Q. Consider the following statements:

1. In sedimentary rocks a number of minerals occur in beds or layers.
2. They have been formed as a result of deposition, accumulation and concentration in vertical strata.
3. Gypsum, potash salt and sodium salt are formed as a result of evaporation especially in arid regions.

Which of the above is / are correct?
Answer: All of the above
Notes: In sedimentary rocks a number of minerals occur in beds or layers. They have been formed as a result of deposition, accumulation and concentration in horizontal strata. Coal and some forms of iron ore have been concentrated as a result of long periods under great heat and pressure. Another group of sedimentary minerals include gypsum, potash salt and sodium salt. These are formed as a result of evaporation especially in arid regions.