Chemical composition of clinoptilolite crystals from ODP Hole 108-661A (Table 2)

• Main Authors: Bohrmann, Gerhard, Stein, Ruediger, Faugeres, Jean-Claude
• Format: Dataset
• Language: English
• Published: PANGAEA 1989
• Subjects: 108-661A; Aluminium; Aluminium oxide; Calcium; Calcium/Potassium ratio; Calcium oxide; DEPTH; sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Electron microprobe (EMP); Iron; Iron oxide; Fe2O3; Joides Resolution; Leg108; Magnesium; Magnesium oxide; North Atlantic Ocean; Ocean Drilling Program; ODP; Potassium; Potassium oxide; Sample code/label; Sample code/label 2; Silicon; Silicon/Aluminium ratio; Silicon dioxide; Sodium; Sodium oxide; North Atlantic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.667198; https://doi.org/10.1594/PANGAEA.667198

At ODP Site 661 from the continental margin of Northwest Africa, authigenic clinoptilolites were investigated in detail. Based on chemical data, crystal size and shape and their intergrowth with associated mineral phases, two types of clinoptilolite (type A and B) occur representing different diagenetic conditions under which the formation of zeolites took place. Clinoptilolite type A was found in a sediment section comprises numerous hiatuses and stratigraphically condensed sediments and could have been formed during early diagenesis. In contrast, clinoptilolite type B was precipitated in Campanian sediments during later diagenesis, after the transformation from opal-A to opal-CT had taken place. At Site 661, the silica source for the authigenesis of both clinoptilolite types is biogenic opal. Volcanic ash material occurs, but in low amounts and thus is not a prerequisite for the formation of clinoptilolite at Site 661.