FIGURESFigure 1. Proposed drill sites and ports for ODP Leg 202. Large symbols with ship track indicate primary sites. Small symbols indicate optional sites to be drilled on a time-available basis.
Figure 2. Cross-section of subsurface water masses in a transect through the drilling sites, characterized by (a) dissolved oxygen (b) phosphate, and (c) salinity concentrations (Levitus et al., 1993). Bathymetry map is schematic. Southward-spreading middepth waters (labeled pcw for Pacific Central Water) are characterized by relatively low oxygen and salinity and high phosphate. Northward-spreading bottom waters, below ~3 km depth starts as relatively oxygen-rich Antarctic Circumpolar Deep Water (cpdw). Northward-spreading Antarctic Intermediate Water (aaiw), above 1 km depth, his high in oxygen but is low in both phosphate and salinity. Proposed ODP drilling sites (circles) span the water masses. White circles are primary sites. White circles with diagonal slashes are the highest priority optional sites to be drilled on a time-available basis. Open circles are alternate or optional sites. gu = Gunther Undercurrent, npiw = North Pacific Intermediate Water.
Figure 3. Major near-surface current systems of the southeast Pacific eastern boundary. The Peru Current is also known as the Humboldt Current or the Peru-Chile Current. PCCC = Peru-Chile Counter Current, PUC = Peru Undercurrent (also known as the Gunther Undercurrent), PCC = Peru Coastal Current, SEC = South Equatorial Current, EUC = Equatorial Undercurrent.
Figure 4. Modern annual-average sea-surface temperatures in the southeast Pacific.
Figure 5. Modern annual average sea-surface salinities in the southeast Pacific.
Figure 6. Modern annual average sea-surface phosphate in the southeast Pacific.
Figure 7. Magnetic lineations and bathymetry from the Cocos Rise area (after Lonsdale and Klitgord, 1978), illustrating the locations of alternate sites COC-3A (solid circle = high-priority alternate), COC-2A, and COC-4A (open circle = lower-priority alternate).
Figure 8. Magnetic lineations and bathymetry from the Carnegie Ridge area (after Lonsdale and Klitgord, 1978), illustrating the locations of Sites CAR-1C, CAR-2C, and PAN-2A (solid squares = indicate top-priority sites).
Figure 9. Magnetic lineations and bathymetry from the central Nazca Plate area (after Cande and Haxby, 1991), illustrating the locations of Sites NAZCA-10A, NAZCA -14A, NAZCA-16A, NAZCA -17A, and SEPAC-9A, SEPAC-13A, and SEPAC14A (solid squares indicate top-priority sites and open circles indicate lower-priority alternates).
Figure 10. Magnetic lineations and bathymetry from the southern Nazca plate and Antarctic plate areas (after Cande and Leslie, 1986), illustrating the locations of Sites SEPAC-5A, SEPAC-10A, and SEPAC19A (solid circle indicates a high-priority alternate, and open circles indicate lower priority alternates.
Figure 11. Plate tectonic backtrack of primary drill sites and high-priority alternates (see Figure 1 for site names). Large dots give modern location. Successive dots give backtrack position at 1-m.y. intervals. The number at the end of the backtrack path is the estimated basement age.
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