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Earth Evolution
Earth Materials

Earth Evolution
Geological History
Solar System
Archean Proterozoic Early
Late Paleozoic Mesozoic Cenozoic

Cenozoic 65 million years ago to present
Continents in Collision
5. Building the Highest Mountain on Earth – Qomolangma (Mount Everest)

Collision between the Indian and Asian continents during the Cenozoic resulted in formation of the largest active and fastest growing orogen in existence, the Himalayan mountain belt, with its highest peak, Qomolangma (Mount Everest) at 8848 m above sea level.

Viewed from the Tibetan (north) side Qomolangma today is a pyramid-shaped horn, sculpted by the erosional power of glacial ice into three massive faces and three major ridges during Pleistocene.

Qomolangma is composed of multiple layers of rocks folded back on themselves and separated by thrust and detachment faults:

Low-angle uplift-related normal faults and thrusts.
Qomolangma Formation (QF): An unmetamorphosed shallow marine Ordovician limestone that rose from the floor of the ancient Tethys ocean to become the summit of Qomolangma, now 8848m above sea level.
Yellow Band (YB): A metamorphosed shallow marine limestone that was uplifted to become the characteristic "Yellow Band" of Qomolangma.
Everest Series (ES): Low-grade (greenschist facies) metamorphosed sedimentary rocks, mica schists and phyllites.
Rongbuk Formation (RF): High grade metamorphosed sillimanite-bearing schists and gneisses
and Leucogranites (LG): Collision-related crustal melts "injected" into high-grade metamorphosed sillimanite-bearing schists and gneisses.

The tremendous compressional plate tectonic forces generated during this continent-continent collision crumbled buoyant rocks on both continents into spectacular folds and fractured them along almost flat faults called “thrusts” that pile layers of Tethyan sedimentary rocks on top of one another. These mountain building processes caused ongoing crustal shortening and thickening, developing a crustal thickness of 65 km. At the same time vertical uplift due to isostatic adjustment has resulted in extensional normal faulting in some portions of the mountain belt.

The accumulation of such a pile of thick layers of rock exerted immense pressure and increasing temperature on the rocks buried underneath resulting in prograde metamorphism towards the base of the mountain belt culminating in partial melting that generated leucogranites


4. Asian Extrusion