The View from the Top

The View from the Top. . , Five thousand feet below and about 20 degrees warmer is the city of Albuquerque. It is situated in the Rio Grande basin within the Rio Grande Rift, a zone of faults that has formed basins and ranges from southern Colorado into Mexico. This rift is five miles deep, one of the greatest troughs on Earth., The ancient Rio Grande began invading the rift about three million years ago. You can see the Rio Grande in the valley below lined with the 'bosque" forest composed primarily of cottonwood, elm, salt cedar and Russian olive trees., Two large blocks of earth created the Sandia Mountains about five million years ago. One block was forced upward along a fault and tilted eastward 15 degrees to make the Sandias, while the other block dropped downward to form the Rio Grande basin. Movement can still be detected along this fault zone. Fifteen thousand feet of water-deposited sand and mud now fill the basin underneath Albuquerque. Most of Albuquerque's water is trapped in the pore spaces of this sediment., Volcanic activity during rifting produced large quantities of volcanic rocks in the rift. Note Mount Taylor in front of you 66 miles to the west. This extinct volcano rises nearly half a mile above its base and reaches an elevation of 11,301 ft. The Albuquerque volcanoes (small, black cones 19 miles west of the Sandia Mountains) are young in the scope of geologic time - only 190,000 years old!