This week I traveled to the Himalayas. A convergent-plate margin between the Indian and Eurasian plates. Unlike the divergent boundaries, the interaction between these adjacent plates resulted in one of the most impressive examples of orogenesis. Rapidly rising mountain ranges were formed as the two plates collided as the Indian plate subducted below the Eurasian plate. The geology of this area is composed of Ordovician Limestone, Marble, Shales, Pelites, Leucogranites, and Sillimanite gneisses. The top of Everest is Ordovician Limestone with a marble layer just under that. I was surprised to see limestone on the top of such a high mountain, and yet, it makes sense as this was once the ocean floor. The type of structural deformation I observed was mostly sheering. The Indian continent is a reddish color that sits below the Leucogranites sheets known as the Asian mass, or more specifically, the Kohistan mass. These sutures are where the sheering occurred. Common to these collision zones, reverse faults and thrust faults pushed up the Himalayan mountain range. Earthquakes are often more common here because of the tension between the two plates. The largest earthquake was a magnitude 8.0 that is known as the 1934 Nepal-Bihar earthquake. This event occurred on April 25, 2015.
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| Retrieved from https://www.insidehimalayas.com/wp-content/uploads/2016/04/nepal-everest-1-750x357.jpg |
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| Retrieved from http://legacy.earlham.edu/~pinema/pics/Convergence%20map.gif |
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| Retrieved from https://sites.google.com/site/thehimalayanmountains/_/rsrc/1401701932527/formation-of-the-himalayan-mountains/himalayan%20formation.jpeg?height=241&width=320 |
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