Detrital sedimentary rocks are classified and named principally on the basis of

d. particle size

Detrital sedimentary rocks are rocks are particles that may have derived from physical weathering or chemical weathering. These are those whose material has been transported as solid particles but settled from a fluid, either water or air. They are classified on the basis of their size or grain, They are  also called clastic sedimentary rocks,  

a mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics. this uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.a geomagnetic reversal is a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged.