Editing Magma (section)

==== Mafic magmas ====
''Mafic'' or [[basalt]]ic magmas have a silica content of 52% to 45%. They are typified by their high ferromagnesian content, and generally erupt at temperatures of {{convert|1100 to 1200|°C}}. Viscosities can be relatively low, around 10<sup>4</sup> to 10<sup>5</sup> cP (10 to 100 Pa⋅s), although this is still many orders of magnitude higher than water. This viscosity is similar to that of [[ketchup]].{{sfn|Philpotts|Ague|2009|pp=23-25}} Basalt lavas tend to produce low-profile [[shield volcano]]es or [[flood basalt]]s, because the fluidal lava flows for long distances from the vent. The thickness of a basalt lava, particularly on a low slope, may be much greater than the thickness of the moving lava flow at any one time, because basalt lavas may "inflate" by supply of lava beneath a solidified crust.{{sfn|Philpotts|Ague|2009|p=53-55, 59-64}} Most basalt lavas are of ''[[ʻAʻā]]'' or ''[[pāhoehoe]]'' types, rather than block lavas. Underwater, they can form [[pillow lavas]], which are rather similar to entrail-type pahoehoe lavas on land.{{sfn|Schmincke|2003|pp=128-132}}