Comparison of Transmitted light (TL) and Cathode Luminescense (CL) microscopy.
images of the lower Paleocene interval above 794.11m, (not contested). Happily together occur numerous (real!) foraminifers and scattered dolomite crystals that display the same zoned overgrowth as the crystals in the transitional interval 794.11-794.60m.

 last updated:October 5, 2004
See also these foraminifers from Piobbico and these dolomite rhombs and foraminifers from ODP site 1049
CL, foraminifer TL, foraminifer CL, dolomite crystal TL, dolomite crystal
Sample 325 (see position in core), (entire thin section). Scattered dolomite crystals mixed with foraminifers in a micrite matrix. In Cathode luminescence (CL) the dolomite crystals all have a light rim, and dark interior, the foraminifers often the reverse, light interior, dark rim!. The reason being that the foraminiferal rim is a pure calcite (not reflective in CL), the chambers are filled with 'dirty' micrite, which is CL reflective due to higher Fe content. This is also in other micrite settings the case, (see example from Gubbio, and from ODP site 1049, Blake Nose). Here below is shown a superficial morphological resemblance to an uppermost Maastrichtian foraminifer.
See how much a dolomite crystal resembles the form "determined" by Keller as Plummerita hantkeninoides (1) sample 325

 

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