The negative effects of geological structures in our environment can be landslides occurring on unfavorably oriented geological structures causing damage and sometimes loss of life on highways and railways, for example.A positive effect of geological structures is that where there are subduction zones, mineral deposits can form above them on the adjoining continents like in British Columbia on the west coast of North America. Also, faults and fractures can allow hydrothermal fluids charged with metals to form ore deposits.
The answer in finding the age of a sedimentary rock layer through radiometric dating can be assumed <span>between the absolute ages of the two igneous units.
Sedimentary rocks don't have radioactive elements so the beast way to know the age is through understanding what can elements in between can provide as evidence</span>
Oxygen was absent on earth
