Petrology of the prehistoric lavas and dyke of the Barren Island, Andaman Sea, Indian Ocean

Journal of Earth system science

D Chandrasekharam1³  P B Santo3²  P Manetti4⁴  B Capaccioni3²  M A Alam1³  O Vaselli2¹ 

[1] Department of Earth Sciences, University of Florence, Florence 50121, Italy$$;Institute of Volcanology and Geochemistry, University of Urbino, Urbino 61029, Italy$$;Department of Earth Sciences, Indian Institute of Technology, Bombay, Mumbai 400 076, India$$;CNR-Institute of Geosciences and Earth Resources, Pisa 56124, Italy$$

关键词: Barren Island;    lava flows;    dyke;    petrology;    Sunda Arc.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

Although Barren Island (Andaman Sea, Indian Ocean) witnessed several volcanic eruptions during historic times, the eruptions that led to the formation of this volcanic island occurred mainly during prehistoric times. It is still active and currently in the fumarolic stage. Its volcanic evolution appears to be characterized by a constructive phase with the piling up of lava flows and scoria deposits and Strombolian activities, followed by a sudden collapse of the main cone. Deposits of a possible caldera-forming eruption were not recognized earlier. After a period of peri-calderic hydromagmatic activity, whose deposits presently mantle inner and outer caldera walls, a new phase of intracalderic Vulcanian activities took place. A prominent dyke in the SE inner side of the caldera wall was recognized. Petrographically the lava flows and dyke are similar but they differ in their chemical composition (viz., SiO2, MgO, Ni, Cr) significantly. Similarity in major, minor and trace element composition (viz., K/La, K/Nb, K/Rb, K/Ti ratios) of these rocks together with Chondrite normalized trace element (Rb, Ba, Sr, P, Zr, Ti and Nb) and REE (La, Ce, Nd and Y) patterns of the Barren Island prehistoric lava flows and dyke and low-K lavas of Sunda Arc indicates that Barren Island must have evolved from a source similar to that of Sunda Arc lavas during the Quaternary Period.

【 授权许可】

Unknown