ESCI 1001 Lecture Notes - Lecture 9: Asthenosphere, Basalt, Marie Tharp
Document Summary
India: evidence of warm climates in places that are now cold, coal and plant fossils in antarctica. What he got right: the continents do move (they just don"t (cid:498)drift(cid:499). At the time, everyone thought the seafloor was the oldest part of earth"s tectonics) Problem = no mechanism to explain the motion of the continents. So continents had to move across (or plow through) older seafloor rock. However, no viable mechanism that could account for continental drift (so surface the idea was not widely accepted) In the 1950s the idea of drift was rejuvenated, ironically as an outgrowth of. Meanwhile, studies of geomagnetism made a surprising contribution. The plate tectonic theory was largely the product of paleomagnetism and earthquake studies. William gilbert (1600: first to explain the connection between compass and earth overlap, variation of inclination over surface lodestone, earth as a magnet. Geomagnetic field at surface is similar to a magnetic dipole.
