Course materials for Plate Tectonics, GEOL 3700, University of Nebraska at Omaha. Instructor: H. D. Maher Jr., copyright. This material may be used for non-profit educational purposes with appropriate attribution of authorship. Otherwise please contact author.

Some answers to questions for Week 1: When the earth moves: an introduction to vertical and horizontal tectonics through history of geologic thought.

What are various indications of vertical movement, uplift and subsidence?

What were unsatisfactory aspects of geosynclinal theory?

What is isostasy? Simply put, the crust acts like it is floating. Put a load on and it sinks. Take it off and it rises. Response time is on the order of thousands to tens of thousands of years.

Reasons for the general rejection of Wegener's hypothesis:

Where does the rock's magnetic field component comes from?

Curie temperature = point at which a stable magnetic field is imprinted or destroyed in a rock.

If rock has magnetic minerals these align with the earth's field at time they pass through Curie temperature, or if at lower T, at time the mineral forms. A fossil field or Natural Remanent Magnetization (NRM) is thus acquired. Various types exist such as: