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Khunale
Selam is a ''tabia'' or municipality in the Dogu'a Tembien district of the Tigray Region of Ethiopia. The ''tabia'' centre is in Addi Werho village, located approximately 3 km to the northeast of the ''woreda'' town Hagere Selam. Geography The ''tabia'' stretches down north of the ridge occupied by the main road towards the Tinsehe gorge. The highest peak is Imba Khoboro (2730 m a.s.l.) and the lowest place at the foot of the waterfall in Tinsehe (2000 m a.s.l.). Geology From the higher to the lower locations, the following geological formations are present: * Phonolite plugs * Upper basalt * Interbedded lacustrine deposits * Lower basalt * Amba Aradam Formation * Antalo Limestone * Quaternary alluvium and freshwater tufa Geomorphology and soils The main geomorphic units, with corresponding soil types are: Hagere Selam Highlands, along the upper basalt and sandstone ridge * Associated soil types ** shallow soils with high stone contents ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tigray Region
The Tigray Region, officially the Tigray National Regional State, is the northernmost Regions of Ethiopia, regional state in Ethiopia. The Tigray Region is the homeland of the Tigrayan, Irob people, Irob, and Kunama people, Kunama people. Its capital and largest city is Mekelle. Tigray is the fifth-largest by area, the fifth-most populous, and the fifth-most densely populated of the 11 regional states. Tigray's official language is Tigrinya language, Tigrinya, similar to that languages of Eritrea, spoken in Eritrea just to the North. The estimated population as of 2019 is 5,443,000. The majority of the population (c. 80%) are farmers, contributing 46% to the regional gross domestic product (2009). The highlands have the highest population density, especially in Misraqawi Zone, eastern and Maekelay Zone, central Tigray. The much less densely populated lowlands comprise 48% of Tigray's area. Like many parts of Africa, Tigray is far from a religious monolith. Despite the historic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Degua Tembien
Dogu'a Tembien (, "Upper Tembien", sometimes transliterated as Degua Tembien) is a woreda in Tigray Region, Ethiopia. It is named in part after the former province of Tembien. Nowadays, the mountainous district is part of the Southeastern Tigray Zone. The administrative centre of this woreda is Hagere Selam. History Dogu’a Tembien holds numerous prehistoric sites, which have been dated to the Middle Stone Age in Ayninbirkekin, or Pastoral Neolithic in Aregen and Menachek. Geography Topography and landscapes Major mountains :* Tsatsen, 2815 metres, a wide mesa between Hagere Selam and Inda Maryam Qorar () :* Ekli Imba, 2799 metres, summit of the Arebay massif in Arebay ''tabia'' or district () :* Imba Zuw’ala, 2710 metres, near Hagere Selam () :* Aregen, 2660 metres, in Aregen ''tabia'' () :* Dabba Selama, 2630 metres, in Haddinnet ''tabia'' () (not to be confused with the homonymous monastery) :* Imba Dogu’a, 2610 metres, in Mizane Birhan ''tabia'' () :* I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phonolite Series In North Ethiopia
The phonolite or clinkstone of northern Ethiopia is a shallow-seated igneous rock. The phonolites intruded and punctured the Mesozoic sedimentary rocks and the Tertiary flood basalts some 19 to 11 million years ago. Stratigraphic context The formation occurs as plugs that have punctured the Tertiary flood basalts of the Ethiopian plateau, and form the highest peaks in their surrounding. Lithology These phonolites are composed of alkali pyroxenes and nephelines; there are also elongated plagioclase crystals. Pyroxenes have a skeletal texture, whereas nepheline crystals are hexagonal to rectangular. The phonolites of pink to light grey colour. The outcrops hold massive (up to 25 metres long), moderately weathered blocks, generally of elongated shape; in some locations it also forms spherical outcrops. Geographical extent These silica-poor rocks belong to the Adwa-Aksum trachy-phonolite volcanic field. They are also exposed in Addi Amyuq, some 3 kilometres north of Hagere Selam, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intra-volcanic Sedimentary Rock In North Ethiopia
Between 29 and 27 million years ago, the extrusion of Ethiopia’s flood basalts was interrupted and deposition of continental sediments occurred. Inter-trappean beds outcrop in many places of the Ethiopian highlands. They consist of fluvio-lacustrine deposits, that are generally a few tens of metres thick. Often, these interbedded fluvio-lacustrine deposits are very visible because their bright colours strongly contrast with the basalt environment. Name and definition The formation, also called ''silicified limestone'' and ''interbedded lacustrine deposits'' was first extensively characterised in the 1930s by Merla and Minucci. Stratigraphic context The formation is generally at the interface between the lower Ashangi Basalts, and the upper Alaji Basalts. Environment The sediments were deposited in shallow lakes and marshes in large topographic depressions. The dense vegetation hosted mammals and birds, which found their food between the reeds of the lake shores. The decompos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambisol
A Cambisol in the World Reference Base for Soil Resources (WRB) is a soil in the beginning of soil formation. The horizon The horizon is the apparent line that separates the surface of a celestial body from its sky when viewed from the perspective of an observer on or near the surface of the relevant body. This line divides all viewing directions based on whether i ... differentiation is weak. This is evident from weak, mostly brownish discolouration and/or structure formation in the soil profile. Cambisols are developed in medium and fine-textured materials derived from a wide range of rocks, mostly in alluvial, colluvial and aeolian deposits. Most of these soils make good agricultural land and are intensively used. Cambisols in temperate climates are among the most productive soils on earth. Cambisols cover an estimated 15 million square kilometres worldwide. They are well represented in temperate and boreal regions that were under the influence of glaciation du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alluvium
Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is typically geologically young and is not consolidated into solid rock. Sediments deposited underwater, in seas, estuaries, lakes, or ponds, are not described as alluvium. Floodplain alluvium can be highly fertile, and supported some of the earliest human civilizations. Definitions The present consensus is that "alluvium" refers to loose sediments of all types deposited by running water in floodplains or in alluvial fans or related landforms. However, the meaning of the term has varied considerably since it was first defined in the French dictionary of Antoine Furetière, posthumously published in 1690. Drawing upon concepts from Roman law, Furetière defined ''alluvion'' (the F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tufa
Tufa is a variety of limestone formed when carbonate minerals precipitate out of water in unheated rivers or lakes. Geothermally heated hot springs sometimes produce similar (but less porous) carbonate deposits, which are known as travertine. Tufa is sometimes referred to as (meteogene) travertine. It should not be confused with hot spring (thermogene) travertine. Tufa, which is calcareous, should also not be confused with tuff, a porous volcanic rock with a similar etymology that is sometimes also called "tufa". Classification and features Modern and fossil tufa deposits abound with wetland plants; as such, many tufa deposits are characterised by their large macrobiological component, and are highly porous. Tufa forms either in fluvial channels or in lacustrine environments. Ford and Pedley (1996) provide a review of tufa systems worldwide. Fluvial deposits Deposits can be classified by their depositional environment (or otherwise by vegetation or petrographically). P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geomorphic
Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand why landscapes look the way they do, to understand landform and terrain history and dynamics and to predict changes through a combination of field observations, physical experiments and numerical modeling. Geomorphologists work within disciplines such as physical geography, geology, geodesy, engineering geology, archaeology, climatology, and geotechnical engineering. This broad base of interests contributes to many research styles and interests within the field. Overview Earth's surface is modified by a combination of surface processes that shape landscapes, and geologic processes that cause tectonic uplift and subsidence, and shape the coastal geography. Surface processes com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the Eritrea–Ethiopia border, north, Djibouti to the Djibouti–Ethiopia border, northeast, Somalia to the Ethiopia–Somalia border, east and northeast, Kenya to the Ethiopia–Kenya border, south, South Sudan to the Ethiopia–South Sudan border, west, and Sudan to the Ethiopia–Sudan border, northwest. Ethiopia has a total area of . As of 2022, it is home to around 113.5 million inhabitants, making it the List of countries and dependencies by population, 13th-most populous country in the world and the List of African countries by population, 2nd-most populous in Africa after Nigeria. The national capital and largest city, Addis Ababa, lies several kilometres west of the East African Rift that splits the country into the African Plate, Africa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regosol
A Regosol in the World Reference Base for Soil Resources (WRB) is very weakly developed mineral soil in unconsolidated materials. Regosols are extensive in eroding lands, in particular in arid and semi-arid areas and in mountain regions. Internationally, Regosols correlate with soil taxa that are marked by incipient soil formation such as Entisols in the USDA soil taxonomy or Rudosols and possibly some Tenosols in the Australian Soil Classification. The group of Regosols is a taxonomic rest group containing all soils that could not be accommodated in any of the other groups. Excluded from the Regosols are weakly developed soils that classify as Leptosols (very shallow soils), Arenosols (sandy soils) or Fluvisols (in recent alluvial deposits). These soils have AC- profiles. Profile development is minimal as a consequence of young age and/or slow soil formation. Land use and management of Regosols vary widely. Some Regosols are used for capital-intensive irrigated farming but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary
The Quaternary ( ) is the current and most recent of the three period (geology), periods of the Cenozoic era (geology), Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today, although a third epoch, the Anthropocene, has been proposed but is not yet officially recognised by the ICS). The Quaternary Period is typically defined by the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. Research history In 1759 Giovanni Arduino (geologist), Giovanni Arduino proposed that the geological strata of northern Italy could be divided into four successive formations or "orders" ( it, quattro ord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
