Geomorphic analysis of transient landscapes in the Sierra Madre de Chiapas and Maya Mountains (northern Central America): implications for the North American–Caribbean–Cocos plate boundary

L Andreani,R Gloaguen

doi:10.5194/esurf-4-71-2016

Abstract

Abstract. We use a geomorphic approach in order to unravel the recent evolution of the diffuse triple junction between the North American, Caribbean, and Cocos plates in northern Central America. We intend to characterize and understand the complex tectonic setting that produced an intricate pattern of landscapes using tectonic geomorphology, as well as available geological and geophysical data. We classify regions with specific relief characteristics and highlight uplifted relict landscapes in northern Central America. We also analyze the drainage network from the Sierra Madre de Chiapas and Maya Mountains in order to extract information about potential vertical displacements. Our results suggest that most of the landscapes of the Sierra Madre de Chiapas and Maya Mountains are in a transient stage. Topographic profiles and morphometric maps highlight elevated relict surfaces that are characterized by a low-amplitude relief. The river longitudinal profiles display upper reaches witnessing these relict landscapes. Lower reaches adjust to new base-level conditions and are characterized by multiple knickpoints. These results backed by published GPS and seismotectonic data allow us to refine and extend existing geodynamic models of the triple junction. Relict landscapes are delimited by faults and thus result from a tectonic control. The topography of the Sierra Madre de Chiapas evolved as the result of (1) the inland migration of deformation related to the coupling between the Chiapas Massif and the Cocos forearc sliver and (2) the compression along the northern tip of the Central American volcanic arc. Although most of the shortening between the Cocos forearc sliver and the North American Plate is accommodated within the Sierra de Chiapas and Sierra de los Cuchumatanes, a small part may be still transmitted to the Maya Mountains and the Belize margin through a "rigid" Petén Basin.

Highlights

The aim of this work is to examine geomorphic features along two key areas in order to test existing models of the North American–Caribbean–Cocos plate boundary (e.g., Malfait and Dinkelman, 1972; Burkart, 1983; GuzmánSpeziale et al, 1989; Lyon-Caen et al, 2006; Ratschbacher et al, 2009; Authemayou et al, 2011)
We demonstrate that a geomorphic analysis allows for classification of zones of similar relief patterns that we assume witnessed different tectonic and erosive histories
Using DEMbased geomorphic indices, we examined the topography of the Sierra Madre de Chiapas and the Maya Mountains

Summary

Introduction

The aim of this work is to examine geomorphic features along two key areas (the Sierra Madre de Chiapas and the Maya Mountains, Fig. 1) in order to test existing models of the North American–Caribbean–Cocos plate boundary (e.g., Malfait and Dinkelman, 1972; Burkart, 1983; GuzmánSpeziale et al, 1989; Lyon-Caen et al, 2006; Ratschbacher et al, 2009; Authemayou et al, 2011). The oceanic Cocos Plate is subducted beneath the North American and Caribbean plates along the Middle America Trench, while the North American–Caribbean plate boundary is a sinistral transform system which accommodates the eastward escape of the Caribbean Plate (e.g., Lyon-Caen et al, 2006; Manea and Manea, 2006; Andreani et al, 2008a; Authemayou et al, 2011). Gloaguen: Geomorphic analysis of transient landscapes in northern Central America

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