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doi:10.2204/iodp.proc.307.207.2009

Methods and materials

Sediment cores were collected from 11 holes drilled at three sites within and adjacent to Challenger Mound during Expedition 307 in April and May 2005 (Fig. F2). A total of 361 smear slides of sediments were prepared and examined during coring on board the JOIDES Resolution and during the core description party in Bremen, Germany, in October 2005. Further analysis of smear slides was carried out at Oklahoma State University (USA). Five petrographic thin sections also were prepared from partly indurated sediment samples and analyzed.

A total of 209 powder X-ray diffraction (XRD) analyses were made on board the JOIDES Resolution during coring using a computer automated Phillips X-ray diffractometer. Scans were made from 2° to 70°2θ with 0.02° steps at 0.5 s/step. A total of 195 additional XRD analyses were made on core samples at Oklahoma State University using a computer automated Phillips PW 1830 X-ray diffractometer. Scans were made from 15° to 55°2θ with 0.025° steps at 0.5 s/step.

Scanning electron microscope (SEM) analysis was performed at Oklahoma State University using a JEOL JXA-35 SEM equipped with backscattered electron image and energy dispersive spectrometry capabilities and a JEOL 733 electron microprobe equipped with four crystal spectrometers and backscattered electron image and energy dispersive spectrometry capabilities. Both fractured samples and polished thin sections were carbon coated and examined using backscattered and secondary electron imagery. Compositional chemistry was analyzed with energy dispersive and wavelength dispersive spectrometry.

Shipboard interstitial water samples were obtained from 5–20 cm long whole-round intervals that were cut on the catwalk immediately after cores were recovered, capped, and taken to the laboratory. Sediments were placed in a titanium squeezer, and pore water was collected and analyzed using standard IODP protocol (for details see the “Methods” chapter).