Publication Date:
2023-08-28
Description:
Leg 14 of the Deep Sea Drilling Project completed 9 holes; 7 were located off NW Africa, 1 in Ceara Abyssal Plain, and 1 on Demerara Rise. Quaternary and Pliocene sediments consist of nanno chalk oozes and brown clay. The facies boundary (CCD) is near 5000 meters. Sedimentation rates are between 10 and 30 meters/million years (m/My) for chalk ooze and 2 to 4 m/My for pelagic clay. Redeposition off the Amazon produces terrigenous and bioclastic turbidite sequences with rates increasing, on the average, from 50 to 150 m/My. Small manganese nodules (coarse sand and small pebbles) are common in sediments associated with hiatuses at Sites 135 (Eocene-Miocene, Core SW1), 136 (Late Cretaceous- Miocene, Cores 3 to 6), and to a lesser extent at 141 (Middle Miocene-Pliocene, Core 7). Additional occurrences were noted in the pelagic clays at Site 137 (Late Cretaceous to Miocene). At 135-8 (Cenomanian) micro-nodules occur within a mixture of siltstone fragments, compressed planktonic foraminifera, fish debris, as well as chert pebbles and other redeposited components. Manganese concretions are generally younger than Turonian and are restricted to the predominantly oxidized part of the sequences, that is, where sediments are mostly red, brown, or yellow-colored.
Keywords:
14-135; 14-136; 14-137; 14-141; Comment; Deep Sea Drilling Project; Deposit type; DEPTH, sediment/rock; Description; DRILL; Drilling/drill rig; DSDP; Event label; Glomar Challenger; Identification; Leg14; NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS; North Atlantic/DIAPIR; North Atlantic/HILL; North Atlantic/PLAIN; Position; Quantity of deposit; Sample code/label; Sediment type; Size; Substrate type; Visual description
Type:
Dataset
Format:
text/tab-separated-values, 72 data points
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