(Table 2) Geochemistry of K-feldspars and associated plagioclase phenocrysts and rims at DSDP Legs 69, 52, 51 and 19

DOI

Basalts from some holes of the Deep Sea Drilling Project contain secondary K-feldspar which forms pseudomorphs after calcic (>76% An) Plagioclase cores, whereas Plagioclase of rims and microlites (68-74% An) remains unaltered. In basalts of Hole 504B two such grains with relics of Plagioclase in the central parts of phenocysts were recovered. The composition of the Plagioclase rims and of non-replaced phenocrysts is An79-81; the composition of relics is An83. The An and Ab contents of the K-feldspar is higher than in K-feldspar from altered basalt in Hole 418A in the Atlantic Ocean near the Bermuda Rise. Replacement of plagioclases by K-feldspar evidently is caused by oxygen-rich nearbottom sea water penetrating into basalts. The temperature interval of K-feldspathization is probably in the range 30 to 80°C, more-calcic Plagioclase being replaced by K-feldspar at higher temperatures.

Calculation of mineral composition in percent was made on the assumption that the sum of atomic amounts of Ca, K, and Na is equal to 1.0.

Supplement to: Pertsev, Nikolay N; Boronikhin, V A (1983): Secondary K-feldspar in basalts at Deep Sea Drilling Project Hole 504B and the problem of K-feldspathization in oceanic basalts. In: Cann, JR; Langseth, MG; Honnorez, J; Von Herzen, RP; White, SM; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 69, 589-591

Identifier
DOI https://doi.org/10.1594/PANGAEA.816468
Related Identifier https://doi.org/10.2973/dsdp.proc.69.132.1983
Related Identifier https://doi.org/10.2973/dsdp.proc.515253.148.1980
Related Identifier https://doi.org/10.2973/dsdp.proc.19.114.1973
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.816468
Provenance
Creator Pertsev, Nikolay N; Boronikhin, V A
Publisher PANGAEA
Publication Year 1983
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 249 data points
Discipline Earth System Research
Spatial Coverage (-68.041W, 1.227S, 164.714E, 53.010N); North Pacific/GUYOT; North Atlantic/CONT RISE; North Pacific/GRABEN
Temporal Coverage Begin 1971-08-30T00:00:00Z
Temporal Coverage End 1979-10-07T00:00:00Z