CAJ | 학술논문

白垩纪深水古海洋学研究仍处于早期发展阶段,一方面是由于来自钙质底栖有孔虫的稳定同位素和地球化学数据的缺乏,其原因在于白垩纪高碳酸盐补偿深度;另一方面在于深水有机质胶结有孔虫示踪古海洋还没有充分发展起来.深海环境深水胶结有孔虫的分布主要取决于碳酸盐可利用状况、原始生产的输入通量、深水交换、环境波动(深海洋流、浊流和快速沉积事件)和底层沉积类型,因此对于重建深海环境具有非常巨大的潜力.东、西特提斯Campanian-Maastrichtian深水底栖有孔虫组合的统计分析揭示出6个生物相,代表着明显不同的沉积环境.包括:深海红色泥岩与矮小深海生物组合(生物相1);红色深海泥灰岩 ("Couches Rouges"相),含钙质胶结有孔虫组合(生物相3);深水远洋灰岩("Scaglia Rossa"相),含易碎的Rhizammina组合(生物相2);绿色-灰色半远洋泥灰岩,含适应高输出通量生物组合(生物相4);半远洋泥岩和粉砂岩,含Aschemocella-Nothia 组合(生物相5);陆源浊积层序,含"复理石型"Rhabdammina 组合(生物相6).Campanian-Maastrichtian红色氧化深水环境动物组合与现今深海类似,而白垩纪贫氧深海环境胶结组合在现今无法找到相类似物.随着古生态信息的增加和数据库的扩展,深水胶结有孔虫有望成为揭示古海洋条件的重要工具,尤其是对于非均变的白垩纪深海沉积的形成而言,比如深海黑色页岩和广泛分布的大洋红层.
백성기심수고해양학연구잉처우조기발전계단,일방면시유우래자개질저서유공충적은정동위소화지구화학수거적결핍,기원인재우백성기고탄산염보상심도;령일방면재우심수유궤질효결유공충시종고해양환몰유충분발전기래.심해배경심수효결유공충적분포주요취결우탄산염가이용상황、원시생산적수입통량、심수교환、배경파동(심해양류、탁류화쾌속침적사건)화저층침적류형,인차대우중건심해배경구유비상거대적잠력.동、서특제사Campanian-Maastrichtian심수저서유공충조합적통계분석게시출6개생물상,대표착명현불동적침적배경.포괄:심해홍색니암여왜소심해생물조합(생물상1);홍색심해니회암 ("Couches Rouges"상),함개질효결유공충조합(생물상3);심수원양회암("Scaglia Rossa"상),함역쇄적Rhizammina조합(생물상2);록색-회색반원양니회암,함괄응고수출통량생물조합(생물상4);반원양니암화분사암,함Aschemocella-Nothia 조합(생물상5);륙원탁적층서,함"복리석형"Rhabdammina 조합(생물상6).Campanian-Maastrichtian홍색양화심수배경동물조합여현금심해유사,이백성기빈양심해배경효결조합재현금무법조도상유사물.수착고생태신식적증가화수거고적확전,심수효결유공충유망성위게시고해양조건적중요공구,우기시대우비균변적백성기심해침적적형성이언,비여심해흑색혈암화엄범분포적대양홍층.
Cretaceous deep-water paleoceanography is still in an early stage, since stable isotope analysis and geochemical data from calcitic benthic foraminifera are generally unavailable owing to an unusually high calcite compensation depth, and since the use of organically cemented deep-water agglutinated foraminifera as tracers is still insufficiently exploited. Distribution patterns of deep-water agglutinated foraminifera in the deep-sea are mainly dependent on carbonate availability, export fluxes from primary production, deep-water ventilation, environmental disturbance (deep-sea currents, turbidites and rapid sedimentation events) and substrate types and have thus significant potential to reconstruct the environments of the deep-sea. Statistical analysis of deep-water benthic foraminiferal assemblages from the Campanian-Maastrichtian of the Western Tethys reveals six biofacies, which occur in distinct depositional environments. Assemblages from Campanian-Maastrichtian red oxic deep oceanic settings exhibit remarkable similarities to modern deep-sea faunas, whereas agglutinated assemblages of Cretaceous dysaerobic deep-sea settings have no real modern analogue. With increasing paleoecological information and an expanded database, Late Cretaceous deep-water agglutinated foraminifers have the potential to become a powerful tool for understanding the palaeoceanographic conditions under which non-uniformitarian Cretaceous deep-sea sediments such as deep-sea "black shales" and the widely distributed oceanic red beds formed.