Radiolarian chert is a sedimentary rock composed predominantly of silica, formed from the accumulation of radiolarian skeletons. These rocks are significant in paleontology and stratigraphy for understanding deep-sea environments, the global carbon cycle, and the age dating of oceanic crust.
Reference: Moore, T. C. (1973). “Radiolarian Stratigraphy and the Cenozoic History of the Equatorial Pacific.” Geological Society of America Bulletin, 84(5), 1803-1828.