San Diego Hydrogeology


Geology Datasets Merged for the San Diego Hydrogeology Study

Abstract

The two primary objectives of this study are (1) to develop an integrated, comprehensive understanding of the geology and hydrology of the San Diego area, focusing on the San Diego Formation and the overlying alluvial deposits, and (2) to use this understanding to evaluate expanded use of the alluvial deposits and the San Diego Formation for recharge and extraction. The geology is to be used in a hydrostratigraphic model of the San Diego - Tijuana region. Several of the units were used to generate surfaces for groundwater modeling. This study will benefit local water purveyors by providing an improved understanding of the source of water to their existing production wells, and the likely effects of increased ground-water extraction. Benefits to others in the San Diego area will be from having a comprehensive investigation of the primary aquifer in the region. Benefits to the nation include quantifying the resources of an important coastal city, and developing the background information necessary to manage a complex coastal biologic-hydrologic environment.

Use limitations

These data should not be used at scales larger than 1:100,000. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data. Parts of the data from Mexico were based on various map scales. Data from Mexico may not have had an age associated with the lithology, therefore, several sources were compared and a judgment was made as to which unit from the US side was most comparable.

Geology data sources

Surficial Geology of San Diego-Tijuana Area, USA and Mexico
(v 1.2 – Sept. 17, 2015)


Digital Geology Sources – Polygons and Geologic Descriptions

The sources described below correspond to numbered sections in the associated figure.

  1. Kennedy and Tan (2005)
    • Digital polygons and geologic descriptions are used as defined
  2. Ludington et al. (2005)
    • Digital polygons and geologic descriptions are used as defined
    • Geologic polygons that intersect the source regions of Kennedy and Tan (2005) and Todd (2004) are referenced against, and modified to accommodate those sources.
  3.  Kennedy and Tan (2008)
    • Digital polygons and geologic descriptions are used as defined
  4. Todd (2004)
    • Digital polygons and geologic descriptions area used as defined
  5. Legg (1985)
    • Geomorphologic boundaries digitized from original maps to form mappable polygons. Geology of these polygons (rock type and age) are extrapolated from the original manuscript, Kennedy and Tan (2008), Vedder et al. (1974), Vedder (1990) and SGM (2003).
  6. IMPlan (2008)
    • Digital geomorphic polygons from this source serve as the primary geologic boundaries. Geology (rock type and age) are determined from the original geomorphologic descriptions, CESAR (2007), and SEG (2003).
    • Rock type and age cannot be determined for certain geomorphologic polygons due to uncertainties between the geomorphology, CESAR (2007), and SEG (2003). In these few instances, the geologic polygons and definitions of CESAR (2007) are used.
    • Along the U.S./Mexico international border, geologic descriptions assigned to IMPLAN polygons are referenced against, and modified to accommodate, the geologic definitions of Kennedy and Tan (2008) and Todd (2004).
  7.  CESAR (2007)
    • Digital polygons and geologic descriptions are used as defined.
    • Along the U.S./Mexico international border, geologic descriptions are referenced against, and modified to accommodate, the geologic definitions of Todd (2004).
    • A few discrepancies in coverage exist between the regional study area boundary and the CESAR (2007) dataset. Geology from the NIE (2005) digital dataset was used to define these minor polygon areas.

Regional Map Geology Groupings

The digital geologic polygons described above are combined into simplified formation groupings that reflect the regional geology. The regional units are defined by rock type and age and are listed here:

  • Undifferentiated Sedimentary Deposits
    • Quaternary
  • Undifferentiated Sedimentary Rocks
    • Plio-Pleistocene
    • Miocene
    • Oligocene
    • Eocene
    • Cretaceous
  • Volcanic (onshore) and undivided volcanic and sedimentary rocks (offshore)
    • Miocene
  • Metavolcanic and Metasedimentary Rocks (Mesozoic)
    • Santiago Peak Volcanics – (e.g. Todd [2004])
    • Undivided
  • Crystalline Rocks (Mesozoic)
    • Intrusive
    • Metamorphic

References

Center for Earth Systems Analysis Research (CESAR), 2007,
Tijuana River Watershed Digital Geology File: Center for Earth Systems Analysis Research; El Colegio de la Frontera Norte, Tijuana River Watershed GIS Database, map.
Garrity, C.P., and Soller, D.R., 2009,
Database of the Geologic Map of North America; adapted from the map by J.C. Reed, Jr. and others (2005): U.S. Geological Survey Data Series 424, scale 1:5,000,000.
Available at http://pubs.usgs.gov/ds/424/
IMPlan, 2008,
Programa de Desarrollo Urbano del Centro de Población de Tijuana, B.C. 2002-2025. PDUCPT_MEDIO NATURAL-Nov_02 p29_44.pdf accessed at http://www.implantijuana.com/files/PDUCPT_Medio.pdf
Kennedy, M.P., and Tan, S.S. 2005,
Geologic Map of the Oceanside 30' x 60' Quadrangle, California - Digital Preparation by Kelly R. Bovard, Rachel M. Alvarez, Michael J. Watson, and Carlos I. Gutierrez: Department of Conservation, California Geological Survey; U.S. Geological Survey -- Southern California Areal Mapping Project (SCAMP), Regional Geologic Map Series, 1:100,000 Scale, RGM Map No. 2, accessed 2/10/2015 at ftp://ftp.consrv.ca.gov/pub/dmg/rgmp/Published_GIS_Data/RGM_002_Oceanside_100k_v1/
Kennedy, M.P., and Tan, S.S. 2008,
Geologic Map of the San Diego 30' x 60' Quadrangle, California - Digital Preparation by Kelly R. Bovard, Anne G. Garcia, Diane Burns, and Carlos I. Gutierrez: Department of Conservation, California Geological Survey; U.S. Geological Survey, Regional Geologic Map Series, 1:100,000 Scale, RGM Map No. 3, accessed 2/10/2015 at ftp://ftp.consrv.ca.gov/pub/dmg/rgmp/Published_GIS_Data/RGM_003_San_Diego_100k_v1/
Legg, M.R., 1985,
Geologic structure and tectonics of the inner continental borderland offshore northern Baja California, Mexico: University of California Santa Barbara Ph.D. thesis.
Ludington, Steve, Moring, B.C., Miller, R.J., Flyn, K.S., Stone, P.A., Bedford, D.R., 2005,
Preliminary integrated databases for the United States - Western States: California, Nevada, Arizona, and Washington, Version 1.0: U.S. Geological Survey Open-File Report 2005-1305, available online at http://pubs.usgs.gov/of/2005/1305/#CA.
National Institute of Ecology, 2005,
Project Three Californias, Baja California Chapter, Geology of the State of Baja California, scale 1:250,000, vector data, accessed 2/10/2015.
Servicio Geológico Mexicano (SGM) (antes Consejo Recursos), 2003,
Carta Geológico-Minera Tijuana I11-11: Consejo de Recursos Minerales (ahora Servicio Geológico Mexicano), Pachuca, Hgo. México, escala 1:250 000, 1 map.
Todd, V.R., 2004,
Preliminary Geologic Map of the El Cajon 30' x 60' Quadrangle, Southern California - Digital preparation by Rachel M. Alvarez and TGS, Techni Graphic Systems, Inc.: U.S. Geological Survey, Open-File Report 2004-1361, 1:100,000 Scale, 1 map, accessed 2/10/2015 at http://pubs.usgs.gov/of/2004/1361/
Vedder, J.G., Beyer, L.A., Junger, A., Moore, G.W., Roberts, A.E., Taylor, J.C., Wagner, H.C., 1974,
Preliminary report on the geology of the continental borderland of Southern California: USGS Publications Warehouse, Miscellaneous Field Studies Map, scale 1:500,000.
Available at http://pubs.er.usgs.gov/publication/mf624
Vedder, J. G., 1990,
Maps of California continental borderland showing compositions and ages of bottom samples acquired between 1968 and 1979: USGS Publications Warehouse, Miscellaneous Field Studies Map 2122, 3 Plates: 32.32 x 51.98 inches and smaller, scale 1:250,000.
Available at http://pubs.er.usgs.gov/publication/mf2122

Datasets are publicly available from the resources described below.


Geology Datasets

1. Preliminary Geologic Map of the El Cajon 30' x 60' Quadrangle, Southern California

Todd, V.R., 2004,
Preliminary Geologic Map of the El Cajon 30' x 60' Quadrangle, Southern California - Digital preparation by Rachel M. Alvarez and TGS, Techni Graphic Systems, Inc.: U.S. Geological Survey, Open-File Report 2004-1361, 1:100,000 Scale, 1 map, accessed 2/10/2015 at http://pubs.usgs.gov/of/2004/1361/

This data set maps and describes the geology of the El Cajon 30' x 60' quadrangle, southern California. Compilation of the El Cajon quadrangle is based upon published mapping at various scales, unpublished mapping at 1:24,000 scale, and reconnaissance mapping. Mapping was done by fieldwork and the use of aerial photographs at 1:24,000 scale.

The El Cajon quadrangle includes parts of two physiographic provinces: the Peninsular Ranges Province on the west underlies the major part of the quadrangle; the western Colorado Desert (locally called the Anza-Borrego Desert) underlies the northeastern corner. The approximate boundary between these two provinces is the Neogene Elsinore Fault Zone, the westernmost on-land strand of the San Andreas Fault System. Movements within the Elsinore Fault Zone are believed to have resulted in the uplift and westward rotation of the Peninsular Ranges block relative to the western Colorado Desert (Gastil and others, 1975). As a result, elevations in the El Cajon quadrangle increase from less than 100 m in the westernmost part of the quadrangle to ~2000 m along the irregular mountainous spine of the Peninsular Ranges (the Cuyamaca, Laguna, Tierra Blanca, and Jacumba Mountains); elevations then decrease rapidly eastward to <100 m in the Anza-Borrego Desert.

Southwest of the Elsinore Fault Zone, the El Cajon quadrangle is underlain by Jurassic and Cretaceous plutonic rocks of the composite Peninsular Ranges Batholith, which contains screens of variably metamorphosed Mesozoic supracrustal rocks. Late Jurassic and Early Cretaceous volcanic and volcaniclastic rocks that are exposed in the western part of the quadrangle represent an older, superjacent part of the Peninsular Ranges magmatic arc. Upper Cretaceous and Eocene marine and nonmarine strata were deposited widely upon the eroded batholith but are preserved only in the westernmost part of the quadrangle (the San Diego embayment). Pliocene and Pleistocene coastal terrace deposits rest unconformably upon the early Tertiary rocks in the southwestern corner of the quadrangle.

Northeast of the Elsinore Fault Zone, the El Cajon quadrangle exposes extensive Neogene nonmarine and marine sedimentary and volcanic rocks of the Fish Creek-Vallecito basin. Basement uplifts in this region are composed of crystalline rocks of the eastern Peninsular Ranges Batholith (the Vallecito, Fish Creek, and Coyote Mountains).

Purpose: The data set for the El Cajon 30' x 60' quadrangle was prepared under the U.S. Geological Survey Southern California Areal Mapping Project (SCAMP) as part of an ongoing effort to develop a regional geologic framework of southern California, and to utilize a Geographic Information System (GIS) format to create regional digital geologic databases. These regional databases are being developed as contributions to the National Geologic Map Database of the National Cooperative Geologic Mapping Program of the USGS.


 

2. Geologic Map of the San Diego 30' x 60' Quadrangle, California

Kennedy, M.P., and Tan, S.S. 2008,
Geologic Map of the San Diego 30' x 60' Quadrangle, California - Digital Preparation by Kelly R. Bovard, Anne G. Garcia, Diane Burns, and Carlos I. Gutierrez: Department of Conservation, California Geological Survey; U.S. Geological Survey, Regional Geologic Map Series, 1:100,000 Scale, RGM Map No. 3, accessed 2/10/2015 at ftp://ftp.consrv.ca.gov/pub/dmg/rgmp/Published_GIS_Data/RGM_003_San_Diego_100k_v1/

The San Diego 100k quadrangle lies within the Peninsular Ranges Geomorphic Province of southern California, and encompasses the greater San Diego area, the second largest metropolitan area of California. The Peninsular Ranges of southern California form a northwest-trending geomorphic province that occupies the southwestern corner of California and extends southeastward to form the Baja California peninsula. Its physiography is characterized principally by steep mountain highlands and dramatic intermontane basins, valleys, and rivers. The highlands are flanked on the west by a relatively narrow, westward sloping coastal margin that includes the San Diego embayment. On the east the highlands are bounded from the adjoining Colorado Desert and the Gulf of California by precipitous fault scarps. The area within the San Diego 30' x 60' quadrangle is tectonically and seismically active and includes parts of four major Pacific/North American Plate boundary fault zones.

The eastern part of the San Diego 100k quadrangle is underlain by plutonic rocks of the western Peninsular Ranges batholith and a thick sequence of Mesozoic fore-arc and fore-arc basin volcanic and volcaniclastic deposits. The western part of the quadrangle is underlain by a relatively thick succession of Upper Cretaceous, Tertiary and Quaternary sedimentary rocks that unconformably overlie basement rocks. They consist of marine, paralic, and continental claystone, siltstone, sandstone and conglomerate. The Upper Cretaceous rocks are composed of marine turbidites and continental fan deposits.


 

3. Geologic Map of the Oceanside 30' x 60' Quadrangle, California

Kennedy, M.P., and Tan, S.S. 2005,
Geologic Map of the Oceanside 30' x 60' Quadrangle, California - Digital Preparation by Kelly R. Bovard, Rachel M. Alvarez, Michael J. Watson, and Carlos I. Gutierrez: Department of Conservation, California Geological Survey; U.S. Geological Survey -- Southern California Areal Mapping Project (SCAMP), Regional Geologic Map Series, 1:100,000 Scale, RGM Map No. 2, accessed 2/10/2015 at ftp://ftp.consrv.ca.gov/pub/dmg/rgmp/Published_GIS_Data/RGM_002_Oceanside_100k_v1/

The Oceanside 1:100,000-scale quadrangle lies between 33° and 33°30' N. latitude and 117° and 118° W. longitude. It underlies a rapidly urbanizing part of southern California. The area is tectonically and seismically active and is dissected by four major, northwest trending, oblique right slip, Pacific/North American Plate boundary fault zones. They include the Elsinore Fault Zone in the northeastern corner of the quadrangle, the Newport-Inglewood-Rose Canyon Fault Zone in the center of the quadrangle (origin of the 1933, M=6.3, Long Beach earthquake), the Coronado Bank Fault in the near offshore region and the San Diego Trough Fault Zone in the southwestern corner of the quadrangle (origin of the 1986, ML=5.3, Oceanside earthquake). Landslides are abundant in the western and offshore parts of the quadrangle. Also, seismic hazards are numerous throughout the area. A tsunami hazard exists along the coastal margin.

The quadrangle is underlain by a thick sequence of forearc and forearc-basin Jurassic and Cretaceous (mostly low grade greenschist facies but partly unmetamorphosed) andesitic flows, sedimentary and volcaniclastic breccias and marine metasedimentary rocks that have been intruded in their older part by the Peninsular Ranges Batholith. The batholith is Cretaceous in age and in part coeval with the forearc and forearc-basin rocks. The batholithic rocks are mostly tonalite and granodiorite with less common gabbro, diorite, monzogranite and granite. Pegmatite dikes are common in these intrusive rocks. The western part of the quadrangle is underlain by a relatively thick (>1000m) succession of Upper Cretaceous, Tertiary and Quaternary sedimentary and volcanic rocks that unconformably overlie the older plutonic and forearc basement rock sequence. These rocks consist chiefly of beds of marine, paralic, and non marine claystone, siltstone, sandstone and conglomerate and minor flows consisting mostly of Neogene basalt. Many cycles of uplift, erosion, subsidence and deposition since the Late Mesozoic have created the complexity of the existing stratigraphic and structural settings.

Fractured and deeply weathered bedrock associated with K/T boundary subaerial extremes mantles much of the interior highlands and particularly the steep slopes adjacent to and southwest of the Elsinore Fault Zone. Quaternary deposits derived from the weathered rock mantles the lower slopes and stream channels of much of the quadrangle. Areas underlain by these deposits that have been subjected to intense wildfire heat become unstable and prone to failure during periods of high rainfall.


 

4. Preliminary integrated databases for the United States - Western States: California, Nevada, Arizona, and Washington, version 1.0

Ludington, Steve, Moring, B.C., Miller, R.J., Flyn, K.S., Stone, P.A., Bedford, D.R., 2005,
Preliminary integrated databases for the United States - Western States: California, Nevada, Arizona, and Washington, Version 1.0: U.S. Geological Survey Open-File Report 2005-1305, available online at http://pubs.usgs.gov/of/2005/1305/#CA.

Abstract: These digital maps are a reformulation of previously published maps, primarily maps of states. The reformulation gives all the maps the same structure and format, allowing them to be combined into regional maps. The associated data tables have information about age and lithology of the map units, also in a standard format.

Purpose: Provide digital maps and databases that, because of their common structure and format, allow creation of regional maps that depict age and lithology of map units.

Supplemental_Information: The data is provided in decimal degrees and in Lambert Conformal Conic projection. The data is provided in both coverage and shapefile format, and includes supplemental attribute tables. No attempt was made to reconcile differences in mapping across state boundaries.


 

5. Tijuana River Watershed Digital Geology File: Center for Earth Systems Analysis Research; El Colegio de la Frontera Norte, Tijuana River Watershed GIS Database

Center for Earth Systems Analysis Research, 2007,
Tijuana River Watershed Digital Geology File: Center for Earth Systems Analysis Research; El Colegio de la Frontera Norte, Tijuana River Watershed GIS Database, map.

The Tijuana River Watershed digital geology file was created as part of the Tijuana River Watershed GIS database project. This digital layer consists of polygons of rock formations in the Tijuana River Watershed.

The Tijuana River Watershed GIS Database project provides a fully integrated cross border geographic information system. One of the layers in the dataset is a digital geology layer. This layer provides information on the underlying rock formations of the watershed, important for environmental studies and modeling.


 

6. Programa de Desarrollo Urbano del Centro de Población de Tijuana, B.C. 2002-2025

IMPlan, 2008,
Programa de Desarrollo Urbano del Centro de Población de Tijuana, B.C. 2002-2025. PDUCPT_MEDIO NATURAL-Nov_02 p29_44.pdf accessed at http://www.implantijuana.com/files/PDUCPT_Medio.pdf

From us about the geological composition of materials, field of Tijuana has poor consolidation, characteristic which, together with the outstanding conditions the urban growth for the serious risks of mudslides and landslides, and the possible flaws in the techniques of buildings utilzados and materials, so care must be taken that the standards of buildings are consistent with the specifications of resistance and Stability aspects of such materials.

According to the geological clasificaion INEGI, the various geological materials are classified by origin, compaction, grain size, site training, etc., in extrusive igneous rocks, intrusive ingneas, metamorphic and sedimentary, which define the particular characteristics of Recommended resistance for different purposes.



 

7. Vector Set of Geological Data. National continuum

National Institute of Statistics, Geography and Informatics (INEGI), 2002,
Vector Set of Geological Data. National continuum: Instituto Nacional de Estadística, Geografía e Informática - INEGI, Aguascalientes, Ags., México, Scale 1 : 1,000,000, accessed 2/10/2015 at http://www.inegi.org.mx/geo/contenidos/recnat/geologia/infoescala.aspx

The national continuum Vector set of geological data, representing the various rock units outcropping in the area, referred to a geological time ( chronostratigraphic units ) and geological structures caused by tectonic events, one of these are the volcanoes which active and inactive are identified, also includes geothermal areas and points are shown with mineral resources ( mines).


 

8. Project Three Californias, Baja California Chapter, Geology of the State of Baja California

National Institute of Ecology, 2005,
Project Three Californias, Baja California Chapter, Geology of the State of Baja California, scale 1:250,000, vector data, accessed 2/10/2015.

GEOLOGY OF THE STATE OF BAJA CALIFORNIA, SCALE 1: 250,000, VECTOR SET D EDATOS GEOLOGICOS.

PROJECT THREE CALIFORNIAS , BAJA CALIFORNIA CHAPTER


 

9. Geologic  structure  and  tectonics  of  the  inner  continental  borderland  offshore  northern  Baja  California,  Mexico

Legg, M.R., 1985,
Geologic structure and tectonics of the inner continental borderland offshore northern Baja California, Mexico: University of California Santa Barbara Ph.D. thesis.

The Inner Continental Borderland west of northern Baja California, Mexico, Is an active p art of the geologically complex Pacific-North American lithospheric plate boundary. To further understand the late Cenozoic tectonic style and evolution of this continental margin plate boundary, It is necessary to study the geologic structure and tectonic style of the California Continental Borderland. This dissertation presents a relatively complete, marine geological study of the Inner Continental Borderland. Detailed bathymetric maps prepared from both conventional single beam, and multi-, narrow-beam (Sea Beam) echo sounding data show that the Inner Borderland is a regionally distinct physiographic province. Numerous tectonic landforms commonly associated with recently-actlve faults onshore are shown by the detailed, Sea Beam bathymetric charts made along the San Clemente fault. Hlgh-resolution, single-channel, seismic reflection profiles also show that the region is crossed by numerous, late Cenozoic faults which are associated with four principal wrench fault zones: (1) San Clemente-San Isidro; (2) San Diego Trough-Bahl'a Soledad; (3) Coronado Bank-Agua Blanca; (4) Rose Canyon and Descanso-Estero. Estimates of average late Quaternary sedimentation rates, based upon published piston core analyses, and seismic stratigraphy are used to infer late Quaternary ages for fault activity and submarine canyon/fan development. Right-slip of several kilometers along the major faults is Inferred from postulated offset channels and submarine fan/slope apron deposits. The major fault zones are further grouped into two, major wrench fault systems, i.e., San Clemente and Agua Blanca. Each Is similar in configuration to the well-known San Andreas and Alpine-Marlborough faults, respectively. Systematic variations in fault character both along strike and at depth in these fault zones are attributed to changes in fault geometry, and/or reorientation of principal strain and inferred stress directions in the region. These variations are inferred to demonstrate that the Inner Borderland is a regionally distinct structural province and th at the entire southern California-northern Baja California region may be considered as a broad shear zone associated with transform fault tectonics of Pacific-North American plate interaction.

 

 

Referenced Geology Used for Verification

1. Preliminary report on the geology of the continental borderland of Southern California

Vedder, J.G., Beyer, L.A., Junger, A., Moore, G.W., Roberts, A.E., Taylor, J.C., Wagner, H.C., 1974,
Preliminary report on the geology of the continental borderland of Southern California: USGS Publications Warehouse, Miscellaneous Field Studies Map, scale 1:500,000.
Available at http://pubs.er.usgs.gov/publication/mf624

Appraisal of the mineral resource potential and assessment of environmental problems of any specific area require an understanding of the regional geology. The geology of the coastal zone and offshore islands from Point Conception to the Mexican boundary serves as a frame of reference from which rock units and structures can be extrapolated into submerged parts of the borderland (sheet 1). Such extrapolations should be used with caution, for the tectonic evolution and depositional history of parts of the borderland may not have paralleled those of the mainland. On shore, rocks and structures can be observed directly with supplemental aid from deep drill holes; but in areas covered by deep water, only indirect techniques such as geophysical methods and shallow coring provide information from which geologic interpretations can be made.

For many years the California Continental Borderland has been envisioned as a region of high petroleim potential, and exploration in the Santa Barbara Channel has partly substantiated this premise. Early in 1974, the Bureau of Land Management released a map (sheet 2) showing the proposed area for nomination of future lease tracts. Inasmuch as a possible lease sale is scheduled for the late spring of 1975, publication of this preliminary report is intended to affo;rd a geologic base from which additional appraisals can be made.

The principal sources used in preparation of this report are published papers and unpublished data in the files of universities and government aqencies. Many new subbottom profiles, gravity and magnetic traverses, and seafloor samples, gathered mainly during recent cruises by the U.S. Geological Survey research vessels KELEZ and LEE, are incorporated to supplement the information in previously available reports.

 

 

2. Maps of California continental borderland showing compositions and ages of bottom samples acquired between 1968 and 1979

Vedder, J. G., 1990,
Maps of California continental borderland showing compositions and ages of bottom samples acquired between 1968 and 1979: USGS Publications Warehouse, Miscellaneous Field Studies Map 2122, 3 Plates: 32.32 x 51.98 inches and smaller, scale 1:250,000.
Available at http://pubs.er.usgs.gov/publication/mf2122

In support of regional-framework and geologic-hazards investigations of the California Continental Borderland, bottom sampling was attempted at nearly 3,000 sites between March 1968 and May 1979. Of this number, 2,000 were tried during U.S. Geological Survey cruises with success at approximately 90 percent of the sites.Joint cruises involving U.S. Geological Survey and university personnel aboard other research vessels resulted in more than 800 supplementary samples. Scripps Institution of Oceanography provided information on 20 dredge hauls.

The purpose of these maps is to show the location of selected sampling sites as well as to give an indication of the general composition and age of the material collected. Not only are the maps intended as a means of showing the distribution of different rock types but also as a guide for planning future sampling cruises. The samples include a variety of basement rocks, volcanic rocks, and sedimentary rocks that range in age from Cretaceous to Quaternary. In some cases, Quaternary designations are based upon degree of cohesiveness, composition, and color rather than on contained fossils.

Most of these samples originally were described in the U.S. Geological Survey Open-File Reports, and these reports should be consulted for details on composition and age. Descriptions for the 1975 R/V VELERO cruise to Cortes Bank and Tanner Bank are incomplete; but judging from observations recorded in the shipboard log sheets for this cruise most of the unplotted samples are Quaternary

 

 

3. Database of the Geologic Map of North America; adapted from the map by J.C. Reed, Jr. and others (2005)

Garrity, C.P., and Soller, D.R., 2009,
Database of the Geologic Map of North America; adapted from the map by J.C. Reed, Jr. and others (2005): U.S. Geological Survey Data Series 424, scale 1:5,000,000.
Available at http://pubs.usgs.gov/ds/424/.

The Geological Society of America's (GSA) Geologic Map of North America (Reed and others, 2005; 1:5,000,000) shows the geology of a significantly large area of the Earth, centered on North and Central America and including the submarine geology of parts of the Atlantic and Pacific Oceans. This map is now converted to a Geographic Information System (GIS) database that contains all geologic and base-map information shown on the two printed map sheets and the accompanying explanation sheet. We anticipate this map database will be revised at some unspecified time in the future, likely through the actions of a steering committee managed by the Geological Society of America (GSA) and staffed by scientists from agencies including, but not limited to, those responsible for the original map compilation (U.S. Geological Survey, Geological Survey of Canada, and Woods Hole Oceanographic Institute).

Regarding the use of this product, as noted by the map's compilers: 

"The Geologic Map of North America is an essential educational tool for teaching the geology of North America to university students and for the continuing education of professional geologists in North America and elsewhere. In addition, simplified maps derived from the Geologic Map of North America are useful for enlightening younger students and the general public about the geology of the continent."

With publication of this database, the preparation of any type of simplified map is made significantly easier. More important perhaps, the database provides a more accessible means to explore the map information and to compare and analyze it in conjunction with other types of information (for example, land use, soils, biology) to better understand the complex interrelations among factors that affect Earth resources, hazards, ecosystems, and climate.

 

 

4. Carta Geológico-Minera Tijuana

Servicio Geológico Mexicano (antes Consejo Recursos), 2003
Carta Geológico-Minera Tijuana I11-11: Consejo de Recursos Minerales (ahora Servicio Geológico Mexicano), Pachuca, Hgo. México, escala 1:250 000, 1 map.

The Carta Geológico-Minera provides geologic information with the purpose of bringing together the most important aspects of interest to the mining sector. This map constitutes a basic infrastructure for the analysis, interpretation and identification of suitable areas for prospecting and mining exploration at regional and/or local levels.

 

 

Project Chief: Wes Danskin
Phone: 619-225-6132
Email: wdanskin@usgs.gov


Welcome to the United States Geological Survey (USGS) San Diego Hydrogeology project website, which provides geologic and hydrologic information for the transboundary San Diego–Tijuana area, USA and Mexico. This website provides background information about the project; a variety of news items; a large amount of data, in particular for USGS multiple-depth, monitoring-well sites; geologic and hydrologic models; and additional resources including photos, illustrations, and references. Last updated: April 2016

Some additional data may be available from the USGS database National Water Information System (NWIS).


Questions about San Diego Hydrogeology? Please contact Wes Danskin (email: wdanskin@usgs.gov or send a letter). 619.225.6132