Transport a. Currents can erode, transport, or deposit sediment, based on the grain size and current speed. The relationship between these parameters is shown in Fig. 5-2. Surprisingly, clay particles require higher current speeds for erosion than do sand particles. This is because they are flat particles and are more cohesive than sand. The number of these particles has increased since 1965, perhaps because of increasing aridity of the deserts.
Lithogenous sediments are from continental masses or volcanic activity in the open ocean.
The elements and compounds making up these rocks are called minerals. Less than 24 of the 2000 existing minerals are important in the Earth's crust. This latter ion is called a silicate tetrahedron. Nonferromagnesian minerals are other common rock-forming minerals which do not contain iron and magnesium. Igneous rocks are rocks that solidify from a molten mass and are classified according to texture and mineral composition.