372:
106:
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and other small depressions and fractures. The fine particles within glaciers polished the bedrock, while striations are scratch-marks created when larger rock fragments were dragged over the pre-existing rock surface by glaciers. The shape of the striations evidences that the ice flow direction was
600:
in northern
Ethiopia reshaped the topography. Later on this topography was covered by more recent sediments. In places where these sediments were again eroded, the ancient landforms have become visible. They are sometimes millimeters and sometimes kilometres wide. These ancient landforms are mainly
528:
The Edaga Arbi
Glacials may reach a thickness of 200 metres. Similar to most other tillites, they hold many different types of sediment. Generally, the sediments are rich in mud (clay and silt), in contrast to the
661:
536:. Basal till that was deposited directly under the ice holds many rock fragments. In other places, the settling in water of suspended fine-grained sediment resulted in massive stratified
794:
Bussert, R (2010). "Exhumed erosional landforms of the Late
Palaeozoic glaciation in northern Ethiopia: Indicators of ice-flow direction, palaeolandscape and regional ice dynamics".
606:
560:
Pollen and spores have been found in the Edaga Arbi
Glacials. Their age confirms that the Edaga Arbi Glacials date back to the Late Palaeozoic ice age.
452:
basement and in Early
Palaeozoic sediments. These valleys were often several kilometres wide and tens of meters deep. Indeed, northern Ethiopia was
416:. The matrix is composed of grey, black and purple clays (locally silt), that contains rock fragments up to 6 metres across. Pollen dating yields a
484:
of overlying rocks. This is one of the few places in the world where the
Palaeozoic glacial deposits are well exposed and can be easily accessed.
111:
759:
Bussert, R.; Schrank, E. (2007). "Palynological evidence for a latest
Carboniferous-Early Permian glaciation in Northern Ethiopia".
834:
437:
605:
basement bedrock surface. For instance, the larger valleys correspond to the path that the glaciers followed. More in detail, the
371:
697:
646:
724:
Bussert, R. (2014). "Depositional environments during the Late
Palaeozoic ice age (LPIA) in northern Ethiopia, NE Africa".
217:
682:
Evidence of the 'Snowball Earth' and Other
Ancient Glaciations from the Border Areas of the Dogu'a Tembien District
432:
The name was coined by geologist D.B.Dow and colleagues They referred to the wide outcrops surrounding the town of
448:
The Edaga Arbi
Glacials fill the bottom of north-south oriented valleys, that were carved by glaciers, into the
256:
839:
210:
472:; ~300 Ma). This has led to the presence of glacial sediments as well as erosional landforms in eastern
544:
lenses. As they were formed under water, the mudstone and the sandstone contain (sometimes very large)
500:. As usual, these moraines and tillites are composed of large rock fragments in a fine earth mass.
533:
803:
768:
733:
130:
618:
within the Edaga Arbi Glacials were probably created by flowing meltwater under glaciers.
8:
610:
477:
807:
772:
737:
703:
417:
157:
33:
780:
745:
707:
693:
642:
573:
530:
144:
140:
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have been uplifted and the Edaga Arbi Glacials have been exposed as a result of the
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335:
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119:
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27:
540:. Still elsewhere, the underwater movement of sand by gravity resulted in
602:
549:
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39:
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453:
436:. So far the nomenclature has not been proposed for recognition to the
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These glaciogenic sediments were deposited directly by the glacier as
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Palaeozoic glacial rocks recently discovered in northern Ethiopia
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684:. GeoGuide. Cham, Switzerland: SpringerNature. pp. 91–105.
509:
496:. They have been consolidated, what allows to name them as
508:, what indicates that the sediment was often deposited in
516:. The tillites have often been deformed by (underwater)
637:
Nyssen, Jan; Jacob, Miro; Frankl, Amaury, eds. (2019).
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639:Geo-trekking in Ethiopia's Tropical Mountains
568:The deposits are exposed locally as south as
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16:Palaeozoic geological formation in Africa
443:
438:International Commission on Stratigraphy
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427:
476:. Over the last 30 million years the
580:massif. They are widespread around
13:
504:are predominant. Often, they hold
14:
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761:Journal of African Earth Sciences
781:10.1016/j.jafrearsci.2007.09.003
746:10.1016/j.jafrearsci.2014.04.005
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313:
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835:Geologic formations of Ethiopia
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420:(~323 million years or Ma) to
386:Edaga Arbi Glacials (Ethiopia)
1:
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601:visible on the exposed older
592:Exposed glacial geomorphology
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250:Approximate paleocoordinates
7:
690:10.1007/978-3-030-04955-3_6
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607:polished bedrock surfaces
548:, deposited from melting
456:in the Early Palaeozoic (
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816:10.1016/j.gr.2009.10.009
404:geological formation in
167:200 m (660 ft)
584:and further north into
555:
460:; ~445 Ma), and in the
534:fluvioglacial deposits
444:Stratigraphic context
840:Geography of Eritrea
680:Bussert, R. (2019).
131:Geological formation
808:2010GondR..18..356B
773:2007JAfES..49..201B
738:2014JAfES..99..386B
614:towards the north.
564:Geographical extent
478:Ethiopian Highlands
428:Name and definition
398:Edaga Arbi Glacials
268: /
229: /
28:Stratigraphic range
22:Edaga Arbi Glacials
418:Late Carboniferous
233:14.2037°N 39.255°E
34:Late Carboniferous
699:978-3-030-04954-6
648:978-3-030-04954-6
531:Enticho Sandstone
514:pro-glacial lakes
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145:Enticho Sandstone
141:Adigrat Sandstone
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820:
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802:(2–3): 356–369.
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767:(4–5): 201–210.
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110:Roadcut between
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726:J Afr Earth Sci
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616:Glacial grooves
598:glacial erosion
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462:Late Palaeozoic
458:Late Ordovician
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424:(~295 Ma) age.
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641:. p. 38.
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143:, coeval with
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120:Dogu’a Tembien
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466:Carboniferous
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796:Gondwana Res
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342:Type section
334:, northeast
732:: 386–407.
603:Precambrian
488:Environment
450:Precambrian
275: /
236: /
211:Coordinates
155:Precambrian
829:Categories
622:References
611:striations
582:Idaga Arbi
546:dropstones
506:dropstones
434:Idaga Arbi
408:(northern
402:Palaeozoic
352:Idaga Arbi
224:39°15′18″E
221:14°12′13″N
195:Dropstones
708:199106886
574:Abergelle
550:ice rafts
542:sandstone
538:mudstones
524:Lithology
502:Mudstones
454:glaciated
412:) and in
347:Named for
199:Sandstone
172:Lithology
164:Thickness
137:Underlies
609:display
518:slumping
498:tillites
494:moraines
410:Ethiopia
361:D.B. Dow
358:Named by
350:Town of
310:Ethiopia
205:Location
185:Mudstone
158:basement
151:Overlies
112:Werqamba
804:Bibcode
769:Bibcode
734:Bibcode
586:Eritrea
482:erosion
470:Permian
414:Eritrea
332:Eritrea
321:Eritrea
298:Country
272:0°N 0°E
181:Tillite
177:Primary
116:Hawzien
706:
696:
645:
510:fjords
474:Tigray
406:Tigray
400:are a
336:Tigray
327:Extent
318:
307:
292:Tigray
288:Region
704:S2CID
570:Samre
191:Other
694:ISBN
643:ISBN
596:The
572:and
556:Life
396:The
277:0; 0
127:Type
114:and
40:PreꞒ
812:doi
777:doi
742:doi
686:doi
512:or
263:0°E
260:0°N
831::
810:.
800:18
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197:,
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90:Pg
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468:-
464:(
95:N
85:K
80:J
75:T
70:P
65:C
60:D
55:S
50:O
45:Ꞓ
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