Over millions of years, pressure can convert peat into ____. |
coal |
A coarse-grained, plutonic igneous rock is ____. |
granite |
A very light, porous, volcanic igneous rock is ____. |
marble |
A black, glassy, volcanic igneous rock is ____. |
obsidian |
A metamorphic rock derived from shale is ____. |
pumice |
A metamorphic rock derived from limestone is ____. |
quartzite |
Limestone, sandstone, and ____ are sedimentary rocks. |
shale |
A metamorphic rock derived from sandstone is ____. |
slate |