Geologic map of the Harvard Lakes 7.5' quadrangle, Park and Chaffee Counties, Colorado
Scientific Investigations Map
3267
Links
- More information: USGS Index Page
- Document: Report
- Plate: Sim 3267 (pdf)
- Companion File: Companion Files
- Download citation as: RIS | Dublin Core
Abstract
The Harvard Lakes 1:24,000-scale quadrangle spans the Arkansas River Valley in central Colorado, and includes the foothills of the Sawatch Range on the west and Mosquito Range on the east. The Arkansas River valley lies in the northern end of the Rio Grande rift and is structurally controlled by Oligocene and younger normal faults mostly along the west side of the valley. Five separate pediment surfaces were mapped, and distinctions were made between terraces formed by the Arkansas River and surfaces that formed from erosion and alluviation that emanated from the Sawatch Range. Three flood deposits containing boulders as long as 15 m were deposited from glacial breakouts just north of the quadrangle. Miocene and Pliocene basin-fill deposits of the Dry Union Formation are exposed beneath terrace or pediment deposits in several places. The southwestern part of the late Eocene Buffalo Peaks volcanic center, mostly andesitic breccias and flows and ash-flow tuffs, occupy the northeastern corner of the map. Dated Tertiary intrusive rocks include Late Cretaceous or early Paleocene hornblende gabbro and hornblende monzonite. Numerous rhyolite and dacite dikes of inferred early Tertiary or Late Cretaceous age also intrude the basement rocks. Basement rocks are predominantly Mesoproterozoic granites, and subordinately Paleoproterozoic biotite gneiss and granitic gneiss.
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Geologic map of the Harvard Lakes 7.5' quadrangle, Park and Chaffee Counties, Colorado |
| Series title | Scientific Investigations Map |
| Series number | 3267 |
| DOI | 10.3133/sim3267 |
| Year Published | 2013 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Reston, VA |
| Contributing office(s) | Geosciences and Environmental Change Science Center |
| Description | Report: iv, 18 p.; 1 Map: 36.00 x 33.00 inches; Downloads Directory |
| Country | United States |
| State | Colorado |
| County | Chaffee County;Park County |
| Online Only (Y/N) | Y |
| Additional Online Files (Y/N) | Y |
| Google Analytic Metrics | Metrics page |