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The Himalayas border the Indo-Gangetic Plain to the south, Pamir Mountains to the west in Central Asia, and the Hengduan Mountains to the east on the China–Myanmar border. From east to west the Himalayas are divided into 3 regions, Eastern Himalaya, Central Himalaya, and Western Himalaya, which collectively house several nations and states.
the Lesser Himalayan Sequence, which is mainly composed of low-grade Proterozoic metasediments to unmetamorphosed rocks, fringed by the Main Boundary Thrust and the Main Central Thrust; the Greater Himalayan Crystalline complex, which is mainly composed by high-grade gneiss and migmatite , fringed below by the Main Central Thrust and the South ...
In geology, metasedimentary rock is a type of metamorphic rock. Such a rock was first formed through the deposition and solidification of sediment. Then, the rock was buried underneath subsequent rock and was subjected to high pressures and temperatures, causing the rock to recrystallize. The overall composition of a metasedimentary rock can be ...
The Himalayan range is one of the youngest mountain ranges on Earth and is made up of uplifted sedimentary and metamorphic rocks. It was formed more than 10 mya due to the subduction of the Indian tectonic plate with the Eurasian Plate along the convergent boundary.
One of the major depositional strata in the Himalaya is the Lesser Himalayan Strata from the Paleozoic to Mesozoic eras. It had a quite different marine succession during the Paleozoic, as most parts of it are sparsely fossiliferous or even devoid of any well-defined fossils.
The Tibetan-Tethys Himalayas generally begins from the top of the Higher Himalayan Zone and extends to the north in Tibet. In Nepal these fossiliferous rocks are well developed in Thak Khola , Manang and Dolpa area. This zone is about 40 km wide and composed of fossiliferous sedimentary rocks such as shale, sandstone and limestone etc.
It is hypothesized that the middle part of the Tibet continental crust was partially melted at that time and was bounded by a "channel" formed from the rigid upper and lower crust. The molten middle crust is thought to be represented by high-temperature rock suites in the Greater Himalayan Crystalline Complex. Since the upper crust was rather ...
The Precambrian North China Craton is predominately metamorphosed island-arc igneous rocks that formed between 3.5 and 3 billion years ago. The craton had fully formed by 1.7 billion years ago. [1] Thick sediments were deposited on the craton from 1000 to 539 million years ago. [21]