Abstract
Leaf physiognomy provides estimates of environmental parameters, including mean annual enthalpy, which is a thermodynamic parameter of the atmosphere that varies with altitude. Analyses of 12 mid-Miocene floras from western Nevada indicate that this part of the Basin and Range Province stood ~3 kilometers above sea level at 15 to 16 million years ago, which is 1 to 1.5 kilometers higher than its present altitude. Much, if not all, of the collapse to present-day altitudes seems to have been achieved by ~13 million years ago. The crust in much of this area has been extended and thinned throughout the past 40 to 50 million years, and the isostatic balance of a thinning crust requires subsidence, not uplift as suggested by previous paleobotanical work.
Original language | English (US) |
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Pages (from-to) | 1672-1675 |
Number of pages | 4 |
Journal | Science |
Volume | 276 |
Issue number | 5319 |
DOIs | |
State | Published - Jun 13 1997 |
All Science Journal Classification (ASJC) codes
- General