GEOL 114 Lecture Notes - Lecture 13: Mid-Ocean Ridge, Seismic Refraction, Andes
Document Summary
Continental crust is thicker and less dense than oceanic. It"s thickest in mountainous regions due to their thick (cid:498)root(cid:499) and thinnest in plains and coastal areas. Age: we can use radioactive dating and deformation to determine the age of rocks. The ages we determine refer to the most recent deformation. There are areas where rocks are highly metamorphosed, indicating they formed deep within the crust and are now exposed at the surface. Dating rocks in north america shows us that the center of the continent consists of older rocks, which progressively get younger moving outward toward the oceans. Taking pangea into consideration, we need to reconstruction the supercontinent to see that mountain belts formed in the collisions leading to pangea are continuous between continents. Structure: can look at the structure in detail using long lines of seismometers to observe changes in wave velocity.
