Volcanic sludge - marine , mainly bathyal sediment , deposited near terrestrial or underwater volcanoes at a depth of 70 to 5000 m or more. In fact, it is a blue silt enriched with volcanic ash.
The composition of volcanic sludge includes shells of foraminifera and other calcareous and siliceous organisms (22.31%), mineral grains (40.82%) and silty matter (36.87%).
Volcanic sludge can be dark gray, brown or black. Also, it is characterized by the heterogeneity and acute-angular shape of the grains and the predominance of sanidine , plagioclases , augite , olivine , glass , and hornblende in their composition. Volcanic silt is developed off the coast of Kamchatka , Japan and some other Pacific islands .
Sources
- Volcanic silt - the meaning of the term in the Encyclopedia of the Scientific Library.