Maria fold and thrust belt facts for kids

The Maria Fold-and-Thrust-Belt (MFTB) is a special area of mountains and valleys in southeastern California and western Arizona. It's part of a much larger mountain system called the North American Cordillera.

What makes the Maria Fold-and-Thrust-Belt unique is how its rocks were squeezed and pushed together. Most of the Cordillera was squeezed from east to west. But in the MFTB, the squeezing happened mostly from north to south. This created many interesting geological features, like metamorphic core complexes, which are deep rocks brought to the surface. The Whipple Mountains in California are a great example of this.

Geology of the Maria Fold-and-Thrust-Belt

The Maria Fold-and-Thrust-Belt is where the direction of squeezing that formed the North American Cordillera suddenly changed. North of this belt, mountains usually run north to south. This is because the land was squeezed from east to west. This squeezing happened as the Farallon slab (a huge piece of Earth's crust) slid under western North America.

However, at the Maria Fold-and-Thrust-Belt, the squeezing changed direction. It became more of a north-south push. This caused the front edge of the mountains to run mostly east to west. This line then curves slightly to the southeast, where the mountain-building forces spread out into a wide area in northeastern Mexico.

Another cool thing about the MFTB is that it involves some of the oldest and strongest rocks of the North American craton. The rest of the Cordillera mostly involves younger rocks that were once near the coast or under the ocean.

Ecology and Wildlife

The Maria Fold-and-Thrust-Belt acts like a natural boundary for many plants and animals. This is because the soil and climate are different on each side of this geological area.

For example, the endangered California Fan Palm (Washingtonia filifera) is a good example. You won't find this type of palm tree growing naturally north of the Maria Fold-and-Thrust-Belt. More specifically, it doesn't grow north of the Turtle Mountains, which are part of this belt.

Mountain Ranges in the Belt

The Maria Fold-and-Thrust-Belt includes many mountain ranges. These ranges are found in the southeastern Mojave Desert and northwestern Sonoran Desert. Some of these ranges include:

Nearby Landforms and Features

Here are some other important landforms and features found near the Maria Fold-and-Thrust-Belt: