Abstract
Pillow basalts occurring as lenses within the Sewaragan Formation of southwestern Panay contain phenocrysts of forsteritic olivine, diopsidic augite and magnesian chromite, set in a glassy mesostasis with abundant spinifex pyroxene, acicular biotite and skeletal magnetite. Plagioclase is absent as a modal phase. The lavas are midly undersaturated to saturated with respect to SiO 2, with high concentrations of K 2O, MgO, NiO and Cr 2O 3, and low concentrations of Al 2O 3 and TiO 2. Present understanding of the tectonics of the central Philippines places the Sewaragan Formation within a forearc region related to mid-Miocene, eastward-directed subduction along the northward continuation of the Negros Trench. SiO 2-undersaturation and the preponderance of biotite differentiate these lavas from arc tholeiite and boninite. The rock is a potassic basalt with unusually high Mg and low Ti, and has many similarities to some komatiitic rocks. In view of its distinctive chemistry, mineralogy and texture, the name panayite is proposed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
