Peculiarities of the kinematics of the west scotia mid-oceanic ridge

Abstract

The first map of the acoustic basement and a new map of the C4-C12 chrons are made for the area of the paleospreading West Scotia Ridge. The analysis of the constructed maps and the calculations showed that the bottom growth in the ridge axes began in the southeast in the interval of chron C12r (31.116–33.266 Ma B.P.). In the period of chron C11r (30.217–30.627 Ma), a hundred-kilometer northwestward jump of the spreading axis occurred. The maximal values of the bottom growth (about 6.3 cm/yr) were in the interval of chrons C6–C6B (18.748–22.546 Ma); then, the spreading began to fade. In the time of chron C3n.1r (3.300–4.493 Ma B.P.), the axis of the paleo-mid-oceanic ridge died. The spreading was accompanied with northeastward propagating of the axes, and the propagating proper had an impulse character.