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Collisional Processes in the Crust of the Northern Tien Shan Inferred From Velocity and Attenuation Tomography Studiesстатья
- Авторы: Sychev Ilya V., Koulakov Ivan, Sycheva Nailia A., Koptev Alexander, Medved Irina, Khrepy Sami El, Al-Arifi Nasir
- Журнал: Journal of Geophysical Research
- Том: 123
- Номер: 2
- Год издания: 2018
- Издательство: William Byrd Press for John Hopkins Press
- Местоположение издательства: United States
- Первая страница: 1752
- Последняя страница: 1769
- DOI: 10.1002/2017jb014826
- Аннотация: Based on seismic data from existing seismic networks in Kyrgyzstan, we have constructed newcrustal models of seismic velocity and attenuation for P and S wave s beneath the Kyrgyz Tien Shan. With datafrom more than 6,000 events recorded by the international KNET network, the most detailed structureswere detected in the central-northern part of the study region, where the Kazakh Shield collides with thenorthern Tien Shan. The independently computed 3-D distributions of P and S wave attenuation showfeatures that are consistent with the main structural elements. The high-attenuation areas correspond tofolded areas of the northern Tien Shan, whereas the partitions of the stable Kazakh Shield and the Issyk Kulblock match with the low-attenuation areas. The velocity model reveals some structures that help todetermine the details of the collision processes in the northern Tien Shan. In the upper crust, we observe thealternation of several higher- and lower-velocity anomalies that likely represent the interaction of brittle andductile crustal layers of the collided Kazakh and Tien Shan plates. In deeper sections, both P and S wavevelocity models show a prominent low-velocity anomaly just beneath the northern boundary of Tien Shan.We propose that this anomaly represents an anomalous crustal thickening at the point of underthrusting ofthe Kazakh Plate beneath Tien Shan.
- Добавил в систему: Сычева Найля Абдулловна