Sample preparation
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For microthermometric analysis of stalagmite fluid inclusions, we prepare sections of 200-300 μm thickness. Sample preparation involves the following steps:
1. The stalagmite is cut in halves parallel to the growth axis, and then a slab of ca. 10 mm thickness cut from one of the two halves. For the cutting we use a diamond wire saw (Well, Model 6500) with a wire thickness of 0.5 mm. The maximum sample length is 300 mm.
2. Using the same saw, cut a 20 mm wide stripe from the slab either on the left- or right-hand side of the central growth axis. This stripe is finally divided into blocks of maximum 40 mm length.
3. The blocks are then attached to standard (28 x 48 mm) microscope glass slides using superglue. Subsequently, the glass slide with the sample block is fixed on a Buehler Isomet low-speed saw equipped with a 0.4 mm thick blade to cut the thick sections.
A first section is commonly prepared for petrographic analysis. The section is cut to a thickness of 500 μm and then ground and polished to a final thickness of 100-200 μm. This section stays on the glass slide. The remaining block is then attached to a new glass slide and a second section that will be used for fluid inclusion microthetrmometry is cut to a thickness of 200-300 μm. The cut faces of this section do not get polished to keep the mechanical stress on the sample at a minimum. The microthermometry section is further cut into 5 mm wide stripes parallel to the growth direction with a small diamond wire saw (Well, Model 3241). After photographic documentation, the section is removed from the glass slide in an acetone bath.
Note: For petrographic sections, the blocks can also be attached to the glass slides with epoxy resin, but curing must proceed at room temperature to avoid stretching of the inclusions.
For more information, please watch our tutorial video Sample selection and preparation.
