Sooty sweat stains or tourmaline spots? The Argonauts on the Island of Elba (Tuscany) and the spread of Greek trading in the Mediterranean Sea

Abstract

In various ancient authors (e.g. the ‘Argonautika’ of Apollonios Rhodios) curious news about the Island of Elba can be found, concerning the existence, somewhere on the shore near Portoferraio, of pebbles that are ‘dirty’ from the Argonauts' sweat. The Argonauts are said to have stopped on the island during their journey back from the looting of the ‘Golden Fleece’. These pebbles are found to be typical of the gravelly beaches below the Capo Bianco cliffs. Such walls are made up of a bony-white aplitic rock dotted with blue-black tourmaline spots. Capo Bianco aplite is the uncommon result of the solidification of a boron-rich magma in a subvolcanic setting. Here, the separation of a boron-rich fluid phase gave way to the crystallization of peculiar spherical dark tourmaline clots in a very fine-grained white groundmass. This rock was noted by Argonauts (i.e. the ancient travellers they represent) and used as a lighthouse to the harbour of Argoos limen (now Portoferraio). Also in the myth, the unique mottled pebbles were recorded as stained by the Argonauts' sweat. The occurrence, within the same, complex myth, of ‘data’ concerning navigation (the white cliffs) and geology (description of the spotted aplite) identify the Argonauts as a blending of mineral prospectors, explorers and early eighteenth century-like naturalists, legitimatizing the commercial/political presence of Greeks in the region.

GBS-derived SNP catalogue unveiled wide genetic variability and geographical relationships of Italian olive cultivars

“…It is noteworthy that varieties cultivated in geographically distant but culturally close areas are part of this group. This is probably due to close trading ties between the Etruscans/Italiote populations (Campania: Rosciola, Puntella, Caiazzana; Umbria/Lazio: Dolce Agogia) and the Magno-Greek colonies 89 .…”

New data on the paleogeography of Southern Tuscany (Italy) since Late Miocene time

“…The petrographic and geochemical data indicate that the porphyric aplite clasts have strong textural and compositional similarities with the Capo Bianco aplite that presently crops out in central-western Elba (e.g., along the Portoferraio-Capo Bianco-Capo d'Enfola coast, Fig. 5a, and at Cava di Caolino north of Marciana), which intruded the Ligurids at a depth of 2.4-3.7 km (Dini et al , 2007Maineri et al 2003). In particular, the porphyric aplite clasts of Southern Tuscany and the Capo Bianco Aplite in the Elba Island share the following relevant petrographic features (Fig.…”

“…The porphyric aplite clasts were analyzed to define their textural, petrographic, and chemical (major and trace elements, Sr and Nd isotopic composition) features; microprobe analyses were also performed on the tourmaline of the porphyric aplite clasts. These textural and compositional data were compared with those of analogous magmatic rocks cropping out in the central-western Elba Island (e.g., Capo Bianco aplite: Dini et al 2002Dini et al , 2007.…”

Tourmaline as a Tracer of Late-Magmatic to Hydrothermal Fluid Evolution: The World-Class San Rafael Tin (-Copper) Deposit, Peru

“…3 and 4) are typical of magmatic tourmaline in evolved peraluminous granites (e.g., London and Manning, 1995;London et al, 1996;Balen and Broska, 2011;Balen and Petrinec, 2011;Drivenes et al, 2015). The formation of tourmaline nodules has been widely discussed in the literature and three main hypotheses have been proposed for their origin: (i) post-magmatic hydrothermal alteration of granitic bodies by externally derived boron-rich fluids (e.g., Rozendaal and Bruwer, 1995); (ii) crystallization from immiscible, hydrous, boron-aluminosilicate melts or boron-rich aqueous fluids that separated from coexisting silicate melt (e.g., Dini et al, 2007;Balen and Broska, 2011;Drivenes et al, 2015;Burianek et al, 2016); and (iii) products of magmatic crystallization on the liquid line of descent of boron-rich granitic melts (e.g., Perugini and Poli, 2007;Balen and Petrinec, 2011;Valentini et al, 2015). The Tur 1 nodules observed in the San Rafael granites are devoid of alteration features (i.e., absence of veins, dissolution-reprecipitation texture, and pervasive alteration), thus arguing against a hydrothermal origin related to post-magmatic alteration.…”