Search

It has been almost 60 years since the first results from the Early Permian Bolzano Quartz Porphyries from the Trento Plateau of northern Italy (Southern Alps) showed paleomagnetic inclinations steeper than inclinations from broadly coeval units from central Europe. This experimental discrepancy, confirmed ever since at varying levels of magnitude and certitude, implied that northern Italy had paleolatitudes too northerly relative to Europe to be considered part of the European continent. On the other hand, it became progressively more apparent that paleomagnetic data from northern Italy were more compatible with data from Africa than with data from Europe, and this observation revived and complemented Argand’s original concept of Adria as a promontory of Africa. But if Adria was part of Africa, then the paleolatitude anomaly of Adria relative to Europe translated into a huge crustal misfit of Gondwana relative to Laurasia when these landmasses were forced into a classic Wegenerian Pangea as typified by the Bullard fit of the circum-Atlantic continents. This crustal misfit between Gondwana and Laurasia was shown to persist in the ever-growing paleomagnetic database even when data from Adria were provisionally excluded as non-cratonic in nature. Various solutions were offered that ultimately involved placing Gondwana to the east (allowing it to be more northerly) relative to Laurasia and envisaging a dextral shear occurring in the Tethys (Mediterranean) realm between these supercontinental landmasses. This shear or transformation was initially thought to occur as a continuum over the course of the Mesozoic–Cenozoic (the so-called ‘Tethys Twist’) but soon afterwards when plate tectonics came into play and limited the younger extent, as a discrete event during the post-Triassic, Triassic or most probably – as in the latest and preferred reconstructions – the Permian between a configuration of Pangea termed B – with the northwestern margin of Africa against southern Europe – to a configuration termed Pangea A-2, with the northwestern margin of Africa against eastern North America, that is more proximal in shape to the classic Pangea A-1 that started fragmenting in the Jurassic with the opening of the Atlantic Ocean. The Permian timing and presumed locus of the ~2300 km dextral shear is supported by rotated tectonic domains in Sardinia and elsewhere along the interface between Lauarasia and Gondwana. The concept of Pangea B and its transformation into Pangea A developed therefore in close conjunction with the concept and paleomagnetic support of Adria as a promontory of Africa, and has ramifications to many aspects of tectonics, climate change and biogeography yet to be explored.

The Triassic sedimentary succession, cropping our in the island of Hydra, starts with a few metres of quartzarenites (Aghios Nikolaos Fm., Scythian) vertically making transition to a thick carbonate unit (Eros Lmst., Spathian-Pelsonian) subdivided into three lithozones and one member. During Pelsonian an extensional tectonic phase dissects the Eros carbonate platform. Its consequent downwarping results in the deposition of a pelagic sequence spanning the Pelsonian-Late Triassic time interval. This succession generally consists of few metres of nodular limestones (Han Bulog Lmst., Late Pelsonian-Early Ladinian) associated with green tuffs, followed by few hundred metres of cherty limestones (Adhami Lmst.). In the eastern part of the island a thick carbonate bank (Pantokrator Lmst.) develops, spanning the lllyrian to Late Triassic time interval. An overlying pelagic sequence, Jurassic in age, marks the downwarping of the Pantokrator carbonate platform. A typical passive continental margin succession is thus recorded in the Triassic of Hydra, suggesting its affinity with the Subpelagonian domain.

The Island of Chios (northern Egean Sea, Greece) is known for a well-preserved Paleozoic to Mesozoic sedimentary sequence. This paper is focused on the micropaleontology and biostratigraphy of the Marmarotrapeza Formation (Lower/Middle Triassic) and of the overlying Bunte Serie Unit (Middle Triassic), outcropping near the Marathovouno Hillock section proposed by Assereto (1974) as type-section for the Aegean substage (Lower Anisian). The results obtained allow to better define the age of the Bunte Serie basin and of the coeval carbonate platform, which ranges from the Anisian (?Pelsonian) to the Norian-?Rhaetian.

We update critical reviews of sites bearing hominin remains and/or tools from Europe (including the Balkans and Greece) and conclude that the only compelling evidence of hominin presence in these regions was after ~0.9 Ma (million-years-ago), bracketed by the end of the Jaramillo subchron (0.99 Ma) and the Brunhes-Matuyama boundary (0.78 Ma) and straddling the climatic late Early Pleistocene revolution (EPR) at the onset of enhanced glacial/interglacial activity that reverberated worldwide. Europe may have become initially populated during the EPR when, possibly for the first time in the Pleistocene, vast and exploitable ecosystems were generated along the Danube-Po Gateway. These newly formed settings, characterized by lowlands with open grasslands and reduced woody cover during glacial/interglacial transitions, represented the closest analogues to the savanna environment to which several large mammals linked with hominins in a common food web were adapted. It was only after stable and vast grassland-savanna environments opened that large mammals (e.g. megaherbivores) could expand into Europe along the Danube-Po Gateway in conjunction with the attached food web to which hominins belonged.

We present the magnetostratigraphy and conodont biostratigraphy across the Carnian-Norian boundary from a 70 m-thick limestone section located at Guri Zi in northern Albania. A total of 14 magnetozones were observed. The Carnian-Norian boundary is placed in a thin stratigraphic interval between the last occurrence of Paragondolella nodosa and the first occurrence of Epigondolella abneptis. Data from Guri Zi are in substantial agreement with already published data from Silicka Brezova in Slovakia and Pizzo Mondello in Sicily, which complessively indicate that the conodont Carnian-Norian boundary, when magnetostratigraphically traced onto the Newark astrochronological polarity time scale (APTS), has an age of ~228-227 Ma.

The Prati di Stuores/Stuores Wiesen section (Dolomites, Italy) is proposed as a candidate Global Stratotype Section and Point for the base of the Carnian Stage. In addition to being a famous, richly fossiliferous locality, it includes the type-section of the Cordevolian substage. The section is located near Pralongià, along the southern slope of the crest separating the Badia/Abtei and Cordevole valleys. Below the levels with Trachyceras aon, the section contains a rich ammonoid fauna that chacterizes the lower part of the Regoledanus Subzone and subsequently records the first appearances of the mid-high latitude genus Daxatina (Daxatina sp., D. cf. canadensis) and of traditional Trachyceras with species different from T. aon. Moreover, the Daxatina cf. canadensis Subzone is recognised above the Regoledanus Subzone. Very rare conodonts of the Budurovignatus group and species of Gladigondolella from the diebeli Assemblage Zone occur. Gondolella polygnatyformis, already known from the Aon Subzone, is absent. Palynomorphs, foraminifers, gastropods, bivalves, brachiopods, microcrinoids and holothurian sclerites were studied. Variations in frequency and taxonomic diversity of these faunas suggest anaerobic-disaerobic bottom conditions for the lower-middle part of the section (0-105 m), followed by a more stable oxygen content in the upper portion. Magnetostratigraphy showed four intervals with normal polarity and three intervals with reversed polarity. The Daxatina cf. canadensis Subzone falls close to the normal polarity interval S2n. The present study proposes the FAD of the cosmopolitan genus Daxatina as a marker of the base of the Carnian Stage, placing it at a lower stratigraphic level than previously indicated in the Stuores area. The Prati di Stuores section is proposed as GSSP of the Ladinian-Carnian boundary.