Geologic map of the Julian 7.5' quadrangle, San Diego County, California
Links
- More information: USGS Index Page
- Document: Pamphlet (pdf)
- Plate: Map (pdf)
- Additional Report Pieces:
- Companion Files:
- Database (zip) ESRI ArcGIS 10.2 File Geodatabase
- Shapefile (zip)
- ESRI Styles
- Metadata: Metadata (txt)
- Read Me: Readme (txt)
- NGMDB Index Page: National Geologic Map Database Index Page
- Download citation as: RIS | Dublin Core
Abstract
The Julian 7.5' quadrangle lies within the Jurassic-Cretaceous Peninsular Ranges batholith of southern California and Baja California. Four granitic plutonic units and one gabbroic unit, most comprising a number of individual plutons, have been mapped in the Julian quadrangle and informal names have been assigned. The formal name Cuyamaca Gabbro has been retained. In addition to these plutonic units, metasedimentary and minor metavolcanic rocks occur in steeply dipping tabular bodies, or screens, within and between plutons.
Jurassic plutons in the Julian quadrangle underwent synkinematic metamorphism with the result that plutonic contacts and foliation are concordant with those in the surrounding metamorphosed country rocks. Foliation in Jurassic plutons consists of the planar orientation of recrystallized mineral grains and aggregates; deformation textures include augen gneiss, mylonitic gneiss, and mylonite. Structural studies indicate that a significant part of this deformation took place in the Cretaceous and, therefore, the regional foliation in this part of the batholith clearly postdates intrusion of many Cretaceous plutons.
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Geologic map of the Julian 7.5' quadrangle, San Diego County, California |
| Series title | Open-File Report |
| Series number | 94-16 |
| DOI | 10.3133/ofr9416 |
| Year Published | 2015 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Reston, VA |
| Contributing office(s) | Geology, Minerals, Energy, and Geophysics Science Center |
| Description | Pamphlet: ii, 18 p.; 1 Plate: 31.99 × 32.00 inches; Readme; Metadata; Database; Shapefile |
| Country | United States |
| State | California |
| County | San Diego County |
| Other Geospatial | Julian quadrangle |
| Online Only (Y/N) | Y |
| Additional Online Files (Y/N) | N |
| Google Analytic Metrics | Metrics page |