6. It is a mixture of sand and clay that contains large amount of decayed plants and animals L_AM 7. It is the uppermost layer of soil rich in organic materials and minerals needed for plant growth. T_PSOL 8. It is located just below the topsoil. It is composed of loosely arranged rocks, sand, and clay. S_BS_IL 9. It is composed of rocks that are slowly breaking apart and is exposed to very little weathering PRNT ROCK 10. It is the lowest of the soil layers and is made up of undisturbed large boulders and gravel B_DR_CK