The large-scale dynamics of grain-size variation in alluvial

basins, 1: Theory

first # 2: Application to syntectonic conglomerate

Chris Paola, Paul L. Heller and Charles L. Angevine

Basin Research (1992) 4

Sediment Flux

Subsidence

Gravel Fraction

Diffusivity

Fig. 2 Slow Variation (T>>Teq)Isochrons (equal lines of time) are every 1,000,000 years

What are the differences among A-D?

Fig. 4 Rapid Variation (T<<Teq)

Sediment Flux

Subsidence

Gravel Fraction

Diffusivity

Isochrons are every 10,000 years

How are A-D different than the slow case?

Fig 5. Equilibrium Variation (T=Teq)

(isochrons are every 100,000 years)

Sediment Flux

Subsidence

Gravel Fraction

Diffusivity

Slow EQ Fast

How important is the equilibrium timescale to interpretation?

Fig. 7T>>Teq (slow variation)

Differing BasinCross-sectional Shapes.

Flux-driven

Subsidence-driven

Distribution driven

The end?