TY - JOUR

T1 - Unknown large ancient earthquakes along the Kurai fault zone (Gorny Altai)

T2 - new results of palaeoseismological and archaeoseismological studies

AU - Deev, E. V.

AU - Turova, I. V.

AU - Borodovskiy, A. P.

AU - Zolnikov, I. D.

AU - Oleszczak, L.

N1 - Publisher Copyright: © 2016 Informa UK Limited, trading as Taylor & Francis Group. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.

PY - 2017/2/17

Y1 - 2017/2/17

N2 - Palaeoseismological and archaeoseismological studies in the Kurai fault zone, along which the Kurai Range is thrust onto Cenozoic deposits of the Chuya intramontane basin, led to the identification of a long reverse fault scarp 8.0 m high. The scarp segments are primary seismic deformations of large ancient earthquakes. The scarp’s morphology, results of trenching investigations, and deformations of Neogene deposits indicate a thrusting of the piedmont plain onto the Kurai Range, which is unique for the Gorny Altai. Similarly for Northern Tien Shan, we explain this by the formation of both a thrust transporting the mountain range onto the depression and a branching thrust dislocation that forms the detected fault scarp. In a trench made in one of the scarp segments, we identified the parameters of the seismogenic fault–a thrust with a 30° dipping plane. The reconstructed displacement along the fault plane is 4.8 m and the vertical displacement is 2.4 m, which indicates a 7.2–7.6 magnitude of the ancient earthquake. The 14C age of the humus-rich loamy sand from the lower part of the colluvial wedge constrains the age of the earthquake at 3403–3059 years BP. Younger than 2500 years seismogenic displacements along the fault scarp are indicated by deformations of cairn structures of the Turalu–Dzhyurt-III burial mound, which was previously dated as iron age between the second half of I BC and I AD.

AB - Palaeoseismological and archaeoseismological studies in the Kurai fault zone, along which the Kurai Range is thrust onto Cenozoic deposits of the Chuya intramontane basin, led to the identification of a long reverse fault scarp 8.0 m high. The scarp segments are primary seismic deformations of large ancient earthquakes. The scarp’s morphology, results of trenching investigations, and deformations of Neogene deposits indicate a thrusting of the piedmont plain onto the Kurai Range, which is unique for the Gorny Altai. Similarly for Northern Tien Shan, we explain this by the formation of both a thrust transporting the mountain range onto the depression and a branching thrust dislocation that forms the detected fault scarp. In a trench made in one of the scarp segments, we identified the parameters of the seismogenic fault–a thrust with a 30° dipping plane. The reconstructed displacement along the fault plane is 4.8 m and the vertical displacement is 2.4 m, which indicates a 7.2–7.6 magnitude of the ancient earthquake. The 14C age of the humus-rich loamy sand from the lower part of the colluvial wedge constrains the age of the earthquake at 3403–3059 years BP. Younger than 2500 years seismogenic displacements along the fault scarp are indicated by deformations of cairn structures of the Turalu–Dzhyurt-III burial mound, which was previously dated as iron age between the second half of I BC and I AD.

KW - ancient earthquakes

KW - Fault scarp

KW - Gorny Altai

KW - Kurai fault zone

KW - palaeoseismology

KW - TIEN-SHAN

KW - CHUYA EARTHQUAKE

KW - DEEP-STRUCTURE

KW - DISPLACEMENT-FIELDS

KW - SIBERIAN ALTAI

KW - SOUTHERN GREAT ALTAI

KW - QUATERNARY SEDIMENTS

KW - AREA

KW - CENTRAL-ASIA

KW - SOUTHEASTERN ALTAI

UR - http://www.scopus.com/inward/record.url?scp=85004011423&partnerID=8YFLogxK

U2 - 10.1080/00206814.2016.1258675

DO - 10.1080/00206814.2016.1258675

M3 - Article

AN - SCOPUS:85004011423

VL - 59

SP - 293

EP - 310

JO - International Geology Review

JF - International Geology Review

SN - 0020-6814

IS - 3

ER -