Dike along the Scenic Highway of Legends

 

 

 

 

 

This dike along the scenic Highway of Legends in south central Colorado between La Veta and Cuchara was created 25-million (or more) years ago when molten rock (magma), from deep within the earth, pushed toward the surface and oozed into cracks in the sedimentary rocks of the earths crust. This process was much like mud oozing between your toes. Pressure pushed that extremely hot molten rock (magma) into these cracks. When that molten rock slowly cooled 1,000' or more beneath the surface it formed extremely hard igneous rock like granite and rhyolite. Over the next 25-million plus years the much softer sedimentary rock has eroded away exposing these dikes of hard igneous rock that once filled those cracks deep within the earth's crust. Sedimentary rocks erode in strange ways depending on a number of factors. In this picture we can see where the sedimentary rock on the right side of the dike has eroded much faster than the sedimentary rock on the left side. I suspect that more water was flowing on the side where the most erosion occurred but I do not know that. In any event you can see the erosion process in vivid detail in this picture. Keep in mind I have no clue how deep this intrusion of igneous rock is. In places these dikes make impressive stone walls for miles and miles, some as long as 14-miles.

Dike in Stonewall along the Scenic Highway of Legends

 

 

 

 

This is the dike or "stone-wall' that the south central Colorado town of Stonewall was named for. Joyce took this picture of the "stone-wall" or dike that the town was named for.

 

Dike along the Scenic Highway of Legends between La Veta and Cuchara

 

 

 

 

 

In this exposed dike we were concentrating on how there were windows in the dike. Those windows were created when the molten rock was forced into cracks in the sedimentary rock then slowly hardened deep underground. As erosion exposed this dike the much softer sedimentary rock was eroded away. In this case leaving a window.

One other thing I will point out is the different colored rock on the side of this dike. That lighter colored rock is metamorphic rock. You will recall from earth science class in grade school, that metamorphic rock is a rock that has changed because of heat and or pressure. In this case sedimentary rocks were changed into schists & gneisses (metamorphic rocks) that are much harder than the original sedimentary rocks.

 

Emerging dike along the Scenic Highway of Legends south of La Veta

 

 

 

 

 

 

 

Only a small portion of this dike is exposed. How much will be exposed with another thousand or so years of erosion?

Exposed dike along the Scenic Highway of Legends

 

 

 

 

 

 

 

 

 

 

Massive dike along the Scenic Highway of Legends north of Cuchara