Stromatolites from Steep Rock Lake
The Steep Rock Lake Limestone from northwestern Ontario, west of Lake Superior,
is a stromatolitic limestone of Archean age (~2.9 billion years old).
Stromatolites are calcareous structures created by cyanobacteria (blue-green
algae). The photos below are of a specimen of the limestone that
was cut into a thin slice approximately 1.5 mm thick. The photos
were taken with a low power microscope. The fields of view are approximate.
The black specks in the photos are small hunks of carbon. I speculate
that the greenish gray blobs are original algal structures. Note
that the color in the photomicrographs is greener than the actual specimen.
The whole slab picture below gives a better indication of the specimen
color. Also note that jpeg compression has introduced some artifacts into
the images. I can provide copies of the original tiff images via
emial to anyone who is interested. I would like to find someone with
the proper equipment to search this specimen for fossil cell structures.
| Field of View: 5mm
|| Field of View: 2.5mm
||Field of View: 2.5mm
|| Field of View: 1.5mm
Below is a view of the whole specimen. The wavy pattern is characteristic
|Field of View: 25cm
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All images ©1999 Daniel Moore