<P> The absolute motion of the Nazca Plate has been calibrated at 3.7 cm / yr east motion (88 °), one of the fastest absolute motions of any tectonic plate . The subducting Nazca Plate, which exhibits unusual flat - slab subduction, is tearing as well as deforming as it is subducted (Barzangi and Isacks). The subduction has formed, and continues to form, the volcanic Andes Mountain Range . Deformation of the Nazca Plate even affects the geography of Bolivia, far to the east (Tinker et al .). The 1994 Bolivia earthquake occurred on the Nazca Plate; this had a magnitude of 8.2 M w (\ displaystyle M_ (w)), which at that time was the strongest instrumentally recorded earthquake occurring deeper than 300 km . </P> <P> Aside from the Juan Fernández Islands, this area has very few other islands that are affected by the earthquakes that are a result of complicated movements at these junctions . </P> <P> The precursor of both the Nazca Plate and the Cocos Plate (to its north) was the Farallon Plate, which split in the late Oligocene, about 22.8 Mya, a date arrived at by interpreting magnetic anomalies . Subduction under the South American continent began about 140 Mya, although the formation of the high parts of the Central Andes and the Bolivian orocline did not occur until 45 Mya . It has been suggested that the mountains were forced up by the subduction of the older and heavier parts of the plate, which sank more quickly into the mantle . </P>

Convergence rate between nazca plate and south american plate