|
Arabian-Nubian Shield
The Arabian-Nubian Shield (ANS) is an exposure of Precambrian crystalline rocks on the flanks of the Red Sea. The crystalline rocks are mostly Neoproterozoic in age. Geographically - and from north to south - the ANS includes parts of Israel, Jordan, Egypt, Saudi Arabia, Sudan, Eritrea, Ethiopia, Yemen, and Somalia. The ANS in the north is exposed as part of the Sahara Desert and Arabian Desert, and in the south in the Ethiopian Highlands, Asir province of Arabia and Yemen Highlands. The ANS was the site of some of man's earliest geologic efforts, principally by the ancient Egyptians to extract gold from the rocks of Egypt and NE Sudan. This was the most easily worked of all metals and does not tarnish. All of the gold deposits in Egypt and northern Sudan were found and exploited by Egyptians. The earliest preserved geologic map was made in 1150 BCE to show the location of gold deposits in Eastern Egypt; it is known as the Turin papyrus. New gold discoveries have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saharan Metacraton
The Saharan Metacraton is a term used by some geologists to describe a large area of continental crust in the north-central part of Africa. Whereas a craton is an old and stable part of the lithosphere, the term "metacraton" is used to describe a craton that has been remobilized during an orogenic event, but where the characteristics of the original craton are still identifiable. The geology of the continent has only been partially explored, and other names have been used to describe the general area that reflect different views of its nature and extent. These include "Nile Craton", "Sahara Congo Craton", "Eastern Saharan Craton" and "Central Saharan Ghost Craton". This last term is because the older rocks are almost completely covered by recent sediments and desert sands, making geological analysis difficult. Extent The "metacraton" covers an area of about . It lies between the Tuareg shield to the west, the Congo craton to the south, the Arabian-Nubian Shield to the east, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asir
The ʿAsir Region ( ar, عَسِيرٌ, ʿAsīr, lit=difficult) is a region of Saudi Arabia located in the southwest of the country that is named after the ʿAsīr tribe. It has an area of and an estimated population of 2,211,875 (2017). It is surrounded by Mecca Province to the north and west, Al-Bahah Province to the northwest, Riyadh Province to the northeast, Jazan Province to the south, and Najran Province to the southeast. ʿAsir also shares a short border with the Saada Governorate of Yemen to the south. The capital of the ʿAsir Region is Abha. Other towns include Khamis Mushait, Bisha and Bareq. The regional governor is Turki bin Talal bin Abdul Aziz Al Saud (appointed 27 December 2018), a son of Prince Talal bin Abdulaziz Al Saud. He replaced his cousin, Faisal bin Khalid bin Abdulaziz Al Saud, on the same day. Geography The ʿAsir Region is situated on a high plateau that receives more rainfall than the rest of the country and contains the country's highest pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyke Cutting Granite Of The Arabian-Nubian Shield
Dyke (UK) or dike (US) may refer to: General uses * Dyke (slang), a slang word meaning "lesbian" * Dike (geology), a subvertical sheet-like intrusion of magma or sediment * Dike (mythology), ''Dikē'', the Greek goddess of moral justice * Dikes, diagonal pliers, also called side-cutting pliers, a hand tool used by electricians and others * Dyke (automobile company), established 1899 Structures * Dyke (embankment) or dike, a natural or artificial slope or wall to regulate water levels, often called a levee in American English * Ditch, a water-filled drainage trench * A regional term for a dry stone wall People * Dyke (surname) * Dyke baronets, a title in the Baronetage of England * Dykes (surname), a British surname found particularly in northern England Places Settlements * Dike, Iowa, United States * Dykes, Missouri, United States * Dyke, Moray, Scotland * Dike, Texas, United States * Dyke, Virginia, United States * Dyke, Lincolnshire, England * Little Dyke, Nova Scotia, C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mahd Adh Dhahab
The Mahd Al Thahab ( ar, مَـهـد الـذّهـب, "Cradle of (the) Gold"), is a small gold area in the Arabian Peninsula. It is located in the Province of Al-Madinah, in the Hejazi region of Saudi Arabia. Gold was first mined in Arabia c. 3,000 BC. A second period of activity was during the Islamic Abbasid period between 750 and 1258 AD. The latest activities by Saudi Arabian Mining Syndicate began in 1936 using both open-pit and underground mines at Mahd Al Thahab. The Saudi Arabian Directorate General of Mineral Resources carried out further gold exploration in the 1970s, following the 1971 suspension of the US$-gold exchange rate and the consequent rise in value of the metal. Gold mining is done today by the Saudi Arabian Mining Company. The mine will close on 2023 as now only low grade gold is being mined because of the depleting resources. Antiquity There is a possibility that the ''Cradle of Gold'' is mentioned in the Biblical story of the Garden of Eden in '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porphyry (geology)
Porphyry ( ) is a textural term for an igneous rock consisting of coarse-grained crystals such as feldspar or quartz dispersed in a fine-grained silicate-rich, generally aphanitic matrix or groundmass. The larger crystals are called phenocrysts. In its non-geologic, traditional use, the term ''porphyry'' refers to the purple-red form of this stone, valued for its appearance. The term ''porphyry'' is from the Ancient Greek (), meaning "purple". Purple was the color of royalty, and the "imperial porphyry" was a deep purple igneous rock with large crystals of plagioclase. Some authors claimed the rock was the hardest known in antiquity. Thus, "imperial"-grade porphyry was prized for monuments and building projects in Imperial Rome and thereafter. Subsequently, the name was given to any igneous rocks with large crystals. The adjective ''porphyritic'' now refers to a certain texture of igneous rock regardless of its chemical and mineralogical composition. Its chief characteris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syenite
Syenite is a coarse-grained intrusive igneous rock with a general composition similar to that of granite, but deficient in quartz, which, if present at all, occurs in relatively small concentrations (< 5%). Some syenites contain larger proportions of components and smaller amounts of felsic material than most granites; those are classed as being of . The equivalent of syenite is |
Igneous Rock
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. The magma can be derived from Partial melting, partial melts of existing rocks in either a Terrestrial planet, planet's mantle (geology), mantle or crust (geology), crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive (geology), extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form Volcanic glass, natural glasses. Igneous rocks occur in a wide range of geological settings: shields, platforms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egyptian Pyramids
The Egyptian pyramids are ancient masonry structures located in Egypt. Sources cite at least 118 identified "Egyptian" pyramids. Approximately 80 pyramids were built within the Kingdom of Kush, now located in the modern country of Sudan. Of those located in modern Egypt, most were built as tombs for the country's pharaohs and their consorts during the Old and Middle Kingdom periods. The earliest known Egyptian pyramids are found at Saqqara, northwest of Memphis, although at least one step-pyramid-like structure has been found at Saqqara, dating to the First Dynasty: Mastaba 3808, which has been attributed to the reign of Pharaoh Anedjib, with inscriptions, and other archaeological remains of the period, suggesting there may have been others. The otherwise earliest among these is the Pyramid of Djoser built during the Third Dynasty. This pyramid and its surrounding complex are generally considered to be the world's oldest monumental structures constructed of dresse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aswan
Aswan (, also ; ar, أسوان, ʾAswān ; cop, Ⲥⲟⲩⲁⲛ ) is a city in Southern Egypt, and is the capital of the Aswan Governorate. Aswan is a busy market and tourist centre located just north of the Aswan Dam on the east bank of the Nile at the first cataract. The modern city has expanded and includes the formerly separate community on the island of Elephantine. Aswan includes five monuments within the UNESCO World Heritage Site of the Nubian Monuments from Abu Simbel to Philae (despite Aswan being neither Nubian, nor between Abu Simbel and Philae); these are the Old and Middle Kingdom tombs of Qubbet el-Hawa, the town of Elephantine, the stone quarries and Unfinished Obelisk, the Monastery of St. Simeon and the Fatimid Cemetery. The city's Nubian Museum is an important archaeological center, containing finds from the International Campaign to Save the Monuments of Nubia prior to the Aswan Dam's flooding of all of Lower Nubia. The city is part of the UNESCO Cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granite
Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers. Granite is typical of a larger family of ''granitic rocks'', or ''granitoids'', that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF classification), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites) contain almost no dark minerals. Granite is nearly alway ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turin Papyrus Map
The Turin Papyrus Map is an ancient Egyptian map, generally considered the oldest surviving map of topographical interest from the ancient world. It is drawn on a papyrus reportedly discovered at Deir el-Medina in Thebes, collected by Bernardino Drovetti (known as Napoleon's Proconsul) in Egypt sometime before 1824 AD and now preserved in Turin's Museo Egizio. The map was drawn about 1150 BC by the well-known Scribe-of-the-Tomb Amennakhte, son of Ipuy. It was prepared for Ramesses IV's quarrying expedition to the Wadi Hammamat in the Eastern Desert, which exposes Precambrian rocks of the Arabian-Nubian Shield. The purpose of the expedition was to obtain blocks of ''bekhen''-stone (metagraywacke sandstone) to be used for statues of the king. Description The map shows a 15-kilometre stretch of Wadi Hammamat and has depictions of this wadi's confluence with wadis Atalla and el-Sid, the surrounding hills, the ''bekhen''-stone quarry, and the gold mine and settlement at Bir Umm Fawa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Map
A geologic map or geological map is a special-purpose map made to show various geological features. Rock units or geologic strata are shown by color or symbols. Bedding planes and structural features such as faults, folds, are shown with strike and dip or trend and plunge symbols which give three-dimensional orientations features. Stratigraphic contour lines may be used to illustrate the surface of a selected stratum illustrating the subsurface topographic trends of the strata. Isopach maps detail the variations in thickness of stratigraphic units. It is not always possible to properly show this when the strata are extremely fractured, mixed, in some discontinuities, or where they are otherwise disturbed. Symbols Lithologies Rock units are typically represented by colors. Instead of (or in addition to) colors, certain symbols can be used. Different geologic mapping agencies and authorities have different standards for the colors and symbols to be used for rocks of differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
