21. Torfaj�kull last erupted in 1477 and consists of the largest area of silicic extrusive rocks in Iceland. 22. Over large areas extrusive rocks lie in flat undisturbed piles on a Tertiary surface of moderate relief. 23. Within the rugged terrain serpentinized peridotite and gabbro are capped with a thin layer of extrusive basalt. 24. It is commonly produced in volcanic arcs, and in cordilleran extrusive volcanic equivalent rock type is andesite. 25. Defensive extrusive ectosymbionts of Euplotidium ( Ciliophora ) that contain microtubule-like structures are bacteria related to Verrucomicrobia. 26. The most common rock type in this area is extrusive igneous group that include basalt, andesite, and rhyolite. 27. Many of the extrusive rocks and some of the Pseudoleucite is an abundant constituent of many of the igneous rocks. 28. The degree to which these practices took place was based off the two modes of social death, intrusive and extrusive . 29. Rhyolite is the same as granite chemically; however it is an extrusive rock, whereas granite is an intrusive rock. 30. In contrast, an " extrusion " consists of extrusive rock; rock formed above the surface of the crust.
