Sedimentary regimes at the Macquarie Ridge Complex: interaction of Southern Ocean circulation and plate boundary bathymetry

Seafloors tructurea t the MacquarieR idgeC omplexs tronglyin fluencesth e intensitya nd circulationp attern of oceanc urrentss outho f New Zealand.N ew marineg eophysicadl atas howh eterogeneousse dimentareyn vironments on Macquaries eafloorth atr eflecti nteractiono f highlyv ariableb athymetryw ith theA ntarcticC ircumpolaCr urrenta nd northf lowingA ntarcticB ottomW ater.A cousticb ackscattebr,a thymetrya, nd seismicr eflectiond atac ollecteda board R/V Rig Seismicin 1994 showf ive bathymetricallcyo nstrainesde dimentarpyr ovincesfl ankingt he ridge complex:( 1) northwestM acquarie hemipelagicd rifts, (2) current-modifiedS olanders ubmarinef an complex, (3) southwest Macquariem anganesneo dulep rovince,( 4) EmeraldB asinp elagicd rift province,a nd (5) sediment-freoe ceanicc rust relatedt o the 53.5øSp assagein the MacquarieR idgeC omplexT. he lateM iocene-Pliocenoep eningo f a 53.5øSp assage in the ridge complexc auseda major increasein the intensityo f oceanc urrentc irculations, edimentr eworking,a nd erosioni n all sedimentaryp rovinces.