Publication Date:
2023-08-28
Description:
Ferromanganese concretions from the Svalbard shelf in the Barents Sea show slightly convex shale-normalized REE patterns with no Eu anomalies. Concretions from the Gulf of Bothnia, northern part of the Baltic Sea, exhibit an enrichment of light REE and negative Eu anomalies. This difference is interpreted as a consequence of different conveyor mechanisms of the REE to the sediment. It is suggested that dissolving biogenic debris contributes to the convex pattern obtained in the Barents Sea, whereas an inorganic suspended fraction with scavenged REE is the main carrier in the Gulf of Bothnia. During oxic diagenesis in the sediment, the scavenged REE are set free into the porewater and contribute to the distribution pattern in concretions found in the Gulf of Bothnia. Small Mn-rich spheroidal concretions are enriched two to five times in REE compared to average shale, whereas Mn-poor flat concretions are low in REE. Specific surface area of the concretion and the depth of burial in the oxidized surface sediment are two factors that strongly affect the enrichment of the REE. Weak Ce anomalies are present in the analysed concretions and a redox level dependence is seen.
Keywords:
1979 STN 15; 1979 STN 1A; 1979 STN 76; 1979 STN 8; 1982 STN 10; 1983 STN 18; 1983 STN 5; Barents Sea, E of Svalbard; Bothnian Sea; Cerium; Date/Time of event; Deposit type; DEPTH, sediment/rock; Description; Dredge; DRG; Dysprosium; Elevation of event; Erbium; Europium; Event label; Gadolinium; Gulf of Bothnia; Holmium; ICP-OES, Inductively coupled plasma - optical emission spectrometry; Insoluble residue; Iron; Lanthanum; Latitude of event; Longitude of event; Lutetium; Manganese; Neodymium; NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS; Norvarg; NRM_76-77; NRM_77-12; NRM_77-22; NRM_79-15; NRM_79-1A; NRM_79-76; NRM_79-8; NRM_80-BH16; NRM_80-BH19; NRM_80-BH26; NRM_80-BH27; NRM_82-10; NRM_83-18; NRM_83-5; Praseodymium; Samarium; Sample code/label; Sample ID; Scandium; Shape; Size; Strombus; SVALBARDEKSPEDISJONEN-1980; Wet chemistry; Ytterbium; Yttrium
Type:
Dataset
Format:
text/tab-separated-values, 371 data points
Permalink
