12. Data Report: Interlaboratory Analyses of Fresh and Altered Dacites from Ocean Drilling Program Leg 1931

D.J. Miller,2 R.A. Binns,3 and H. Paulick4


Two interlaboratory reference samples were prepared from material collected during Ocean Drilling Program (ODP) Leg 193. These samples are composites of dacite representing fresh lava from Site 1191 (Sample 1191A) and altered lava from Site 1188 (Sample 1188B). The sample from Site 1188 was prepared from two fist-sized pieces of altered dacite recovered in the advanced diamond core barrel while attempting to deepen the hole. These pieces were not curated since we could not know where in the 72 m of penetration the pieces originated. The sample from Site 1191 was prepared as a composite by picking small fragments of fresh dacite from the working halves of the three cores recovered from Hole 1191A. No curated depth is assigned to either sample. These samples were collected and prepared only for comparison of analytical results from various laboratories.

Site 1188 is at the Snowcap hydrothermal site (Fig. F1), an area with low-temperature diffuse venting. The interlaboratory reference sample prepared from this site is pervasively altered, bleached from white to light gray, and sparsely vesicular. Rare vesicles are lined by anhydrite, with minor pyrite. Site 1191 is situated in the Satanic Mills hydrothermal site between the Snowcap (Site 1188) and Roman Ruins (Site 1189) hydrothermal sites (Fig. F1). The material in Sample 1191 is virtually aphyric. Rare plagioclase, clinopyroxene, and magnetite microphenocrysts are present but are <0.5% of the volume of the rock. The most abundant microphenocryst phase is plagioclase, and the largest laths are <1 mm long.

After Leg 193, the samples were trimmed with a rock saw to remove weathered surfaces, cleaned in deionized water, dried overnight at 100°C, crushed, and then milled in an alumina-ceramic shatterbox vessel at the ODP shore-based laboratory. Aliquots of the powders were distributed to requesting shipboard scientists for analysis. Analyses reported in this paper were performed at the Commonwealth Scientific and Industrial Research Organisation (CSIRO; Sydney, Australia), Technische Universität Berkakademie Freiberg, Universität Bonn (Germany; listed in Table T1 as "TU Freiberg" analyses), and Acme Analytical Laboratories, Vancouver, BC (Canada; listed in Table T1 as "TAMU analyses").

1Miller, D.J., Binns, R.A., and Paulick, H., 2006. Data report: Interlaboratory analyses of fresh and altered dacites from Ocean Drilling Program Leg 193. In Barriga, F.J.A.S., Binns, R.A., Miller, D.J., and Herzig, P.M. (Eds.), Proc. ODP, Sci. Results, 193 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/193_SR/207/207.htm>. [Cited YYYY-MM-DD]

2Integrated Ocean Drilling Program, Texas A&M University, 1000 Discovery Drive, College Station TX 77845-9547, USA. miller@iodp.tamu.edu

3Division of Exploration and Mining, Commonwealth Scientific and Industrial Research Organisation (CSIRO), PO Box 136, North Ryde NSW 1670, Australia.

4Mineralogisches und petrologisches Institut, Universität Bonn, Poppelsdorfer Schloss, 53115 Bonn, Germany.

Initial receipt: 8 October 2003
Acceptance: 4 January 2006
Web publication: 9 June 2006
Ms 193SR-207