(Table 2, page 96) Observation of manganese deposits on basaltic rocks from the Rift Valley in the Atlantic Ocean near 36°N, supplement to: Hekinian, Roger; Hoffert, Michel (1975): Rate of palagonitization and manganese coating on basaltic rocks from the Rift Valley in the Atlantic Ocean near 36°50′N. Marine Geology, 19(2), 91-109


Various types of rocks consisting of plagioclase basalts, olivine basalts, pyroxene basalts, picritic basalts and volcanoclastics were found in the Rift Valley between 36°52'N and 36°47'N in the Atlantic Ocean. Palagonite and manganese are the main coating materials encountered on the chilled margins of the pillow-lava fragments. Palagonite is often associated with montmorillonite and chlorite. The thickness of palagonite coating the chilled margins increases in the fragments found from the innerfloor axis towards the walls of the Rift Valley. There is a linear correlation between the thickness of palagonite and that of the manganese encrustation. Considering a rate of manganese and palagonite accumulation of about 3my/10**3 year it is speculated that the age of a hill located near the axis of the inner floor near 36°50'N is between 3,000 and 12,000 years. The relative age of the inner floor near the intersection of the Rift Valley walls is less than 120,000 years. The specimens having a thicker manganese and palagonite crust located at 4-6 km away from the inner floor axis are 130,000–482,000 years old.

DOI https://doi.org/10.1594/PANGAEA.873551
Related Identifier https://doi.org/10.1016/0025-3227(75)90056-0
Related Identifier https://doi.org/10.7289/V52Z13FT
Related Identifier https://doi.org/10.7289/V53X84KN
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.873551
Creator Hekinian, Roger; Hoffert, Michel
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 1975
Rights Creative Commons Attribution 3.0 Unported
OpenAccess true
Language English
Resource Type Supplementary Dataset
Format text/tab-separated-values
Size 187 data points
Discipline Earth System Research
Spatial Coverage (-33.354W, 36.781S, -33.218E, 36.873N); Rift Valley, Atlantic Ocean
Temporal Coverage Begin 1972-09-12T00:00:00Z
Temporal Coverage End 1973-08-01T00:00:00Z