Polished cross section of the petrified trunk of Araucaria sp., a coniferous tree dating from the late Triassic period and now extinct. The petrification of trees in this area took resulted from repeated volcanic activity in this area during this period, some 220 million year ago. The rapid burial of the wood under volcanic ashes ensured its preservation and subsequent conversion of the wood into silica (SiO2) The growth rings of the wood stand out by variations in colour, resulting from various trace elements admixed in the silica. Provenance is the Petrified Forest Park in Arizona, USA. Widest diameter of this slab is 80 cm. | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Wiersma, Dirk |
Bildgröße: | 5522 px × 3803 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |