Red Rocks Geo Card  E-mail this product to a friend

Back of the card reads: The red rock layers west of Denver are composed of conglomerate, sandstone, and siltstone. The names of the rocks are determined by the size of the grains that make up the rock, with conglomerate containing the largest grains and siltstone the smallest. These rocks record two mountain building events. The rocks themselves record deposition during the older event (~300 million years ago). The layers were then tilted during the younger event (40-80 million years ago). The present high mountains of Colorado were uplifted during and third event that is continuing today.