Garzanti, E.

Posenato, R.

Sciunnach, D.

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Discussion
Discussion on the article “Remarks on the Permian-Triassic 
transition in Central and Eastern Lombardy (Southern Alps, Italy)” 
by G. Cassinis, M. Durand and A. Ronchi
Discusión sobre el artículo “Apuntes sobre el tránsito Pérmico-Triásico en Lombardía 
central y oriental (Alpes Meridionales, Italia)” de G. Cassinis, M. Durand y A. Ronchi
R. Posenato1, D. Sciunnach2, E. Garzanti3 
1 Dipartimento di Scienze della Terra, Università di Ferrara, Via Saragat 1, 44100 Ferrara (Italy)
 psr@unife.it
2 Regione Lombardia, Infrastruttura per l’Informazione Territoriale, Via Sassetti 32/2, 20124 Milano (Italy)
3 Dipartimento di Scienze Geologiche e Geotecnologie, Università di Milano-Bicocca, Piazza della Scienza 4, 20126 
Milano (Italy)
Received: 17/1/08 / Accepted: 23/01/08
ISSN (print): 1698-6180. ISSN (online): 1886-7995
www.ucm.es /info/estratig/journal.htm
Journal of Iberian Geology 35 (1) 2009:  69-71
In their paper “Remarks on the Permian-Triassic 
transition in Central and Eastern Lombardy (Southern 
Alps, Italy)”, Cassinis et al. (2007) propose regional 
correlations in the Southalpine area (Northern Italy) 
around the P/Tr boundary. Their reconstructions are 
based on the integration of paleontological, strati-
graphic, and sedimentological data from published 
works and original analyses on the studied succes-
sion, spanning from the Early Permian (Cisuralian) 
to the Olenekian. The authors attempt to integrate 
their observations in a coherent scenario, but their 
conclusions are largelly biased by the incorrect pre-
conception that climatically-controlled sedimentary 
features should be necessarily synchronous, even if 
in contrast with biostratigraphic evidence.
Speciﬁcally, the occurrence of ventifacts (wind-
worn pebbles, interpreted as markers of arid climate) 
is not only assigned an undemonstrated chronostrati-
graphic signiﬁcance, but even claimed to merit predomi-
nance on the occurrence of the cosmopolitan marker 
Claraia (Valsassina, Orobic Alps, Posenato et al., 1996). 
The Claraia horizon of the Servino Formation, repre-
senting the Lower Triassic in the western Southern Alps 
(Sciunnach, 2005), is thus arbitrarily shifted upwards in 
the stratigraphic chart, to comply with preconceived ideas 
based on equivocal sedimentological evidence.
The Valsassina Claraia horizon is located in the mid-
dle Servino Formation about 7 m above the basal Prato 
Solaro Member (Posenato et al., 1996; Sciunnach et al., 
1996, 1999), which contains the ventifacts of Cassinis 
et al. (2007). The fossiliferous horizon only yields the 
bivalve Claraia, an opportunistic crisis progenitor taxon 
(sensu Kauffman and Harries, 1996), which is character-
ised here, as everywhere, by a wide range of morphologi-
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70 Posenato et al. / Journal of Iberian Geology 35 (1) 2009:  69-71
phase which “may correlate to the late Dienerian to early 
Smithian interval” (Durand, 2006, p. 291). However, a 
younger dating for the Volpriehausen Formation is known 
in literature, e.g. a middle-late Smithian age has been pro-
posed by Kozur and Bachmann (2005). In the Germanic 
basin, another, older arid episode is recorded in the up-
permost Nordhausen Fm (now Calvörde Fm) which was 
correlated to the Andraz Horizon (Werfen Formation) of 
the Dolomites (Kozur, 1989), a prevailing evaporitic unit 
located between the Claraia wangi-griesbachi and C. 
clarai subzones (Broglio Loriga et al., 1990). The Prato 
Solaro Member may thus be correlated with the Andraz 
Horizon, consistently with the correlation between the 
Claraia beds of the Valsassina and the transitional Claria 
claraia - C. aurita beds (Siusi Member) of the Dolomites 
proposed by us (Posenato et al., 1996). This part of the 
Siusi Member records the MFS of the second Scythian 
sequence (Sc 2) of the Dolomites (Gianolla et al., 1998; 
Neri, 2007).
In summary, we consider the hypothesis that ventifacts 
should necessarily occur in a single interval during the 
Early Triassic, as proposed by Cassinis et al. (2007), 
as unjustiﬁable and biased by an unscientiﬁc approach. 
Incidentally, we note that because of incomplete fossil 
record of central Europe continental successions, and 
consequently uncertain chronostratigraphic framework, 
biostratigraphy, magnetostratigraphy, and sequence 
stratigraphy of continental Buntsandstein (e.g. Kozur, 
1993; Kozur and Bachmann, 2005; Szurlies, 2007) were 
calibrated by marine Lower Triassic successions (e.g. 
Claraia beds of Western Tethys).
References
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best candidate” (Durand, 2006, p. 290) to record the arid 
35-1.indb   70 08/01/2009   9:20:55
71Posenato et al. / Journal of Iberian Geology 35 (1) 2009:  69-71
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35-1.indb   71 08/01/2009   9:20:55


Discussion on the article “Remarks on the Permian-Triassic transition in Central and Eastern Lombardy (Southern Alps, Italy)” by G. Cassinis, M. Durand and A. Ronchi

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Discussion on the article “Remarks on the Permian-Triassic transition in Central and Eastern Lombardy (Southern Alps, Italy)” by G. Cassinis, M. Durand and A. Ronchi

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