Mineralogy, chemistry and stable isotope composition of hydrothermal altered sheeted dikes of ODP Hole 111-504B, supplement to: Alt, Jeffrey C; Anderson, Thomas F; Bonnell, Linda; Muehlenbachs, Karlis (1989): Mineralogy, chemistry, and stable isotopic compositions of hydrothermally altered sheeted dikes: ODP Hole 504B, Leg 111. In: Becker, K; Sakai, H; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 111, 27-40


During ODP Leg 111 Hole 504B was extended 212 m deeper into the sheeted dikes of oceanic Layer 2, for a total penetration of 1288 m within basement. Study of the mineralogy, chemistry, and stable isotopic compositions of the rocks recovered on Leg 111 has confirmed and extended the previous model for hydrothermal alteration at the site: axial greenschist hydrothermal metamorphism was followed by seawater recharge and subsequent off-axis alteration. The dikes are depleted in 18O (mean delta18O = +5.1 per mil +/- 0.6 per mil ) relative to fresh mid-ocean ridge basalt. Oxygen isotopic data on whole rocks and isolated secondary minerals indicate temperatures during axial metamorphism of 250°-350°C and water/rock ratios about one. Increasing amounts of actinolite with depth in the dike section, however, suggest that temperatures increased downward in the dikes.

DOI http://dx.doi.org/doi:10.1594/PANGAEA.713302
Metadata Access http://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite3&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.713302
Creator Bonnell, Linda;Alt, Jeffrey C;Muehlenbachs, Karlis;Anderson, Thomas F
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 1989
Rights Creative Commons Attribution 3.0 Unported (CC-BY)
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Discipline Earth System Research
Spatial Coverage (1 N,84W)
Temporal Point 1986-10-05T11:59:59Z