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Clinical and toxicological research conducted on volcanic crystalline silica has found little to no evidence of its ability to cause silicosis/pneumoconiosis-like diseases and geochemical analyses have shown that there are inherent factors in the crystalline structure which may render volcanic crystalline silica much less pathogenic than some ...
The types of minerals present in volcanic ash are dependent on the chemistry of the magma from which it erupted. Considering that the most abundant elements found in silicate magma are silicon and oxygen, the various types of magma (and therefore ash) produced during volcanic eruptions are most commonly explained in terms of their silica content.
In the deep ocean, another 26.2 Tmol Si Year −1 is dissolved before being deposited to the sediments as opal silica. [20] At the sediment water interface, over 90% of the silica is recycled and upwelled for use again in the photic zone. [20] Biogenic silica production in the photic zone is estimated to be 240 ± 40 Tmol si year −1. [36]
LSi can either be accumulated "directly" in marine sediments as clastic particles or be transferred into dissolved silica (DSi) in the water column. Within living marine systems, DSi is the most important form of silica [4] Forms of DSi, such as silicic acid (Si(OH) 4), are utilized by silicoflagellates and radiolarians to create their mineral skeletons, and by diatoms to develop their ...
The carbonate-silicate cycle is the primary control on carbon dioxide levels over long timescales. [3] It can be seen as a branch of the carbon cycle , which also includes the organic carbon cycle , in which biological processes convert carbon dioxide and water into organic matter and oxygen via photosynthesis .
Volcanic rocks are named according to both their chemical composition and texture. Basalt is a very common volcanic rock with low silica content. Rhyolite is a volcanic rock with high silica content. Rhyolite has silica content similar to that of granite while basalt is compositionally equal to gabbro.
High-silica rhyolite (HSR), with a silica content of 75 to 77·8% SiO 2, forms a distinctive subgroup within the rhyolites. HSRs are the most evolved of all igneous rocks, with a composition very close to the water-saturated granite eutectic and with extreme enrichment in most incompatible elements .
Magmatic water, also known as juvenile water, is an aqueous phase in equilibrium with minerals that have been dissolved by magma deep within the Earth's crust and is released to the atmosphere during a volcanic eruption.