Acta Scientiarum Naturalium Universitatis Pekinensis

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K-Ar Geochronology of Cenozoic Volcanic Rocks of East Depression in Liaohe Basin and Its Geological Significance

YANG Mohan, HOU Guiting, SHI Ge   

  1. The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing, 100871
  • Received:2004-08-31 Online:2006-03-20 Published:2006-03-20



  1. 北京大学地球与空间科学学院,造山带与地壳演化教育部重点实验室,北京,100871

Abstract: Liaohe basin is a Cenozoic rift valley with numerous volcanic activities developed in East Depression. Based on the large amount of K-Ar geochronology, petrology and geochemistry data, the Cenozoic volcanic activities in this depression are divided into 4 periods, which are Fangshenpao, Shasan, Shayi and Dongying periods. The Shasan and Dongying periods are two summits of volcanic activities, with accurate isotopic age of 43~38Ma and 32~25Ma respectively. This paper provides an accurate isotopic chronology constraints for the study of Cenozoic tectonic evolution of Bohai basin and Eastern China.

Key words: volcanic rocks, K-Ar dating, Cenozoic, east depression, Liaohe basin

摘要: 辽河盆地是中、新生代发育起来的裂谷盆地,东部凹陷是辽河盆地新生代火山活动最为频繁的地区,发育大量火山岩。通过对东部凹陷测得的28个火山岩样品K-Ar年龄数据,结合区域火山岩石学、地球化学研究结果,对比前人曾发表的K-Ar年龄数据,将本区新生代火山活动分为房身泡、沙三、沙一和东营4个时期,始于65Ma,并在42~38Ma和32~25Ma经历2个活动高峰期。这为渤海湾盆地新生代构造演化乃至中国东部新生代裂谷活动研究,增加了同位素年代学方面的有力证据。

关键词: 火山岩, K-Ar定年, 新生代, 东部凹陷, 辽河盆地

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