Laserfiche WebLink
<br />~ <br />00 <br />L" <br />... <br /> <br />c. <br /> <br />. <br /> <br />. <br /> <br />6 <br /> <br />Stratioraphy <br /> <br />Although no igneous or metamorphic rocks outcrop in the project area, a <br />great variety of sedimentary rock formations does occur. These strata <br />range in age from late Precambrian (approximately 1.2 billion years old) <br />to Holocene (stream deposits still forming today). Spectacular exposures <br /> <br />of the Precambrian and Paleozoic formations occur in Cross Mountain Canyon <br />and Juniper Canyon, where the Yampa River has cut down into the centers of <br />the respective anticlines (thus, to lower stratigraphic levels). Cretaceous <br /> <br />strata underlie most of the area to be flooded by the Juniper Reservoir, and <br />are very well exposed in the area surrounding the upper reaches of that <br /> <br />potential body of water where the Yampa River has entrenched itself through <br /> <br />massive hogbacks made of thick Cretaceous sandstones. Most of the Cross <br />Mountain Reservoir site is underlain and surrounded by the Tertiary Brown's <br /> <br />Park Formation, but due to its relative non-resistance exposures are gener- <br /> <br />ally poor. <br /> <br />The ages and lithologic characteristics of all rock formations exposed in <br /> <br /> <br />the Juniper - Cross Mountain Project area are summarized in the following <br /> <br />chart. <br /> <br />.. or----' <br />