•Antecedent Landform Reflecting Paleotectonic Processes and Differential Weathering of Rocks and Structures
Feature
Patuca-Coco anticlinorium (pre-Coco-Patuca rivers)
Description
Topographic feature that separated alluvial Patuca and Coco rivers prior to entrenchment
Origin
Exposure and differential weathering of Montana de Colon fold-thrust belt
Age of landform
Paleocene
Feature
Northeast flowing meandering bedrock rivers of eastern Chortis block
Description
Largest rivers on Chortis block (Patuca and Coco) flow down topographic axis of Chortis block.
Origin
River positions are pinned in place by uplift (see below). River positions have NOT changed with eastward movement of Chortis block. May reflect Maya block position to north.
Age of landform
Miocene (?)
Feature
Highlands of Chortis Block
Description
Ranges and relatively high valleys (overprinted to west by extension) north of back-arc .
Includes meandering bedrock rivers, water and wind gaps, and dissected erosion surfaces.
Origin
Differential weathering of rocks and structures subjected to epeirogenic uplift. Erosion accentuating lithologic differences and fault systems.
Age of landform
Post-Middle Miocene Padre Miguel Group.
Probably late Neogene.
•Areas Displaying Evidence of Epeirogenic Uplift
Feature
Bedrock Meanders and Canyons "Boqueron"
Description
Fluvial meanders entrenched >300 meters into bedrock. Contiguous in east, disrupted in west.
Origin
Epeirogenic uplift of Chortis block entrenched fluvial meanders.
Age of landform
Post-Middle Miocene Padre Miguel Group.
Probably late Neogene.
•Meandering Bedrock Rivers
