Types of rocks

Question 1

Maya watches a small waterfall after a heavy rain and notices how the rock wall above the pool changes. Which description puts the three processes—weathering, erosion, and deposition—in the correct order they occur?

Accepted Answer

First, the rain and freeze‑thaw cracks the rock wall (weathering); then the broken pieces are swept away by the water (erosion); finally, the stream slows and drops the material, forming a gravel bar (deposition).

Answer

First, the water slows and drops the material, forming a gravel bar (deposition); then the current carries the pieces downstream (erosion); finally, the rock wall cracks from freezing (weathering).

Answer

First, the current carries the broken pieces away (erosion); then the pieces settle in the pool (deposition); after that, wind and rain break more rock from the wall (weathering).

Answer

First, wind and rain crack the rock wall (weathering); then the pieces settle where they fall (deposition); finally, the stream moves the sediments farther downstream (erosion).

Question 2

Sam found three different rocks during his field trip: a black glassy rock from the volcano, a layered rock with tiny shells on the beach, and a shiny banded rock from deep in the mountain. Which statement correctly explains how each of these rocks was formed?

Accepted Answer

The glassy rock is igneous, formed when molten magma cools quickly; the layered rock with shells is sedimentary, formed from layers of sediment that were compacted and cemented; the banded rock is metamorphic, formed when an existing rock was altered by intense heat and pressure.

Answer

The glassy rock is igneous, formed when lava hardens slowly; the layered rock with shells is metamorphic, formed from compressed shells; the banded rock is sedimentary, formed from melted rock that settled.

Answer

The glassy rock is sedimentary, formed from cooled lava; the layered rock with shells is igneous, formed when shells melted into magma; the banded rock is metamorphic, formed by wind erosion.

Answer

The glassy rock is metamorphic, formed by pressure on sand; the layered rock with shells is igneous, formed from solidified magma; the banded rock is sedimentary, formed from stacked layers of ash.

Question 3

During a school field trip Maya finds three rocks: a dark, glassy piece near an old lava flow, a light, crumbly rock that has sand grains and tiny leaf fossils, and a hard, wavy rock with colorful bands that was discovered high in a mountain that used to be a deep‑sea floor. Which sentence correctly names each rock type and explains how it formed?

Accepted Answer

The glassy rock is igneous because it cooled from lava, the crumbly rock with sand grains and leaf fossils is sedimentary because layers of sediment were compacted and cemented, and the hard, wavy rock with color bands is metamorphic because existing rock was altered by heat and pressure deep underground.

Answer

The glassy rock is igneous because it formed from compacted sand, the crumbly rock with leaf fossils is sedimentary because it was heated by magma, and the wavy rock with bands is metamorphic because it cooled from lava.

Answer

The glassy rock is igneous because it cooled from lava, the crumbly rock with sand grains is metamorphic because it was squeezed, and the wavy, banded rock is sedimentary because layers of mud settled on the sea floor.

Answer

The glassy rock is sedimentary because it contains tiny fragments, the crumbly rock with fossils is igneous because it solidified from melted rock, and the wavy, banded rock is metamorphic because it was pressed together.

Try three questions

Maya watches a small waterfall after a heavy rain and notices how the rock wall above the pool changes. Which description puts the three processes—weathering, erosion, and deposition—in the correct order they occur?

Sam found three different rocks during his field trip: a black glassy rock from the volcano, a layered rock with tiny shells on the beach, and a shiny banded rock from deep in the mountain. Which statement correctly explains how each of these rocks was formed?

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