Dr. Jeff Marshall - Research
Central America and southern México
Research Project: Geomorphology and
physiographic provinces of Central America and southern México (Chapter 3 in Central America: Geology,
Resources, and Hazards, ed. by Bundschuh & Alvarado)
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Map of the physiographic
provinces of Central America as defined in this study. Solid lines indicate
province boundaries. Numbers on map refer to the list of physiographic
provinces at right. Yucatán platform and Chortis highlands sub-regions: a,
Northern pitted karst plain; b, Southern hilly karst plateau; c, Petén karst
plateau and lowlands; d, Eastern block-faulted coastal plain; e, Central
Chortis plateau; f, Western rifted highlands; g, Eastern dissected plateau;
h, Honduran borderlands. Digital elevation model derived from NASA Shuttle
Radar Topography Mission (SRTM) image PIA03364. |
Book Cover: Bundschuh, J. and Alvarado, G., eds.,
Central America: Geology, Resources, and Hazards, Taylor and Francis,
London. For complete table of
contents and publisher information click on the links below. |
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Project Overview: Several years ago, I
was invited to write a book chapter on the geomorphology of Central America
for a new comprehensive volume entitled Central America: Geology,
Resources, and Hazards, edited by Jochen Bundschuh and Guillermo Alvarado
(published in 2007 by Taylor & Francis). For this project, I decided to write a general review of
geomorphic research in Central America, including my own work in Costa
Rica. In preparing this chapter,
I encountered an astounding array of geomorphic research on many topics, but
soon realized that no one had previously defined a system of regional
physiographic provinces for Central America. I decided that this would be the primary contribution of
this chapter and would serve as a structure for organizing my review of prior
work. The figure above shows my
map of the newly defined physiographic provinces for Central America. The following paragraphs are excerpts
from the book chapter introduction. Book Information: Central America: Geology, Resources, and
Hazards,
2007, (Volumes 1 & 2), Bundschuh, J. and Alvarado, G., Taylor and
Francis, London. Geomorphology Chapter Overview: Chapter 3: The Geomorphology and Physiographic Provinces of Central
America Jeffrey S. Marshall “We have been sailing
placidly along the coast…all day - a broad, low land, densely clad in a
green, tropical vegetation…. In full view are three noble mountains - tall,
symmetrical cones, with sides furrowed with wrinkle-like valleys veiled in a
dreamy, purple mist that is charming to the eye, and summits swathed in a
grand turban of rolling clouds. They say these are volcanoes, but we cannot
see any smoke. No matter - it is a fairy landscape that is very pleasant to
look upon.” Mark Twain, December 1866, letter
written aboard the steamer Columbia offshore of Guatemala, published in the
San Francisco Alta California, March 15, 1867 Central America
encompasses an intricate mosaic of dynamic landscapes shaped by a wide range
of Earth surface processes. Few other regions worldwide exhibit a comparable
magnitude of geomorphic diversity. Along the length of the Central American
isthmus, highly variable tectonic, lithologic, and climatic domains are
superimposed across a small land area (0.4 % of Earth’s total land surface).
The resulting physiography is characterized by a heterogeneous array of
geomorphic provinces, each featuring a distinctive landform assemblage that
preserves a unique history of landscape evolution. Over 1500 km in length, Central America
reaches from the rugged Maya highlands of Guatemala in the north, to the
humid coast ranges of Panama’s Darién isthmus in the south. This narrow land
bridge links the two American continents and forms a critical divide between
the Pacific and Atlantic ocean basins, varying in width from less than 100 km
at the Panama Canal, to over 400 km across the interior highlands of
Nicaragua and Honduras. From towering volcanic peaks (>4000 m elevation)
to jungle-shrouded alluvial lowlands, and from rugged tectonic shorelines to
passive-margin lagoons, Central America embodies a geomorphic microcosm of
remarkable diversity. As a whole, the Central
American isthmus forms a geologically tenuous land bridge that links the two
American continents and creates a topographic divide between the Atlantic and
Pacific Ocean basins. This narrow landmass plays a vital role in directing
the ecological evolution of the Americas, and may also profoundly influence
ocean circulation and global climate. During the Cenozoic, a diverse array of
landscapes has developed along the isthmus in response to dynamic
interactions between regionally variable rock types, complex plate-boundary
tectonics, and an energetic tropical climate. Central America therefore
serves as a unique laboratory for the study of a wide range of geomorphic processes
and consequent pathways of landscape evolution. This chapter explores the regional
geomorphology of Central America and defines a system of physiographic
provinces that characterizes the overall landscape diversity of this dynamic
region. The chapter is organized into sections that provide an overview of
the characteristic landforms and geomorphic processes that define each of the
physiographic provinces. The first half of the chapter looks at the
geomorphic provinces of northern Central America, and the second half
examines those of southern Central America. Each section provides a brief
review of current geomorphic research within the physiographic provinces. Due
to the wide range of possible topics, it is impractical to cover every aspect
of these diverse landscapes. The discussion is therefore limited to a subset
of critical topics that provide a general flavor for the regional
geomorphology of Central America. Several of these topics are explored in
greater detail in the four chapters that follow: Volcanism and volcanic
landforms (Chapter 4), Karst landscapes (Chapter 5), Glacial geology and
geomorphology (Chapter 6), and Coastal morphology and coral reefs (Chapter
7). Pre-print of
Chapter 3 (draft version): Marshall, J.S., 2007, Geomorphology
and Physiographic Provinces of Central America: in Bundschuh, J. and
Alvarado, G., eds., Central America: Geology, Resources, and Hazards, Taylor and Francis,
London, p 75-122. Images: Back to: |
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