The radiolarian chert rocks are one of the most important indications of the existence of ophiolites because they are a source of silica supply. These rocks have been studied to refute and reject the idea that ophiolites do not existed. The Si/(Si+Al+Fe+Ca) ratio in the radiolarian chert indicates that the silica is of biogenic origin and adds SiO2 from the shale fraction through diag... https://www.unitedssports.shop/product-category/basketball-accessories-skill-training/