by webolife » Sun Jan 02, 2022 10:10 pm
The pictures you were able to referenced are similar to if not identical in appearance to rocks I've collected in Eastern Washington, among the Basalt flows of the Columbia plateau. I have collected petrified wood samples from large petrified logs exposed a few miles south of Vantage, where the Ginko Petrified Forest museum is located, which look exactly like classical petrified wood, concentric rings, etc. as would be expected. But these rocks you are inquiring about appear to be something the the locals refer to as petrified "bog". I have several examples of petrified "bog" which pictured (if I knew how to post them) look virtually identical to the samples you referenced. But there is another type of "petrified" material I have a significant collection of, ie. diatomaceous opal, found in the middle of lens-shaped beds of diatomaceous earth up to 40' deep. The diatomaceous earths, sandstones, shales, gravels, and clays found between otherwise extensive and "conformable" layers of basalt are all sites where different petrified woods have been found, as well as these petrified "bogs" similar to the rocks you are referencing. In any case, the mineral is quartz infused with water, known as "common opal", denoting the medium in which they were transported/deposited/underwent petrifaction. One interesting case shown in the Ginko Petrified Forest museum is a sample of "coalified" wood that was not petrified, though found in a layer several basalts deep in the plateau. The problem with this comparison is that Finnish Geology is largely metamorphic sequences atop granitic archaean bedrock. These are not the usual regions to find petrified materials.
The pictures you were able to referenced are similar to if not identical in appearance to rocks I've collected in Eastern Washington, among the Basalt flows of the Columbia plateau. I have collected petrified wood samples from large petrified logs exposed a few miles south of Vantage, where the Ginko Petrified Forest museum is located, which look exactly like classical petrified wood, concentric rings, etc. as would be expected. But these rocks you are inquiring about appear to be something the the locals refer to as petrified "bog". I have several examples of petrified "bog" which pictured (if I knew how to post them) look virtually identical to the samples you referenced. But there is another type of "petrified" material I have a significant collection of, ie. diatomaceous opal, found in the middle of lens-shaped beds of diatomaceous earth up to 40' deep. The diatomaceous earths, sandstones, shales, gravels, and clays found between otherwise extensive and "conformable" layers of basalt are all sites where different petrified woods have been found, as well as these petrified "bogs" similar to the rocks you are referencing. In any case, the mineral is quartz infused with water, known as "common opal", denoting the medium in which they were transported/deposited/underwent petrifaction. One interesting case shown in the Ginko Petrified Forest museum is a sample of "coalified" wood that was not petrified, though found in a layer several basalts deep in the plateau. The problem with this comparison is that Finnish Geology is largely metamorphic sequences atop granitic archaean bedrock. These are not the usual regions to find petrified materials.