], vs. 3.25 ± 0.08 wt% [1 ] for the rest of the unit).
Three intervals of Holes SEG01A and SEG01B were analyzed with a portable XRF spectrometer (see "X-Ray Fluorescence Analyses" in the "Explanatory Notes" chapter). These analyses gave broadly similar results, consistent with their interpretation as part of a single igneous unit. The shipboard XRF analyses from the igneous units in Holes SEG01A, SEG01B, and SEG02A are presented in Table T2. In order to improve counting statistics and to check for sample heterogeneity, each analysis was performed in triplicate. Several intervals were analyzed to assess heterogeneity within the flow unit. Three of the measured intervals from Hole SEG02A gave similar results, but the fourth interval (163X-SEG02A-8-1, 28 cm) has distinctly lower TiO2 (2.88 ± 0.06 wt% [1 ], vs. 3.25 ± 0.08 wt% [1 ] for the rest of the unit).
An average composition for each of these units, as determined by shore-based XRF procedures, is included in Table T2 for comparison with the shipboard XRF data. It is readily apparent from these results that portable XRF analysis is reasonably accurate for TiO2 and Sr, less so for Zr and FeO (total Fe), and completely unreliable for Rb, Cr, and Ni. Most significantly, it was possible to establish the high TiO2 content of the igneous units soon after the core was received on deck.
A total of four samples from igneous units were analyzed by shore-based XRF procedures. The results are summarized in Table T3. All units are evolved basalts with Mg numbers between 0.47 and 0.36, TiO2 contents of 2.3 to 3.6 wt%, and are mostly slightly hypersthene normative (Hy = 1.5–2.6 wt%). Alteration is moderate with volatile content between 1.3 and 2.1 wt%. Fe2O3/FeO ratios are between 0.37 and 0.87, with the high values reported for the highly fractured unit from Hole SEG02A.
The Transect SEG66 lavas share a close compositional affinity with the lavas from nearby Site 988 and the bulk of the main onshore plateau lava sequence along the Blosseville Kyst. They are quite unlike the majority of offshore lavas drilled much farther south at 63°N during ODP Legs 152 and 163. The Transect EG63 units in general have low TiO2 (<2 wt%), and the few samples with higher TiO2 also have relatively high Sr contents (>300 ppm) in contrast to the data for Sites SEG01 and SEG02 (TiO2 = 2.3 and 3.6 wt%, Sr = 241 and 257 ppm; respectively).
