Chronostratigraphic Database for Upper Cretaceous Oceanic Red Beds (CORBs)
Chronostratigraphic Database for Upper Cretaceous Oceanic Red Beds (CORBs)
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DOI：
10.2110/sepmsp.091.035
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发表时间：
2009
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影响因子：
--
通讯作者：
R. Scott
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文献类型：
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作者：
R. Scott
一个综合的，可测试的年代地层数据库的晚白垩世生物事件在众多的参考部分，以测试全球同步的上白垩世大洋红层-CORB-和精确测量其沉积物的积累速度。图形相关是选择的方法，因为它是基于物种清单，因为范围预测是透明的和可测试的。阶段边界由GSSP或含菊石、南极有孔虫和超微化石的关键参考剖面以及磁年代确定。通过同生化石的图形对比，将参考剖面中定义的层序界面和其他沉积标志物投影到数据库中。该数据库的规模校准到上白垩纪阶段的放射性年龄，大致类似于2004年的时间尺度。该数据库被用于三个领域来解释CORB的沉积，北大西洋，瑞士前阿尔卑斯山和奥地利东部阿尔卑斯山。北大西洋CORB间隔在六个核心范围内的年龄从Turonian马斯特里赫特。这一系列沉积在两个不同的深水区。一个Turonian-Santonian含氧水体与一个相对较浅的方解石补偿深度（CCD）托管红层沉积和底栖有孔虫的多样化。在晚白垩世海底火山活动期间，北大西洋存在深水、低pH条件。良好的含氧Campanian-Maastrichtian水团以上的CCD，钙质化石保存在第二次底栖有孔虫多样化事件。红色海相粘土和浊积岩与灰色和绿色层交替出现。沉积物的积累率一般是较高的坎帕尼亚-马斯特里赫特时期比在早期。瑞士前阿尔卑斯山脉的CORB地层在不同的时间、不同的地点以不同的时间和不同的速度沉积，从阿普第阶开始，零星地持续到桑顿阶。在阿尔卑斯山东部，上白垩纪海相红层与碰撞板块之间的宾夕法尼亚洋中沉积的硅质岩和钙质相互层。最古老的CORB沉积记录在Albian，并在Campanian期间持续存在。红色和灰色地层的互层记录了构造控制的海侵事件期间的气候强迫。CORB沉积的持续时间在陆表海盆地一般比在大洋盆地短，但沉积物积累的平均速率在陆表海盆地和大洋盆地趋于相似。均匀层状CORB沉积在相同的平均持续时间均匀层状存款，但均匀层状CORB积累速度比均匀存款。许多重复互层的大洋红层以接近轨道频率的速率沉积，可能与气候强迫有关。
An integrated, testable chronostratigraphic database of Late Cretaceous bioevents in numerous reference sections was constructed in order to test the global synchrony of Upper Cretaceous oceanic redbeds—CORBs—and to measure precisely their rates of sediment accumulation. Graphic correlation was the method of choice because it is based on species checklists and because the range projections are transparent and testable. Stage boundaries are defined by GSSP or key reference sections with ammonites, planktic foraminifera, and nannofossils, as well as with magnetochrons. Sequence boundaries and other sedimentary markers as defined in reference sections are projected into the database by graphic correlation of the co-occurring fossils. The database scale is calibrated to radiometric ages of Upper Cretaceous stages that are generally similar to those of the 2004 time scale. This database is used in three areas to interpret deposition of CORBs, the North Atlantic, the Swiss Pre-Alps, and the Eastern Austrian Alps. North Atlantic CORB intervals in six cores range in age from Turonian to Maastrichtian. This succession was deposited within two distinct deep water masses. A Turonian–Santonian oxygenated water mass with a relatively shallow calcite compensation depth (CCD) hosted red-bed deposition and diversification of benthic foraminifera. Deep-water, low pH conditions existed in the North Atlantic during Late Cretaceous submarine volcanism. The well oxygenated Campanian–Maastrichtian water mass was above the CCD, and calcareous fossils were preserved during a second benthic foraminifer diversification event. Red marine clay and turbidites alternated with gray and green beds. Rates of sediment accumulation generally were higher during the Campanian–Maastrichtian period than during the earlier period. CORB strata in the Swiss Pre-Alps were deposited at different times in different places for varying durations and at different rates beginning in the Aptian and continued sporadically into the Santonian. In the Eastern Alps Upper Cretaceous marine red beds are interbedded with siliciclastic and calcareous facies deposited in the Penninic Ocean between colliding plates. Oldest CORB deposition is recorded in the Albian and became persistent during the Campanian. Interbedded red and gray strata record climatic forcing during tectonically controlled transgressive events. The duration of CORB deposition generally was shorter in epicontinental basins than in oceanic basins, but the average rate of sediment accumulation tended to be similar in epicontinental and oceanic basins. Even-bedded CORBs were deposited at the same average duration as homogeneously bedded deposits, but even-bedded CORBs accumulated faster than homogeneous deposits. Many repetitively interbedded oceanic red beds were deposited at rates close to orbital frequencies and may have been related to climatic forcing.