联邦德国Amrum岛海滩和潮坪沉积环境

本文根据实地考察,描述和讨论了Amrum岛周围各种环境的自然地理和生物生态特征,指出环境能量决定生物种群以及海侵条件下的潮坪砂可能产生烃类,并认为地质教育中应十分重视现代地质作用的考察。

SEDIMENTARY ENVIRONMENTS OF THE BEACH AND TIDAL-FLATS AROUNO ISLAND AMRUW, FRG

The physical, biotic community and ecologic characteristics around Island Amrum, FRG, have been dis- cribed and discussed on the basis of on-the-spot investigations. Being worked by strong waves and currents of North Sea, the beach sediments are lack of mud and nutrients and periodically in motion, which results in the absence of au- tochthonous fauna at the beach. A bay of minimum wave-energy is located at south end of the beach by the cut-off a sand barrier. Here organic ooze under anaerobic condition dominates and the fauna variability drops to minimum extent. A broad intertidal zone to the east of Amrum is characterized by moderate energy-level, medium clay-content and plenti- ful oxygen, resulting in fauna boom. Dense borings and algal mats are present on sand flat near the inlet while extremely abundant benthic fauna on mud flat relatively far from the inlet. Consequently, it is first concluded that biota and ecology are controlled by environmental physical-chemical conditions. Secondly, abundant organic matter is contained in the sedi- ments 20-30cm beneath surface of the beach and tidal flat. These sediments might serve as potentional sources of hydro- carbon under given conditions. The third, investigations and studies of modern sedimentation should be greatly stressed in geological education.