Geochronologic, Isotopic, and Geochemical Data from Igneous Rocks in the Lane Mountain Area, San Bernardino County, California
Links
- Document: Report (9.7 MB pdf)
- Related Works:
- Open-File Report 2021-1094 - Geochronologic, Isotopic, and Geochemical Data from Pre- Cretaceous Plutonic Rocks in the Lane Mountain Area, San Bernardino County, California
- Open-File Report 2022-1115 - Geochronologic and Geochemical Data from Metasedimentary and Associated Rocks in the Lane Mountain Area, San Bernardino County, California
- Download citation as: RIS | Dublin Core
Abstract
We present new geochronologic, isotopic, and geochemical data for selected igneous rocks in the Lane Mountain area, California. We determined SHRIMP-RG U-Pb zircon ages for the following units: (1) Larrea complex (~253 Ma and ~149–146 Ma); (2) Daisy granodiorite (~151 Ma); (3) Jack Spring quartz monzonite (~85–82 Ma); (4) unnamed porphyritic dikes and stocks (~80–73 Ma); and (5) Lane Mountain volcanics (~22 Ma). These results confirm and refine previous age determinations for the Larrea complex, Jack Spring quartz monzonite, and Lane Mountain volcanics, and provide the first reliable ages for the Daisy granodiorite and the unnamed porphyritic rocks. Sri of the plutonic rocks increases from ~0.704 to ~0.705–0.706 to ~0.708–0.709 for samples dated as ~250, ~150, and ~85–70 Ma, respectively, which indicates progressively greater involvement of Precambrian continental lithosphere in magma generation through time. The Sri and geochemical data suggest that the most significant change in magmatic source occurred between ~150 and 85 Ma.
Suggested Citation
Stone, P., Brown, H.J., Cecil, M.R., Fleck, R.J., Vazquez, J.A., Fitzpatrick, J.A., and Rosario, J., 2019, Geochronologic, isotopic, and geochemical data from igneous rocks in the Lane Mountain area, San Bernardino County, California: U.S. Geological Survey Open-File Report 2019–1070, 34 p., https://doi.org/10.3133/ofr20191070.
ISSN: 2331-1258 (online)
Study Area
Table of Contents
- Abstract
- Introduction
- Geographic Setting
- Previous Investigations and General Geologic Framework
- Purpose and Scope
- Methods
- Results
- Discussion
- Summary
- Acknowledgments
- References Cited
- Figures and Tables
Publication type | Report |
---|---|
Publication Subtype | USGS Numbered Series |
Title | Geochronologic, isotopic, and geochemical data from igneous rocks in the Lane Mountain area, San Bernardino County, California |
Series title | Open-File Report |
Series number | 2019-1070 |
DOI | 10.3133/ofr20191070 |
Year Published | 2019 |
Language | English |
Publisher | U.S. Geological Survey |
Publisher location | Reston, VA |
Contributing office(s) | Geology, Minerals, Energy, and Geophysics Science Center |
Description | 34 p. |
Country | United States |
State | California |
County | San Bernardino County |
Online Only (Y/N) | Y |
Google Analytic Metrics | Metrics page |