Basaltic rocks are igneous rocks formed from the rapid cooling of lava flows. They are typically dark-colored, fine-grained, and rich in magnesium and iron. Here are some examples of basaltic rocks:
Extrusive (volcanic) basalts:
* Pahoehoe lava: Smooth, ropey lava flows.
* A'a lava: Rough, blocky lava flows.
* Pillow lava: Rounded, pillow-shaped lava formed underwater.
* Scoria: Vesicular (porous) basalt with many gas bubbles.
* Basaltic ash: Fine-grained fragments of volcanic glass.
* Tuff: Consolidated volcanic ash.
* Basalt breccia: Angular fragments of basalt cemented together.
Intrusive (plutonic) basalts:
* Dolerite: A coarse-grained basalt that cooled slowly underground.
* Gabbro: A very coarse-grained basalt with visible crystals.
Other notable basalt varieties:
* Andesite: A volcanic rock that is intermediate between basalt and rhyolite.
* Komatiite: An ultramafic volcanic rock, even richer in magnesium than basalt.
Famous examples of basaltic formations:
* The Giant's Causeway: A stunning rock formation in Northern Ireland, composed of hexagonal basalt columns.
* Hawaii's volcanoes: Known for their extensive basalt flows.
* The Deccan Traps: A massive volcanic plateau in India, formed by ancient basalt eruptions.
* The Columbia River Basalt Group: A vast region of basalt flows in the northwestern United States.
Note: These are just a few examples of the many types of basaltic rocks found around the world. The exact composition and appearance of basaltic rocks can vary depending on the specific minerals present and the conditions under which they formed.