Sentences with word «gabbro»

The formation of the lowermost crust, made up of a dark, magnesium - rich rock called gabbro, is still largely a mystery, one that holds the key to the workings of the magma source that feeds the whole process.

This end - member process stands in contrast to the «gabbro glacier» hypothesis, in which all oceanic plutonic rocks crystallize in a single, shallow melt lens and undergo ductile flow downward and outward to «fill» the lower crust.

The term basalt is at times applied to shallow intrusive rocks with a composition typical of basalt, but rocks of this composition with a phaneritic (coarser) groundmass are generally referred to as diabase (also called dolerite) or, when more coarse - grained (crystals over 2 mm across), as gabbro.

Assays are expected in early January but the company reported intervals of net textured gabbro totalling 164.3 metres, along with a 14.9 - metre intercept of mineralized biotite gabbro.

In 2006 they released their findings: After drilling through nearly a mile of sediment and crust, they finally hit the gabbro layer for the first time.

There they found just the right piece of crust — not too hot, not too thick, and not too crumbly — to drill down to the gabbro.