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Djebel Ressas is a high and rugged outcropping of Jurassic limestone situated on the horizon southeast of Tunis, Tunisia. Competing in the foreground, the familiar profile of Djebel Boukornine may appear taller, but at 795 metres Ressas is the dominant peak. Along the highway between Tunis and Hammamet there are excellent views of the mountain as one looks south from near the tollbooths, just past the exit to Mornag. ==Geology== The geologic origins of Djebel Ressas and the neighboring peaks date to earlier than 100 million years ago. The surrounding region was then a vast and swampy tropical area abundant with life.〔(Science Encyclopedia Volume II, Diatoms )〕 The large carnivorous dinosaurs Spinosaurus aegyptiacus hunted nearby in what is currently the Sahara desert in southern Tunisia.〔(Bervoets, Fred (2000), DinoData )〕〔Bulletin de la Societe Geologique de France; September 2002; v. 173; no. 5; p. 415-421; © 2002, A new specimen of Spinosaurus (Dinosauria, Theropoda) from the Lower Cretaceous of Tunisia, with remarks on the evolutionary history of the Spinosauridae, Eric Buffetaut1 and Mohamed Ouaja ()〕 Meanwhile, just to the north, minuscule prehistoric animals, known as radiolarians, dwelt in a primordial sea that eventually became today’s Mediterranean. Covering much of what we now call the Maghreb of northern Africa, masses of these shelled microorganisms inhabited that exotic marine environment,〔Radiolarians: The Hooper Virtual Natural History Museum, (1996), The Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada, Radolarians: Introduction & Morphology,()〕 depositing their tiny crusty carcasses on the bottom as they died. Countless layers of their organic remains were compacted and cemented into limestone, eventually forming the base of the ancient seafloor and ultimately providing the limestone fabric for a future mountain range. Over eons, tectonic forces laterally compressed southern regions of this sedimentary basement, thrusting the seafloor upward along contorted faults and displacing the sea northward to its present shoreline. The Atlas Mountains gradually wrinkled their way across the northern, leading edge of Africa, with Ressas at the northeastern terminus of the range. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Djebel Ressas」の詳細全文を読む スポンサード リンク
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