Should a Nephelinitic Series—Bearing Oceanic Island Be Drilled for Carbonatites, Kimberlites, and Ultrapotassic Rocks?
Titel:
Should a Nephelinitic Series—Bearing Oceanic Island Be Drilled for Carbonatites, Kimberlites, and Ultrapotassic Rocks?
Auteur:
Doe, Bruce
Verschenen in:
International geology review
Paginering:
Jaargang 46 (2004) nr. 2 pagina's 158-161
Jaar:
2004-02
Inhoud:
Carbonatites are known in the oceanic islands of the Cape Verde and Canary archipelagos near the continental margin of Africa. Such rocks are proposed to exist in oceanic islands far from the continents, like Hawaii, based on trace-element studies of nephelinitic-series rocks and experimental phase investigations. Although not observed on any oceanic islands, kimberlites likewise may well exist with depth in nephelinitic series-bearing oceanic islands based on trace-element, petrologic, and experimental phase studies. Ultrapotassic lamproites are also not observed on oceanic islands but the K2O-rich metasomatized sources proposed for carbonatite and kimberlite formation could also well lead to ultrapotassic lamproites. A proposal is made to deep drill an oceanic island bearing the nephelinitic-series volcanic rocks to discover carbonatite, kimberlite, and/or ultrapotassic lamproites. Salt Lake Crater on Oahu Island of the Hawaiian Islands is suggested as one logical candidate for drilling.