Shock metamorphism in the Rubielos de la Cérida impact basin (Eocene-Oligocene Azuara multiple impact event, Spain) – reappraisal and photomicrograph image gallery
by Kord Ernstson1 and Ferran Claudin2 (April 2021)
Abstract. – We present a new compilation of previously abundantly studied and published shock effects in minerals and rocks of the Middle Tertiary Rubielos de la Cérida Impact Basin in northeastern Spain. Typologically, we organize by: shock melt – accretionary lapilli – diaplectic glass – planar deformation features (PDF) – deformation lamellae in quartz – isotropic twins in feldspar – kink banding in mica and quartz – micro-twinning in calcite – shock spallation. Included are the newly associated Jiloca-Singra impact in the so-called Jiloca graben and the Torrecilla ring structure, which immediately adjoins the Rubielos de la Cérida basin to the northeast. The compilation and presentation also opposes once more the still existing fundamental rejection of an impact genesis of the Azuara impact event by leading impact researchers of the so-called impact community and by regional geologists from the University of Zaragoza.
Lechatelierite in Moldavite Tektites: New Analyses of Composition. – Martin Molnár, Stanislav Šlang, Karel Ventura. Kord Ernstson.
The Enigmatic Holmajärvi (Northern Sweden) Diamictite: Evidence of a Meteorite Impact Deposit. – Peder Minde and Kord Ernstson
Zhamanshinite-Like Black-Glass Melt Rocks from the Saarland (Germany) Meteorite Impact Site. – Kord Ernstson – Dominic Portz – Werner Müller – Michael Hiltl
The Steinheim Basin, the Ries crater “double disaster” and the mistaken Steinheim crater diameter
by Kord Ernstson1 & Ferran Claudin2 (Febr. 2021)
Abstract. – The article, which we comment here, interprets sedimentological findings (seismite horizons) at a distance of 80 – 180 km from the two impact structures, the Ries crater and the Steinheim basin, to the effect that, contrary to the impacts at a distance of only 40 km from each other, which have always been assumed to be synchronous, the Steinheim basin is supposed to be several 10 000 years younger than the Ries impact. This is against all probability, but because of the purely statistical impact events, it cannot be completely ruled out. This article therefore does not criticize the statement itself, but refers to equally probable alternatives that have not been considered, as well as to a lack of literature citations. The article loses its fundamental significance to the point of the simple alternative: it may be, but it also may not be, a finding without recognizable importance. A major point of criticism of the article is the common practice in the impact literature of suppressing the diameter of the Steinheim impact structure, which at around 7-8 km is actually twice as large, as it was proven almost 40 years ago by detailed morphological analyses and gravimetric measurements and published in a renowned journal. Since the size of the Steinheim Basin is included in the estimates for the formation of the seismites, it must be stated that the authors started from partly false premises. Here, the findings on the much larger Steinheim impact structure, which cannot be explained away, are presented again, combined with the wish to deal with scientific findings more honestly.
1 University of Würzburg, 97074 Würzburg (Germany); email@example.com; 2 Associate Geological Museum Barcelona (Spain); firstname.lastname@example.orgContinue reading “The Steinheim Basin, the Ries crater “double disaster” and the mistaken Steinheim crater diameter”
Comment on: ” Schmieder, M. and Kring, D. A. (2020) Earth’s Impact Events Through Geologic Time: A List of Recommended Ages for Terrestrial Impact Structures and Deposits. – Astrobiology, 20, 91-141.”
by Kord Ernstson1 & Ferran Claudin2 (Jan. 2021)
Abstract: We use Schmieder and Kring’s article to show how science still works within the so-called “impact community” and how scientific 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 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.
1 University of Würzburg, 97074 Würzburg (Germany); email@example.com. 2 Associate Geological Museum Barcelona (Spain); firstname.lastname@example.org
Taklamakan Desert (China): a mega-impact structure?
University of Würzburg, 97074 Würzburg (Germany), email@example.com
Abstract.- A Google Earth-based morphological analysis of the Taklamakan Desert in the north of the Himalayas shows characteristics of a 1000 km mega-sized impact structure with an elliptical basin and a pronounced elliptical morphological rim. The elliptical structure may possibly have originated from the thrust of the Indian plate and the Himalayas. A gravity anomaly corresponds with the structure. More impact evidence is not known so far.
Key words: Taklamakan Desert, China, impact structure, gravity anomaly, Indian plate
__________________________________________Continue reading “To play with Google Earth …”
When modeling ignores observations: The Jiloca graben (NE Spain) and the Rubielos de la Cérida impact basin
by Kord Ernstson1 and Ferran Claudin2
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), firstname.lastname@example.org
2 Associate Geological Museum Barcelona (Spain); email@example.com