Composition of fossil manganese nodules from Costa Rica

doi:doi:10.1594/PANGAEA.858477

Composition of fossil manganese nodules from Costa Rica

Horizons of several types of Upper Jurassic to Lower Cretaceous manganese nodules occur locally in sequences of radiolarian cherts within the Nicoya Ophiolite Complex (NW Costa Rica). Field studies, X-ray diffraction analysis, petrographic, chemical and experimental studies give evidence of a sedimentary, early diagenetic origin of the nodules, in contrast to earlier suggestions. Smooth, discoidal, compact and very dense nodules with diameters of some mm to 9 cm dominate. They are characterized by braunite, hollandite, pyrolusite and quartz as well as 39-61% Mn, 0.9-1.6% Fe, 5-26% SiO2, 1.3-1.9% Al2O3, 1.5-3.0% Ba, 460-5400 ppm Cu, 85-340 ppm Ni and 40-130 ppm Co, among others. It is suggested that the original mineralogy (todorokite?) was altered during thermometamorphic (braunite) and hydrothermal (hollandite. pyrolusite) events. Petrographic similarities between the fossil nodules and modern deep-sea nodules are striking. Using standard hydrothermal techniques in an experimental study it is shown that under special conditions, braunite can be produced from modern nodule material.

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Cite this as

Halbach, Peter, Gursky, H J, Gursky, M M, Schmidt-Effing, R, Maresch, W V (1992). Dataset: Composition of fossil manganese nodules from Costa Rica. https://doi.org/10.1594/PANGAEA.858477

DOI retrieved: 1992

Additional Info

Field	Value
Imported on	November 30, 2024
Last update	November 30, 2024
License	CC-BY-3.0
Source	https://doi.org/10.1594/PANGAEA.858477
Author	Halbach, Peter
Given Name	Peter
Family Name	Halbach
More Authors	Gursky, H J Gursky, M M Schmidt-Effing, R Maresch, W V
Source Creation	1992
Publication Year	1992
Resource Type	application/zip - filename: Halbach_1992
Subject Areas	Name: Chemistry Name: Lithosphere
Related Identifiers	Title: Composition and formation of fossil manganese nodules in Jurassic to Cretaceous radiolarites from the Nicoya Ophiolite Complex (NW Costa Rica) Identifier: https://doi.org/10.1007/BF00197101 Type: DOI Relation: IsSupplementTo Year: 1992 Source: Mineralium Deposita Authors: Halbach Peter , Gursky H J , Gursky M M , Schmidt-Effing R , Maresch W V . Title: The NOAA and MMS Marine Minerals Geochemical Database Identifier: https://doi.org/10.7289/V52Z13FT Type: DOI Relation: References Year: 1992 Source: National Geophysical Data Center, NOAA Authors: Grant John Bruce , Moore Carla J , Alameddin George , Chen Kuiying , Barton Mark , Warnken Robin R , Virden William T , Moore Carla J . Title: Fig.3 Selection of fossil manganese nodules from the Punta Conchal Formation, Costa Rica Identifier: hdl:10013/epic.46913.d001 Type: DOI Relation: References Authors: Grant John Bruce , Moore Carla J , Alameddin George , Chen Kuiying , Barton Mark , Warnken Robin R , Virden William T , Moore Carla J . Title: The NOAA and MMS Marine Minerals Bibliography Identifier: https://doi.org/10.7289/V53X84KN Type: DOI Relation: References Year: 1992 Source: National Geophysical Data Center, NOAA Authors: Grant John Bruce , Moore Carla J , Alameddin George , Chen Kuiying , Barton Mark , Warnken Robin R , Virden William T , Moore Carla J .