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generation, lava flowed out over the surface, in successive flows. Some part of it disappeared within the next 1 to 3 million years due to weathering and erosion, while other parts remained present. Within the basalt, columnar joints occur as a result of cooling; they are visible along the flanks of
376:
that developed before the magma reached the earth surface. These basalts are weathered, partially eroded and have a sub-horizontal stratification, particularly at the lower part. This series was created during the first period of the
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the ridges. The columnar joints are perpendicular to the surface of the lava flows; they are mostly vertical, but may also be strongly inclined. The lower succession, the one that overlies the
430:
134:
601:
Hofmann, C. and colleagues (1997). "Timing of the
Ethiopian flood basalt event and implications for plume birth and environmental change".
458:
holds vertical and closely spaced columnar joints. A common characteristic of the columnar joints observed in the
Ashangi Basalts is their
405:
in Tigray, which is surrounded by large outcrops of the formation. So far the nomenclature has not been proposed for recognition to the
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The volcanic rock cover of the Dogu'a
Tembien massif. In: Geo-Trekking in Ethiopia's Tropical Mountains, the Dogu'a Tembien District
650:
631:
Observations on the geology and zoology of
Abyssinia, made during the progress of the British expedition to that country in 1867-68
406:
321:
582:
181:
545:
Justin-Visentin, E. (1974). "Petrografia, chimismo e petrogenesi dei corpi subvulcanici di Macallè (Tigrai
Etiopia)".
398:
481:) is located on the Ashangi Basalts, as can be seen from the typical building materials of houses and fences
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174:
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Memorie dell'Istituto di
Geologia e Mineralogia, Universita di Padova
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382:
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minerals, surrounded by a matrix of fine-grained plagioclases and
522:
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are separated from the
Mesozoic formations below it by basal
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Rock sample of extremely porphyritic basalt, collected at
361:, hence they are in the lowest position. These dark
429:. In many places, on its upper side, deposits of
642:
544:
490:The Ashangi Basalts are made of coarse-grained
441:These volcanic rocks formed through melting of
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101:
596:
594:
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407:International Commission on Stratigraphy
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517:The Ashangi formation occurs widely in
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643:
591:
512:
388:
498:; some iron oxides are also present.
473:The upper part of Gumuara village in
571:Miruts Hagos and colleagues (2019).
381:eruptions in north Ethiopia, in the
13:
14:
677:
393:The name was coined by geologist
421:sedimentary rocks, particularly
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320:
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34:
651:Geologic formations of Ethiopia
431:intra-volcanic sedimentary rock
399:British Expedition to Abyssinia
135:Intra-volcanic sedimentary rock
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1:
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214:Approximate paleocoordinates
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634:. London: Macmillan and Co.
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336:Ashangi Basalts (Ethiopia)
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628:Blanford, W.T. (1870).
395:William Thomas Blanford
310:William Thomas Blanford
197:12.5823°N 39.51984986°E
509:
482:
466:shape (in plan view).
397:, who accompanied the
504:
472:
452:Amba Aradam Formation
423:Amba Aradam Formation
417:The formation covers
413:Stratigraphic context
145:Amba Aradam Formation
202:12.5823; 39.51984986
121:Geological formation
666:Oligocene volcanism
513:Geographical extent
389:Name and definition
372:. The basalts hold
285:Ethiopian Highlands
232: /
193: /
25:Stratigraphic range
577:. SpringerNature.
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483:
656:Basalt formations
584:978-3-030-04954-6
456:Adigrat Sandstone
427:Adigrat Sandstone
350:are the earliest
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661:Oligocene Africa
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401:in 1868, after
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348:Ashangi Basalts
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107:West of Kerene
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19:Ashangi Basalts
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527:Dogu’a Tembien
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475:Dogu’a Tembien
443:Earth's mantle
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355:volcanic rocks
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109:Dogu'a Tembien
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519:Tigray Region
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403:Lake Hashenge
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370:conglomerates
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300:Lake Hashenge
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131:Alaji Basalts
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379:flood basalt
347:
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291:Type section
609:: 838–841.
492:plagioclase
437:Environment
374:phenocrysts
363:porphyritic
239: /
200: /
175:Coordinates
160:Porphyritic
645:Categories
533:References
460:pentagonal
188:39°31′11″E
185:12°34′56″N
525:area and
523:May Ch'ew
496:pyroxenes
486:Lithology
464:hexagonal
383:Oligocene
357:in north
296:Named for
283:Northern
151:Lithology
127:Underlies
31:Oligocene
479:Ethiopia
454:and the
445:. After
419:Mesozoic
359:Ethiopia
352:Tertiary
306:Named by
274:Ethiopia
169:Location
141:Overlies
553:: 1–33.
433:occur.
366:basalts
262:Country
236:0°N 0°E
156:Primary
603:Nature
581:
507:Mashih
280:Extent
271:
256:Tigray
252:Region
163:Basalt
447:magma
579:ISBN
425:and
346:The
241:0; 0
117:Type
37:PreꞒ
611:doi
607:389
462:or
227:0°E
224:0°N
647::
605:.
593:^
559:^
551:31
549:.
529:.
409:.
385:.
133:,
87:Pg
27::
617:.
613::
587:.
477:(
111:)
92:N
82:K
77:J
72:T
67:P
62:C
57:D
52:S
47:O
42:Ꞓ
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