carbonatite

The carbonatite rocks have been dated as having cooled between 94 to 104 million years ago.

The ore was exploited from magnetite, probably associated to carbonatite body.

More on the Khanneshin carbonatite may be found online.

A carbonatite mine is located near the town.

That same year he published an essay on the chimney alkaline and carbonatite.

It has been reported from volcanic fumaroles and in association with carbonatite related veins.

Oldoinyo Lengai is the only active carbonatite volcano in the world.

In the carbonatite lava it is associated with the potassium bearing gregoryite.

Prospectors here are particularly interested in carbonatite deposits including Rare earth elements and tungsten.

The bottom periphery, 0.5 km wide, is mostly built of feldspatic rocks and little or no carbonatite.

Ore minerals are essentially part of the unusual mineralogy of carbonatite.

Other older carbonatite volcanoes are located in the same region, including Homa Mountain.

The basalt lavas are related to carbonatite intrusions in the Zambezi valley.

The intrusive members are syenite and carbonatite.

Units within the complex include carbonatite, nepheline syenite, phonolite, and ijolite.

The carbonatite is broadly of three types:

A few older extinct carbonatite volcanoes are located nearby, including Homa Mountain.

The pyroclastic series base consists of agglomerate with carbonatite volcanic bombs and lapilii.

Porphyric carbonatite are formed by fast cooling of semicrystallized magma, or in contact with cool environment.

It can also occur as a hydrothermal mineral in granite, alkalic syenite and carbonatite.

A specific type of hydrothermal alteration termed fenitization is typically associated with carbonatite intrusions.

Of major scientific interest is the consolidated carbonatite near Altvogtsburg und Schelingen.

Several varieties of carbonatite are present in the area as well as lamprophyre, ijolite and other highly alkalic rocks.

Sovite (sövite) is the coarse grained variety or facies of a carbonatite intrusive.

Laterite covers are formed on both sides of carbonatite ring with accumulation of residual ferruginous-manganese minerals.