Various millimetre-, centimetre- and metre-scale soft-sediment deformation structures (SSDS) have been identified in the Upper Ordovician and Lower-Middle Silurian from deep drilling cores in the Tarim Basin (NW China). These structures include liquefied-sand veins, liquefaction-induced breccias, boudinage-like structures, load and diapir- or flame-like structures, dish and mixed-layer structures, hydroplastic convolutions and seismic unconformities. The deformed layers are intercalated by undeformed layers of varying thicknesses that are petrologically and sedimentologically similar to the deformed layers.
The SSDS developed in a shelf environment during the early Late Ordovician and formed initially under shear tensile stress conditions, as indicated by boudinage-like structures; during the latest Ordovician, SSDS formed under a com-pressional regime. The SSDS in the Lower-Middle Silurian consist mainly of mixed layers and sand veins; they formed in shoreline and tidal-flat settings with liquefaction features indicating an origin under a compressional stress regime. By Silurian times, the centre of tectonic activity had shifted to the south-eastern part of the basin.
The SSDS occur at different depths in wells that are close to the syn-sedimentary Tazhong 1 Fault (TZ1F) and associated reversed-thrust secondary faults. Based on their characteristics, the inferred formation mechanism and the spatial association with faults, the SSDS are interpreted as seismites. The Tazhong 1 fault was a seismogenic fault during the later Ordovician, whereas the reversed-direction secondary faults became active in the Early-Middle Silurian.
Multiple palaeo-earthquake records reflect pulses and cyclicity, which supports secondary tectonic activity within the main tectonic movement. The range of SSDS structures reflects different developments of tectonic activity with time for the various tectonic units of the centralbasin. The effects of the strong palaeo-earthquake activity coincide with uplift, fault activity and syn-tectonic sedimentation in the study area during the Late Ordovician to Middle Silurian.
Allen, J.R.L., 1982. Sedimentary structures, their character and physical basis,Vol. 2. Developments in Sedimen-tology. Elsevier (Amsterdam) 30B, 663 pp.
Blanc, E.J.P., Blanc-Alétru, M.C. & Mojon, P.O., 1998. Soft-sediment deformation structures interpreted as seismites in the uppermost Aptian to lowermost Al-bian transgressive deposits of the Chihuahua Basin (Mexico). Geologische Rundschau86, 875-883.
Brodzikowski, K. & Van Loon, A.J., 1987. A systematic classification of glacial and periglacial environments, facies and deposits. Earth-Science Reviews24, 297-381.
Chen, J., Van Loon, A.J., Han, Z. & Chough, S.K., 2009. Funnel-shaped, breccia-filled clastic dykes in the Late Cambrian Chaomidian Formation (Shandong Province, China). Sedimentary Geology221, 1-6.
Chen, J.S., Wang, Z.Y., Dai, Z.Y., Ma, Q., Jiang, Y.Q. & Tan, X.C., 1999. Study of the middle and upper Or-dovician rimmed carbonate platform system in the Tazhong area, Tarim Basin. Journal of Palaeogeography1, 8-17 (in Chinese with English abstract).
Du, Y.S., 2011. Discussion about studies of earthquake event deposit in China. Journal of Palaeogeography13, 581-590 (in Chinese with English abstract).
Du, Y. & Han X., 2000. Seismo-deposition and seismites. Advances in Earth Science15, 389-394 (in Chinese with English abstract).
Ettensohn, F.R., Zhang, C., Gao, L., & Lierman, R.T., 2011. Soft-sediment deformation in epicontinental carbonates as evidence of paleoseismicity with evidence for a possible new seismogenic indicator: accordion folds. Sedimentary Geology235, 222-233.
Fan, T.L., Yu, B.S. & Gao, Z.Q., 2007. Characteristics of carbonate sequence stratigraphy and its control on oil-gas in Tarim Basin. Geoscience21, 57-65 (in Chinese with English abstract).
Feng, Z.Z., Bao, Z.D., Wu, M.B., Jin, Z.K. & Shi, X.Z., 2005. Lithofacies paleogeography of the Cambrian and Ordovi-cian in Tarim area in China.Beijing Publishing House (Beijing), 186 pp. (in Chinese with English abstract).
Gu, J.Y., Zhang, X.Y., Luo, P., Luo, Z. & Fang, H., 2005. Development characteristics of organic reef-bank complex on Ordovician carbonate platform margin in Tarim Basin. Oil & Gas Geology26, 277-283 (in Chinese with English abstract).
Guiraud, M. & Plaziat, J.C., 1993. Seismites in the fluvia-tile Bima sandstones: identification of paleoseisms and discussion of their magnitudes in a Cretaceous synsedimentary strike-slip basin (Upper Benue, Nigeria). Tectonophysics225, 493-522.
He, B.Z., Jiao, C.L., Wang, S.L., Deng, G.Z., Wang, G.H. & He, X.P., 2009. Characteristics and exploration prospect of carbonate platform margin of Late Ordovician Lianglitage Formation in Tazhong area, Tarim Basin. Acta Geologica Sinica 83, 1039-1046 (in Chinese with English abstract).
He, B.Z., Qiao, X.F., Xu, Z.Q., Jiao, C.L., Cai, Z.H., Zhang, Y.L. & Su, D.C., 2010. The character and significance of paleo-seismic records of the Late Ordovician in Manjiaer Depression and its adjacent area, Tarim Basin, Xinjiang. Acta Geologica Sinica84, 1805-1816 (in Chinese with English abstract).
He, B.Z., Xu, Z.Q., Jiao, C.L., Li, H.B. & Cai, Z.H., 2011. Tectonic unconformities and their forming: implication for hydrocarbon accumulations in Tarim Basin. Acta Petrologica Sinica27, 253-265 (in Chinese with English abstract).
He, B.Z., Jiao, C.L., Xu, Z.Q., Liu, S.L., Cai, Z.H., Li, H.B. & Zhang, M., 2013. Unconformity structural architecture and tectonic paleo-geography environment: a case of the Middle Caledonian on the northern margin of Tibet Plateau and Tarim Basin. Acta Petrologica Sinica29, 2184-2198 (in Chinese with English abstract).
He, D.F., 1995. Unconformities and oil and gas accumulation in Tarim Basin. Acta Petrolei Sinica16(3): 14-21 (in Chinese with English abstract).
He, D.F., Jia, C.Z., Li, D.S., Zhang, C.J., Meng, Q.R. & Shi, X., 2005. Formation and evolution of polycyclic superimposed Tarim Basin. Oil & Gas Geology26, 64-77 (in Chinese with English abstract).
Jia, C.Z., Sun, D.L. & Zhou, Y.X., 2004. Paleozoic plate tectonic and continental dynamics of Tarim.Petroleum Industry Press (Beijing), 202 pp. (in Chinese with English abstract).
Jia, C.Z., Wei, G.Q. & Yao, H.J., 1995. Oil and gas exploration books in Tarim Basin - tectonic evolution and regional structural geology.Petroleum Industry Press (Beijing), 70 pp. (in Chinese with English abstract).
Jin, Z.J., Zhang, Y.W. & Chen, S.P., 2005. The process of fluctuations in structure and deposition, Tarim Basin. Science in China Series D - Earth Sciences35, 530-539 (in Chinese).
Kuenen, Ph.H., 1958. Experiments in geology. Transactions, Geological Society Glasgow23, 1-28.
Li, D.H., Liang, D.G., Jia, C.Z., Wang, G., Wu, Q.Z. & He, D.F., 1996. Hydrocarbon accumulation in Tarim Basin, China. American Association of Petroleum GeologistsBulletin80, 1587-1603.
Li, Y.J., Wu, G.Y., Meng, Q.L., Yang, H.J., Han, J.F., Li, X.S. & Dong, L.S., 2008. Fault systems in central area of the Tarim Basin: geometry, kinematics and dynamic settings. Chinese Journal of Geology43, 82-118 (in Chinese with English abstract).
Liang, D.G., Zhang, S.C., Zhang, B.M. & Wang, F.Y., 2000. Understanding on marine oil generation in China based on Tarim Basin. Earth Science Frontiers7, 534547 (in Chinese with English abstract).
Lin, C.S., Li, S.T., Liu, J.Y., Qian, Y.X., Luo, H., Chen, J.Q., Peng, L. & Rui, Z.F., 2011. Tectonic framework and paleogeographic evolution of the Tarim basin during the Paleozoic major evolutionary stages. Acta Petro-logica Sinica27, 210-218 (in Chinese with English abstract).
Lin, C.S., Yang, H.J., Liu, J.Y., Rui, Z.F., Cai, Z.Z., Li, S.T. & Yu, B.S., 2012. Sequence architecture and depositional evolution of the Ordovician carbonate platform margins in the Tarim Basin and its response to tecto-nism and sea-level change. Basin Research24, 559-582.
Liu, Z.B., Yu, B.S., Chen, X.L., Gao, Z.Q., Chao, Q.G., Li, T.Y. & Yu, Z.B., 2003. Sequence stratigraphy and sedimentary characters of submarine fan of middle-upper Ordovician, in Tadong area, the Tarim basin. Geoscience - Journal of Graduate School, China University of Geosciences17, 408-414 (in Chinese with English abstract).
Lowe, D.R., 1975. Water escape structures in coarsegrained sediments. Sedimentology22, 157-204.
Lowe, D.R. & LoPiccolo, R.D., 1974. The characteristics and origins of dish and pillar structures. Journal of Sedimentary Petrology44, 484-501.
Maltman, A., 1984. On the term ‘soft-sediment deformation’. Journal of Structural Geology6, 589-592.
Maltman, A.J., 1987. Shear zones in argillaceous sediments - an experimental study. [In:] M.E. Jones & R.M.F. Preston (Eds): Deformation of sediments and sedimentary rocks.Geological Society, London, Special Publications, 29 pp.
Maltman, A. (Ed.), 1994. The geological deformation of sediments.Chapman & Hall (London), 362 pp.
Marco, S. & Agnon, A., 1995. Prehistoric earthquake deformations near Masada, Dead Sea graben. Geology 23, 695-698.
McCalpin, J. (Ed.), 1996. Paleoseismology.Academic Press (New York), 382 pp.
Miao, Q. & Fu, H., 2013. Sequence stratigraphy of the Silurian strata in the northern and central Tarim Basin. Sedimentary Geology and Tethyan Geology33, 34-41 (in Chinese with English abstract).
Mills, P.C., 1983. Genesis and diagnostic value of soft-sediment deformation structures - a review. SedimentaryGeology35, 83-104.
Montenat, C., Barrier, P., d'Estevou, P.O. & Hibsch, C., 2007. Seismites: an attempt at critical analysis and classification. Sedimentary Geology196, 5-30.
Moretti, M., Alfaro, P., Caselles, O. & Canas, J.A., 1999. Modelling seismites with a digital shaking table. Tec-tonophysics304, 369-383.
Moretti, M. & Van Loon, A.J., 2014. Restrictions to the application of ‘diagnostic’ criteria for recognizing ancient seismites. Journal of Palaeogeography3 (162-173).
Mount, J.F., 1984. Mixing of siliciclastic and carbonate sediments in shallow shelf environments. Geology12, 432-435.
Nichols, R.J., Sparks, R.S.J. & Wilson, C.J.N., 1994. Experimental studies of the fluidization of layered sediments and the formation of fluid escape structures. Sedimentology41, 233-253.
Obermeier, S.F., 1996. Use of liquefaction-induced features for paleoseismic analysis - an overview of how seismic liquefaction features can be distinguished from other features and how their regional distribution and properties of source sediment can be used to infer the location and strength of Holocene paleo-earthquakes. Engineering Geology44, 1-76.
Obermeier, S.F., 1998. Liquefaction evidence for strong earthquakes of Holocene and latest Pleistocene ages in the states of Indiana and Illinois, USA. EngineeringGeology50, 227-254.
Obermeier, S.F., Olson, S.M. & Green, R.A., 2005. Field occurrences of liquefaction-induced features: a primer for engineering geologic analysis of paleoseismic shaking. Engineering Geology76, 209-234.
Ogg, J.G., Ogg, G. & Gradstein, F.M., 2008. The concise geological time scale.Cambridge University Press (London), 77 pp.
Oliveira, C.M.M., Hodgson, D.M. & Flint, S., 2009. Aseis-mic controls on in situ soft-sediment deformation processes and products in submarine slope deposits of the Karoo Basin, South Africa. Sedimentology56, 1201-1225.
Owen, G., 1987. Deformation processes in unconsolidated sands. [In:] M.E. Jones & R.M.F. Preston (Eds): Deformation of sediments and sedimentary rocks.Geological Society, London, Special Publications 29, 11-24.
Owen, G. & Moretti, M., 2011. Identifying triggers for liquefaction-induced soft-sediment deformation in sands. Sedimentary Geology235, 141-147.
Owen, G., Moretti, M. & Alfaro, P., 2011. Recognising triggers for soft-sediment deformation: current understanding and future directions. Sedimentary Geology235, 133-140.
Pan, Y.S., Zhou, W.M., Xu, R.H., Wang, D.A., Zhang, Y.Q. & Xie, Y.W., 1996. Geological characteristics and evolution of the Kunlun Mountains region during the Early Palaeozoic. Science in China, Series D - Earth Sciences 39, 337-347 (in Chinese).
Perucca, L.P., Godoy, E. & Pantano, A., 2014. Late Pleis-tocene-Holocene earthquake-induced slumps and soft-sediment deformation structures in the Acequion River valley, Central Precordillera, Argentina. Geolog-os20, 147-156.
Qiao, X.F., Song, T., Gao, L.Z., Peng, Y., Li, H.B, Gao, L., Song, B. & Zhang, Q.D., 1994. Seismic sequence in carbonate rocks by vibrational liquefaction. Acta Geologi-ca Sinica7, 243-265 (in Chinese with English abstract).
Qiao, X.F., Song, T.R., Gao, L.Z., Li, H.B., Peng, Y., Zhang, C.H., & Zhang, Y.X., 2006. Seismic records in strata (ancient earthquake).Geological Publishing House (Beijing), 263 pp. (in Chinese with English abstract).
Qiao, X.F., Li, H.B., Wang, S.T., Guo, X.P., Si, J.L. & Zong, W.G., 2008. Paleoseismic evidence of the Ta-las-Ferghana srike-slip fault during early Jurassic, Xinjiang. Acta Geologica Sinica82, 721-730. (in Chinese with English abstract)
Qiao, X.F. & Li, H.B., 2009. Effect of earthquake and ancient-earthquake on sediments. Journal of Palaeogeog-raphy11, 593-610. (in Chinese with English abstract)
Qiao, X.F., Guo, X.P., Ye, L.S., He, B.Z. & Zhou, W., 2011. Paleoseismic evidence of the Caledonian Movement at Kartarke Uplift in the Central Tarim, Xinjiang. Acta Petrologica Sinica27, 243-252 (in Chinese with English abstract).
Rodríguez-López, J.P., Meléndez, N., Soria, A.R., Liesa, C.L. & Van Loon, A.J., 2007. Lateral variability of ancient seismites related to differences in sedimentary facies (the syn-rift Escucha Formation, mid-Cretaceous, eastern Spain). Sedimentary Geology201, 461484.
Rodríguez-Pascua, M.A., Calvo, J.P., Vicente, G.D. & Go-mez-Gras, D., 2000. Soft-sediment deformation structure interpreted as seismites in lacustrine sediments of the Prebetic Zone, SE Spain, and their potential use as indicators of earthquake magnitude during the Late Miocene. Sedimentary Geology135, 117-135.
Sarkar, S., Choudhuri, A., Banerjee, S., Van Loon, A.J. & Bose, P.K., 2014. Seismic and non-seismic soft-sediment deformation structures in the Proterozoic Bhander Limestone, central India. Geologos20, 89-103.
Seilacher, A., 1969. Fault-grade beds interpreted as seis-mites. Sedimentology13, 155-159.
Seilacher, A., 1984. Sedimentary structures tentatively attributed to seismic events. Marine Geology55, 1-12.
Simms, M.J., 2003. Uniquely extensive seismites from the latest Triassic of the United Kingdom: evidence for bolide impact? Geology31, 557-560.
Sims, J.D., 1975. Determining earthquake recurrence intervals from deformational structures in young lacustrine sediments. Tectonophysics29, 141-152.
Sims, J.D., 1978. Annotated bibliography of penecontem-poraneous deformational structures in sediments. United States Geological Survey Open File Report78-510, 79 pp.
Song T.R. & Liu, Y.X., 2009. Ancient earthquake records and litho-paleogeography. Acta Sedimentologica Sinica27, 872-879 (in Chinese with English abstract).
Tang, L.J. & Jia, C.Z., 2007. Structure interpretation and stress field analysis in superposition Tarim basin / Series of typical superposition basin hydrocarbon formation and distribution prediction in China.Science Publishing House (Beijing), 149 pp. (in Chinese with English abstract).
Tian, Z.Y. & Zhang, Q.C., 1997. Discussion of hydrocarbon-bearing depositional basin of China.Petroleum Industry Press (Beijing), 275 pp.
Üner, S., 2014. Seismogenic structures in Quaternary lacustrine deposits of Lake Van (eastern Turkey). Geolo-gos20, 79-87.
Valente, A., Slączka, A. & Cavuoto, G., 2014. Soft-sediment deformation in Miocene deep-sea clastic deposits (Cilento, southern Italy). Geologos20, 67-78.
Van Loon, A.J. & Brodzikowski, K., 1987. Problems and progress in the research on softsediment deformations. Sedimentary Geology50, 167-193.
Van Loon, A.J., 2009. Soft-sediment deformation structures in siliciclastic sediments: an overview. Geologos 15, 3-55.
Van Loon, A.J., 2014a. The life cycle of seismite research. Geologos20, 61-66.
Van Loon, A.J., 2014b. The Mesoproterozoic ‘seismite’ at Laiyuan (Hebei Province, E China) re-interpreted. Ge-ologos20, 139-146.
Van Loon, A.J. & Pisarska-Jamroźy, M., 2014. Sedimen-tological evidence of Pleistocene earthquakes in NW Poland induced by glacio-isostatic rebound. Sedimentary Geology300, 1-10
Waldron, J.W.F. & Gagnon, J.F., 2011. Recognizing soft-sediment structures in deformed rocks of orogens. Journal of Structural Geology33, 271-279.
Wei, C.G., Zhang, S.Q., Jiang, Z.X. & Zhu, J.Q., 2007. Character and significance of Silurian seismite in the Tarim Basin. Acta Geologica Sinica81, 828-833 (in Chinese with English abstract).
Xu, X.S., Wang, Z.J, Wan, F. & Fu, H., 2005. Tectonic paleogeographic evolution and source rocks of the Early Paleozoic in the Tarim Basin. Earth Science Frontiers12, 49-57 (in Chinese with English abstract).
Xu, Z.Q., Yang, J.S., Li, H.B., Zhang, J.X. & Wu, C.L., 2007. Orogenic plateau: terrain amalgamation, collision and uplift in the Qinghai-Tibet plateau.Geological Publishing House (Beijing), 458 pp. (in Chinese with English abstract).
Xu, Z.Q., Li, S.T., Zhang, J.X., Yang, J.S., He, B.Z., Li, H.B., Ling, C.S. & Cai, Z.H., 2011. Paleo-Asian and Tethyan tectonic systems with docking the Tarim block. Acta Petrologica Sinica27, 1-22 (in Chinese with English abstract).
Yang, J.S., Robison, P.T., Jiang, C.F. & Xu, Z.Q., 1996. Ophiolites of the Kunlun Mountains, China and their tectonic implications. Tectonophysics258, 215-231.
Zhang, C.H., Liu, D.B., Zhang, C.L. & Wang, Z.Q., 2006. Early Permian seismically induced soft-sediment deformation structure in Bogda region, Xinjiang: stratigraphy records of earthquake in the retroarc collisional foreland basin. Earth Science Frontiers13, 255-266 (in Chinese with English abstract).
Zhang, J.X., Mattinson, C.G., Meng, F.C. & Yu, S.Y., 2005. An Early Palaeozoic HP/HT granulite-garnet perido-tite association in the south Altyn Tagh, NW China: P-T history and U-Pb geochronology. Journal of Meta-morphic Geology23, 491-510.
Zhao, Z.J., Jia, C.Z., Zhou, X.Y. & Wang, Z.M., 2006. Key factors of oil-gas reservoir-forming and exploration targets in Ordovician in Tazhong area, Tarim Basin. China Petroleum Exploration11(4): 6-15 (in Chinese with English abstract).
Zhao, Z.J., Pan, M., Yang, H.J., Yu, G. & Xu, Y.J., 2010. The source rock of turbidites of Middle Upper Ordovician in Tarim Basin and its tectonic significance. Geology Science45, 681-697 (in Chinese with English abstract).
Zhao, Z.X., Pan, W.Q. & Xiao, J.N., 2000. Palaeozoic strataand conodonts in Xinjiang.Petroleum Industry Press (Beijing), 340 pp. (in Chinese)
Zheng, R.C., Zhou, G., Hu, Z.G & Dong, X., 2010. The characteristics of hybrid facies and hybrid sequence of Xiejiawan Member of Ganxi Formation in the Long-menshan area. Acta Sedimentologica Sinica28, 33-41 (in Chinese with English abstract).