Chemistry and origin of zeolites in sandstones at DSDP sites 445 and 446, Daito Ridge and Basin Province, Northwest Pacific

Author(s): Lee, Yong Il
Author Affiliation(s): Primary:
Seoul Natl. Univ., Dep. Geol. Sci., Seoul, South Korea
Volume Title: Chemical Geology
Source: Chemical Geology, 67(3-4), p.261-273. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0009-2541 CODEN: CHGEAD
Note: In English. 41 refs.; illus. incl. 2 tables, sketch map
Summary: Andesitic volcaniclastic sandstones of Middle Eocene age recovered from DSDP sites 445 and 446, a back-arc basin, contain clinoptilolite, heulandite and analcite as a pore-filling cement. Clinoptilolite and heulandite at the sites have different chemical compositions from other deep-sea clinoptilolites and heulandites. The dominant cation in both minerals is Na+, indicating that Na+ ion activity in pore-water was greater at the time of their formation. Volcanic glass acted as a precursor although biogenic silica may have played a similar role. Downhole, high Na+ activity in pore-water also helped to transform clinoptilolite and heulandite into analcite. The necessary Na+ ions might have been provided by hydrothermal circulation of seawater through more permeable sandstones deposited during early stages of back-arc basin rifting.
Year of Publication: 1988
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 02 Geochemistry; 06 Petrology, Sedimentary; 07 Marine Geology and Oceanography; Authigenesis; Back-arc basins; Basins; Cenozoic; Clastic rocks; DSDP Site 445; DSDP Site 446; Daito Basin; Daito Ridge; Deep Sea Drilling Project; Deep-sea environment; Diagenesis; Eocene; Framework silicates; Geochemistry; IPOD; Leg 58; Marine environment; Metasomatism; Middle Eocene; North Pacific; Northwest Pacific; Pacific Ocean; Paleogene; Philippine Sea; Pore water; Processes; Sandstone; Sedimentary petrology; Sedimentary rocks; Sedimentation; Silicates; Tertiary; Volcaniclastics; West Pacific; Zeolite group; Zeolitization
Coordinates: N240000 N253000 E1340000 E1323000
Record ID: 1988025280
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom