| Autor: |
A. G. Panagos, S. P. Varnavas |
| Rok vydání: |
1984 |
| Předmět: |
|
| Zdroj: |
Syngenesis and Epigenesis in the Formation of Mineral Deposits ISBN: 9783642700767 |
| DOI: |
10.1007/978-3-642-70074-3_48 |
| Popis: |
In this paper the genesis of some Mn deposits in the Orthrys and Perachora areas is investigated. These deposits are characterized by high concentrations of Mn, low Fe/Mn ratios and low trace metal contents. Their chemistry and stratigraphic location suggest that they are syngenetic and have been formed by rapid precipitation from hydrothermal exhalations, related to leaching of magmatic rocks, and which have been discharged onto the sea floor during Triassic-Cretaceous. The fractionation of Fe from Mn is due to its earlier precipitation in the form of sulfides. In the Orthrys area Cu-rich pyrite forms dikes in the diabase underlain the chert horizon with the Mn deposits. The depletion of the Mn deposits in trace metals is due to their absence from the hydrothermal exhalations and to the rapid precipitation of the Mn-phases which did not allow scavenging from the normal sea water. The precipitation of the sulfides within the fractures of the diabase may acted as “filters” absorbing trace metals from the passing hydrothermal solutions. The trace metal concentrations of the Perachora deposits support a greater hydrogenous influence in their formation compared with the Orthrys deposits. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
