To increase the amount of virtual memory go to Control Panel > System > Advanced > Performance > Settings > Advanced > Virtual Memory Change > Custom Size > adjust as needed. 2 times your physical RAM is a good minimum and 3 times your physical memory in MB is good for your maximum.
Mafic lavas are lavas rich in iron and magnesium, while being low in silica. Basalt is the solidified version of mafic lava. Mafic lavas are the most common lava type on earth. Mafic lavas are also the hottest lavas and normally erupt at over 900 degrees Celsius - that's 1,650 degrees Fahrenheit!
If the lava has low viscosity then the molten material will act fluidly and flow fast down the volcano flanks. As lava travels down the volcano sides, the surface of the flow will cool much more rapidly. The surface of the flow forms two different types called 'aa' and 'pahoehoe'. Aa lava (pronounced ah-ah) has a rough, jagged surface due to the gas explosions tearing apart the external crust. It looks like a pile of blocks and rock fragments but underneath lies molten lava. As the lava flow advances it is churned and folded over itself, allowing gas to escape.