Deformation in tiger ironstone. Band of haematite (iron oxide) deformed into a peak shape (upper centre). The iron oxide layer is part of banded ironstone,or a banded iron formation (BIF). This sedimentary rock is formed from haematite layers alternating with other rocks,here tiger eye. At greater than 3 billion years of age these are among the oldest rocks on Earth. They were laid down in shallow seas where primitive bacteria caused iron to be oxidised and precipitated. Subsequent deep burial of the rocks,and tectonic movements,have caused the rock to alter and deform. The rock has been cut open to expose the banding,and polished for display. Many BIFs come from Western Australia | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Wiersma, Dirk |
Bildgröße: | 3644 px × 4846 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |