The islands came into existence during the Pre-Miocene and Miocene period (about 25 Million-35 Million years ago).
BATANES is located in the northernmost part of the Philippines and consists of 10 islands. It is about 680 kilometres north of Manila. The area is bounded on the north by Bashi Channel, on the east by the Pacific Ocean, on the south by the Balintang Channel, and on the west by the South China Sea. The 10 islands are Batan, Itbayat, Sabtang, Ivuhos, Dequey, Dinem, Siayan, Ditarem, Misanga, and Mavudis. Only the first 3 islands are inhabited. Based on the geologic information from the Bureau of Mines and the Soil Survey Report of Batanes (1974), the islands came into existence during the Pre-Miocene and Miocene period (about 25 Million-35 Million years ago). The islands were very much bigger than what they are at present. They have undergone degradation followed by several periods of uplift. The volcanic islands were not formed by a single volcanic eruption but by several effusions. The islands rose in a series of uplifts. The uplifts of Batan and Sabtang have continued to the present. The province can be divided geologically into three groups: ►The island of Sabtang and the southern part of Batan Island which is found on undulating to rolling to steep with moderate to highly dissected landscapes which are largely of volcanic agglomerates, particularly in the southern portion of Sabtang. ►The islands of Mavudis, Misanga, Ditarem, Siayan and the northern part of Batan Island which are of recent volcanic origin. The materials consist largely of basalts and andesites with subsidiary agglomerates containing volcanic bombs; and ►Itbayat, Ivuhus, Dequey, and Dinem islands and the narrow fringe along the coastal portions of Batan Island and from the northern end of Baluarte Bay to Songsong Bay and of Sabtang Islands which are of coral, lime stones. | 
