Probable Geohazards in PNOC-EDC’s Proposed North Luzon Wind Power Projects in Ilocos Norte, Philippines

Winston Philip C. Pioquinto*, Joeffrey A. Caranto and Lauro F. Bayrante

PNOC Energy Development Corporation,
Merritt Road, Fort Bonifacio, Taguig City 1634, Philippines

* Corresponding author. Tel.: +63-2893-6001; fax: +63-2840-1580
 

Abstract

Two development blocks are intended for PNOC-EDC’s 120 MW wind farm development in the province of Ilocos Norte. The first block is in Burgos and the other one is in the municipality of Pagudpud. Block 1 (Burgos) comprised of Barangays Bayog, Pagali-Saoit, Bantoc, Agaga and Dungon-dungon (aggregate area = 6,990 has.) while Block 2 (Pagudpud) covered Balaoi, Subec, Caparispisan and Ayoyo barangays (aggregate area = 4,125 has.). The northern coastal strip of Ilocos Norte is mantled by a sedimentary layer of Pliocene Laoag Formation which is unconformably underlain by Miocene volcanics of the Bojeador Formation. Highly serpentinized ultramafic peridotites and schists formed the basement in the region. A major geologic structure called the Vigan-Aggao Fault defines the major regional structural feature in the project areas. The probable geologic and/ or natural hazards identified in the area are the following: landslides, soil erosion, seismic, tsunami/surge, and sinkholes. Detailed engineering geologic mapping and geotechnical investigations were already undertaken in the vicinity of Saoit and Bantoc.