive article on one of the biggest, most attractive and scientifically most instructive impact ejecta deposits worldwide


PDF article, 81 p., 92 Figs. – The full article can be clicked HERE.

Abstract. – The Pelarda Formation (Fm.), located in the Iberian System in northeast Spain, is a sedimentary deposit with an extension of roughly 12 km x 2.5 km and an estimated thickness of no more than 400 m. The formation was first recognized as a peculiar unit in the early seventies and underwent interpretations like a fluvial or an alluvial fan deposit having a postulated age between Paleogene and Quaternary. Since the early nineties the Pelarda Formation has been considered an impact ejecta deposit originating from the large ca. 40 km-diameter Azuara impact structure and meanwhile being among the largest and most prominent terrestrial impact ejecta occurrences, which however is questioned by regional geologists still defending the fluvial and alluvial fan models. Roughly speaking, the Pelarda Fm. is a grossly unsorted, matrix-supported diamictite with grain sizes between silt fraction and meter-sized clasts and a big intercalated megablock. Strong clast deformations and abundant shock metamorphic effects like planar deformation features (PDF) are observed throughout the Pelarda F. deposit compatible with its impact ejecta origin. Aligned bigger clasts and smaller intercalated bands of sandstones, siltstones and clayey material indicate some local stratification obviously adjusted to flow processes within the impact ejecta curtain. This suggests that gravitational flows predominated in a transport by water in both liquid and gas states. Transport and deposition as a kind of pyroclastic surge are discussed. A sketch sequence describes the emplacement process of the Pelarda Fm. as part of the Azuara crater formation and the integration in the general frame of pre-impact geology and some post-impact layering.

Key words: Pelarda Formation, Iberian System, Upper Eocene/Oligocene, Azuara impact structure, proximal impact ejecta, pyroclastic flow

Lairg (Northern Scotland): evidence of Europe’s largest impact structure

New article: Michael J. Simms and Kord Ernstson (2019): A reassessment of the proposed ‘Lairg Impact Structure’ and its potential implications for the deep structure of northern Scotland. – 

Bouguer gravity residual anomaly of the Lairg proposed impact structure. A buried complex structure with an inner peak ring of 50 km diameter und derived 100 km full diameter.
Probably the source for the Stac Fada Precambrian impact ejecta deposit.

Gravity residual profiles across the Lairg impact structure revealing an inner peak ring and peripheral depressions.


State of research on the Chiemgau Impact 2017 – English translation of the full article


Collision in prehistory. – The Chiemgau Impact: research in a Bavarian meteorite crater strewn field. – Zeitschrift für Anomalistik, vol. 17 (2017), p. 235-260. 

State of research on the Chiemgau Impact 2017 – English translation of the full article – click here.



Article: Pelarda Formation – prominent ejecta deposit of the Azuara impact structure (Spain)

La formación Pelarda: eyecta de la estructura de impacto de Azuara (España): características deposicionales, edad y génesis. Click the article!

[Pelarda Formation – ejecta deposit of the Azuara impact structure (Spain): Deposition characteristics, age and genesis].

New article about one of the most important impact ejecta deposits in the world: 75 pages, more than 90 illustrations – most current version. Spanish with English abstract. 

Ferran Claudin & Kord Ernstson

Abstract. – The Pelarda Formation (Fm.), located in the Iberian System in northeast Spain is a sedimentary deposit with an extension of roughly 12 km x 2.5 km and an estimated thickness of no more than 400 m. The formation was first recognized as a peculiar unit in the early seventies and underwent interpretations like a fluvial or an alluvial fan deposit having a postulated age between Paleogene and Quaternary. Since the early nineties the Pelarda Formation has been considered an impact ejecta deposit originating from the large c. 40 km-diameter Azuara impact structure and meanwhile being among the largest and most prominent terrestrial impact ejecta occurrences, which however is questioned by regional geologists still defending the fluvial and alluvial fan models. Roughly speaking, the Pelarda Fm. is a grossly unsorted, matrix-supported diamictite with grain sizes between silt fraction and meter-sized clasts. Strong clast deformations and abundant shock metamorphic effects like planar deformation features (PDF) are observed throughout the Pelarda F. deposit compatible with its impact ejecta origin. Aligned bigger clasts and smaller intercalated bands of sandstones, siltstones and clayey material indicate some local stratification obviously adjusted to flow processes within the impact ejecta curtain. This suggests that gravitational flows predominated in a transport by water in both liquid and gas states. Transport and deposition as a kind of 2 pyroclastic surge are discussed. A sketch sequence describes the emplacement process of the Pelarda Fm. as part of the Azuara crater formation and the integration in the general frame of pre-impact geology and some post-impact layering.

   Quartzite megaclast from the Pelarda Fm ejecta deposit. PDF in shocked quartz grain; quartzite clast from the ejecta deposit..


Pink quartz – a new, meteorite impact-related origin?

pink quartz Chiemgau meteorite impact

Part 1: Observations and first hypothesis of formation

Kord Ernstson* (2018)

Abstract. – Pink quartz, not to be confused with rose quartz, is an extremely rare color variety, which is completely transparent and is only known from a few occurrences worldwide. It is believed that the pink color is due to small amounts of aluminum and phosphorus that substitute silicon, and exposure of the quartz to natural gamma radiation. Sands with a dominating proportion of pink quartz excavated from the soil and extracted from a breccia layer in the crater strewn field of the Chiemgau meteorite impact suggest that normally colorless quartz sand was irradiated during the impact event and may possibly be found at other impact sites.

Key words: Pink and rose quartz, Chiemgau meteorite impact, neutron-gamma radiation


*Faculty of Philosophy I, University of Würzburg, Germany, email:


1 Introduction

Colors from ionizing radiation is an effect that occurs in many minerals as a result of natural and artificial exposure. Well known colored quartz transparent crystal varieties are amethyst, citrine and smoky quartz.

Pink quartz crystals were first discovered in the 1930’s in Maine, USA, and later in 1959 in Minas Gerais in Brazil (Dake, et al. 1938, Akhavan 2005-2013). In both cases the pink quartz was considered as common rose quartz that formed crystals. Only recently pink quartz crystals have been found also in the Himalayan Mountains, and pink quartz in general goes round in esoteric circles as so-called “healing stones”.

This “crystalline rose quartz” raised the interest of mineralogists who found distinct differences between pink quartz and common rose quartz, which is now generally accepted (Balitsky et al. 1998, Hori 2001, Maschmeyer and Lehmann 1983, Rykart 1995). In their opinion the pink quartz forms in phosphorous-rich pegmatites where few silicon is replaced by phosphorous and aluminum, and the color is the result of gamma ray radiation from uranium, thorium and potassium-40 decay in the rock, which may affect existing trapped-hole centers. Exposure to sunlight (UV) and heating above 200°C leads to discoloration.

Here I report on the discovery of quartz sands composed of a dominating fraction of pink quartz grains that are suggested to be related with the meanwhile established Chiemgau meteorite impact in Bavaria, Southeast Germany.

2 The Chiemgau impact event

The Chiemgau impact strewn field (Schüssler et al. 2005; Rappenglück et al. 2009; Ernstson et al. 2010, 2012; B. Rappenglück et al. 2010; Liritzis et al. 2010; Hiltl et al. 2011) discovered in the early new millennium and dated to the Bronze Age/Celtic era comprises about 100 rimmed craters scattered in a region of about 60 km length and ca. 30 km width in the very South-East of Germany (Fig. 1). The crater diameters range between a few meters and a few hundred meters, among them Lake Tüttensee with a rim-to-rim diameter of about 600 m and an extensive ejecta blanket. SONAR echosounder measurements show a striking structure at the bottom of Lake Chiemsee, which is completely untypical for the bottom of an ice-age lake. The structure measuring about 800 m x 400 m is a doublet crater with a ring wall. Since the crater strewn field extends beyond Lake Chiemsee, it is plausible that fragments of the large meteorite have also fallen into Lake Chiemsee and created craters on the ground (Fig. 1). The height of the resulting tsunami could exceed several decameters. Clear indications of such a tsunami are provided by diamictites with pronounced block layers and cross bedding, as they can be found in various gravel pits on the eastern side of Lake Chiemsee (Ernstson 2016).

Geologically, the craters occur in Pleistocene moraine and fluvio-glacial sediments. The craters and surrounding areas are featuring heavy deformations of the Quaternary cobbles and boulders, abundant fused rock material such as impact melt rocks and various glasses, strong shock metamorphism (planar deformation features [PDFs] in quartz and feldspar, diaplectic glass from quartz and feldspar), geophysical (gravity, geomagnetic, ground penetrating radar) anomalies (Ernstson et al. 2010; Neumair and Ernstson 2011, Rappenglück et al. 2017) and widespread impact-induced rock liquefaction features (Ernstson et al. 2011, Ernstson and Neumair 2011, Ernstson and Poßekel 2017). Impact ejecta deposits in a catastrophic mixture contain polymictic breccias, shocked rocks, melt rocks, and artifacts from Neolithic and Bronze Age/Iron Age people The impact is substantiated by the abundant occurrence of metallic, glass and carbonaceous spherules, accrecionary lapilli and microtektites (Ernstson et al. 2012, 2014). Strange, probably meteoritic matter in the form of iron silicides like gupeiite, xifengite, hapkeite, naquite and linzhite, various carbides like, e.g., moissanite SiC and khamrabaevite (Ti,V,Fe)C, and calcium-aluminum-rich inclusions (CAI), minerals krotite and dicalcium dialuminate (Hiltl et al. 2011; Rappenglück et al. 2014) add to the finds. Carbonaceous spherules contain fullerene-like structures and nanodiamonds that point to an impact-related origin (Yang et al. 2008). Such spherules were found embedded in the fusion crust of cobbles from a crater as well as a possible outfall in soils widespread over Europe (Rösler et al. 2005; Hoffmann et al. 2006; Yang et al., 2008). Abundant finds of glass-like carbon fragments with pumice texture, which has been given the name chiemite, contain the carbon allotropes diamond and carbyne in a largely amorphous matrix of more than 90 % carbon (Shumilova et al. 2018). A formation of a direct airburst shock transformation of the target vegetation (wood, peat) to carbon melt and vapor in the impact event is suggested.

Physical and archeological dating confines the impact event to have happened most probably between 2,200 and 500 B.C. (Rappenglück et al. 2010; Liritzis et al. 2010). The impactor is suggested to have been a roughly 1,000 m sized low-density disintegrated, loosely bound asteroid or a disintegrated comet in order to account for the extensive strewn field (Ernstson et al. 2010, Rappenglück et al. 2017).

Chiemgau impact location map pink quartzFig. 1. Location map for the two pink quartz occurrences within the roughly elliptically encircled Chiemgau meteorite impact strewn field.

3 The pink quartz places of discovery

The pink quartz sands were discovered when soil and rock samples from interesting impact locations were systematically examined for potentially impact-related microparticles like glass, metallic and carbon spherules. Experienced observers could not overlook the concentration of so many pink quartz grains (Fig. 2), especially when they used a strong magnet to separate the magnetic fraction and found that the pink quartz grains could also be separated by an obviously slightly enhanced susceptibility of the basically paramagnetic quartz. The first sample was excavated near the village of Marwang north of the Lake Tüttensee crater (Fig. 1) during a campaign of recording magnetic susceptibility profiles of the upper 50 cm to map a known distinct peak of enhanced magnetic susceptibility (Fig. 3), which was first measured in the northern part of the impact strewn ellipse (Hoffmann et al. 2004). The Marwang magnetic peak is connected to a horizon enriched with fractured pebbles, cindery glass and carbonaceous spherules, which is considered to represent the original directly impact-affected Earth surface. Here, an accumulation of pink quartz grains attracted attention.

pink quartz grains - formation in the Chiemgau meteorite impact event

Fig. 2. Typical magnetic sand fraction with an enrichment of pink quartz grains. The dark fraction is mostly composed of ore and amphibolite. Field of view 4 mm.

pink quartz horizon Chiemgau impact

Fig. 3. Soil magnetic susceptibility profile with the suggested impact peak and sampling of the pink quartz grains.

The second sample comes from the diamictic layer found during the Stöttham archeological excavation a few hundred meters apart from the shoreline of Lake Chiemsee (Fig. 1). The several decimeters thick diamictite (Fig. 4) is embedded in colluvium layers and contains brecciated and heavily corroded clasts, abundant organic material like wood, charcoal, fractured animal bones and teeth, and intermixed archeological artifacts. High-temperature signature is characterized by partly melted silica limestone, a typical rock from the Alps, and sandstone clasts with sporadically interspersed glass. Moderate shock is indicated by an abundant and strong kink banding of micas in gneiss clasts from the diamictite, and most recently the author has established strong shock metamorphism in quartz in polymictic breccias from the horizon. Millimeter-sized glass and tiny carbonaceous spherules were extracted from the diamictite mud, the pink quartz grains being an important side effect. The outcrop has in detail been described in Ernstson et al. (2012), and there is no doubt about the connection with the Chiemgau impact event. The early description as a tsunami deposit (D. Sudhaus, pers. report) has meanwhile received full support (Ernstson 2016).

Stöttham archeological site Chiemgau impact pink quartz occurrence

Fig. 4. The Stöttham impact catastrophic layer hosting pink quartz grains.

4 Formation hypothesis

The hypothesis of the formation of pink quartz in the Chiemgau impact strewn field is based on the original explanation of pink coloration by gamma irradiation in pegmatites, in which little quartz silicon was substituted by phosphorous and aluminum (see 1 Introduction). The following sequence of processes could have taken place in the Chiemgau impact event (Fig. 5): A huge plasma cloud in the airburst of the comet or asteroid approaches the Earth. – Fast neutrons from the plasma bombard the Earth’s surface and hit exposed water-bearing quartz sands. – The fast neutrons are captured by collision with hydrogen nuclei and lose most of their energy due to the same mass, to become slow or thermal neutrons. – The capture process is accompanied by the emission of a strong gamma radiation. – The gamma radiation hits mineralogically “well prepared” quartz grains to now obtain their pink color. – Immediate post-impact sedimentation by probably enormous precipitations prevents exposure to sunlight and discoloration. So much for a physical scenario of a possible formation of the pink quartz grains in the Chiemgau impact strewn field, the significance of which is discussed below.

Model of pink quartz formation in a meteorite impact

Fig. 5. Model of pink quartz formation in the Chiemgau meteorite impact event. See text.

5 Discussion and Conclusions

The following observations are fulfilled: In the Chiemgau impact crater strewn field quartz sands were excavated that contain a certain amount of pink quartz. The grains are as clear as rock crystal quartz. The pink grains are slightly enhanced paramagnetic, as they can be separated from normal grains with a strong magnet. This property has not yet been reported for other pink quartz. Originally surprising for the author, but now understood was the observation that the pink color disappeared after the grains were exposed to daylight for some time, which has also been reported for other pink quartz (see 1 Introduction).

A chemical analysis of the pink quartz grains by e.g. SEM EDS has not been done so far and will be performed when new samples are available. The general context with earlier discovered pink quartz (see above) is given, taking into account the delivery area for the quartz sands that are the nearby Alpine mountains where quartz pegmatites and phosphorous mineralization are common. Direct observations of pink quartz in the Alps are unknown, and in view of the herds of mineral collectors, the discovery of this rare variety would have been reported. On the other hand, it cannot be ruled out that other rare chemical elements that replace silicon may also be susceptible to irradiation pink coloring, which must be checked. This also applies to the slightly enhanced magnetic susceptibility of the Chiemgau pink quartz, and a superparamagnetic behavior cannot be excluded.

This reminds of an unusual observation in the Chiemgau impact strewn field, namely the occurrence of strongly magnetized Quaternary limestone cobbles and boulders from the Alps, which were excavated, for example, from the smaller Kaltenbach and Mauerkirchen impact craters showing much evidence of impact overprint (Neumair and Ernstson 2011, Procházka and Trojek 2017. Moreover, the limestones, which are normally magnetic sterile, have demonstrably acquired considerable ferrimagnetism and associated superparamagnetism (Neumair and Ernstson 2011, Procházka and Kletetschka 2016). As the limestone cobbles and boulders are completely untouched at the outside, shock magnetization is considered. It can currently be speculated whether superparamagnetism was shock-generated not only in the otherwise “nonmagnetic” limestones, but also in the pink quartz grains with a slightly different chemistry than “normal” quartz.

This does not affect the irradiation hypothesis for the pink coloring as related to an impact neutron bombardment of water-bearing quartz sands and a secondary gamma radiation (Fig. 5) postulated for the other pink quartz occurrences.

A heavy neutron bombardment during the Chiemgau impact event has been discussed by us earlier when several radiocarbon (14C) ages for deep-seated (2 – 3 m) organic matter (bones, wood) in impact catastrophe layers (Lake Tüttensee ejecta layer; Ernstson et al. 2010) gave far too high 14C values corresponding to impossible medieval and even today’s ages. Inconclusive radiocarbon ages are not unknown for dating of young impacts (e.g., Rasmussen et al. 2000). In our case an impact plasma neutron bombardment could have initiated what normally happens in the atmosphere to produce the more or less constant 14C level as the known basis for the radiocarbon dating. In the atmosphere, spallation neutrons collide with nitrogen 14N nuclei, which leads to a nuclear reaction and production of the radioactive 14C. Neutrons that bombard the Earth’s surface in an impact event could collide with 14N isotopes in organic matter, and the same reaction as in the atmosphere could occur, which produces excess 14C and today’s too young ages.

In conclusion: There is much evidence from earlier investigations in the Chiemgau impact strewn field that huge airbursts could have played a major role (Ernstson et al 2010, Rappenglück et al. 2017, Shumilova et al. 2018). Plasma formation has inevitably bombarded the earth’s surface with strong neutron showers. Fast neutron collisions with hydrogen nuclei from water-bearing quartz sands produced the gamma radiation for pink quartz coloring, which is considered to be the cause for the previously known sites of pink quartz.

The next steps in the investigation of the Chiemgau pink quartz will be reported in an article’s Part 2. A systematic search for more occurrences is planned and, with a positive result, a documentation of their distribution in relation to other impact features in the crater strewn field and possibly at places definitely outside the crater field. Pink quartz grain sizes will be measured, whereby a preferred sorting is checked. SEM EDS analyses for phosphorous, aluminum or other elements will be performed. A test of magnetic behavior and rock-magnetic properties, e.g. for superparamagnetism, are planned. A controlled observation of a possible discoloring in daylight may follow.

If these or other data are available, it may be possible to confirm or question the impact neutron-gamma radiation hypothesis, and a search for pink quartz in other impact structures may be promising.


Akhavan, A.C. © 2005-2013 (accessed July 31, 2018).

Balitsky, V.S., Makhina, I.B., Prygov, V.I., Mar’in, A.A., Emel’henko, A.G., Fritsch, E., McClure, S.F., Taijing, L., DeGhionno, D., Koivula, J.I., Shigley, J.E. (1998). Russian Synthetic Pink Quartz. Gems and Gemology: 34: 34-43.

Bauer, F., Hiltl, M., Rappenglück, M.A., Neumair, A., & Ernstson, K. (2013). Fe2Si (Hapkeite) from the subsoil in the alpine foreland (Southeast Germany): Is it associated with an impact? Meteoritics & Planetary Science, 48 (S1) (76th Annual Meeting of the Meteoritical Society), Abstract #5056.

Dake, H.C., Fleener, F.L., Wilson, B.H. (1938). Quartz Family Minerals: A Handbook for the Mineral Collector, 304 p., Whittlesey House, McGraw-Hill Book Company.

Ernstson, K. (2016). Evidence of a meteorite impact-induced tsunami in lake Chiemsee (Southeast Germany) strengthened. 47th Lunar and Planetary Science Conference, Abstract #1263.

Ernstson, K., Mayer, W., Neumair, A., Rappenglück, B., Rappenglück, M.A., Sudhaus, D., & Zeller, K. (2010). The Chiemgau crater strewn field: Evidence of a Holocene large impact event in Southeast Bavaria, Germany. Journal of Siberian Federal University Engineering & Technologies, 1/3, 72–103.

Ernstson, K., Mayer, W., Neumair, A., & Sudhaus, D. (2011). The sinkhole enigma in the Alpine Foreland, Southeast Germany: Evidence of impact-induced rock liquefaction processes. Central European Journal of Geosciences, 3/4, 385–397.

Ernstson, K., Sideris, C., Liritzis, I., & Neumair, A. (2012). The Chiemgau meteorite impact signature of the Stöttham archaeological site (Southeast Germany). Mediterranean Archaeology and Archaeometry, 12/2, 249–259.

Ernstson, K., Shumilova, T. G., Isaenko, S. I., Neumair, A., & Rappenglück, M. A. (2013). From biomass to glassy carbon and carbynes: Evidence of possible meteorite impact shock coalification and car- bonization. Modern problems of theoretical, experimental and applied mineralogy (Yushkin Memorial Seminar–2013): Proceedings of mineralogical seminar with international participation (S. 369–371). Syktyvkar: IG Komi SC UB RAS.

Ernstson, K., Hiltl, M., & Neumair, A. (2014). Microtektite-like glasses from the Northern Calcareous Alps (Southeast Germany): Evidence of a proximal impact ejecta origin. 45th Lunar and Planetary Science Conference, Abstract #1200.

Ernstson, K. & Neumair, A. (2011), Geoelectric Complex Resistivity Measurements of Soil Liquefaction Features in Quaternary Sediments of the Alpine Foreland, Germany, Abstract NS23A-1555 presented at 2011 Fall Meeting, AGU, San Francisco, Calif., 5-9 Dec.

Ernstson, K., & Poßekel, J. (2017). Meteorite impact „earthquake“ features (Rock liquefaction, surface wave deformations, seismites) from ground penetrating radar (GPR) and geoelectric complex resistivity/induced polarization (IP) measurements, Chiemgau (Alpine Foreland, Southeast Germany). Abstract (EP53B-1700) presented at 2017 Fall Meeting, AGU, New Orleans, LA.

Hiltl, M., Bauer, F., Ernstson, K., Mayer, W., Neumair, A., & Rappenglück, M.A. (2011). 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? 42nd Lunar and Planetary Science Conference, Abstract #1391.

Hoffmann, V., Rösler, W., and Schibler, I., (2004). Anomalous magnetic signature of top soils in Burghausen area, SE Germany. Geophysical Research Abstracts, 6: 05041.

Hoffmann, V., Tori, M., Funaki, M. (2006). Peculiar magnetic signature of FeSilicide phases and dia- mond/fullerene containing carbon spherules. Travaux Géophysiques XXVII – Abstracts of the 10th „Castle Meeting“ – New Trends in Geomagnetism, Paleo, Rock and Environmental Magnetism, 52–53.

Hori, H. (2001). Nomenclature of Quartz Color Variation: Pink and Rose. Mineralogical Record: 32(1).

Isaenko, S. I., Shumilova, T. G., Ernstson, K., Shevchuk, S., Neumair, A., & Rappenglück, M. (2012). Carbynes and DLC in naturally occurring carbon matter from the Alpine Foreland, South-East Germany: Evidence of a probable new impactite. European Mineralogical Conference, 1, EMC 2012–217.

Liritzis, I., Zacharias, N., Polymeris, G.S., Kitis, G., Ernstson, K., Sudhaus, D., Neumair, A., Mayer, W., Rappenglück, M.A., & Rappenglück, B. (2010). The Chiemgau meteorite impact and tsunami event (Southeast Germany): First osl dating. Mediterranean Archaeology and Archaeometry 10/4, 17–33.

Maschmeyer, G. Lehmann (1983). A trapped-hole center causing rose coloration of natural quartz. Zeitschrift für Kristallographie, 163, 181-196.

Neumair, A. & Ernstson, K. (2011), Geomagnetic and morphological signature of small crateriform structures in the Alpine Foreland, Southeast Germany, Abstract GP11A-1023 presented at 2011 Fall Meeting, AGU, San Francisco, Calif., 5-9 Dec.

Procházka, V., & Trojek, T. (2017). XRF- and EMP- investigation of glass coatings and melted domains of pebbles from craters in Chiemgau, Germany. 48th Lunar and Planetary Science Conference, Abstract #2401.

Procházka, V. & Kletetschk, G. (2016). Evidence for superaparamagnetic nanoparticles in limestones from Chiemgau crater field, SE Germany. 47th Lunar and Planetary Science Conference (2016); Abstract #2763.pdf.

Rappenglück, B., Rappenglück, M., Ernstson, K., Mayer, W., Neumair, A., Sudhaus, D., & Liritzis, I. (2010). The fall of Phaeton: a Greco-Roman geomyth preserves the memory of a meteorite impact in Bavaria (south-east Germany). Antiquity, 84, 428–439.

Rappenglück, M., Schüssler, U., Mayer, W., & Ernstson. K. (2005). Sind die Eisensilizide aus dem Impakt-Kraterstreufeld im Chiemgau kosmisch? European Journal of Mineralogy, 17(1), 108.

Rappenglück, M. A., Bauer, F., Hiltl, M, Neumair, A., & K. Ernstson, K. (2013). Calcium-aluminium-rich inclusions in iron silicide (xifengite, gupeiite, hapkeite) matter: Evidence of a cosmic origin. Meteoritics & Planetary Science, 48(S1), (76th Annual Meeting of the Meteoritical Society), Abstract #5055.

Rappenglück, M. A., Bauer, F., Ernstson, K., & Hiltl, M. (2014). Meteorite impact on a micrometer scale: Iron silicide, carbide and CAI minerals from the Chiemgau impact event (Germany). Proceedings of Problems and Perspectives of Modern Mineralogy (Yushkin Memorial Seminar – 2014), Syktyvkar, 106–107.

Rappenglück, M.A,., Rappenglück, B. & Ernstson. K. (2017). Kosmische Kollision in der Frühgeschichte. Der Chiemgau-Impakt: Die Erforschung eines bayerischen Meteoritenkrater-Streufelds. Zeitschrift für Anomalistik, 17, 235-260.

Rasmussen, K.L., AAby, B., Gwozdz, R. (2000). The age of the Kaalijärvi meteorite craters. Meteoritics & Planetary Science, 35, 1067-1071.

Rösler, W., Hoffmann, V., Raeymaekers, B., Schryvers, D., & Popp, J. (2005). Carbon spherules with diamonds in soils. Paneth Kolloquium, Abstract PC2005 #026.

Rykart, R. (1995). Quarz-Monographie – Die Eigenheiten von Bergkristall, Rauchquarz, Amethyst, Chalcedon, Achat, Opal und anderen Varietäten. 413 p., Ott, Thun.

Schryvers, D., & Raeymaekers, B. (2005). EM characterisation of a potential meteorite sample. Proceedings of EMC, Antwerp, vol. II, 859–860.

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

Shumilova, T.G., Isaenko, S.I., Makeev, B.A., Ernstson, K., Neumair, A., & Rappenglück, M.A. (2012). Enigmatic poorly structured carbon substances from the Alpine Foreland, Southeast Germany: Evidence of a cosmic relation. 43rd Lunar and Planetary Science Conference, Abstract & Poster #1430.

Shumilova, T.G., Isaenko, S.I, Ulyashev, V.V., Makeev, B.A., Rappenglück, M.A., Veligzhanin, A.A., & Ernstson, K. (2018). Enigmatic glass-like carbon from the Alpine 12 Foreland (Southeast Germany): Formation by a natural carbonization process. Acta Geologica Sinica – English Edition, in press.

Yang, Z. Q., Verbeeck, J., Schryvers, D., Tarcea, N., Popp, J., & Rösler, W. (2008). TEM and Raman characterisation of diamond micro- and nanostructures in carbon spherules from upper soils. Diamond & Related Materials, 17, 937–943.