In an area east and west of Aksum and Adwa and extending for some 230 km about 20 occurrences of peralkaline trachytic lavas are found, several of which are more that 10 km in diameter.
Age possibly Pliocene (Abbate & Sagri in Merla et al. 1979).

Approx coords range: 13º50' - 14º40'N; 37º15' - 39º25'E.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List

ⓘ Aegirine

ⓘ 'Alkali Feldspar'

ⓘ 'Amphibole Supergroup'

5 valid minerals.

Rock Types Recorded

Select Rock List Type

Alphabetical List Tree Diagram

ⓘ 'Grorudite'

ⓘ 'Peralkaline trachyte'

ⓘ 'Sölvsbergite'

ⓘ 'Tinguaite'

ⓘ Trachyte

Detailed Mineral List:

ⓘ Aegirine

Formula: NaFe³⁺Si₂O₆

References:

Blanford, W. T. (1870). Observations on the Geology and Zoology of Abyssinia: Made During the Progress of the British Expedition to that Country in 1867-68. Macmillan and Company.

Prior, G. T. (1899) Riebeckite in Trachytic Rocks from Abyssinia. Mineralogical Magazine and Journal of the Mineralogical Society, 12 (55) 92-95 doi:10.1180/minmag.1899.012.55.04

Prior, G. T. (1900). Ægirine and Riebeckite Anorthoclase Rocks Related to the “Grorudite-Tinguaite” series, from the neighbourhood of Adowa and Axum, Abyssinia. Mineralogical Magazine and Journal of the Mineralogical Society, 12(57), 255-273. doi.org/10.1180/minmag.1900.012.57.06

Merla, G., & Minucci, E. (1938). Missione geologica nel Tigrai: Rome, Reale Accademia d'Italia. Centro Studi per l'Africa Orientale Italiana, Roma, 3.

Mohr, P. A. (1962). The geology of Ethiopia: Univ. Coll. of Addis Ababa Press, Addis Ababa.

Le Bas, M. J., & Mohr, P. A. (1968). Feldspathoidal rocks from the Cainozoic volcanic province of Ethiopia. Geologische Rundschau, 58(1), 273-280. doi.org/10.1007/BF01820608

Merla, G., Abbate, E., Azzaroli, A., Bruni, P., Fazzuoli, M., Sagri, M., & Tacconi, P. (1979). Geological map of Ethiopia and Somalia (1973). 1:2000000 and comments with a map of major landforms. Consiglio Nazionale delle Ricerche Italy. Centro Stampa, Firenze.

ⓘ 'Alkali Feldspar'

References:

Blanford, W. T. (1870). Observations on the Geology and Zoology of Abyssinia: Made During the Progress of the British Expedition to that Country in 1867-68. Macmillan and Company.

Prior, G. T. (1899) Riebeckite in Trachytic Rocks from Abyssinia. Mineralogical Magazine and Journal of the Mineralogical Society, 12 (55) 92-95 doi:10.1180/minmag.1899.012.55.04

Merla, G., & Minucci, E. (1938). Missione geologica nel Tigrai: Rome, Reale Accademia d'Italia. Centro Studi per l'Africa Orientale Italiana, Roma, 3.

Mohr, P. A. (1962). The geology of Ethiopia: Univ. Coll. of Addis Ababa Press, Addis Ababa.

Le Bas, M. J., & Mohr, P. A. (1968). Feldspathoidal rocks from the Cainozoic volcanic province of Ethiopia. Geologische Rundschau, 58(1), 273-280. doi.org/10.1007/BF01820608

ⓘ 'Amphibole Supergroup'

Formula: AB₂C₅(T₈O₂₂)W₂

References:

Blanford, W. T. (1870). Observations on the Geology and Zoology of Abyssinia: Made During the Progress of the British Expedition to that Country in 1867-68. Macmillan and Company.

Prior, G. T. (1899) Riebeckite in Trachytic Rocks from Abyssinia. Mineralogical Magazine and Journal of the Mineralogical Society, 12 (55) 92-95 doi:10.1180/minmag.1899.012.55.04

Merla, G., & Minucci, E. (1938). Missione geologica nel Tigrai: Rome, Reale Accademia d'Italia. Centro Studi per l'Africa Orientale Italiana, Roma, 3.

Mohr, P. A. (1962). The geology of Ethiopia: Univ. Coll. of Addis Ababa Press, Addis Ababa.

Le Bas, M. J., & Mohr, P. A. (1968). Feldspathoidal rocks from the Cainozoic volcanic province of Ethiopia. Geologische Rundschau, 58(1), 273-280. doi.org/10.1007/BF01820608

ⓘ Nepheline

Formula: Na₃K(Al₄Si₄O₁₆)

References:

Blanford, W. T. (1870). Observations on the Geology and Zoology of Abyssinia: Made During the Progress of the British Expedition to that Country in 1867-68. Macmillan and Company.

Prior, G. T. (1899) Riebeckite in Trachytic Rocks from Abyssinia. Mineralogical Magazine and Journal of the Mineralogical Society, 12 (55) 92-95 doi:10.1180/minmag.1899.012.55.04

Merla, G., & Minucci, E. (1938). Missione geologica nel Tigrai: Rome, Reale Accademia d'Italia. Centro Studi per l'Africa Orientale Italiana, Roma, 3.

Mohr, P. A. (1962). The geology of Ethiopia: Univ. Coll. of Addis Ababa Press, Addis Ababa.

Le Bas, M. J., & Mohr, P. A. (1968). Feldspathoidal rocks from the Cainozoic volcanic province of Ethiopia. Geologische Rundschau, 58(1), 273-280. doi.org/10.1007/BF01820608

ⓘ Quartz

Formula: SiO₂

References:

Blanford, W. T. (1870). Observations on the Geology and Zoology of Abyssinia: Made During the Progress of the British Expedition to that Country in 1867-68. Macmillan and Company.

Prior, G. T. (1899) Riebeckite in Trachytic Rocks from Abyssinia. Mineralogical Magazine and Journal of the Mineralogical Society, 12 (55) 92-95 doi:10.1180/minmag.1899.012.55.04

Merla, G., & Minucci, E. (1938). Missione geologica nel Tigrai: Rome, Reale Accademia d'Italia. Centro Studi per l'Africa Orientale Italiana, Roma, 3.

Mohr, P. A. (1962). The geology of Ethiopia: Univ. Coll. of Addis Ababa Press, Addis Ababa.

Le Bas, M. J., & Mohr, P. A. (1968). Feldspathoidal rocks from the Cainozoic volcanic province of Ethiopia. Geologische Rundschau, 58(1), 273-280. doi.org/10.1007/BF01820608

ⓘ Riebeckite

Formula: ◻Na₂(Fe²⁺₃Fe³⁺₂)Si₈O₂₂(OH)₂

References:

Blanford, W. T. (1870). Observations on the Geology and Zoology of Abyssinia: Made During the Progress of the British Expedition to that Country in 1867-68. Macmillan and Company.

Prior, G. T. (1899) Riebeckite in Trachytic Rocks from Abyssinia. Mineralogical Magazine and Journal of the Mineralogical Society, 12 (55) 92-95 doi:10.1180/minmag.1899.012.55.04

Merla, G., & Minucci, E. (1938). Missione geologica nel Tigrai: Rome, Reale Accademia d'Italia. Centro Studi per l'Africa Orientale Italiana, Roma, 3.

Mohr, P. A. (1962). The geology of Ethiopia: Univ. Coll. of Addis Ababa Press, Addis Ababa.

Le Bas, M. J., & Mohr, P. A. (1968). Feldspathoidal rocks from the Cainozoic volcanic province of Ethiopia. Geologische Rundschau, 58(1), 273-280. doi.org/10.1007/BF01820608

ⓘ Zircon

Formula: Zr(SiO₄)

References:

Blanford, W. T. (1870). Observations on the Geology and Zoology of Abyssinia: Made During the Progress of the British Expedition to that Country in 1867-68. Macmillan and Company.

Prior, G. T. (1899) Riebeckite in Trachytic Rocks from Abyssinia. Mineralogical Magazine and Journal of the Mineralogical Society, 12 (55) 92-95 doi:10.1180/minmag.1899.012.55.04

Merla, G., & Minucci, E. (1938). Missione geologica nel Tigrai: Rome, Reale Accademia d'Italia. Centro Studi per l'Africa Orientale Italiana, Roma, 3.

Mohr, P. A. (1962). The geology of Ethiopia: Univ. Coll. of Addis Ababa Press, Addis Ababa.

Le Bas, M. J., & Mohr, P. A. (1968). Feldspathoidal rocks from the Cainozoic volcanic province of Ethiopia. Geologische Rundschau, 58(1), 273-280. doi.org/10.1007/BF01820608

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘ	Quartz	4.DA.05	SiO₂
Group 9 - Silicates
ⓘ	Zircon	9.AD.30	Zr(SiO₄)
ⓘ	Aegirine	9.DA.25	NaFe³⁺Si₂O₆
ⓘ	Riebeckite	9.DE.25	◻Na₂(Fe²⁺₃Fe³⁺₂)Si₈O₂₂(OH)₂
ⓘ	Nepheline	9.FA.05	Na₃K(Al₄Si₄O₁₆)
Unclassified
ⓘ	'Alkali Feldspar'	-
ⓘ	'Amphibole Supergroup'	-	AB₂C₅(T₈O₂₂)W₂

List of minerals for each chemical element

H	Hydrogen
H	ⓘ Riebeckite	◻Na₂(Fe₃²⁺Fe₂³⁺)Si₈O₂₂(OH)₂
O	Oxygen
O	ⓘ Aegirine	NaFe³⁺Si₂O₆
O	ⓘ Amphibole Supergroup	AB₂C₅(T₈O₂₂)W₂
O	ⓘ Nepheline	Na₃K(Al₄Si₄O₁₆)
O	ⓘ Quartz	SiO₂
O	ⓘ Riebeckite	◻Na₂(Fe₃²⁺Fe₂³⁺)Si₈O₂₂(OH)₂
O	ⓘ Zircon	Zr(SiO₄)
Na	Sodium
Na	ⓘ Aegirine	NaFe³⁺Si₂O₆
Na	ⓘ Nepheline	Na₃K(Al₄Si₄O₁₆)
Na	ⓘ Riebeckite	◻Na₂(Fe₃²⁺Fe₂³⁺)Si₈O₂₂(OH)₂
Al	Aluminium
Al	ⓘ Nepheline	Na₃K(Al₄Si₄O₁₆)
Si	Silicon
Si	ⓘ Aegirine	NaFe³⁺Si₂O₆
Si	ⓘ Nepheline	Na₃K(Al₄Si₄O₁₆)
Si	ⓘ Quartz	SiO₂
Si	ⓘ Riebeckite	◻Na₂(Fe₃²⁺Fe₂³⁺)Si₈O₂₂(OH)₂
Si	ⓘ Zircon	Zr(SiO₄)
K	Potassium
K	ⓘ Nepheline	Na₃K(Al₄Si₄O₁₆)
Fe	Iron
Fe	ⓘ Aegirine	NaFe³⁺Si₂O₆
Fe	ⓘ Riebeckite	◻Na₂(Fe₃²⁺Fe₂³⁺)Si₈O₂₂(OH)₂
Zr	Zirconium
Zr	ⓘ Zircon	Zr(SiO₄)

Other Regions, Features and Areas containing this locality

AfricaContinent

East African Rift System (EARS)Zone (Tectonic)

African Plate

Arabian-Nubian Shield
- Nakfa TerraneVolcanic Arc

Arabian Plate

Nubian ShieldShield

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References

Blanford, W. T. (1870). Observations on the Geology and Zoology of Abyssinia: Made During the Progress of the British Expedition to that Country in 1867-68. Macmillan and Company.

Prior, G. T. (1899) Riebeckite in Trachytic Rocks from Abyssinia. Mineralogical Magazine and Journal of the Mineralogical Society, 12 (55) 92-95 doi:10.1180/minmag.1899.012.55.04

Merla, G., & Minucci, E. (1938). Missione geologica nel Tigrai: Rome, Reale Accademia d'Italia. Centro Studi per l'Africa Orientale Italiana, Roma, 3.

Mohr, P. A. (1962). The geology of Ethiopia: Univ. Coll. of Addis Ababa Press, Addis Ababa.

Le Bas, M. J., & Mohr, P. A. (1968). Feldspathoidal rocks from the Cainozoic volcanic province of Ethiopia. Geologische Rundschau, 58(1), 273-280. doi.org/10.1007/BF01820608

Woolley, A. R. (2001) Alkaline Rocks and Carbonatites of the World, Part 3: Africa - Alkaline Rocks and Carbonatites of the World. The Geological Society of London.p.73

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Aksum-Adwa Complex, Tigray Region, EthiopiaiRegional Level TypesAksum-Adwa ComplexComplex Tigray RegionRegion EthiopiaCountry function showexplain() { $("#locexplain").toggle(); if (typeof movemap === "function") movemap(); }

Select Mineral List Type

Mineral List

Rock Types Recorded

Select Rock List Type

Detailed Mineral List:

Gallery:

List of minerals arranged by Strunz 10th Edition classification

List of minerals for each chemical element

Other Regions, Features and Areas containing this locality

References

Aksum-Adwa Complex, Tigray Region, Ethiopia i
Regional Level Types
Aksum-Adwa Complex Complex
Tigray Region Region
Ethiopia Country