Earthquake and its resultant tsunami, as a kind of disaster events in geological history, may be recorded as event deposits of seismite and tsunamite. Typical characteristics of seismite and tsunamite, including seism...Earthquake and its resultant tsunami, as a kind of disaster events in geological history, may be recorded as event deposits of seismite and tsunamite. Typical characteristics of seismite and tsunamite, including seismo-fracture bed, synsedimentary microfracture, micro-corrugated lamination, molar tooth structure, hummocky bedding, occurs in Mesoproterozoic Dalongkou Formation of Kunyang Group in central Yunnan Province. Three types of sedimentary units have been recognized: seismite (unit-A, including limestone with molar tooth structure, seismic shattering rock, seismic corrugated rock, autoclastic breccia and intraclastic parabreccia), tsunamite (unit-B, intraclastic limestone with hummocky or parallel beddings) and background deposits (unit-C). Various stackings of these units construct three distinct sedimentary sequences: A-B-C, A-C and B-C. A-B-C represents an event sedimentary sequence of earthquake-tsunami-background deposits, A-C represents the sequence of earthquake and background deposits (no tsunami occur-ring), and B-C represents the sequence of tsunami and background deposits (far from the center of earthquake). As the central Yunnan Province was located in a tectonic setting of rift basin in Mesoproterozoic Era, the earthquake event deposits of the Dalongkou Formation are sedimentary response to tectonic activity of the rift basin.展开更多
基金the "SSER" and the Ministry of Science and Technology of China (Grant No. 95-special-04).
文摘Earthquake and its resultant tsunami, as a kind of disaster events in geological history, may be recorded as event deposits of seismite and tsunamite. Typical characteristics of seismite and tsunamite, including seismo-fracture bed, synsedimentary microfracture, micro-corrugated lamination, molar tooth structure, hummocky bedding, occurs in Mesoproterozoic Dalongkou Formation of Kunyang Group in central Yunnan Province. Three types of sedimentary units have been recognized: seismite (unit-A, including limestone with molar tooth structure, seismic shattering rock, seismic corrugated rock, autoclastic breccia and intraclastic parabreccia), tsunamite (unit-B, intraclastic limestone with hummocky or parallel beddings) and background deposits (unit-C). Various stackings of these units construct three distinct sedimentary sequences: A-B-C, A-C and B-C. A-B-C represents an event sedimentary sequence of earthquake-tsunami-background deposits, A-C represents the sequence of earthquake and background deposits (no tsunami occur-ring), and B-C represents the sequence of tsunami and background deposits (far from the center of earthquake). As the central Yunnan Province was located in a tectonic setting of rift basin in Mesoproterozoic Era, the earthquake event deposits of the Dalongkou Formation are sedimentary response to tectonic activity of the rift basin.
