The stratigraphic significance of the Solenoid Complex in the Permian of Gondwana

Permian woods with preserved primary structures from the southeast of Brazil (Irati Formation, Paraná basin)

“…Xeromorphic features observed in those specimens such as lacunose pith with groups of sclereids and false growth rings may be related to the depositional environment of the Irati Formation. Moreover, similar adaptations are also found in fossil wood from the Whitehill Formation of the Karoo Basin in Africa, which correlates with the Irati Formation, and from the Raniganj Formation in India, a slightly later chronostratigraphic formation (Guerra-Sommer et al 2014). The specific factor that triggered the xeromorphy cannot as yet be determined, but the present study clearly provides more evidence of the dry conditions prevailing during the deposition of the Irati Formation.…”

“…The genera of Solenopitys and Atlanticoxylon are restricted to the Permian, with Solenopitys being more widely distributed in the southern part of Gondwanaland, from the Paraná Basin in the south of Brazil (Irati Formation; Mussa 1986) to the Falkland Islands (Mussa 1986), South Africa and Antarctica (Merlotti and Kurzawe 2011). Atlanticoxylon, on the other hand, was limited to the Paraná Basin (Irati Formation, Mussa 1986; Merlotti and Kurzawe 2011) and India (Guerra-Sommer et al 2014).…”

“…The presence of these anatomic features in the wood described here may be related to the depositional environment of the Irati Formation. As commented in the section BGeological Setting^, the Assistência Member of the Irati Formation consists of a basal carbonate breccia containing evaporites, as well as beds of dolomite and stromatolites, all associated with relatively dry climates (Guerra-Sommer et al 2014;Rohn et al 2015, Calça et al 2016. It must be emphasised, however, that the climatic conditions during the growth of these trees cannot have been extremely arid, since other plants also found in the Irati Formation developed relatively large trunks, with diameters between 20 to 60 cm for the specimens (CP1/20, CP1/ 266, CP1/ 271 and CP1/272).…”

“…The Gondwana I Supersequence corresponds to a complete transgressive-regressive cycle, and consists of three groups, starting with the Itararé Group (Pennsylvanian glacial deposits), the Cissuralian Guatá Group (transgressive coastal and marine deposits, including discrete coal beds) and the Passa Dois Group, in which the fossils described here were found. Deposition of Passa Dois Group lasted from the Cissuralian to the Lopingian (Santos et al 2006;Ferreira-Oliveira and Rohn 2010;Holz et al 2010, Guerra-Sommer et al 2014 or to the Early Triassic (Milani et al 2007), a regressive period when the Paraná Basin apparently maintained a relatively limited connection to the Panthalassa Sea. The Passa Dois Group consists of four formations, the oldest of which is the Irati Formation (late Artinskian, Santos et al 2006).…”

Floristic similarities of the Artinskian Siderópolis Member macroflora, Rio Bonito formation (Paraná Basin, Brazil) with Cisuralian paleofloras of India

“…On the other hand, the paleoflora typical of the overlying upper Barakar Stage (Kungurian) is characterized by the presence of the Solenoid-complex woods (Barakaroxylon, Polysolenoxylon and Atlanticoxylon) which are similar to those of the Irati Formation in Brazilian Paraná Basin (Mussa, 1982;Prasad, 1982;Maheshwari and Bajpai, 2001;Guerra-Sommer et al, 2014).…”