Portland Limestone thin section slide exhibiting micro oolites. Portland stone formed in sub-tropical seas where wave action resulted in the formation of micro oolites during the Tithonian stage of the Upper Jurassic. A very thin film of calcite cement can be seen holding grains together and in some micro oolites a tiny nucleous can be identified. The section is made to 30 microns thickness and the glass is 46 x 27 mm in size with a cover slip. Supplied in a protective card sleeve with a label, ideal for microscopy.
