Varianten
The lower series consists of alternating basalt lava, tuff breccia, tufite, and siliceous rock, whereas the upper one is dominated by diabase .
It is also a widespread constituent of a variety of igneous and metamorphic rocks and is occasionally found in pegmatites and in related veins marginal to igneous rock units ranging from granite to diabase .
If natural stone, such as basalt or diabase , is used, the product is called rock wool.
Intrusion of diabase at Mt. Butters has resulted in low-grade contact metamorphism of the pre-existing sedimentary strata.
Many such dikes in western Maine are classified as alkali diabase .