Answer:
A. volcanic ash layers were regularly interspersed between the sedimentary strata.
Step-by-step explanation:
- In order to assign the absolute dates to the fossil records of the sedimentary core that have been deposited n the inland areas of the seafloor bottoms.
- The geologist studies the ash layers and sedimentary gaps that are found between them and as to find out the irregulars and the regularities that existed in the rocks at that time.