
The Huab Formation is an
Early Permian 01 or '01 may refer to:
* The year 2001, or any year ending with 01
* The month of January
* 1 (number)
Music
* 01'' (Richard Müller album), 2001
* ''01'' (Son of Dave album), 2000
* ''01'' (Urban Zakapa album), 2011
* ''O1'' (Hiroyuki Sawano ...
(
Artinskian
In the geologic timescale, the Artinskian is an age or stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Artinskian likely lasted between and million years ago (Ma) according to the most recent revision of th ...
to
Kungurian
In the geologic timescale, the Kungurian is an age or stage of the Permian. It is the latest or upper of four subdivisions of the Cisuralian Epoch or Series. The Kungurian lasted between and million years ago (Ma). It was preceded by the Art ...
) geologic
formation
Formation may refer to:
Linguistics
* Back-formation, the process of creating a new lexeme by removing or affixes
* Word formation, the creation of a new word by adding affixes
Mathematics and science
* Cave formation or speleothem, a secondary ...
correlated with the
Ecca Group
The Ecca Group is the second of the main subdivisions of the Karoo Supergroup of geological strata in southern Africa. It mainly follows conformably after the Dwyka Group in some sections, but in some localities overlying unconformably over much ...
and designated "Ecca" Group, because it does not belong to the
Karoo
The Karoo ( ; from the Afrikaans borrowing of the South Khoekhoe !Orakobab or Khoemana word ''ǃ’Aukarob'' "Hardveld") is a semi- desert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its ...
, in the southwestern
Kunene Region
Kunene is one of the fourteen regions of Namibia. Its capital is Opuwo, its governor is Marius Sheya. The region's name comes from the Kunene River which forms the northern border with Angola. Besides the capital Opuwo, the region contains th ...
and northern
Erongo Region
Erongo is one of the 14 regions of Namibia. The capital is Swakopmund. It is named after Mount Erongo, a well-known landmark in Namibia and in this area. Erongo contains the municipalities of Walvis Bay, Swakopmund, Henties Bay and Omaruru, as ...
of northwestern
Namibia
Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and e ...
. The Huab Formation represents the oldest sedimentary unit of the
Huab Basin, overlying the
basement
A basement or cellar is one or more Storey, floors of a building that are completely or partly below the storey, ground floor. It generally is used as a utility space for a building, where such items as the Furnace (house heating), furnace, ...
. The
oil shale
Oil shale is an organic-rich fine-grained sedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons can be produced. In addition to kerogen, general composition of oil shales constitu ...
s within the formation were deposited in a shallow
lacustrine
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...
environment
Environment most often refers to:
__NOTOC__
* Natural environment, all living and non-living things occurring naturally
* Biophysical environment, the physical and biological factors along with their chemical interactions that affect an organism or ...
, and the formation marks the transition from terrestrial deposits under
glacial
A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...
climatic circumstances towards a warmer fluvial and marine deltaic environment.
The Huab Formation is correlated with a series of formations in the
Pelotas
Pelotas () is a Brazilian city and municipality (''município''), the third most populous in the southern state of Rio Grande do Sul. It is located 270 km (168 mi) from Porto Alegre, the state's capital city, and 130 km (80.8&n ...
and
Paraná Basin
The Paraná Basin ( pt, Bacia do Paraná, es, Cuenca del Paraná) is a large cratonic sedimentary basin situated in the central-eastern part of South America. About 75% of its areal distribution occurs in Brazil, from Mato Grosso to Rio Grande ...
s in southeastern Brazil, deposited in a larger basinal area, 150 million years before the break-up of
Pangea
Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million ...
. The abundance of ''
Glossopteris
''Glossopteris'' tymology: from Ancient Greek γλῶσσα (glôssa, " tongue ") + πτερίς (pterís, " fern ")is the largest and best-known genus of the extinct Permian order of seed ferns known as Glossopteridales (also known as Arber ...
'' and ''
Mesosaurus
''Mesosaurus'' (meaning "middle lizard") is an extinct genus of reptile from the Early Permian of southern Africa and South America. Along with it, the genera ''Brazilosaurus'' and '' Stereosternum'', it is a member of the family Mesosauridae ...
'' fossils are characteristic of the
Gondwana
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final st ...
n correlation across present-day South America, Africa, Antarctica and Australia.
Description
The Huab Formation is a lithological unit with an approximate maximum thickness of , deposited in the eponymous
basin
Basin may refer to:
Geography and geology
* Depression (geology)
** Back-arc basin, a submarine feature associated with island arcs and subduction zones
** Debris basin, designed to prevent damage from debris flow
** Drainage basin (hydrology), ...
where it underlies the
Gai-As Formation
The Gai-As Formation is an Early to Middle Permian ( Kungurian to Wordian) geologic formation correlated with the Ecca Group and designated "Ecca" Group, because it does not belong to the Karoo, in the southwestern Kunene Region and northern E ...
, separated by a significant hiatus,
[Wanke, 2000, p.25] and overlies the
basement
A basement or cellar is one or more Storey, floors of a building that are completely or partly below the storey, ground floor. It generally is used as a utility space for a building, where such items as the Furnace (house heating), furnace, ...
.
[Horsthemke et al, 1990, p.68] The formation crops out south of the
Huab River
The Huab River is an ephemeral river in the Kunene Region of north-western Namibia. Its source is southeast of Kamanjab, from where it flows westwards through Mopane savanna until it reaches the Skeleton Coast and the Atlantic Ocean. Inflows of ...
,
[Duncan et al., 1989, p.5] extending from the
Atlantic coast to
Twyfelfontein
Twyfelfontein ( Afrikaans: ''uncertain spring''), officially known as ǀUi-ǁAis ( Damara/Nama: ''jumping waterhole''), is a site of ancient rock engravings in the Kunene Region of north-western Namibia. It consists of a spring in a valley flan ...
. The thickness in the coastal area is about .
[Wanke, 2000, p.20]
Lithologies
Part of the formation in the west is composed of
carbonate
A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonat ...
s (domal
stromatolite
Stromatolites () or stromatoliths () are layered sedimentary formations ( microbialite) that are created mainly by photosynthetic microorganisms such as cyanobacteria, sulfate-reducing bacteria, and Pseudomonadota (formerly proteobacteria). ...
s with an east to west orientation and thin laminae of less than ). The stromatolites occur in a wide zone, reaching from east of the
Uniab Fault to east of the
Bergsig Fault system.
[ The eastward sections comprise oolitic conglomeratic horizons of up to thick. The carbonates ( mudstones and marls) are overlain by silty, partly calcareous ]shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especia ...
s. The shales interfinger with sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks.
Most sandstone is composed of quartz or feldspar (both silicates ...
s and in certain parts coal
Coal is a combustible black or brownish-black sedimentary rock, formed as stratum, rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen ...
beds are found. In the eastern domain around the Doros crater, dark iron-oxide cements occur in the upper conglomerate horizons.[Wanke, 2000, p.21] In virtually all lithological units, bones of the amphibious reptile ''Mesosaurus tenuidens
''Mesosaurus'' (meaning "middle lizard") is an extinct genus of reptile from the Early Permian of southern Africa and South America. Along with it, the genera ''Brazilosaurus'' and ''Stereosternum'', it is a member of the family Mesosauridae ...
'' can be encountered in concretions.[ The laminated mudstones and marls contain a diverse ]ichnofauna Ichnofauna is the diversity of fauna based on the ichnological ( tracks and footprints) evidences. This term is often used by vertebrate paleontologists.Mateus, O., & Milàn, J. 2010. A diverse Upper Jurassic dinosaur ichnofauna from central‐west ...
including ''Skolithos
''Skolithos'' (formerly spelled ''Scolithus'' or ''Skolithus'') is a common trace fossil ichnogenus that is, or was originally, an approximately vertical cylindrical burrow. It is produced by a variety of organisms in shallow marine environment ...
'', '' Planolites'', and large exemplars of '' Rhizocorallium irregulare''.[Wanke, 2000, p.23]
Depositional environments
The depositional environment is interpreted as ranging from glacial
A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...
(tillite
image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is d ...
) at the very base,[ followed by a glacio-]fluvial
In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluv ...
setting, and a warmer climate fluvial environment.[Horsthemke et al., 1990, p.69] The sequence higher up is formed by a fan deltaic setting,[Horsthemke et al., 1990, p.70] with a lateral shallow lake with increased salinity
Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...
where stromatolite bioherms were formed.[Section 2, Cycle 2, Unit 5]
at Fossilworks
Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world.
History
Fossilworks was cre ...
.org[Horsthemke et al., 1990, p.72]Stromatolitic bioherm of the Huab Formation
/ref> The uppermost section of the Huab Formation, underlying the Gai-As Formation, was deposited in an estuarine
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environmen ...
environment.[Horsthemke et al., 1990, p.73]
The depositional environments have been described in detail by Wanke in 2000 as follows:[Wanke, 2000, pp.22–23]
;Western and central domain
Stromatolitic bioherms acted as a barrier towards the open sea in the west. Their preferred E-W orientation coincides with tidal- and wave induced currents perpendicular to the palaeo-coastline. Lagoon
A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into '' coastal lagoons'' (or ''barrier lagoons' ...
al environments were established landwards of the bioherm belts, in which laminated shales developed. The lamination is due to suspension fallout in slightly agitated water. Erosive based interbeds of coarse to gritty sandstones formed during storm events and are therefore interpreted as
tempestite
Tempestites are storm deposits that can be recognized throughout the geologic record. They are studied in the scientific disciplines of sedimentary geology and paleotempestology. The deposits derive their meaning from the word ''tempest'', a vi ...
s. West of the bioherm belts, the fair weather wave basis reached the ground, expressed in oscillation-rippled surfaces.
Channels between bioherm ridges have been interpreted as tidal channels. They host flat-pebble conglomerates, which are characterized by a high ooid content. These ooid bearing flat-pebble conglomerates support the facies concept of shallow, wave dominated water in the vicinity of the bioherms: Ooids form in very shallow, fairly agitated, carbonate saturated water probably under warm climate. The flat pebbles derived from desiccated layers of unlithified cohesive fine clastics that had been reworked, preferentially under the influence of storm waves. Tidal flats or lagoons provide the conditions for the generation of both, ooids and flat-pebble conglomerates.
;Eastern domain
Shales and mudstones besides algal laminites represent deposition in a slightly agitated, shallow water body with relatively intensive carbonate production. Oscillating water-levels resulted in the formation of paleosol
In the geosciences, paleosol (''palaeosol'' in Great Britain and Australia) is an ancient soil that formed in the past. The precise definition of the term in geology and paleontology is slightly different from its use in soil science.
In geol ...
s, which were reworked in flat pebble conglomerates after flooding. Autochthonous breccia
Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix.
The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of d ...
s give clear evidence for frequent sea level fluctuations, that refer to palustrine soils, which underwent periodically subaerial exposure. Coarse sandstones, partly channelized, reveal fluvial influence. The coarser material was probably sourced by a nearby delta that was temporarily flooded during storm events. The dominance of those coarse sandstones towards the top of the eastern flat-pebble facies association might indicate delta progradation. The iron-oxide cements are interpreted as ferricretes, that either formed autochthonous or derived from adjacent reworked ferricrete crusts. An early uplift of the eastern hinterland
Hinterland is a German word meaning "the land behind" (a city, a port, or similar). Its use in English was first documented by the geographer George Chisholm in his ''Handbook of Commercial Geography'' (1888). Originally the term was associated ...
might be indicated by coarse, westwardly prograding deltaic deposits of the upper Huab Formation in the eastern Huab area.[Wanke, 2000, p.38]
Correlations
The upper part of the formation is correlated with the Irati Formation
Irati Formation is the name of a geological formation of the Paraná Basin in Brazil. It has previously been dated as Late Permian using palynomorphs, but is now dated as Early Permian using zircon ages obtained from bentonite layers. The base of ...
of the Paraná and Pelotas Basin
The Pelotas Basin ( pt, Bacia de Pelotas, es, Cuenca de Pelotas) is a mostly offshore sedimentary basin of approximately in the South Atlantic, administratively part of the southern states Santa Catarina and Rio Grande do Sul of Brazil and the ...
s in Rio Grande do Sul, Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
, and with the Whitehill Formation
The Whitehill Formation, alternatively written as White Hill Formation and formerly known as White Band or Whitehill or White Hill Member, is a regional Early Permian (Artinskian to Kungurian, dating to around 282 to 275 Ma) geologic formation b ...
in the Karoo Basin
The Karoo Supergroup is the most widespread stratigraphic unit in Africa south of the Kalahari Desert. The supergroup consists of a sequence of units, mostly of nonmarine origin, deposited between the Late Carboniferous and Early Jurassic, a perio ...
of southern Namibia and the Eastern
Eastern may refer to:
Transportation
*China Eastern Airlines, a current Chinese airline based in Shanghai
*Eastern Air, former name of Zambia Skyways
*Eastern Air Lines, a defunct American airline that operated from 1926 to 1991
* Eastern Air L ...
, Northern and Western Cape
The Western Cape is a province of South Africa, situated on the south-western coast of the country. It is the fourth largest of the nine provinces with an area of , and the third most populous, with an estimated 7 million inhabitants in 2020 ...
, South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring count ...
.[ The lower section correlates with the ]Palermo
Palermo ( , ; scn, Palermu , locally also or ) is a city in southern Italy, the capital of both the autonomous region of Sicily and the Metropolitan City of Palermo, the city's surrounding metropolitan province. The city is noted for it ...
and Rio Bonito Formation
The Rio Bonito Formation is a geological formation of the Paraná and Pelotas Basins of Permian age. It is represented by a succession of cyclic sedimentary packages of sandstones, siltstones and shales which bear extensive deposits of coal that ...
s of the Paraná Basin and the Prince Albert Formation
A prince is a male ruler (ranked below a king, grand prince, and grand duke) or a male member of a monarch's or former monarch's family. ''Prince'' is also a title of nobility (often highest), often hereditary, in some European states. The ...
of the Karoo.[Horsthemke et al., 1990, p.74] The Permian sequence in the Huab Basin is much thinner than those of the Paraná and Karoo Basins.[Holzförster et al., 2000, p.255] The fossil assemblages of ''Glossopteris
''Glossopteris'' tymology: from Ancient Greek γλῶσσα (glôssa, " tongue ") + πτερίς (pterís, " fern ")is the largest and best-known genus of the extinct Permian order of seed ferns known as Glossopteridales (also known as Arber ...
'' and ''Mesosaurus'' are known from other parts of Gondwana
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final st ...
; the Vryheid Formation
Vryheid ( zu, IVryheid) is a coal mining and cattle ranching town in northern KwaZulu-Natal, South Africa. Vryheid is the Afrikaans word for "freedom".
History
After Boer farmers, who lived in the Vryheid area, had helped King Dinuzulu defe ...
of South Africa and coal deposits of the Lower Permian in Australia.[
]
See also
* List of fossiliferous stratigraphic units in Namibia
Fossiliferous stratigraphic units in Namibia are not as numerous as in neighboring South Africa, but several formations have provided unique fossil assemblages, particularly the Ediacaran fauna of the Vendian to Cambrian Nama Group, fossil fish ...
* Geology of Namibia
The geology of Namibia encompasses rocks of Paleoproterozoic, Mesoproterozoic and Neoproterozoic and Paleozoic to Cenozoic age. About 46% of the countryʼs surface are bedrock exposure, while the remainder is covered by the young overburden sedi ...
* Ganigobis Formation
The Ganigobis Formation is a Late Carboniferous (Gzhelian) to Early Permian (Artinskian) geologic formation of the Dwyka Group in the ǁKaras Region of southeastern Namibia and the Northern Cape of South Africa. The widespread formation was depos ...
* Gondwanide orogeny
The Gondwanide orogeny was an orogeny active in the Permian that affected parts of Gondwana that are by current geography now located in southern South America, South Africa, Antarctica, Australia and New Guinea. The zone of deformation in Argenti ...
References
Bibliography
*
*
*
* {{cite LSA , last=Wanke , first=Angsar , year=2000 , title=Karoo-Etendeka Unconformities in NW Namibia and their Tectonic Implications (PhD thesis) , url=https://opus.bibliothek.uni-wuerzburg.de/opus4-wuerzburg/frontdoor/deliver/index/docId/271/file/Diss-wanke.pdf , publisher= Julius-Maximilians-Universität Würzburg , pages=1–114 , accessdate=2018-08-26
Geologic formations of Namibia
Permian System of Africa
Artinskian Stage
Kungurian
Shale formations
Oil shale formations
Sandstone formations
Limestone formations
Coal formations
Coal in Namibia
Deltaic deposits
Fluvial deposits
Glacial deposits
Lacustrine deposits
Permian southern paleotemperate deposits
Paleontology in Namibia
Geography of Erongo Region
Geography of Kunene Region