Rocks and Earth Materials

They contain oil and natural gas.

Coal and petroleum are fossil fuels that form from the accumulation and compression of organic matter over millions of years. This process occurs in sedimentary rocks, which are formed through the deposition and cementation of sediments. Metamorphic and igneous rocks like granite do not contain these fossil fuels.

Clay has the smallest particle size of all soil types, with particles less than 0.002mm in diameter. Particle size increases in the order: clay (<0.002mm) < silt (0.002-0.05mm) < sand (0.05-2mm) < gravel (>2mm). This gives clay its smooth texture when wet.

This is the correct answer. The peninsular plateau is composed of igneous and metamorphic rocks with gently rising hills and wide valleys.

Gravel particles are coarse mineral particles ranging from 2mm to 64mm in diameter. They are larger than sand (0.06-2mm) and much larger than clay particles (less than 0.002mm). The term 'coarse particles' accurately describes gravel's size classification in soil particle size analysis.

The lichen which grows like powder dusted on rocks is called leprose lichen.

When a crustose lichen gets old, the centre may start to crack up like old-dried paint. This is called being rimose or areolate, and the island pieces separated by the cracks are called areolas.

Slate is a metamorphic rock formed from the metamorphism of shale. It's characterized by its fine grain and foliation (layering), allowing it to split into thin sheets. Sandstone and limestone are both sedimentary rocks, not metamorphic.

Marble is a metamorphic rock formed from the metamorphism of limestone, not a sedimentary rock. Limestone and sandstone are classic sedimentary rocks formed from compressed sediments. The question asks which is NOT sedimentary, making marble the correct answer.

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO₃).

A caldera is a large collapsed depression formed when a volcano erupts and empties its magma chamber, causing the ground above to collapse downward. This creates a crater much larger than typical volcanic vents. Calderas are not lava types, small mouths, or necessarily multi-vented volcanoes - they are specifically the collapsed basins left after massive eruptions.

Volcanoes release various materials during eruptions, including molten lava, gases, steam, dust, and rock fragments. Different eruptions may produce different combinations of these materials, so 'all of the above' is the most comprehensive answer.

Volcanic eruptions produce materials in all three states of matter: solid (pyroclastics like ash and rocks), liquid (lava/molten rock), and gas (water vapor, CO2, sulfur dioxide). This makes option C the correct answer.

Correct answer is (1). 

A caldera is a large volcanic crater formed by the collapse of a volcano into itself after a massive eruption empties the magma chamber. This creates a collapsed depression, making option C correct. They are not a type of lava, specific to North America, or simply a synonym for volcanoes.