Prof. Simón and geologists from the University of Zaragoza: Azuara, the Pelarda Fm. ejecta, the Revista de la Sociedad Geológica de España, and the manipulation of science – a commentary article
As we recently announced here, we are now publishing our detailed commentary on the unspeakable article by the geologists from the University of Zaragoza regarding the prominent large impact ejecta deposit at the Azuara structure.
Our article has been published on ResearchGate and can be downloaded as a PDF here.
Abstract. – We comment on a recently published (June 2026) article by geologists from the University of Zaragoza (lead author Prof. José L. Simón) in Spanish, titled (translated) The controversial conglomerate complex of Sierra Pelarda (Central Iberian Mountain Range): clast recycling in a comprehensive morphotectonic-sedimentary model. This article is a continuation of all previous efforts—primarily by geologists at the University of Zaragoza—to ignore or discredit the massive multiple impact event at Azuara-Rubielos de la Cérida, which has been described in extensive literature for decades. In the article by Simón et al., two related articles from 1990 and 1992 (i.e., 30 years old) are mentioned in a single brief sentence, but neither the Azuara impact structure nor the Pelarda Formation—one of the world’s largest and most significant impact ejecta deposits—is mentioned again, not even in the abstract. In recent years, the Pelarda Formation impact ejecta have been mentioned and discussed in greater detail in more than a dozen publications, including papers presented at conferences of the Meteoritical Society, the Lunar & Planetary Science Conference, and the American Geophysical Union. A 60-page article on the Azuara and Rubielos de la Cérida impact was printed and published in 2002 by the Treb. Mus. Geol. Barcelona, featuring a lengthy section on the Pelarda Formation. Extensive papers on the Azuara impact structure, including the Pelarda Formation ejecta, are available on publicly accessible websites and can be downloaded there. The most recent presentation also regarding the Pelarda Formation ejecta took place at the annual meeting of the Meteoritical Society in 2023. The impact-related presentations on the Pelarda Formation generally list the globally recognized geological and mineralogical- petrographic findings and evidence that prove the impact. These include widespread, intense shock effects such as impact melts, diaplectic glasses, planar deformation features (PDF and PF), and typical shock-spallation fractures, which are also described for the rocks of the Pelarda Formation. The abundant polymictic breccias in the diamictitic deposits of the Pelarda Formation—featuring polymictic breccia generations otherwise virtually unknown in “normal” geology—cannot be overlooked. This also applies to megaclasts made of Buntsandstein and Eocene rock, up to 9 m in size, that are intercalated within the Pelarda Formation and are difficult to explain using the model proposed by Simón et al. The fact that geologists do not (or do not wish to) understand impact geology has been discussed extensively, but this does not justify the complete suppression of previous research and its extensive and publicly accessible literature. This serious accusation against the geologists at the university applies in particular to the first author, Prof. Simón, who sets a bad example for his students—who are apparently co- authors—of a scientific practice characterized by manipulation. A serious accusation is also directed at the journal Revista de la Sociedad Geológica de España for publishing this fundamentally unscientific article, as well as at the peer reviewers (assuming a peer review took place at all), who apparently condoned this manipulation of science. In the following commentary, we use examples to demonstrate how the authors undermine and contradict all clear impact evidence in favor of their untenable morphotectonic-sedimentary model of the Pelarda Formation.
