The LRO scientists think pockets of the newfound silica-based rock must have been created as basaltic magma
deep in the moon melted some of the silica-containing deep crust.
40-60]) and lack of complementary mafic-ultramafic cumulates, it is inferred that magmas parental to massif-type anorthosite originated from the fractional crystallization and contamination of basaltic magma
in the crust-mantle boundary zone (Duchesne 1984; Ashwal 1993; Emslie et al.
A standard phase diagram of a basaltic magma
(X) undergoing olivine-enstatite fractionation shows that the magma composition in each chamber will be driven down the olivine-enstatitc reaction curve (Fig.
Steam explosions due to heating of water-saturated sand and silt strata from rising basaltic magma
formed Kilbourne Hole.
Kilauea has basaltic magma
, which allows lots of gases to easily escape before erupting, making the lava runny.
The mantle rock begins to melt and form basaltic magma
, which then percolates up toward the surface through cracks and pores in the remaining solid, yet deforming, rock.
These mysterious places deep in the Earth melt holes in the crust, allowing basaltic magma
to rise to the surface.
The Tertiary Capitan dike swarm appears to represent the emanations from a crystallizing and differentiating mafic magma chamber or chambers that were episodically replenished by influxes of basaltic magma
Because the basaltic magma
from the mantle cools constantly as it moves through and heats the crustal granites and sandstones, it doesn't have a chance to assimilate enough crustal rocks to produce the sulfide ores in such quantities, he says.
These rocks are interpreted to have undergone extensive fractional crystallization from an alkali basaltic magma
, although their different geochemical signatures indicate that the rhyolite was not derived from the trachyte via continuous fractional crystallization.
Most crustal melting on Earth comes from intrusions of hot basaltic magma
from the Earth's mantle," said Peter Nabelek, also a geologist at the University of Missouri.
Although partial melting of the mantle typically produces basaltic magma
, in detail, the overall chemical composition of the basalt (especially the trace element and isotopic content) is profoundly influenced by the relative stability of minerals.