Publication Date:
2023-08-28
Description:
Ferromanganese nodules (equivalent to Recent manganese nodules) are described from the Upper Devonian griotte (red pelagic limestone) of the Montagne Noire (S. France) and the Cephalopodenkalk of the Rheinisches Schiefergebirge, West Germany. They occur as encrustations, commonly exhibiting colloform structures, around skeletal material and limestone clasts. The nodules are associated with encrusting foraminifera and a development in the sublittoral environment is envisaged. Chemically, the ferromanganese nodules are depleted in manganese relative to iron, compared with Recent nodules, a loss which is attributed to diagenetic migration of manganese. Electron probe studies show that manganese covaries positively with calcium, but negatively with iron and silicon. Diagenetic enrichment of hematite occurs in the griotte at hardground horizons where two periods of mineralization can be established. The Devonian ferromanganese nodules show that solution of nodules has not occurred on burial.
Keywords:
Combe_Izarne_TCK; Combe d'Izarne, Cabrières; Elevation of event; Event label; Iron; Latitude of event; Longitude of event; Manganese; Mont_Peyroux_TCK; Mont Peyroux; Nickel; NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS; Sample ID; X-ray fluorescence (XRF)
Type:
Dataset
Format:
text/tab-separated-values, 84 data points
