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Fort Point, San Francisco, San Francisco Co., California, USAi
Regional Level Types
Fort PointPoint
San Francisco- not defined -
San Francisco Co.County
CaliforniaState
USACountry

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Latitude & Longitude (WGS84): 37° 48' 38'' North , 122° 28' 35'' West
Latitude & Longitude (decimal): 37.81056,-122.47639
GeoHash:G#: 9q8zhgpqm
Locality type:Point
Köppen climate type:Csb : Warm-summer Mediterranean climate
Nearest Settlements:
PlacePopulationDistance
Sausalito7,156 (2017)5.4km
Chinatown100,574 (2017)6.2km
San Francisco864,816 (2017)6.4km
Belvedere2,121 (2018)7.0km
Marin City2,666 (2011)7.1km


Both a cape and a historical military fort, with a beach (strand) area, under the southern terminus of the Golden Gate Bridge.

Regions containing this locality

North America PlateTectonic Plate

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Mineral List

Mineral list contains entries from the region specified including sub-localities

15 valid minerals.

Detailed Mineral List:

Antigorite
Formula: Mg3(Si2O5)(OH)4
Reference: www.dvminerals.com/thumbs.html
'Apophyllite'
Colour: Colourless
Description: Occurs as minute crystals.
Reference: Schaller, Waldemar Theodore (1905b), Mineralogical notes: USGS Bulletin 262: 124, 126; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 445; www.missourigeologists.org/Min-Loc1-2005.pdf.
Aragonite
Formula: CaCO3
Habit: Slender prisms
Colour: Colourless
Description: Occurs in seams in serpentine.
Reference: Eakle, Arthur Starr (1901), Mineralogical notes; with chemical analyses by W.T. Schaller: University of California, Department of Geological Science Bulletin: 2: 316; Schlocker, J. (1974) Geology of the San Francisco North quadrangle. USGS Professional Paper 782, 109 pp.: 60; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 216; www.missourigeologists.org/Min-Loc1-2005.pdf.
Baryte
Formula: BaSO4
Habit: Tabular
Description: Occurs as crystals in seams in serpentine.
Reference: Eakle, Arthur Starr (1901), Mineralogical notes; with chemical analyses by W.T. Schaller: University of California, Department of Geological Science Bulletin: 2: 316; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 98; www.missourigeologists.org/Min-Loc1-2005.pdf.
Calcite
Formula: CaCO3
Description: Occurs as crystals exhibiting uncommon faces to several cm in size.
Reference: Schaller, Waldemar Theodore (1911a), Mineralogical notes, series 1: USGS Bulletin 490: 103; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 118; www.missourigeologists.org/Min-Loc1-2005.pdf.
Coalingite
Formula: Mg10Fe3+2(OH)24[CO3] · 2H2O
Colour: Golden-brown
Description: Occurs as veinlets 1 to 2 mm thick in serpentine that is largely altered to pyroaurite.
Reference: Learned, E. (1965) Sjogrenite confirmed from California. Gems and Minerals: 332: 54; Schlocker, J. (1974) Geology of the San Francisco North quadrangle. USGS Professional Paper 782, 109 pp.: 59, 62; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 199.
Datolite
Formula: CaB(SiO4)(OH)
Colour: White
Description: Occurs as glassy crystals and white veins in an altered diabase dike in serpentine.
Reference: Eakle, Arthur Starr (1901), Mineralogical notes; with chemical analyses by W.T. Schaller: University of California, Department of Geological Science Bulletin: 2: 317; Kunz, George Frederick (1905a), Gems, jewelers’ materials, and ornamental stones of California: California Division Mines Bulletin 37, 171 pp.: 97; Schaller, Waldemar Theodore (1911a), Mineralogical notes, series 1: USGS Bulletin 490: 103; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 508; Rocks & Minerals (2010): 85: 338-345; www.missourigeologists.org/Min-Loc1-2005.pdf.
Gyrolite
Formula: NaCa16Si23AlO60(OH)8 · 14H2O
Description: Occurs as spherical or massive with apophyllite; platy or plumose aggregates replacing wall rock in fissures of basalt.
Reference: Schaller, Waldemar Theodore (1905b), Mineralogical notes: USGS Bulletin 262: 124, 126; Schaller, Waldemar Theodore (1911a), Mineralogical notes, series 1: USGS Bulletin 490: 103; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 445, 447; www.missourigeologists.org/Min-Loc1-2005.pdf.
Hydromagnesite
Formula: Mg5(CO3)4(OH)2 · 4H2O
Description: Occurs as botryoidal masses and veins 3 to 4 inches (7.5 to 10 cm) wide in serpentine.
Reference: Mining and Scientific Press (1881), Formation of the San Francisco peninsula: Mining and Scientific Press: 42: 28; Eakle, Arthur Starr (1901), Mineralogical notes; with chemical analyses by W.T. Schaller: University of California, Department of Geological Science Bulletin: 2: 316; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 201; rruff.geo.arizona.edu/doclib/hom/hydromagnesite.pdf
Magnesite
Formula: MgCO3
Description: Occurs as seams in serpentine.
Reference: Eakle, Arthur Starr (1901), Mineralogical notes; with chemical analyses by W.T. Schaller: University of California, Department of Geological Science Bulletin: 2: 316; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 249.
Nesquehonite
Formula: MgCO3 · 3H2O
Colour: White
Description: Soft surface efflorescences in moist places in serpentine.
Reference: Schlocker, J. (1974) Geology of the San Francisco North quadrangle. USGS Professional Paper 782, 109 pp.: 62; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 203.
Pectolite
Formula: NaCa2Si3O8(OH)
Description: Occurs as veins of fibrous material in an altered dike that intersects serpentine.
Reference: Eakle, Arthur Starr (1901), Mineralogical notes; with chemical analyses by W.T. Schaller: University of California, Department of Geological Science Bulletin: 2: 316; Kunz, George Frederick (1905a), Gems, jewelers’ materials, and ornamental stones of California: California Division Mines Bulletin 37, 171 pp.: 96; Schaller, Waldemar Theodore (1911a), Mineralogical notes, series 1: USGS Bulletin 490: 103; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 410.
Pyroaurite
Formula: Mg6Fe3+2(OH)16[CO3] · 4H2O
Reference: Schlocker, J. (1974) Geology of the San Francisco North quadrangle. USGS Professional Paper 782, 109 pp.: 59, 62; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 199.
'Pyroaurite-2H'
Formula: Mg6Fe3+2(OH)16(CO3) · 4H2O
Description: Occurws as thin coatings with hydromagnesite on fractures in serpentine.
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 340; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 199.
Quartz
Formula: SiO2
Description: Occurs as pseudomorphs after apophyllite.
Reference: Schaller, Waldemar Theodore (1904), Notes on some California minerals: American Journal of Science, 4th. Series: 17: 191-194; Schaller, Waldemar Theodore (1905b), Mineralogical notes: USGS Bulletin 262: 121; Bailey, Edgar H. (1941b), Skeletonized apophyllite from Crestmore and Riverside, California: American Mineralogist: 26: 566; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 349.
'Serpentine Subgroup'
Formula: D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn
Reference: Eakle, Arthur Starr (1901), Mineralogical notes; with chemical analyses by W.T. Schaller: University of California, Department of Geological Science Bulletin: 2: 316; Kunz, George Frederick (1905a), Gems, jewelers’ materials, and ornamental stones of California: California Division Mines Bulletin 37, 171 pp.: 96; Schlocker, J. (1974) Geology of the San Francisco North quadrangle. USGS Professional Paper 782, 109 pp.: 62; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 203.
Wollastonite
Formula: CaSiO3
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 387.
Xonotlite
Formula: Ca6(Si6O17)(OH)2
Description: Occurs as veins in basalt.
Reference: Eakle, Arthur Starr (1901), Mineralogical notes; with chemical analyses by W.T. Schaller: University of California, Department of Geological Science Bulletin: 2: 316; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 222, 390; Schlocker, J. (1974) Geology of the San Francisco North quadrangle. USGS Professional Paper 782, 109 pp.; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 201-202, 409.

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
Quartz4.DA.05SiO2
Group 5 - Nitrates and Carbonates
Aragonite5.AB.15CaCO3
Calcite5.AB.05CaCO3
Coalingite5.DA.55Mg10Fe3+2(OH)24[CO3] · 2H2O
Hydromagnesite5.DA.05Mg5(CO3)4(OH)2 · 4H2O
Magnesite5.AB.05MgCO3
Nesquehonite5.CA.05MgCO3 · 3H2O
Pyroaurite5.DA.50Mg6Fe3+2(OH)16[CO3] · 4H2O
'Pyroaurite-2H'5.DA.45Mg6Fe3+2(OH)16(CO3) · 4H2O
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
Baryte7.AD.35BaSO4
Group 9 - Silicates
Antigorite9.ED.15Mg3(Si2O5)(OH)4
Datolite9.AJ.20CaB(SiO4)(OH)
Gyrolite9.EE.30NaCa16Si23AlO60(OH)8 · 14H2O
Pectolite9.DG.05NaCa2Si3O8(OH)
Wollastonite9.DG.05CaSiO3
Xonotlite9.DG.35Ca6(Si6O17)(OH)2
Unclassified Minerals, Rocks, etc.
'Apophyllite'-
'Serpentine Subgroup'-D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn

List of minerals arranged by Dana 8th Edition classification

Group 13 - ACID CARBONATES
Miscellaneous
Nesquehonite13.1.5.1MgCO3 · 3H2O
Group 14 - ANHYDROUS NORMAL CARBONATES
A(XO3)
Calcite14.1.1.1CaCO3
Magnesite14.1.1.2MgCO3
Group 16b - HYDRATED CARBONATES CONTAINING HYDROXYL OR HALOGEN
Pyroaurite16b.6.2.3Mg6Fe3+2(OH)16[CO3] · 4H2O
'Pyroaurite-2H'16b.6.1.3Mg6Fe3+2(OH)16(CO3) · 4H2O
Coalingite16b.7.6.1Mg10Fe3+2(OH)24[CO3] · 2H2O
Hydromagnesite16b.7.1.1Mg5(CO3)4(OH)2 · 4H2O
Group 28 - ANHYDROUS ACID AND NORMAL SULFATES
AXO4
Baryte28.3.1.1BaSO4
Group 54 - NESOSILICATES Borosilicates and Some Beryllosilicates
Borosilicates and Some Beryllosilicates with B in [4] coordination
Datolite54.2.1a.1CaB(SiO4)(OH)
Group 65 - INOSILICATES Single-Width,Unbranched Chains,(W=1)
Single-Width Unbranched Chains, W=1 with chains P=3
Pectolite65.2.1.4aNaCa2Si3O8(OH)
Wollastonite65.2.1.1cCaSiO3
Group 66 - INOSILICATES Double-Width,Unbranched Chains,(W=2)
Amphiboles - Ca-Na subgroup
Xonotlite66.3.1.1Ca6(Si6O17)(OH)2
Group 71 - PHYLLOSILICATES Sheets of Six-Membered Rings
Sheets of 6-membered rings with 1:1 layers
Antigorite71.1.2a.1Mg3(Si2O5)(OH)4
Group 73 - PHYLLOSILICATES Condensed Tetrahedral Sheets
Condensed Tetrahedral Sheets with double and single layers
Gyrolite73.2.2c.1NaCa16Si23AlO60(OH)8 · 14H2O
Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
Quartz75.1.3.1SiO2
Unclassified Minerals, Mixtures, etc.
'Apophyllite'-
Aragonite-CaCO3
'Serpentine Subgroup'-D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn

List of minerals for each chemical element

HHydrogen
H HydromagnesiteMg5(CO3)4(OH)2 · 4H2O
H AntigoriteMg3(Si2O5)(OH)4
H DatoliteCaB(SiO4)(OH)
H GyroliteNaCa16Si23AlO60(OH)8 · 14H2O
H XonotliteCa6(Si6O17)(OH)2
H NesquehoniteMgCO3 · 3H2O
H Serpentine SubgroupD3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn
H PyroauriteMg6Fe23+(OH)16[CO3] · 4H2O
H CoalingiteMg10Fe23+(OH)24[CO3] · 2H2O
H Pyroaurite-2HMg6Fe23+(OH)16(CO3) · 4H2O
H PectoliteNaCa2Si3O8(OH)
BBoron
B DatoliteCaB(SiO4)(OH)
CCarbon
C HydromagnesiteMg5(CO3)4(OH)2 · 4H2O
C AragoniteCaCO3
C CalciteCaCO3
C NesquehoniteMgCO3 · 3H2O
C PyroauriteMg6Fe23+(OH)16[CO3] · 4H2O
C CoalingiteMg10Fe23+(OH)24[CO3] · 2H2O
C Pyroaurite-2HMg6Fe23+(OH)16(CO3) · 4H2O
C MagnesiteMgCO3
OOxygen
O HydromagnesiteMg5(CO3)4(OH)2 · 4H2O
O AntigoriteMg3(Si2O5)(OH)4
O DatoliteCaB(SiO4)(OH)
O GyroliteNaCa16Si23AlO60(OH)8 · 14H2O
O AragoniteCaCO3
O BaryteBaSO4
O CalciteCaCO3
O XonotliteCa6(Si6O17)(OH)2
O NesquehoniteMgCO3 · 3H2O
O Serpentine SubgroupD3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn
O PyroauriteMg6Fe23+(OH)16[CO3] · 4H2O
O CoalingiteMg10Fe23+(OH)24[CO3] · 2H2O
O WollastoniteCaSiO3
O Pyroaurite-2HMg6Fe23+(OH)16(CO3) · 4H2O
O QuartzSiO2
O PectoliteNaCa2Si3O8(OH)
O MagnesiteMgCO3
NaSodium
Na GyroliteNaCa16Si23AlO60(OH)8 · 14H2O
Na PectoliteNaCa2Si3O8(OH)
MgMagnesium
Mg HydromagnesiteMg5(CO3)4(OH)2 · 4H2O
Mg AntigoriteMg3(Si2O5)(OH)4
Mg NesquehoniteMgCO3 · 3H2O
Mg Serpentine SubgroupD3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn
Mg PyroauriteMg6Fe23+(OH)16[CO3] · 4H2O
Mg CoalingiteMg10Fe23+(OH)24[CO3] · 2H2O
Mg Pyroaurite-2HMg6Fe23+(OH)16(CO3) · 4H2O
Mg MagnesiteMgCO3
AlAluminium
Al GyroliteNaCa16Si23AlO60(OH)8 · 14H2O
Al Serpentine SubgroupD3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn
SiSilicon
Si AntigoriteMg3(Si2O5)(OH)4
Si DatoliteCaB(SiO4)(OH)
Si GyroliteNaCa16Si23AlO60(OH)8 · 14H2O
Si XonotliteCa6(Si6O17)(OH)2
Si Serpentine SubgroupD3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn
Si WollastoniteCaSiO3
Si QuartzSiO2
Si PectoliteNaCa2Si3O8(OH)
SSulfur
S BaryteBaSO4
CaCalcium
Ca DatoliteCaB(SiO4)(OH)
Ca GyroliteNaCa16Si23AlO60(OH)8 · 14H2O
Ca AragoniteCaCO3
Ca CalciteCaCO3
Ca XonotliteCa6(Si6O17)(OH)2
Ca WollastoniteCaSiO3
Ca PectoliteNaCa2Si3O8(OH)
MnManganese
Mn Serpentine SubgroupD3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn
FeIron
Fe Serpentine SubgroupD3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn
Fe PyroauriteMg6Fe23+(OH)16[CO3] · 4H2O
Fe CoalingiteMg10Fe23+(OH)24[CO3] · 2H2O
Fe Pyroaurite-2HMg6Fe23+(OH)16(CO3) · 4H2O
NiNickel
Ni Serpentine SubgroupD3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn
ZnZinc
Zn Serpentine SubgroupD3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn
BaBarium
Ba BaryteBaSO4

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org

Quaternary
0 - 2.588 Ma



ID: 2709163
Artificial fill

Age: Pleistocene (0 - 2.588 Ma)

Description: Of varying character, consisting of clay, silt, sand, rock fragments, organic material, and (or) man made debris. Distinguished on map only in southern Marin and San Francisco Counties; but present elsewhere, especially within unit Qmf.

Reference: Blake, M.C. Jr., R.W. Graymer, and D.L. Jones. Geologic map and map database of parts of Marin, San Francisco, Alameda, Contra Costa, and Sonoma Counties, California. U.S. Geological Survey Miscellaneous Field Studies MF 2337. [38]

Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License

References

Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Mining and Scientific Press (1881), Formation of the San Francisco peninsula: Mining and Scientific Press: 42: 28.
Eakle, Arthur Starr (1901), Mineralogical notes; with chemical analyses by W.T. Schaller: University of California, Department of Geological Science Bulletin: 2: 316, 317.
Schaller, Waldemar Theodore (1904), Notes on some California minerals: American Journal of Science, 4th. Series: 17: 191-194.
Kunz, George Frederick (1905a), Gems, jewelers’ materials, and ornamental stones of California: California Division Mines Bulletin 37, 171 pp.: 96, 97.
Schaller, Waldemar Theodore (1905b), Mineralogical notes: USGS Bulletin 262: 121-144.
Schaller, Waldemar Theodore (1911a), Mineralogical notes, series 1: USGS Bulletin 490: 103.
Bailey, Edgar H. (1941b), Skeletonized apophyllite from Crestmore and Riverside, California: American Mineralogist: 26: 565-567.
Learned, E. (1965) Sjogrenite confirmed from California. Gems and Minerals: 332: 54.
Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 80, 82, 98, 118, 166, 212, 222, 249, 285, 315, 340, 387.
Schlocker, J. (1974) Geology of the San Francisco North quadrangle. USGS Professional Paper 782, 109 pp.: 59, 60, 62.
Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 199, 201, 203, 216, 349, 410, 445, 447, 508.
Rocks & Minerals (2010): 85: 338-345.

External Links

www.dvminerals.com/thumbs.html

www.missourigeologists.org/Min-Loc1-2005.pdf.

rruff.geo.arizona.edu/doclib/hom/hydromagnesite.pdf

Localities in this Region
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