Alkaline leaching characteristics of biogenic opal in IODP drilled cores from the Bering Sea
Leaching characteristics of biogenic opal in alkaline solutions were studied for Bering Sea sediment samples from the cores obtained during Integrated Ocean Drilling Program (IODP) Expedition 323. Generally, biogenic opal content is measured after alkaline leaching using Na2CO3 solution. Biogenic opal in some sediment samples could not be completely leached by Na2CO3 solutions, particularly in the deeper sections depending on sites: below the depth of ca. 122 m (CCSF-A) with 1.1 Ma at Site U1341 and ca. 211 m (CCSF-A) with 0.8 Ma at Site U1343. Strong alkaline 2M and 4M NaOH solutions were used instead of the standard Na2CO3 solution. As a result of the time-series leaching analysis, silicon contribution rates from clay minerals and other detrital grains were estimated in each of the methods employing two different concentrations of NaOH solutions. This made possible to correct for silicon contribution of clay minerals and other detrital grains.
- 九州大学大学院理学研究院紀要 : Series D, Earth and planetary sciences
九州大学大学院理学研究院紀要 : Series D, Earth and planetary sciences 32(4), 39-44, 2012-03-01
Faculty of Science, Kyushu University