Amorong volcano a small lava dome in NW Luzon Island, 80 km NNE of Pinatubo volcano, and belongs to the Eastern Volcanic Chain or Balungao Group, a chain of subduction volcanoes behind the Manila Trench.
It is the only of a group of several lava domes that still has fumarolic activity. It was active from about 740,000 years ago.
The chemistry of Amorang's lavas is unusual in that is has elevated Niobium (Nb) and high Cr, Ni and Mg concentrations which can not be explained by qan unusual degree of mantle melting alone, and probably involve contamination by crustal rocks as well.
Source:
- Defant et al (1990) "An Example of Island-Arc Petrogenesis: Geochemistry and Petrology of the Southern Luzon Arc, Philippines", Journal of Petrology, V.32 (3), pp 455-50
