Publication Date:
2024-01-09
Description:
We present new isotopic and micropaleontological data from a depth transect on Shatsky Rise that record the response of the tropical Pacific to global biotic and oceanographic shifts during the mid-Maastrichtian. Results reveal a coupling between the upper ocean, characterized by a weak thermocline and low to intermediate productivity, and intermediate waters. During the earliest Maastrichtian, oxygen and neodymium isotope data suggest a significant contribution of relatively warm intermediate water from the North Pacific. Isotopic shifts through the early Maastrichtian suggest that this warmer water mass was gradually replaced by cooler waters originating in the Southern Ocean. Although the cooler water mass remained dominant through the remainder of the Maastrichtian, it was displaced intermittently at shallow intermediate depths by North Pacific intermediate water. The globally recognized "mid-Maastrichtian event" ~69 Ma, manifested by the brief appearance of abundant inoceramid bivalves over shallow portions of Shatsky Rise, is characterized by an abrupt increase (~2°-3°C) in sea surface temperatures, a greater flux of organic matter out of the surface ocean, and warmer (~4°C) intermediate waters. Results implicate simultaneous changes in surface waters and the sources/distribution patterns of intermediate water masses as an underlying cause for widespread biotic and oceanographic changes during mid-Maastrichtian time.
Keywords:
198-1209A; 198-1209C; 198-1210; 198-1212B; COMPCORE; Composite Core; Depth, composite; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Event label; Gavelinella beccariiformis, δ13C; Gavelinella beccariiformis, δ18O; Gavelinella sp., δ13C; Gavelinella sp., δ18O; Globigerinelloides prairiehillensis, δ13C; Globigerinelloides prairiehillensis, δ18O; Globotruncana arca, δ13C; Globotruncana arca, δ18O; Globotruncanita stuartiformis, δ13C; Globotruncanita stuartiformis, δ18O; Inoceramus spp., δ18O; Inoceramus spp. δ13C; Joides Resolution; Leg198; Mass spectrometer Finnigan MAT 252; North Pacific Ocean; Nuttallides truempyi, δ13C; Nuttallides truempyi, δ18O; Ocean Drilling Program; ODP; Planoglobulina multicamerata, δ13C; Planoglobulina multicamerata, δ18O; Rugoglobigerina rugosa, δ13C; Rugoglobigerina rugosa, δ18O; Sample code/label; δ13C, bulk carbonate; δ13C, carbonate; δ18O, bulk carbonate; δ18O, carbonate; ε-Neodymium
Type:
Dataset
Format:
text/tab-separated-values, 1574 data points
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