Indicate your typed answer to the question as a response to…

Indicate your typed answer to the question as a response to A, B, and C. Calcite vs. Aragonite Seas. Oceanic crust production was higher during the Cretaceous than today, given this knowledge answer the three parts below (A-C). A. (2 pts) How did this affect global sea level during the Cretaceous Period? B. (3 pts) How did this affect the magnesium:calcium (Mg/Ca) of seawater during the Cretaceous Period? Describe the processes impacting the Mg/Ca of seawater and where they are happening. C. (3 pts) How did this affect the mineralogy of carbonate (CaCO3) producing and reef-building marine organisms during the Cretaceous?

Use the maps shown below to answer questions A thru D and la…

Use the maps shown below to answer questions A thru D and label your answers as A through D in your typed response. The upper map shows sea-surface salinity and the lower map shows the oxygen isotope (del18O) composition of the surface ocean. Figure 1: Global map showing sea-surface salinity.   Figure 2: Global map showing the oxygen isotope (d18O) composition of the surface ocean.   A. (2 pts) The subtropics in both hemispheres are very arid regions with higher sea-surface salinities, why? B. (2 pts) Sea-surface salinities are relatively low at about 5ºN of the equator in both the Atlantic and Pacific Ocean basins, why? C. (2 pts) Comparison of the two maps clearly shows that surface-ocean del18O composition closely tracks sea-surface salinity, why? D. (2 pts) Look at the map showing surface-ocean del18O. Why does the surface-ocean del18O composition decrease with increasing latitude?