Using the table below, classify each of the following rocks according to their mode of formation: marble, gabbro, dolomite, limestone, slate.

Here are the answers to the questions based on the image provided.

i) horizon A: This is the topsoil, characterized by a high concentration of organic matter (humus), making it dark in color and rich in biological activity.

ii) horizon B: This is the subsoil, where clay, iron, and aluminum compounds accumulate, leached from the A horizon. It is denser and has less organic matter than horizon A.

iii) horizon C: This is the parent material, consisting of partially weathered rock or unconsolidated sediment from which the soil developed. It contains very little organic matter.

iv) horizon D: This is typically the bedrock (R horizon), which is the unweathered, solid rock layer found beneath the C horizon.

b) Classification of rocks by mode of formation:

• Marble: Metamorphic
• Gabbro: Igneous
• Dolomite: Sedimentary
• Limestone: Sedimentary
• Slate: Metamorphic