Name: Fossils in limestone
Classification: Carbonate rock, oolitic-bioclastic grainstone
Mineral composition: Calcite, Dolomite
Fossils:Echinoderms, molluscs
Location: Dibona Refuge (46°32'1.61"N 12° 4'18.87"E)
Formation: Heiligkreuz formation
Era: Lower Carnian (approximately 235 million years ago)
Depositional environment:Carbonate substructure

GAL01 MICROFOSSILIIMG_0297

This complex composition of colours and shades of grey, with some smooth and some textured spots of colour, is a landscape of sand made up of fragments of the fossilised shells of marine organisms. It is a type of calcite, and it is in fact a very common rock: from this we understand that fossils are not rare, on the contrary they are sometimes the main constituent of rocks. Fossils are often microscopic and escape observation.

In this image we recognise at least two types of fossils: at the centre there are two echinoderm fragments. Echinoderms are marine organisms such as starfish, sea urchins, sea lilies and sea cucumbers. Surrounding the two central granules we find elongated granules which are in fact shell fragments. The grains of this “fossil sand” measure approximately 1mm.

 

GALLERY