【摘要】 河北平泉燕山裂陷槽中元古代地层中,藻席-藻团-藻丝-藻屑-泥晶薄层交替形成韵律沉积。经对系列标本(薄片)特征及其不同结构类型的对比分析,认为它们是在风暴浪基面之下,具风暴流浊积特征的深水藻类生物沉积系列。浅海叠层石及其他底栖藻类构成了从浅海至半深海上部浅水一个完整的藻类沉积序列,其不同类型的特征则成为鉴别沉积时各环境要素的可靠依据,即依据不同藻类生物沉积类型———藻席、藻团、藻丝及藻层的组合序列变化,作为判别200～400 m半深海浅水环境的依据。更多还原

【Abstract】 The authors have dealt with a sequence of rhythmic deposition consisting alternatively of algal mats,algal balls,algal filaments,algal pellets and micrites in the strata of the Mesoproterozoic Yanshan aulacogen in Pingquan County,Hebei Province.Based on correlation and analysis on features and structural types of a series of specimens(also thin section),the present authors suggest that the rhythmic deposition represent a sub-abysmal algal sedimental system of storm flow turbidite below storm wave base.The algal sedimentary succession consists of those formed at shallow-sea and at bathyal part.Their different features could serve as a reliable basis for recognizing their sedimentary environments.The present paper presents a new view on the existing depth limit of algal mats.更多还原