Other Important Geographical Features of North America

Please note that major physical features of North American Continent has already been discussed here

🟡 The Great Plains – The Breadbasket of North America

If you carefully look at physical map of North America you may observer, a giant semicircular plateau of grassland, stretching from Texas in the south all the way up to the Arctic Ocean—this is the Great Plains.

🧭 Location:

• Extends from the Rio Grande in the south to the Mackenzie River delta in the north.
• Bounded by:
  • Rockies (West),
  • Interior Lowlands and Canadian Shield (East).
• Covers 10 U.S. states and 3 Canadian provinces: Manitoba, Saskatchewan, Alberta.
• Occupies ~1/3rd of USA’s land area.

🏞️ Terrain:

• Contrary to popular belief, it’s not uniformly flat.
• Llano Estacado (Staked Plains, Texas) – extremely flat.
• Judith Mountains (Montana) – small mountain outcrops rise 1,500–2,000 ft above the plains.

💧 Drainage:

• In the USA:
  • Rivers: Missouri (with tributaries like Yellowstone, Platte, Kansas), Red River, Arkansas, and Rio Grande.
• In Canada:
  • Main river: Saskatchewan River and its tributaries.

The Great Plains is not just a geographical term—it is also a climatic and economic region, crucial for agriculture, cattle ranching, and energy resources (like shale gas).

🟤 The Great Basin – The Bowl of the American West

Now shift your attention to a unique physiographic feature: the Great Basin. You can see a series of rugged mountains enclosing vast closed valleys—a basin without an outlet to the sea.

📌 Location:

• Lies between:
  • Sierra Nevada (West),
  • Wasatch Mountains (East),
  • Columbia Plateau (North),
  • Mojave Desert (South).

🌵 Physical Characteristics:

• Part of the North American Desert system along with Sonoran, Chihuahuan, and Mojave deserts.
• Features alternating mountain ranges and valleys (a horst and graben structure).

💧 Internal Drainage:

• Water does not reach the ocean.
• Example: Humboldt River (Nevada) ends in the Humboldt Sink, a closed basin.

🧠 Insight: This is a classic case of an endorheic basin, where the hydrological cycle is complete within the basin—a significant concept in geomorphology.

🧱 Canadian Shield – The Ancient Core

Now let’s enter deep geological time. The Canadian Shield —a massive expanse of exposed Precambrian rock.

🗺️ Extent:

• Covers about 8 million sq. km across:
  • Eastern, Central, and Northwestern Canada,
  • Parts of Greenland,
  • Northern U.S. states: Minnesota, Wisconsin, Michigan, New York.

🧬 Geological Features:

• Made of ancient crystalline rocks (igneous and metamorphic).
• Shaped over billions of years through:
  • Uplift,
  • Orogeny (mountain-building),
  • Erosion.

🪨 Why important? It’s a storehouse of minerals—nickel, copper, gold, and uranium—and forms the backbone of Canadian economy.

🟠 San Andreas Fault – The Sliding Plates

It is a transform plate boundary—where two tectonic plates slide past each other horizontally.

🌍 Location:

• Between the Pacific Plate and North American Plate.
• Runs through California, from Cape Mendocino to the Mexican border.

🏙️ Plate Placement:

• San Diego & Los Angeles – on Pacific Plate.
• San Francisco & Sacramento – on North American Plate.

🔥 Earthquake Zone:

• Famously caused the 1906 San Francisco Earthquake.
• Visible Features:
  • Carrizo Plain and Olema Trough: Scarps and pressure ridges.
  • Sometimes hidden under alluvium or vegetation.

🧠 Concept: Transform boundaries are zones of shearing motion, unlike convergent (collision) or divergent (spreading) boundaries.

🗾 Dependent/Overseas Territories in North America

Colonial legacy still echoes in North America through several overseas and dependent territories, belonging to European powers and the USA.

Country	Territories
UK	Anguilla, Bermuda, British Virgin Islands, Cayman Islands, Montserrat, Turks & Caicos
France	Guadeloupe, Martinique, Saint Barthélemy, Saint Martin, Saint Pierre and Miquelon
Netherlands	Caribbean Netherlands, Sint Maarten
USA	Puerto Rico, U.S. Virgin Islands
Denmark	Greenland

🧠 These are often strategically located in the Caribbean and North Atlantic, serving naval, economic, and geopolitical functions.

🟢 Central America – The Isthmus of Diversity

Central America is the bridge between North and South America—narrow but extremely diverse.

🌎 Geography:

• Includes seven countries:
  • Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama
• Forms part of the Mesoamerican biodiversity hotspot.
• About 80% is hilly or mountainous.
• Features humid lowlands and coastal swamps.

🧬 Why important?

• It’s not just a land bridge for species, but also a corridor of cultures, migration, and tectonic activity.

🔺 Yucatan Peninsula – Land of the Maya

Finally, let’s zoom into the Yucatan Peninsula, a unique limestone projection into the Gulf of Mexico and Caribbean Sea.

📌 Location:

• Includes three Mexican states:
  • Campeche, Quintana Roo, Yucatan.
• Also extends into Belize and Guatemala.

🪨 Geology:

• Made primarily of porous limestone from coral rock.
• Features sinkholes (cenotes) and caverns due to chemical weathering.

🏛️ Cultural Significance:

• Mayan civilization thrived here.
• They built cities and ceremonial centres over this limestone base.

🧠 Key Concept: The Yucatan is a karst landscape, rich in archaeological, cultural, and hydrogeological significance.