Feature
Median-Nicaragua Back-Arc basin
Description
800 km long structural basin and topographic low behind and parallel to MAT and volcanic arc from Salvador to Nicaragua
Origin
Active extension
- subducted Cocos slab roll-back?
- MAT not keeping pace with eastward movement of Caribbean Plate?
Age of Landform
Late Neogene (?) to Recent
Feature
North-south trending ranges and valleys of western Chortis
Description
Normal and strike-slip fault bounded valleys and ranges west of Honduras Depression and north of back-arc.
Origin
Caribbean-North American Plate interaction across a diffuse margin.
Allowed by post-10 Ma deceleration of convergence between South America and North America.
Age of Landform
Late Neogene to Recent
•Landforms Reflecting Crustal Properties of Chortis Block
Feature
Elevated topographic/ bathymetric portion of Chortis Block
Description
All of Chortis block north of Median Nicaragua back-arc
Origin
Unknown.
Possibly a buoyant response. Implies lower crust - upper mantle involvement
Age of landform
Post - Middle Miocene.
Likely Late Neogene
•Elevated Portion of Chortis Block
Feature
West to East topographic/ bathymetric gradient.
Description
Higher elevations to west, north of back-arc. Includes Eocene to recent sedimentation on Nicaragua Rise
Origin
Crustal buoyancy variation across Chortis block
- Continental crust west of GFS.
- Transitional crust between GFS and Siuna, Nicaragua
Oceanic Crust east of Siuna, Nicaragua
Age of landform
AgeofCrust
Pre-Jurassic Jurassic Cretaceous
•Cross-Chortis Block Elevation Gradient
•Crustal Types of Northern Central America
