In sedimentary rocks, which of these is formed as a result of long periods under great heat and pressure?

1. Your syllabus: "Coal and some forms of iron ore have been concentrated as a result of long periods under great heat and pressure" in sedimentary rocks. 2. Gypsum, potash salt and sodium salt form by evaporation in arid regions. 3. Bauxite is a residual mineral (weathering). 4. Uranium is generally found in igneous/metamorphic settings. _Source: syllabus Social Science (Geography), Ch 5 "Minerals and Energy Resources", §5.1_