Abundant evidence supports the major contentions of the seafloor-spreading theory. First, samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid-ocean ridge is approached, and the sediment cover is thinner near the ridge.irst, samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid-ocean ridge is approached, and the sediment cover is thinner near the ridge.
Polk County Weather. The average temperature of Polk County is 72.96Â°F, which is higher than the Florida average temperature of 71.80Â°F and is much higher than the national average temperature of 54.45Â°F. Historical Weather. Heating Cost Index, #14.
South Florida. South Florida weather records include the counties of Broward, Collier, DeSoto, Highlands, Indian River, Lee, Manatee, Miami-Dade, Monroe, Palm Beach, St Lucie and Sarasota. Climate records for the central Florida region include cities in the counties of Brevard, Hillsborough, Orange, Pinellas, Polk and Volusia. North Florida temperatures are for weather stations in the counties of Alachua, Baker, Columbia, Duval, Hamilton, Madison, Marion, St Johns and Suwannee.