Question

In the petroleum industry, limestone is usually given a name using the Dunham classification, as attached. For any limestone you can follow the flowchart to find its correct name.

This limestone consists mostly of carbonate mud with about 20% shell fragments that do not touch.

rock name __________________________________

This limestone consists of small and large calcite and dolomite crystals. No shells or other carbonate grains are visible.

rock name __________________________________

This limestone has broken shells that touch each other, with about 20% mud between the shells and 15% porosity.

rock name __________________________________

This limestone consists mostly of corals that appear to have grown in their present position before they died and the corals became rock.

rock name __________________________________

This limestone consists of very well sorted, round carbonate grains and some shells that are touching. It has very good porosity, and there is no carbonate mud.

rock name __________________________________

This limestone is dark gray, very fine grained and has no visible shells or crystals.

rock name __________________________________

This limestone consists mostly of shells (therefore it is grain supported), has a little carbonate mud, but also has some quartz grains.

rock name __________________________________

This limestone consists of rounded shell fragments, round carbonate grains, has no mud, and all of the pores have calcite cement.

rock name __________________________________

This limestone has few shells (about 5% of the rock consists of shells) that do not touch each other but consists mostly of carbonate mud.

rock name __________________________________

This limestone consists of 100% shell fragments held together by a calcite cement.

rock name __________________________________

Answer 1

Limestone classification based on durham rules

This limestone consists mostly of carbonate mud with about 20% shell fragments that do not touch.

rock name Mudstone.

This limestone consists of small and large calcite and dolomite crystals. No shells or other carbonate grains are visible.

rock name dolostone

This limestone has broken shells that touch each other, with about 20% mud between the shells and 15% porosity.

rock name tufa

This limestone consists mostly of corals that appear to have grown in their present position before they died and the corals became rock.

rock name coquina

This limestone consists of very well sorted, round carbonate grains and some shells that are touching. It has very good porosity, and there is no carbonate mud.

rock name grainstone

This limestone is dark gray, very fine grained and has no visible shells or crystals.

rock name graywacke

This limestone consists mostly of shells (therefore it is grain supported), has a little carbonate mud, but also has some quartz grains.

rock name rudstone

This limestone consists of rounded shell fragments, round carbonate grains, has no mud, and all of the pores have calcite cement.

rock name mudstone

This limestone has few shells (about 5% of the rock consists of shells) that do not touch each other but consists mostly of carbonate mud.

rock name floatstone

This limestone consists of 100% shell fragments held together by a calcite cement.

rock name boundstone