Pangaea Theory
The Pangaea Theory
The Pangea theory describes that all continents were joined together in one enormous land mass millions of years ago. Later on the continents broke apart and start drifting in opposite directions and still continued to make another arrangement. In 1912, Alfred Wegner, a German meteorologist and geologist gave the hypothesis the all the continents were joined together in a single continental land mass surrounded by a single ocean (Panthalassa) Late Paleozoic times. The Wegner used the term Kontinentalverschiebung for the breakup and displacement of crustal blocks. Pangea situated around where Antarctica is now presently. During Jurassic Period the Pangaea started to break up into smaller units called Laurasia and Gondwanaland. In late Cretaceous period, the continents were further separated and transformed as present day continents (William Lowrie, 2007). Figure-1 shows the reconstruction of Wegener’s continental mass using paleo-climatic data from Carboniferous, Permian, Eocene and to Quarternary.
Figure-1 (a) Pangaea reconstruction by Wegener in Late Carboniferous time (b) continents in Eocene times (c) continents in Early Quaternary, where K, S, W, E refers coal, salt, desert areas, ice sheets respectively (after William Lowrie, 2007).
Evolution of Himalayas
The Himalaya holds very important geological and tectonic history. The arc of Himalayan belt is about 2500 km from northwest to southeast. It comprises of well-known famous peaks like Nanga Parbat, Evereast and Namche Barwa etc. The Himalayan ranges hold a huge concentration of lithospheric mass comprising Precambrian to Recent sediments.
The contnent to continent collision of Indian and Asian plates is considered as the grave reason for the origion and development of Himalaya. This collision occurred in last 100 Ma yielding the uplifting of Himalayan chain of mountains. This lead the closing of Tethyian sea during 60-50 Ma. The over trust sheets and formation of nappe and
The Pangea theory describes that all continents were joined together in one enormous land mass millions of years ago. Later on the continents broke apart and start drifting in opposite directions and still continued to make another arrangement. In 1912, Alfred Wegner, a German meteorologist and geologist gave the hypothesis the all the continents were joined together in a single continental land mass surrounded by a single ocean (Panthalassa) Late Paleozoic times. The Wegner used the term Kontinentalverschiebung for the breakup and displacement of crustal blocks. Pangea situated around where Antarctica is now presently. During Jurassic Period the Pangaea started to break up into smaller units called Laurasia and Gondwanaland. In late Cretaceous period, the continents were further separated and transformed as present day continents (William Lowrie, 2007). Figure-1 shows the reconstruction of Wegener’s continental mass using paleo-climatic data from Carboniferous, Permian, Eocene and to Quarternary.
Figure-1 (a) Pangaea reconstruction by Wegener in Late Carboniferous time (b) continents in Eocene times (c) continents in Early Quaternary, where K, S, W, E refers coal, salt, desert areas, ice sheets respectively (after William Lowrie, 2007).
Evolution of Himalayas
The Himalaya holds very important geological and tectonic history. The arc of Himalayan belt is about 2500 km from northwest to southeast. It comprises of well-known famous peaks like Nanga Parbat, Evereast and Namche Barwa etc. The Himalayan ranges hold a huge concentration of lithospheric mass comprising Precambrian to Recent sediments.
The contnent to continent collision of Indian and Asian plates is considered as the grave reason for the origion and development of Himalaya. This collision occurred in last 100 Ma yielding the uplifting of Himalayan chain of mountains. This lead the closing of Tethyian sea during 60-50 Ma. The over trust sheets and formation of nappe and
References: William Lowrie, [2007], Fundamentals of Geophysics, 2nd edition Anshu Kumar Sinha, [August 6-14, 2008], The evolution of Himalayas and tectonic framework, International Geological Congress, Norway An Yin & T. Mark Harrison, [May 2000], Geologic Evolution of the Himalayan-Tibetan Orogen, Vol. 28 Klootwijk, C.T., Gee, J.S., Peirce, J.W., Smith, G.M. and McFaddan, [P.L. 1992]: An early India–Asia contact: Palaeomagnetic constraint from Ninetyeast Ridge, ODG Leg 121. Geology 20, 395–98 Harald Drewes, [1995], Tectonics of the Potwar Plateau Region and the Development of Syntaxes, Punjab, Pakistan, U.S. geological survey bulletin 2126 A. H. Kazmi & M. Qasim Jan, [1997], Geology & Tectonics of Pakistan