Biology Reference
In-Depth Information
tant fl ora because it is one of the few in northern Latin America that reveals
conditions during the transition between the hothouse interval of the early
Tertiary and the icehouse interval of later Tertiary and Quaternary times.
The Transvolcanic Belt includes basins, such as the Basin of Mexico
where Mexico City is located on former Lake Texcoco. Water is now being
removed at a rate of 60 m
3
/sec causing severe problems for the 20 million
inhabitants of a city where the population increases by about 30,000 people
per year. Cores are necessary to test the foundation for construction like
the Torre Latinoamericana and to rectify the notable sinking of existing
structures like the Palacio de Bellas Artes (images of both buildings are
available at several sites on the Web). The cores from these water-saturated
sediments, and from adjacent basins, contain fossil spores and pollen.
They have been used by Socorro Lozano Garcia and colleagues at UNAM,
and by Sara Metcalfe and coworkers at the University of Nottingham, to
Figure 2.20
Principal plates and subduction zones from southern North America to southern
South America: B.C.
=
Baja California; PRT
=
Puerto Rican Trench; SAF
=
San Andreas Fault.
