1.13 Denudation Chronology
Case Study 1: Denudation Chronology – Western Ghats and Appalachian Mountains
Models/Theories/Laws:
- Davisian Cycle of Erosion – Sequential landform evolution.
- Penck’s Theory of Landscape Evolution – Continuous uplift and erosion.
- Dynamic Equilibrium Model – Balance between uplift and erosion.
- Palimpsest Topography - Polycyclic landscape.
- Uniformitarianism - All landforms undergoing same process.
Recent Data:
- Western Ghats: Erosion rates estimated at ~0.2 mm/year, influenced by monsoonal rainfall.
- Appalachian Mountains: Thermochronology studies indicate long-term erosion over 300 MYA.
- Satellite Imagery Analysis: Shows retreat of escarpments and valley widening.
Spatial Variation:
- Western Ghats: Active erosion shaping deep valleys and steep escarpments.
- Appalachians: Mature landscape characterized by subdued relief.
Temporal Variation:
- Western Ghats: Denudation ongoing for ~65 MYA, linked to tropical climate.
- Appalachians: Erosion-dominated landscape evolution over ~300 MYA.
Insight:
The Western Ghats and Appalachian Mountains exemplify denudation chronology, validating Davis’ and Penck’s models through uplift, erosion, and landscape transformation.
Case Study 2: Denudation Chronology – Colorado Plateau and Tibetan Plateau
Models/Theories/Laws:
- Davis’ Geomorphic Cycle – Youth, maturity, old age.
- Isostatic Uplift Model – Compensation-driven elevation changes.
- Tectonic Denudation – Interaction between tectonics and erosion.
Recent Data:
- Colorado Plateau: Uplift-driven denudation shaping mesas and canyons over ~70 MYA.
- Tibetan Plateau: GNSS confirms ongoing uplift at ~5 mm/year, with erosion-driven compensation.
- GRACE Mission Data: Mass redistribution patterns observed.
Spatial Variation:
- Colorado Plateau: Sediment yield influencing Grand Canyon evolution.
- Tibetan Plateau: Glacial erosion driving relief modification.
Temporal Variation:
- Colorado Plateau: Denudation linked to long-term uplift.
- Tibetan Plateau: Erosion cycles observed over 50 MYA.
Source:
- Oxford Academic: “Denudation and Landscape Evolution in High Plateaus”
- Geoscience Journal: “Denudation Processes and Climate Interactions”
Insight:
The Colorado and Tibetan Plateaus illustrate denudation cycles through uplift, climate-driven erosion, and tectonic interactions.
