NEOTECTONICS NEAR THE NW CORNER OF THE PACIFIC PLATE: MARINE TERRACES ON OZERNOI AND KAMCHATSKIY PENINSULAS, KAMCHATKA,

On Kamchatka, four regional-scale peninsulas are present on the eastern shore, from south to north, Shipunskiy, Kronotskiy, Kamchatskiy, and Ozernoi peninsulasWe studied marine terrace sequences on the northern two peninsulas, which show moderate to strong uplift rates as well as tectonic segmentation such as faulting and tilting. While the Kamchatskiy Peninsula is relatively well understood tectonically as collisional (e.g., Geist & Scholl, 1994; Freitag et al., 2001), the Ozernoi Peninsula remains tectonically enigmatic. The simplest tectonic configuration for this region incorporates the existence of a three plates, Pacific, North America and the Komandorsky Island Block (KIB) (McElfresh et al., 2002). But in fact various alternative plate models have been proposed. This area is also of interest to geoscientists because in the northwestern Pacific, there is a «dramatic shift in subduction dynamics » (Yogodzinski et al., 2001; Levin et al., 2002), where the subducting Pacific plate meets a 90-degree change in its plate boundary. The Komandorsky Basin lies north of the KIB and is characterized by transtensional and extensional elements: high heat flow, magnetic lineaments, and transcurrent faults (Baranov et al.,1991). The Ozernoi Peninsula lies on the eastern margin of the Komandorsky Basin, north of the active subduction zone. Th