Geology Reference
In-Depth Information
Fig. 10.44.
Aptychus
limestone. The thin section displays numerous fragments of aptychi within a fine-grained matrix. The
fragments appear curved due to the slightly domal character of the plates. The exterior ornamentation (white arrows;
T: tangential section of ribbed shell surface) is shown by uniformly oriented ribs. Small dark dots in the shells (black arrows)
are caused by the porous microstructure. The concentration of the shells in particular areas and their irregular distribution
within the sample are characteristics of strong burrowing. Late Jurassic: Karawanken Mountains, Austria. Scale is 1 mm.
limestones corresponds to the standard facies zones 1
and 2 (see Chap.14).
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