Carbonatite is an igneous rock consisting primarily of carbonate minerals crystallized from a carbonate magma. There are three main hypotheses for the origin of carbonatite melts: 1) immiscible separation of parental carbonated silicate magmas, 2) crystal fractionation of carbonated silicate magmas, and 3) low-degree partial melting of carbonated mantle peridotite. Carbonatites can be classified based on their main carbonate mineral component, such as dolomite-carbonatite or ferroan-carbonatite. They commonly occur as shallow intrusive bodies like volcanic necks, dykes, and cone-sheets associated with alkali-rich silicate ig

1. SANA’A UNIVERSITY
FACULTY OF PETROLEUM &
NATURAL RESOURCES
CARBONATITE
PREPARED BY:
ENG. MAGED SALEH AL-
GHODHAIFI
ENG. YOSUF HUSSAIN
AWADH

2. Carbonatite is an igneous rock
consisting chiefly of carbonate minerals
(more than 50%) crystallized from a
carbonate magma.
generally associated with kimberlites and
alkalic rocks.
What
istheCarbonatite?
01.

3. 01.
Photosof
carbonatite

4. Carbonatite is an igneous rock consisting chiefly
of carbonate minerals crystallized from a
carbonate magma.
Carbonatites are often heterogeneous in outcrop,
and any magmatic rock containing more than 50
modal % of igneous carbonate arguably qualifies
as carbonatite, though most contain more.
What
istheCarbonatite?
01.

5. Non-essential minerals- these minerals are common,
sometimes major components, but are not always present:
Mineralogy
ofCarbonatite
02.
Calcite CaCO3
Dolomite CaMg(CO3)2
Ankerite Ca(Fe2+,Mg)(CO3)2
Siderite FeCO3
Gregoryite )Na2,K2,Ca)CO3
along with lesser silicates, phosphate minerals, and oxides.

6. Carbonatite has a fine to
coarse-grained texture.
calcitic sovite (coarse
textured) and alvikite (finer
textured)
texture
ofCarbonatite
03.

7. Discussion
04.

8. Origin
ofCarbonatite
04.
2 1
3
immiscible
separation of
parental
carbonated silicate
magmas at crustal
or mantle
pressures.
crystal fractionation
of parental
carbonated silicate
magmas such as
olivine melilitites or
kamafugites.
There are currently three main hypotheses explaining the origin of
carbonatite melts:
low-degree partial
melting of
carbonated mantle
peridotite below 70
km depth.

9. Classification
ofCarbonatite
05.

10. Classification
ofCarbonatite
05.
In mineralogical terms the following types of carbonatite can be distinguished:

11. Classification
ofCarbonatite
05.
ferrocarbonatite calciocarbonatite

12. forms
ofCarbonatite
06.
Most of the carbonatites are
shallow intrusive bodies of
calcite-rich igneous rocks in
form of volcanic necks, dykes,
and cone-sheets. These
generally occur in association
with larger intrusions of alkali-
rich silicate igneous rocks. The
extrusive carbonatites are
particularly rare, only 49 are
known, and they appear to be
restricted to a few continental
rift zones, such as the Rhine
valley and the East African rift
system

13. Discussion
04.

14. forms
ofCarbonatite
06.
Realistic photo of
carbonatite dikes

15. Economicimportance
ofCarbonatite
06.
Carbonatites may contain economic or anomalous
concentrations of rare-earth
elements, phosphorus, niobium–
tantalum, uranium, thorium, copper, iron, titanium, vanad
ium, barium, fluorine, zirconium, and other rare or
incompatible elements.

16. Occurrence
ofCarbonatite
07.
Overall, 527 carbonatite
localities are known on
Earth, and they are found
on all continents and also
on oceanic islands.

17. 08.
• Abyan Governorate - Lawdar District
• Dykes of carbonate rocks, cutting gneisses in the
Lowder-Mudiah area to the south of Wadi Azzan.
• Locality type: Group of Dikes
• Age: 840 Ma
Carbonatite
InYemen

18. ً
‫شكرا‬
‫لك‬
‫م‬
T H A N K Y O U S O M U C H
M A G E D S A L E H H A D I

19. Classification
ofCarbonatite
04.
In mineralogical terms the following types of carbonatite can be distinguished:
dolomite-carbonatite more than 90% of the carbonate is
dolomite.
ferroan-carbonatite the main carbonate mineral is ferroan dolomite, ankerite or
siderite. These can be distinguished from other carbonates by stain tests.
natrocarbonatite composed essentially of sodium, potassium and calcium
carbonate minerals.
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