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Mahafaly dike swarm, Fotadrevo Commune, Ampanihy District, Atsimo-Andrefana, Madagascari
Regional Level Types
Mahafaly dike swarmDike swarm
Fotadrevo CommuneCommune
Ampanihy DistrictDistrict
Atsimo-AndrefanaRegion
MadagascarCountry

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Latitude & Longitude (WGS84):
24° 15' South , 44° 57' East
Latitude & Longitude (decimal):
-24.25000,44.95000
GRN:
S17E29
Type:
Dike swarm
Köppen climate type:
Aw : Tropical savanna, wet
Mindat Locality ID:
407338
Long-form identifier:
mindat:1:2:407338:6
GUID (UUID V4):
0


Extensive dolerite dike swarm, apparently associated with which are 10 small plugs (Boulanger 1957), all of which consist of ankaratrite.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


3 valid minerals.

Rock Types Recorded

Note: data is currently VERY limited. Please bear with us while we work towards adding this information!

Select Rock List Type

Alphabetical List Tree Diagram

Detailed Mineral List:

ⓘ Analcime
Formula: Na(AlSi2O6) · H2O
References:
Lacroix, Alfred (1923) Minéralogie de Madagascar Tome III - Lithologie Appendice - Index Geographique. Société d'Éditions Géographiques, Maritimes et Coloniales. 450 pp.
Boulanger, Jacques (1957) Le systeme volcanique fissural du pays Mahafaly (SW de Madagascar). Bulletin de la Société Géologique de France, S. 6 Vol. S6-VII (4-5). 529-537 doi:10.2113/gssgfbull.s6-vii.4-5.529
Boulanger, J. (1957) Les dykes du pays Mahafaly. Travaux du Bureau Gèologique de Madagascar 83, 101-112
Besaire, Henri (1970) Feuille 7. Fianarantsoa. 1:500000. Carte géologigues Madagascar 1/500.000, Service Geologique de Madagascar.
Dostal, J., Dupuy, C., Nicollet, C., Cantagrel, J.M. (1992) Geochemistry and petrogenesis of Upper Cretaceous basaltic rocks from southern Malagasy. Chemical Geology, 97 (3) 199-218 doi:10.1016/0009-2541(92)90076-h
ⓘ Augite
Formula: (CaxMgyFez)(Mgy1Fez1)Si2O6
References:
Lacroix, Alfred (1923) Minéralogie de Madagascar Tome III - Lithologie Appendice - Index Geographique. Société d'Éditions Géographiques, Maritimes et Coloniales. 450 pp.
Boulanger, Jacques (1957) Le systeme volcanique fissural du pays Mahafaly (SW de Madagascar). Bulletin de la Société Géologique de France, S. 6 Vol. S6-VII (4-5). 529-537 doi:10.2113/gssgfbull.s6-vii.4-5.529
Boulanger, J. (1957) Les dykes du pays Mahafaly. Travaux du Bureau Gèologique de Madagascar 83, 101-112
Besaire, Henri (1970) Feuille 7. Fianarantsoa. 1:500000. Carte géologigues Madagascar 1/500.000, Service Geologique de Madagascar.
Dostal, J., Dupuy, C., Nicollet, C., Cantagrel, J.M. (1992) Geochemistry and petrogenesis of Upper Cretaceous basaltic rocks from southern Malagasy. Chemical Geology, 97 (3) 199-218 doi:10.1016/0009-2541(92)90076-h
ⓘ 'Fayalite-Forsterite Series'
References:
Lacroix, Alfred (1923) Minéralogie de Madagascar Tome III - Lithologie Appendice - Index Geographique. Société d'Éditions Géographiques, Maritimes et Coloniales. 450 pp.
Boulanger, Jacques (1957) Le systeme volcanique fissural du pays Mahafaly (SW de Madagascar). Bulletin de la Société Géologique de France, S. 6 Vol. S6-VII (4-5). 529-537 doi:10.2113/gssgfbull.s6-vii.4-5.529
Boulanger, J. (1957) Les dykes du pays Mahafaly. Travaux du Bureau Gèologique de Madagascar 83, 101-112
Besaire, Henri (1970) Feuille 7. Fianarantsoa. 1:500000. Carte géologigues Madagascar 1/500.000, Service Geologique de Madagascar.
Dostal, J., Dupuy, C., Nicollet, C., Cantagrel, J.M. (1992) Geochemistry and petrogenesis of Upper Cretaceous basaltic rocks from southern Malagasy. Chemical Geology, 97 (3) 199-218 doi:10.1016/0009-2541(92)90076-h
ⓘ Nepheline
Formula: Na3K(Al4Si4O16)
References:
Lacroix, Alfred (1923) Minéralogie de Madagascar Tome III - Lithologie Appendice - Index Geographique. Société d'Éditions Géographiques, Maritimes et Coloniales. 450 pp.
Boulanger, Jacques (1957) Le systeme volcanique fissural du pays Mahafaly (SW de Madagascar). Bulletin de la Société Géologique de France, S. 6 Vol. S6-VII (4-5). 529-537 doi:10.2113/gssgfbull.s6-vii.4-5.529
Boulanger, J. (1957) Les dykes du pays Mahafaly. Travaux du Bureau Gèologique de Madagascar 83, 101-112
Besaire, Henri (1970) Feuille 7. Fianarantsoa. 1:500000. Carte géologigues Madagascar 1/500.000, Service Geologique de Madagascar.
Dostal, J., Dupuy, C., Nicollet, C., Cantagrel, J.M. (1992) Geochemistry and petrogenesis of Upper Cretaceous basaltic rocks from southern Malagasy. Chemical Geology, 97 (3) 199-218 doi:10.1016/0009-2541(92)90076-h
ⓘ 'Pyroxene Group'
Formula: ADSi2O6
References:
Lacroix, Alfred (1923) Minéralogie de Madagascar Tome III - Lithologie Appendice - Index Geographique. Société d'Éditions Géographiques, Maritimes et Coloniales. 450 pp.
Boulanger, Jacques (1957) Le systeme volcanique fissural du pays Mahafaly (SW de Madagascar). Bulletin de la Société Géologique de France, S. 6 Vol. S6-VII (4-5). 529-537 doi:10.2113/gssgfbull.s6-vii.4-5.529
Boulanger, J. (1957) Les dykes du pays Mahafaly. Travaux du Bureau Gèologique de Madagascar 83, 101-112
Besaire, Henri (1970) Feuille 7. Fianarantsoa. 1:500000. Carte géologigues Madagascar 1/500.000, Service Geologique de Madagascar.
Dostal, J., Dupuy, C., Nicollet, C., Cantagrel, J.M. (1992) Geochemistry and petrogenesis of Upper Cretaceous basaltic rocks from southern Malagasy. Chemical Geology, 97 (3) 199-218 doi:10.1016/0009-2541(92)90076-h

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 9 - Silicates
ⓘAugite9.DA.15(CaxMgyFez)(Mgy1Fez1)Si2O6
ⓘNepheline9.FA.05Na3K(Al4Si4O16)
ⓘAnalcime9.GB.05Na(AlSi2O6) · H2O
Unclassified
ⓘ'Fayalite-Forsterite Series'-
ⓘ'Pyroxene Group'-ADSi2O6

List of minerals for each chemical element

HHydrogen
Hⓘ AnalcimeNa(AlSi2O6) · H2O
OOxygen
Oⓘ AnalcimeNa(AlSi2O6) · H2O
Oⓘ Augite(CaxMgyFez)(Mgy1Fez1)Si2O6
Oⓘ NephelineNa3K(Al4Si4O16)
Oⓘ Fayalite-Forsterite Series
Oⓘ Pyroxene GroupADSi2O6
NaSodium
Naⓘ AnalcimeNa(AlSi2O6) · H2O
Naⓘ NephelineNa3K(Al4Si4O16)
MgMagnesium
Mgⓘ Augite(CaxMgyFez)(Mgy1Fez1)Si2O6
Mgⓘ Fayalite-Forsterite Series
AlAluminium
Alⓘ AnalcimeNa(AlSi2O6) · H2O
Alⓘ NephelineNa3K(Al4Si4O16)
SiSilicon
Siⓘ AnalcimeNa(AlSi2O6) · H2O
Siⓘ Augite(CaxMgyFez)(Mgy1Fez1)Si2O6
Siⓘ NephelineNa3K(Al4Si4O16)
Siⓘ Fayalite-Forsterite Series
Siⓘ Pyroxene GroupADSi2O6
KPotassium
Kⓘ NephelineNa3K(Al4Si4O16)
CaCalcium
Caⓘ Augite(CaxMgyFez)(Mgy1Fez1)Si2O6
FeIron
Feⓘ Augite(CaxMgyFez)(Mgy1Fez1)Si2O6
Feⓘ Fayalite-Forsterite Series

Geochronology

Mineralization age: Late/Upper Cretaceous : 71 ± 3 Ma to 66 ± 1 Ma

Important note: This table is based only on rock and mineral ages recorded on mindat.org for this locality and is not necessarily a complete representation of the geochronology, but does give an indication of possible mineralization events relevant to this locality. As more age information is added this table may expand in the future. A break in the table simply indicates a lack of data entered here, not necessarily a break in the geologic sequence. Grey background entries are from different, related, localities.

Geologic TimeRocks, Minerals and Events
Phanerozoic
 Cenozoic
  Paleogene
   Paleocene
ⓘ Basanite (youngest age)66 ± 1 Ma
 Mesozoic
  Cretaceous
   Late/Upper Cretaceous
ⓘ Basanite (oldest age)71 ± 3 Ma

Other Regions, Features and Areas containing this locality

AfricaContinent
African Plate
Madagascar
Somali PlateTectonic Plate

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Lacroix, Alfred (1923) Minéralogie de Madagascar Tome III - Lithologie Appendice - Index Geographique. Société d'Éditions Géographiques, Maritimes et Coloniales. 450 pp.
Boulanger, Jacques (1957) Le systeme volcanique fissural du pays Mahafaly (SW de Madagascar). Bulletin de la Société Géologique de France, S. 6 Vol. S6-VII (4-5). 529-537 doi:10.2113/gssgfbull.s6-vii.4-5.529
Boulanger, J. (1957) Les dykes du pays Mahafaly. Travaux du Bureau Gèologique de Madagascar 83, 101-112
Besaire, Henri (1970) Feuille 7. Fianarantsoa. 1:500000. Carte géologigues Madagascar 1/500.000, Service Geologique de Madagascar.
Dostal, J., Dupuy, C., Nicollet, C., Cantagrel, J.M. (1992) Geochemistry and petrogenesis of Upper Cretaceous basaltic rocks from southern Malagasy. Chemical Geology, 97 (3) 199-218 doi:10.1016/0009-2541(92)90076-h
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.
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