【摘要】 采用多种物探、钻探技术对北京市顺义断裂带进行了试验探测研究,并通过天文旋回地层学、古地磁磁化率及年代测定等方法研究了断裂带第四纪以来间歇性活动特征,得出~2.5、~2.3、~2.0、1.6~1.8、1.2~1.3、~0.5和~0.3 Ma等7个相对活动强烈期和~0.9 Ma次活动强烈期,其余时段为相对平静期。整个第四纪较长时间内,早更新世早、中期(早于~1.1 Ma)活动强烈,活动方式以粘滑活动为主。而早更新世晚期以来(~1.1 Ma以来),活动速率明显减缓,活动方式转变为以蠕滑活动方式为主。更多还原

【Abstract】 Gravity exploration,shallow seismic investigation and high density resistivity measurement were applied to study Sunyi fault in Beijing,and the data in astronomical cyclostratigraphy,magnetic susceptibility and paleomagnetic chronology from a series of drilling cores were used to infer sporadically activities of the fault’s northern segment since Quaternary. The astronomical time scales of the footwall and hanging wall of the Shunyi fault were established respectively to constrain the stratigraphic age of two walls. Its activity characteristics since the Quaternary were revealed through comparison with the thickness of strata and differences of deposition rate. The Shunyi fault showed hallmark of intermittency. Seven intensive phases( ~ 2. 5 Ma,~ 2. 3 Ma,~ 2. 0 Ma,1. 6 ~ 1. 8 Ma,1. 2 ~ 1. 3Ma,~ 0. 5 Ma and ~0. 3 Ma) and one sub-intensive phase( ~ 0. 9Ma) can be distinguished,and the rest time is considered to be relatively quiet period. Furthermore,Shunyi fault acted intensively in the early and middle Early Pleistocene( earlier than ~ 1. 1Ma) being featured by sink-slip-dominated activity,and became weakprofoundly since the late Early Pleistocene( after ~ 1. 1Ma) with a feature of creep-dominated activity.更多还原