Figure 35. A. Site 1139 igneous rock compositions on the Na2O + K2O vs. SiO2 classification diagram (LeBas et al., 1986); alkalic and tholeiitic basalt fields are distinguished by the Macdonald and Katsura (1964) line. Note that there is one chemical analysis per igneous unit except for Units 5, 18, and 19 from which two, two, and four samples were analyzed, respectively. The less altered Units 18 and 19 samples are marked in bold and other samples from these units show considerable spread because of alteration. B. Site 1139 mafic compositions compared to samples from Kerguelen Plateau Sites 1136, 1137, 1138. The fields represent data from previous dredging and drilling on the southern and central K erguelen Plateau (Sites 738, 747, 749, and 750 and dredge locations reported by Weis et al.,1989). Data sources are Davies et al. (1989), Weis et al. (1989), Alibert (1991), Mehl et al. (1991), Sa lters et al. (1992), Storey et al. (1992), Mahoney et al. (1995), and this study. Numbers indicate ODP sites.
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