MGB R02 geologists undertake geologic mapping in Bicol region
By: Lyndee Rose Basilio
Six geologists from Mines and Geosciences Bureau Regional Office No. II undertook a geologic mapping that covers five quadrangles in the Bicol Region held last April 2-30,2017.
The geologic mapping project aims to identify various faults, types and structures of rocks, and folds to furnish a geologic map which will be used by the public as base map in urban planning and as vital input in different geologic investigations and studies.
The five quadrangles covered were Castilla Quadrangle, Gubat Quadrangle, Bayabas Quadrangle, Daet Quadrangle, and Mandao Quadrangle.
The Castilla Quadrangle is one of the two target quadrangles with no geologic data available.
The team of geologists found out that the rocks are poorly exposed along road cuts, hence, a visit to many creeks/rivers was also undertaken by the team.
Only Bicol Volcanic Arc Complex (BVAC) and Quaternary Alluvium were found to occur in the area. It was also determined by the geologists that the two component members of BVAC were present: Pocdol Volcanic Complex (PVC) and Bulusan Volcanic Complex (BVC).
The PVC occurs on the northern half of the study area while the BVC occurs on the southern half of the study area.
Based on the report of the geologists, no large-scale structures were noted in the field. Only microstructures like drag fold, lense, joint, gouge, and rock contact were observed.
The team of geologists used compasses, GPS units, handlens, scribbers, sample picks, camera, and field base maps during the conduct of the survey.
Rock samples were taken for correlation and systematic archiving. On the other hand, problematic samples were kept for further petrologic and/or paleontologic analysis. Lynds Basilio/with reports from Geosciences Division