Fig. 12


Download original image

U–EF vs. Mo–EF crossplot of samples from the Tithonian-Berriasian. The top inset diagram illustrates the general patterns of U–EF vs. Mo–EF covariation in modern marine environments. The grey field represents “unrestricted marine” environments, characteristic of the eastern tropical Pacific, whereas the yellow field represents the “particulate shuttle” trend, characteristic of depositional systems such as the Cariaco Basin, where intense redox cycling of metal oxyhydroxides (especially Mn-bearing) occurs within the water column. XEF = [(X/Al)sample/(X/Al)PAAS], and X and Al stand for the weight concentrations of element X and Al, respectively. Samples are normalized against the post-Archean average shale (PAAS) compositions of Taylor and McLennan (1985). The trace-element distribution indicates that Sample #1 recorded peculiar, probably euxinic, conditions of deposition, while samples #2 to 40 recorded conditions of depositions under oxic waters and with reducing conditions developing at shallow depth below the sediment-water interface. Samples #41 to 59 recorded fully oxygenated, normal-marine conditions of depositions.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.