Question

pelagic sediments with over 30% biogenous material are known by the general name of blank.

Explanation:

Pelagic sediments with more than 30% biogenous (biologically - produced) material are classified as oozes. This is a key concept in the study of ocean sediments, where oozes are defined by their significant biogenous component (usually from planktonic organisms) making up at least 30% of the sediment.

Answer:

oozes