Khondalite

Khondalite is a foliated metamorphic rock. In India, it is also called Bezwada Gneiss and Kailasa Gneiss.^[1] It was named after the Khond tribe^[2][1] of Odisha and Andhra Pradesh because well-formed examples of the rock were found in the inhabited hills of these regions of eastern India.

Khondalite at Rushikonda, Visakhapatnam, India

Distribution

Khondalite near Anandapuram, India

Khondalite is found in the Eastern Ghats between Vijayawada and Cuttack in India.^[2] but the term khondalite is also used to describe other rocks of similar composition found elsewhere in India as well as in Burma, Sri Lanka,^[3] the northeastern Helanshan region^[4] and the Inner Mongolia region of China.^[5]

Composition

Khondalite is quartz–manganese-rich garnet–rhodonite schist.^[2] It may also contain sillimanite and graphite. Feldspar may occur in some cases.^[1]

Formation

Khondalites are considered to be metasedimentary rocks formed during Archaean era. According to Lewis Leigh Fermor, the khondalite and the related charnockite of the Eastern Ghat region were formed when the Eastern Ghat belt was faulted and buried. It was uplifted later, bringing these metamorphic rocks to the surface.^[1]

Use

Khondalites weather easily but still have been used in buildings and temples, for example, the Konark Sun Temple and Jagannath Temple.^[1]

See also

• Gneiss
• Charnockite

References

1. Kesavulu (1 February 2009). Textbook of Engineering Geology. Macmillan Publishers India Limited. p. 188. ISBN 978-0-230-63870-9. Retrieved 2 August 2013.
2. P. C. Varghese (November 2012). Engineering Geology for Civil Engineers. PHI Learning Pvt. Ltd. p. 126. ISBN 978-81-203-4495-2. Retrieved 2 August 2013.
3. Dash, B. (1990). "Khondalite". In Bowes, Donald (ed.). Petrology. Encyclopedia of Igneous and Metamorphic Petrology. Encyclopedia of Earth Science. Berlin: Springer. pp. 263–264. doi:10.1007/0-387-30845-8_111. ISBN 978-0387335643.
4. Li, Liming; Yang, Fanyan; Li, Mingtao; Liang, Zhirong; Ma, Xuedong; Tian, Jingxiong (1 January 2022). "U–Pb zircon dating of the Paleoproterozoic khondalite series in the northeastern Helanshan region and its geological significance". Open Geosciences. 14 (1): 544–567. doi:10.1515/geo-2022-0380. ISSN 2391-5447. S2CID 249241146.
5. Jiao, Shujuan; Guo, Jinghui; Harley, Simon L.; Windley, Brian F. (2013). "New Constraints from Garnetite on the P–T Path of the Khondalite Belt: Implications for the Tectonic Evolution of the North China Craton". Journal of Petrology. 54 (9): 1725–1758. Bibcode:2013JPet...54.1725J. doi:10.1093/petrology/egt029.