Where are volcanoes with iron-rich rocks found?

Answer 1

Iron rich volcanic rocks are mafic - that is they are compositionally on the basaltic, rather than rhyolitic end of the spectrum. Mafic volcanics are iron-rich, so volcanoes which produce basaltic magmas are what you are seking.

Basaltic magmas are mainly extruded by mid ocean ridge vents, by most hot spot volcanoes, in small amounts from some arc volcanoes, and also from rift-related volcanoes (where they also accompany rhyolitic volcanics).

Mid ocean ridges don't form classic volcanoes - these are mainly fissure eruptions - very long vents with raised rims of chilled magma.

Most other land-based eruptions with basaltic magmas are derived from shield volcanoes, so called because they resemble a slightly curved shield of ancient warfare. They have this shape because the basaltic lava extrudes for large distances from the volcanic vent, gradually buiding up the edges of the volcanoe and raising them into a feature many kilometres wide and up to 2 kilometres high. Rocks such as this are found in the Hawaiian Islands (hot spot volcanism) and Iceland (mid ocean ridge volcanism) as well as in numerous other places on Earth.

Some of the other basal-producing volcanoes also produce greater volumes of acid to intermediate lavas. Because the most abundant lava produced in these is relatively viscous they form high, steep sided cones - the classic Mt Fuji or Mt Kilimanjaro style vents. These can be found in the Pacific Ring of Fire (but dominated by much greater volumes of andesite lava, which is not as iron-rich), and in rift valleys such as Mt Kilimanjaro - where rhyolitic volcanics are also abundant.

Answer 2

Volcanic rock can be found on and near a volcano.

Answer 3

on the islands of Hawaii and iceland.