|Album: Newly acquired collection now being restored. (updated Oct 11, 2005)|
Contains: 20 items.
Viewed: 2515 times.
|Album: ArcheoPaleo Macrofossils - Upper Devonian (Frasnian)|
Contains: 24 items.
Viewed: 3111 times.
|Album: ArcheoPaleo Macrofossils - Upper Ordovician (Mohawkian)|
Contains: 15 items.
Viewed: 2676 times.
|Album: ArcheoPaleo Cephalopod Collection|
Contains: 9 items.
Viewed: 2424 times.
|Album: NEW!! Archeopaleo Misc Fossils - Upper Ordovician (Mohawkian)|
Contains: 13 items.
Viewed: 2638 times.
|Album: ArcheoPaleo Phosphatic Microfossils (Mohawkian)|
This album is part of a collection of images of 150 small (0.5 - 5.0 mm) fossil specimens from the Ordovician Decorah Shale of the Twin Cities area of Minnesota. Specimens were found in iron-stained, calcareous, fossil 'hash' surfaces of highly fossiliferous, lenticular, argillaceous limestone slabs within the otherwise shaly beds typical of the local Decorah Shale. The specimens are phosphatic internal casts. Typical fossil size is 1-2 mm. Actual physical dimension of the specimen is shown for each image. Most are probably fine mud casts preserved as apatite. The crinoid holdfast is pyritic. Not all specimens have been analyzed to verify composition, however. The bryozoans were identified by Prof. Roger Cuffey who cautions that it is difficult to make firm identifications from photos! Other specimens (not shown) include brachiopods, ostracods, pisolites, and many unknown layered plates, 'extrusions' and amorphous shapes. Image details: Nikon FX-35DX w/Fujichrome 100 print film. Primary objective lens 1.5X; Zoom factor .75-4.9X; 4X photo projection lens; developed at 4.17X to 4x6 print; image scanned, cropped, and presented here as JPEG file. Dual fiber-optic light source - closeness of the light source to the specimens has probably thermally corrupted the true colors.
Contains: 18 items.
Viewed: 2589 times.
|Album: ArcheoPaleo Microfossils - Ordovician Scolecodonts|
These(unfortunately)primitive images are partial documentation of the ArcheoPaleo Collection of scattered marine worm jaw element(scolecodont) microfossils mostly from the Upper Ordovician Series(Mohawkian[TS5C?])(about 450 my old)shales of Minnesota. They are typically less than a millimeter in size. NOTE: Each specimen image contains up to 6 views - try clicking on the specimen, select 'slideshow', set to '1 second' and 'loop' for a rotating view. Scolecodonts are now studied as being individual 'elements' of a full 'jaw apparatus'. As you can see, these elements look very different when seen from different views - this may have lead to an excess of 'species' being defined based on these elements by some earlier researchers; the real value of these elements will have to await more study of their relevance to the complete 'apparatus' species and, then that apparatus' acceptance as an index fossil... Since I have found scolecodonts in shales of the Rock Elm structure which is a suspected meteorite impact, knowing the age of the scolecodonts could help define the age of the crater.
Contains: 26 items.
Viewed: 3468 times.
|Album: Canyon Diablo Meteorite|
Contains: 4 items.
Viewed: 1721 times.