Figure 2 shows a
large lateral velocity variation in the upper mantle. The author
suggests that these differences could be a reflection of the temperature
variation within the asthenosphere. Could there be other factors that
contribute to the velocity variation within the Asthenosphere ?
suggests that western North America (e.g., from the Canadian shield
to the Pacific plate margin) contains the largest mantle-velocity
gradient on Earth. If this is true, what do you think causes this
What do you think is
the origin of the high velocity lower crustal layer?
Why authors selected
North America for such study?
How the Proterozoic
lithosphere of Colorado and New Mexico differs from lithosphere beneath
the Archean core of the continent?
How Moho layer
formed at Rocky Mountains as per the authors' point of view?
What does the combined
geophysical and geologic data from the CD-ROM experiment provide?
What does the integrated
data set for the Cheyenne belt, the Farwell-Lester Mountain zone, and
the Jemez lineament, and their corresponding velocity anomalies in the
mantle (to >200 km) indicate?
What are the two
provocative and testable hypotheses concerning lithospheric evolution?
Questions or Comments?
Dr. Ali O. Oncel