The crust consists of several types of deposits. It is dominated by Cenozoic sedimentary rocks, probably originating from the Australian continent; Also present are younger volcanic rocks and more recent alluvial deposits. Sedimentary deposits in the form of silt, peat, sand and mud are mostly found in the river valleys. Metamorphic rocks of slate, schist and arkose dominate the northern part of the island. Very few mineral deposits of Buru have industrial value, and only limestone is mined commercially. However, significant reserves of oil and gas were discovered in the shelf in 2009. There are numerous coral reefs around the island. The soil mostly consists of yellow-red Podsol, Organosol, Grumosol and various mixtures. Climate The climate is equatorial monsoonal, wet, and in general typical for the Maluku Islands. The rainy season extends from October to April with the highest rainfall in December–February. Despite the relatively small size of the island, its mountainous terrain results in several climatic zones. Apart from temperature reduction with altitude, the temperature variations across these zones are negligible, with the annual average of about 26 °C, However the annual precipitation differs and amounts to 1,400–1,800 mm in the north, 1,800–2,000 mm in the center, 2,000–2,500 mm in the south and 3,000–4,000 mm in the mountains, at elevation above 500 m. Flora and fauna As Buru is located at the boundary between the biogeographic zones of Australia and Asia, its flora and fauna are unique and are the subject of national and international scientific research. Of 25 species of mammals found on the island, at least four are endemic to Buru and closest to it islands. The local species of the wild pig named Buru babirusa (Babyrousa babyrussa) is distinguished from the other Babyrousa species by having relatively long and thick body-hair. It also has very low fat content in their meat (only 1.27% compared to 5–15% for domestic pigs) and is regarded as a delicacy among the local population, which favours it to other wild pigs or deer in terms of texture and flavour. Also endemic to Buru are three types of bats: Moluccan flying fox (Pteropus chrysoproctus), Ceram fruit bat Pteropus ocularis and lesser tube-nosed bat (Nyctimene minutus). Of the 178 recorded species of birds, 10 are endemic to Buru and nearby islands: Buru racket-tail (Prioniturus mada), black-lored parrot (Tanygnathus gramineus), blue-fronted lorikeet (Charmosyna toxopei), Buru honeyeater (Lichmera deningeri), Buru cuckooshrike (Coracina fortis), Buru jungle