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28-627: Jadu is located in the Nafusa Mountains , twenty-five kilometers southwest of Tarmeisa ( طرميسة , Ţarmīşah ). Jadu was formerly the capital of the Nafusa Mountains District. Giado, as it was then known by its Italian name, was the site of an Italian concentration camp during the Second World War. In 1942, about 2,600 Jews and other people, who were considered undesirables by Italians, were rounded up throughout Libya and sent to

56-594: A geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob Werner in his theory of the origin of the Earth, which was developed over the period from 1774 to his death in 1817. The concept became increasingly formalized over time and is now codified in such works as the North American Stratigraphic Code and its counterparts in other regions. Geologic maps showing where various formations are exposed at

84-631: A major population and cultural center of the Libu , who repeatedly expanded west. In the aftermath of the great Berber Revolt of the 8th century, Ibadi missionaries that had fled from the Umayyad Caliphate took refuge in the Nafusa Mountains. Preachers converted and organized the native Nafusa people into a fighting force. Under the leadership of Imam Abu al-Khattab al-Ma'afari, the Nafusa descended from

112-526: A newly designated formation could not be named the Kaibab Formation, since the Kaibab Limestone is already established as a formation name. The first use of a name has precedence over all others, as does the first name applied to a particular formation. As with other stratigraphic units, the formal designation of a formation includes a stratotype which is usually a type section . A type section

140-594: A permanent natural or artificial feature of the geographic area in which they were first described. The name consists of the geographic name plus either "Formation" or a descriptive name. Examples include the Morrison Formation , named for the town of Morrison, Colorado , and the Kaibab Limestone , named after the Kaibab Plateau of Arizona. The names must not duplicate previous formation names, so, for example,

168-543: A rebel stronghold, an island of rebel control in the mainly Gaddafi-controlled western part of the country. During the early stages, forces allied to the national transitional government succeeded in evacuating most non-combatants into Tunisia; the Wazzin border crossing was captured and held to ensure supply lines from Tunisia; all the mountain towns were retaken; and the front extended to the plains, cutting regime communications lines and allowing electricity to be restored. They were

196-449: Is not a valid lithological basis for defining a formation. The contrast in lithology between formations required to justify their establishment varies with the complexity of the geology of a region. Formations must be able to be delineated at the scale of geologic mapping normally practiced in the region; the thickness of formations may range from less than a meter to several thousand meters. Geologic formations are typically named after

224-569: Is a stub . You can help Misplaced Pages by expanding it . Nafusa Mountains The Nafusa Mountains ( Arabic : جبال نفوسة ) is a mountain range in the western Tripolitania region of northwestern Libya . It also includes the regions around the escarpment formed where the northern end of the Tripolitanian Plateau meets the Mediterranean coastal plain or the Jefara . The area was

252-412: Is a body of rock having a consistent set of physical characteristics ( lithology ) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column ). It is the fundamental unit of lithostratigraphy , the study of strata or rock layers. A formation must be large enough that it can be mapped at

280-463: Is almost unpopulated, in marked contrast to the situation in Libya. The mountain area is rarely more than 25 km (16 mi) in depth, from its southern boundary, the flat arid plateau some 650 m (2,100 ft) above sea level, to its northern limit on the plain, where the land falls to below 150 m (490 ft). Much of the 500 m (2,000 ft) drop in level is accomplished abruptly, at

308-560: Is central to the geologic discipline of stratigraphy , and the formation is the fundamental unit of stratigraphy. Formations may be combined into groups of strata or divided into members . Members differ from formations in that they need not be mappable at the same scale as formations, though they must be lithologically distinctive where present. The definition and recognition of formations allow geologists to correlate geologic strata across wide distances between outcrops and exposures of rock strata . Formations were at first described as

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336-455: Is ideally a good exposure of the formation that shows its entire thickness. If the formation is nowhere entirely exposed, or if it shows considerably lateral variation, additional reference sections may be defined. Long-established formations dating to before the modern codification of stratigraphy, or which lack tabular form (such as volcanic formations), may substitute a type locality for a type section as their stratotype. The geologist defining

364-811: The 9th century, while the Aghlabids ruled in Ifriqiya, the Ibadi maintained an independent puritan republic in the Nafusa mountains. The Imamate of Nafusa was in close alliance with the other Ibadi remnant, the Rustamid dynasty in Tiaret , both constant thorns on either side of the Aghlabids, in communication with each other across the back highlands of North Africa. In 879, the Tulunids of Egypt invaded Aghlabid Ifriqya and captured Tripoli. But

392-624: The Giado camp. 564 died from typhus and other privations. The camp was liberated by the British Army in January 1943. Jadu's council rejected the draft 2017 constitution . In April 2020, local Amazigh forces were bombed at the end of the Second Libyan Civil War . 31°57′N 12°01′E  /  31.950°N 12.017°E  / 31.950; 12.017 This Libya location article

420-531: The Nafusa challenged and destroyed the Egyptian army in 880. Again the Nafusa victory was short-lived. In 896-97, the Aghlabid emir Ibrahim II of Ifriqiya recovered Tripolitana and defeated the Nafusa in a great battle at Manu (south of Gabès ). In the aftermath, citing them as heretics, Ibrahim II executed all the Nafusa prisoners and put an end to their independent imamate (Tahert fell shortly after, in 911). Despite

448-611: The adjoining Tunisian region of Tatouine , where many had relatives. As towns and villages in the Nafusa Mountains and surrounding areas were liberated from control by forces loyal to Muammar Gaddafi in early summer 2011, and while fierce fighting continued, Berber exhibitions and workshops sprang up to share and spread the Tamazight culture and language, after four decades during which there were severe punishments for speaking and writing Tamazight openly. Formation (stratigraphy) A geological formation , or simply formation ,

476-603: The control of the regime. The Nafusa Mountains form the boundary between the Libyan coastal plain, known as the Jafara, to the north, and the Tripolitanian Plateau to the south. The beds (strata) of the Tripolitanian Plateau slope downwards to the south and tilt upwards towards the north creating the highest portion of the plateau as the Nafusa mountains which rise to over 750 m (2,500 ft). The plateau ends abruptly on

504-579: The course of the Libyan Civil War (2011) , when their initiatives led to the Nafusa Mountains becoming a major front in that war. The terrain and topography of the region are critical strategic factors, constraining mechanised advances from the flat plain and plateau, and favouring guerrilla tactics based on close local knowledge and the advantage of high ground. By the end of June 2011 the Nafusi people had almost succeeded in liberating themselves completely from

532-493: The destruction of their states, Ibadi Islam remained a strong (if clandestine) faith among the Berbers of the Nafusa mountains for centuries after, down to the modern day. The lingering heterodoxy of the Nafusa people has placed them frequently at odds, or under suspicion, by the largely orthodox Sunni population of the rest of Libya. This distinct culture, suppressed and oppressed by the Libyan regime, has risen to new prominence in

560-477: The escarpment, where local topographic prominences may be up to 350 m (1,100 ft). It is from below, on the plain, viewing the steep slopes and sharply-etched skyline that the area appears mountainous; from the plateau the land appears merely hilly, and in fact it is rather flat apart from the effects of differential erosion. Towns in the mountains include Gharyan , Yafran , Zintan , Qotros , Jadu , Kabaw , Al-Qawalish and Nalut , which have all been

588-550: The essential geologic time markers, based on their relative ages and the law of superposition . The divisions of the geological time scale were described and put in chronological order by the geologists and stratigraphers of the 18th and 19th centuries. Geologic formations can be usefully defined for sedimentary rock layers, low-grade metamorphic rocks , and volcanic rocks . Intrusive igneous rocks and highly metamorphosed rocks are generally not considered to be formations, but are described instead as lithodemes . "Formation"

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616-529: The first rebel combatants to be supplied with arms by air-drop. In the course of the civil war, many towns in the area were subjected to shelling by artillery and rockets from both sides, with much damage to infrastructure. Regime forces cut off electricity and water supplies. Médecins Sans Frontières sent a team in Zintan to help the large number of wounded. Al Galaa was without electricity and water for seven weeks, and more than 45,000 refugees fled for safety to

644-522: The formation is expected to describe the stratotype in sufficient detail that other geologists can unequivocally recognize the formation. Although formations should not be defined by any criteria other than primary lithology, it is often useful to define biostratigraphic units on paleontological criteria, chronostratigraphic units on the age of the rocks, and chemostratigraphic units on geochemical criteria, and these are included in stratigraphic codes. The concept of formally defined layers or strata

672-488: The mountains and proceeded to conquer all of the crumbling Fihrid emirate of Ifriqiya - capturing Tripoli in 757 and Kairouan in 758. But the Abbasid Arab governor of Egypt invaded Ifriqya, defeated the Nafusa in a battle at Tawergha in 761 (his third attempt - his first two armies had been repulsed) and put an end to their putative new state. However, the Nafusa mountains themselves remained unconquered. Throughout

700-568: The north with an escarpment which has up to 350 m (1,100 ft) of topographic prominence. A series of deep valleys which drain north toward the Jefara cut into this escarpment. It extends about 250 km (160 mi) within Libya, from just east of the city of Gharyan (about 60 km (40 mi) south of Tripoli) in the east to the city of Wazzin at the Tunisian border in the west. Spurs and isolated upthrusts continue into Tunisia, but this region

728-460: The sites of military action during the 2011 civil war. Since 2007, the mountains stretch across two districts: Jabal al Gharbi District and Nalut District . The mountain villages raise primarily goats, olives and grain, but also have fig and apricot orchards. The Nafusa Mountains became first a hotbed for anti-Gaddafi protests (with protests breaking out relatively early in Nalut and Zintan) and then

756-643: The surface are fundamental to such fields as structural geology , allowing geologists to infer the tectonic history of a region or predict likely locations for buried mineral resources. The boundaries of a formation are chosen to give it the greatest practical lithological consistency. Formations should not be defined by any criteria other than lithology. The lithology of a formation includes characteristics such as chemical and mineralogical composition, texture, color, primary depositional structures , fossils regarded as rock-forming particles, or other organic materials such as coal or kerogen . The taxonomy of fossils

784-432: The surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of

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