03-12-2014, 04:47 AM
Yup, dense Basalt, usually core of a`a flow, also found in wayyy past glacial areas (these were the premier adze mines, having the densest basalt...Basalt tools from our islands have been found throughout Polynesia, most likely because of the superior quality for tool forming...
Scoria is often formed on fast pahoehoe flows, were the gases do not have the time to 'off gas'. (fun to be here when a pahoehoe flow is cooling & puffing as the gases expand (the rock actually tinkles like heat creaking glass)
A`a flows are more crumbly & usually advance slower, bearing in mind that flows can change back & forth, sometimes mid channel..the hot core of the slower moving a`a flow usually forms the blue rock
One easy thing for geologist in Hawaii to answer - "what type of rock is that?", hands down, even with eyes closed, "Basalt" will most likely be correct
Scoria is often formed on fast pahoehoe flows, were the gases do not have the time to 'off gas'. (fun to be here when a pahoehoe flow is cooling & puffing as the gases expand (the rock actually tinkles like heat creaking glass)
A`a flows are more crumbly & usually advance slower, bearing in mind that flows can change back & forth, sometimes mid channel..the hot core of the slower moving a`a flow usually forms the blue rock
One easy thing for geologist in Hawaii to answer - "what type of rock is that?", hands down, even with eyes closed, "Basalt" will most likely be correct