West Roxbury Crushed Stone Quarry (West Roxbury Trap Rock Co. Quarry; Grove St. Quarry), West Roxbury, Boston, Suffolk Co., Massachusetts, USA
| Latitude & Longitude (WGS84): | 42° 16' 2'' North , 71° 9' 30'' West |
|---|---|
| Latitude & Longitude (decimal): | 42.26722,-71.15833 |
| GeoHash: | G#: drt2ky806 |
| Locality type: | Quarry |
| Köppen climate type: | Dfa : Hot-summer humid continental climate |
A large open-pit crushed stone quarry, over 300 feet (91 meters) deep, primarily in coarse-grained Dedham granite. The quarry was opened in 1889 by Thomas F. Welch (b. 1855 West Roxbury, MA). The business was incorporated as West Roxbury Trap Rock Company in 1903.
Select Mineral List Type
Standard Detailed Strunz Dana Chemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded at this locality.Mineral List
20 valid minerals.
Detailed Mineral List:
| ⓘ 'commodity:Aggregates' Reference: From USGS MRDS database |
| ⓘ Albite Formula: Na(AlSi3O8) Reference: Thompson, M. D., et al. (2010): High precision U-Pb zircon dates for Ediacaran granitoid rocks in SE New England; in Tollo, Richard P. et al., ed., From Rodinia to Pangea: The Lithotectonic Record of the Appalachian Region (GSA Memoir 206). |
| ⓘ 'Allanite Group' Formula: {A12+REE3+}{M3+2M32+}(Si2O7)(SiO4)O(OH) Reference: Gleba, 1978. Massachusetts Mineral & Fossil Localities |
| ⓘ 'Amphibole Supergroup' Formula: AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 Reference: P. Cristofono collection |
| ⓘ 'Amphibole Supergroup var: Byssolite' Formula: AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 Reference: P. Cristofono collection |
ⓘ Anatase Formula: TiO2 Reference: P Cristofono collection |
ⓘ Anthophyllite Formula: ☐{Mg2}{Mg5}(Si8O22)(OH)2 Reference: Gleba, 1978. Massachusetts Mineral & Fossil Localities |
ⓘ Babingtonite Formula: Ca2(Fe,Mn)FeSi5O14(OH) Reference: P Cristofono collection |
| ⓘ Calcite Formula: CaCO3 Reference: Gleba, 1978. Massachusetts Mineral & Fossil Localities |
| ⓘ Chalcopyrite Formula: CuFeS2 Reference: Gleba, 1978. Massachusetts Mineral & Fossil Localities |
ⓘ Chamosite Formula: (Fe2+,Mg,Al,Fe3+)6(Si,Al)4O10(OH,O)8 Reference: P Cristofono collection |
| ⓘ Cuprite Formula: Cu2O Reference: S. Pavadore collection |
| ⓘ Epidote Formula: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) Reference: Gleba, 1978. Massachusetts Mineral & Fossil Localities |
| ⓘ Fluorite Formula: CaF2 Colour: purple Reference: P. Cristofono collection |
| ⓘ Galena Formula: PbS Reference: Gleba, 1978. Massachusetts Mineral & Fossil Localities |
| ⓘ Goethite Formula: α-Fe3+O(OH) Colour: black Description: Occurs as pseudomorphs after pyrite crystals. Reference: P. Cristofono collection |
| ⓘ Hematite Formula: Fe2O3 Reference: P. Cristofono collection |
| ⓘ 'Heulandite subgroup' Reference: P Cristofono collection |
| ⓘ Malachite Formula: Cu2(CO3)(OH)2 Reference: S. Pavadore collection |
| ⓘ Microcline Formula: K(AlSi3O8) Colour: pinkish; salmon-colored Reference: P. Cristofono collection, 2012 |
| ⓘ Opal Formula: SiO2 · nH2O Reference: Gleba, 1978. Massachusetts Mineral & Fossil Localities |
| ⓘ Opal var: Opal-AN Formula: SiO2 · nH2O Reference: Gleba, 1978. Massachusetts Mineral & Fossil Localities |
| Pyrite Formula: FeS2 Reference: Harvard Museum of Natural History, no.99813 |
ⓘ Quartz Formula: SiO2 Reference: Gleba, 1978. Massachusetts Mineral & Fossil Localities |
| ⓘ 'Serpentine Subgroup' Formula: D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn Reference: Gleba, 1978. Massachusetts Mineral & Fossil Localities |
ⓘ 'Stilbite subgroup' Reference: P Cristofono collection |
| ⓘ Titanite Formula: CaTi(SiO4)O Reference: Thompson, M. D., et al. (2010): High precision U-Pb zircon dates for Ediacaran granitoid rocks in SE New England; in Tollo, Richard P. et al., ed., From Rodinia to Pangea: The Lithotectonic Record of the Appalachian Region (GSA Memoir 206). |
| ⓘ Zircon Formula: Zr(SiO4) Reference: Thompson, M. D., et al. (2010): High precision U-Pb zircon dates for Ediacaran granitoid rocks in SE New England; in Tollo, Richard P. et al., ed., From Rodinia to Pangea: The Lithotectonic Record of the Appalachian Region (GSA Memoir 206). |
List of minerals arranged by Strunz 10th Edition classification
| Group 2 - Sulphides and Sulfosalts | |||
|---|---|---|---|
| ⓘ | 'Chalcopyrite' | 2.CB.10a | CuFeS2 |
| ⓘ | 'Galena' | 2.CD.10 | PbS |
| ⓘ | Pyrite | 2.EB.05a | FeS2 |
| Group 3 - Halides | |||
| ⓘ | 'Fluorite' | 3.AB.25 | CaF2 |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | 'Anatase' | 4.DD.05 | TiO2 |
| ⓘ | 'Cuprite' | 4.AA.10 | Cu2O |
| ⓘ | 'Goethite' | 4.00. | α-Fe3+O(OH) |
| ⓘ | 'Hematite' | 4.CB.05 | Fe2O3 |
| ⓘ | 'Opal' | 4.DA.10 | SiO2 · nH2O |
| ⓘ | var: Opal-AN | 4.DA.10 | SiO2 · nH2O |
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Group 5 - Nitrates and Carbonates | |||
| ⓘ | 'Calcite' | 5.AB.05 | CaCO3 |
| ⓘ | 'Malachite' | 5.BA.10 | Cu2(CO3)(OH)2 |
| Group 9 - Silicates | |||
| ⓘ | 'Albite' | 9.FA.35 | Na(AlSi3O8) |
| ⓘ | 'Anthophyllite' | 9.DE.05 | ☐{Mg2}{Mg5}(Si8O22)(OH)2 |
| ⓘ | 'Babingtonite' | 9.DK.05 | Ca2(Fe,Mn)FeSi5O14(OH) |
| ⓘ | 'Chamosite' | 9.EC.55 | (Fe2+,Mg,Al,Fe3+)6(Si,Al)4O10(OH,O)8 |
| ⓘ | 'Epidote' | 9.BG.05a | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
| ⓘ | 'Microcline' | 9.FA.30 | K(AlSi3O8) |
| ⓘ | Titanite | 9.AG.15 | CaTi(SiO4)O |
| ⓘ | Zircon | 9.AD.30 | Zr(SiO4) |
| Unclassified Minerals, Rocks, etc. | |||
| ⓘ | 'Allanite Group' | - | {A12+REE3+}{M3+2M32+}(Si2O7)(SiO4)O(OH) |
| ⓘ | 'Amphibole Supergroup' | - | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| ⓘ | 'var: Byssolite' | - | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| ⓘ | 'Heulandite subgroup' | - | |
| ⓘ | Serpentine Subgroup | - | D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn |
| ⓘ | Stilbite subgroup | - | |
List of minerals arranged by Dana 8th Edition classification
| Group 2 - SULFIDES | |||
|---|---|---|---|
| AmXp, with m:p = 1:1 | |||
| ⓘ | Galena | 2.8.1.1 | PbS |
| AmBnXp, with (m+n):p = 1:1 | |||
| ⓘ | Chalcopyrite | 2.9.1.1 | CuFeS2 |
| AmBnXp, with (m+n):p = 1:2 | |||
| ⓘ | Pyrite | 2.12.1.1 | FeS2 |
| Group 4 - SIMPLE OXIDES | |||
| A2X | |||
| ⓘ | Cuprite | 4.1.1.1 | Cu2O |
| A2X3 | |||
| ⓘ | Hematite | 4.3.1.2 | Fe2O3 |
| AX2 | |||
| ⓘ | Anatase | 4.4.4.1 | TiO2 |
| Group 6 - HYDROXIDES AND OXIDES CONTAINING HYDROXYL | |||
| XO(OH) | |||
| ⓘ | Goethite | 6.1.1.2 | α-Fe3+O(OH) |
| Group 9 - NORMAL HALIDES | |||
| AX2 | |||
| ⓘ | Fluorite | 9.2.1.1 | CaF2 |
| Group 14 - ANHYDROUS NORMAL CARBONATES | |||
| A(XO3) | |||
| ⓘ | Calcite | 14.1.1.1 | CaCO3 |
| Group 16a - ANHYDROUS CARBONATES CONTAINING HYDROXYL OR HALOGEN | |||
| ⓘ | Malachite | 16a.3.1.1 | Cu2(CO3)(OH)2 |
| Group 51 - NESOSILICATES Insular SiO4 Groups Only | |||
| Insular SiO4 Groups Only with cations in >[6] coordination | |||
| ⓘ | Zircon | 51.5.2.1 | Zr(SiO4) |
| Group 52 - NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O | |||
| Insular SiO4 Groups and O, OH, F, and H2O with cations in [6] and/or >[6] coordination | |||
| ⓘ | Titanite | 52.4.3.1 | CaTi(SiO4)O |
| Group 58 - SOROSILICATES Insular, Mixed, Single, and Larger Tetrahedral Groups | |||
| Insular, Mixed, Single, and Larger Tetrahedral Groups with cations in [6] and higher coordination; single and double groups (n = 1, 2) | |||
| ⓘ | Epidote | 58.2.1a.7 | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
| Group 65 - INOSILICATES Single-Width,Unbranched Chains,(W=1) | |||
| Single-Width Unbranched Chains, W=1 with chains P=5 | |||
| ⓘ | Babingtonite | 65.4.1.2 | Ca2(Fe,Mn)FeSi5O14(OH) |
| Group 66 - INOSILICATES Double-Width,Unbranched Chains,(W=2) | |||
| Amphiboles - Mg-Fe-Mn-Li subgroup | |||
| ⓘ | Anthophyllite | 66.1.2.1 | ☐{Mg2}{Mg5}(Si8O22)(OH)2 |
| Group 71 - PHYLLOSILICATES Sheets of Six-Membered Rings | |||
| Sheets of 6-membered rings interlayered 1:1, 2:1, and octahedra | |||
| ⓘ | Chamosite | 71.4.1.7 | (Fe2+,Mg,Al,Fe3+)6(Si,Al)4O10(OH,O)8 |
| Group 75 - TECTOSILICATES Si Tetrahedral Frameworks | |||
| Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si | |||
| ⓘ | Quartz | 75.1.3.1 | SiO2 |
| Si Tetrahedral Frameworks - SiO2 with H2O and organics | |||
| ⓘ | Opal | 75.2.1.1 | SiO2 · nH2O |
| Group 76 - TECTOSILICATES Al-Si Framework | |||
| Al-Si Framework with Al-Si frameworks | |||
| ⓘ | Albite | 76.1.3.1 | Na(AlSi3O8) |
| ⓘ | Microcline | 76.1.1.5 | K(AlSi3O8) |
| Unclassified Minerals, Rocks, etc. | |||
| ⓘ | 'Allanite Group' | - | {A12+REE3+}{M3+2M32+}(Si2O7)(SiO4)O(OH) |
| ⓘ | 'Amphibole Supergroup' | - | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| ⓘ | 'var: Byssolite' | - | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| ⓘ | 'Heulandite subgroup' | - | |
| ⓘ | Opal var: Opal-AN | - | SiO2 · nH2O |
| ⓘ | 'Serpentine Subgroup' | - | D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn |
| ⓘ | 'Stilbite subgroup' | - | |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Allanite Group | {A12+REE3+}{M23+M32+}(Si2O7)(SiO4)O(OH) |
| H | ⓘ Amphibole Supergroup | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| H | ⓘ Anthophyllite | ☐{Mg2}{Mg5}(Si8O22)(OH)2 |
| H | ⓘ Babingtonite | Ca2(Fe,Mn)FeSi5O14(OH) |
| H | ⓘ Amphibole Supergroup (var: Byssolite) | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| H | ⓘ Chamosite | (Fe2+,Mg,Al,Fe3+)6(Si,Al)4O10(OH,O)8 |
| H | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
| H | ⓘ Goethite | α-Fe3+O(OH) |
| H | ⓘ Malachite | Cu2(CO3)(OH)2 |
| H | ⓘ Opal | SiO2 · nH2O |
| H | ⓘ Opal (var: Opal-AN) | SiO2 · nH2O |
| H | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn |
| C | Carbon | |
| C | ⓘ Calcite | CaCO3 |
| C | ⓘ Malachite | Cu2(CO3)(OH)2 |
| O | Oxygen | |
| O | ⓘ Albite | Na(AlSi3O8) |
| O | ⓘ Allanite Group | {A12+REE3+}{M23+M32+}(Si2O7)(SiO4)O(OH) |
| O | ⓘ Amphibole Supergroup | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| O | ⓘ Anatase | TiO2 |
| O | ⓘ Anthophyllite | ☐{Mg2}{Mg5}(Si8O22)(OH)2 |
| O | ⓘ Babingtonite | Ca2(Fe,Mn)FeSi5O14(OH) |
| O | ⓘ Amphibole Supergroup (var: Byssolite) | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| O | ⓘ Calcite | CaCO3 |
| O | ⓘ Chamosite | (Fe2+,Mg,Al,Fe3+)6(Si,Al)4O10(OH,O)8 |
| O | ⓘ Cuprite | Cu2O |
| O | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
| O | ⓘ Goethite | α-Fe3+O(OH) |
| O | ⓘ Hematite | Fe2O3 |
| O | ⓘ Malachite | Cu2(CO3)(OH)2 |
| O | ⓘ Microcline | K(AlSi3O8) |
| O | ⓘ Opal | SiO2 · nH2O |
| O | ⓘ Opal (var: Opal-AN) | SiO2 · nH2O |
| O | ⓘ Quartz | SiO2 |
| O | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn |
| O | ⓘ Titanite | CaTi(SiO4)O |
| O | ⓘ Zircon | Zr(SiO4) |
| F | Fluorine | |
| F | ⓘ Amphibole Supergroup | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| F | ⓘ Amphibole Supergroup (var: Byssolite) | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| F | ⓘ Fluorite | CaF2 |
| Na | Sodium | |
| Na | ⓘ Albite | Na(AlSi3O8) |
| Mg | Magnesium | |
| Mg | ⓘ Anthophyllite | ☐{Mg2}{Mg5}(Si8O22)(OH)2 |
| Mg | ⓘ Chamosite | (Fe2+,Mg,Al,Fe3+)6(Si,Al)4O10(OH,O)8 |
| Mg | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn |
| Al | Aluminium | |
| Al | ⓘ Albite | Na(AlSi3O8) |
| Al | ⓘ Amphibole Supergroup | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| Al | ⓘ Amphibole Supergroup (var: Byssolite) | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| Al | ⓘ Chamosite | (Fe2+,Mg,Al,Fe3+)6(Si,Al)4O10(OH,O)8 |
| Al | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
| Al | ⓘ Microcline | K(AlSi3O8) |
| Al | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn |
| Si | Silicon | |
| Si | ⓘ Albite | Na(AlSi3O8) |
| Si | ⓘ Allanite Group | {A12+REE3+}{M23+M32+}(Si2O7)(SiO4)O(OH) |
| Si | ⓘ Amphibole Supergroup | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| Si | ⓘ Anthophyllite | ☐{Mg2}{Mg5}(Si8O22)(OH)2 |
| Si | ⓘ Babingtonite | Ca2(Fe,Mn)FeSi5O14(OH) |
| Si | ⓘ Amphibole Supergroup (var: Byssolite) | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| Si | ⓘ Chamosite | (Fe2+,Mg,Al,Fe3+)6(Si,Al)4O10(OH,O)8 |
| Si | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
| Si | ⓘ Microcline | K(AlSi3O8) |
| Si | ⓘ Opal | SiO2 · nH2O |
| Si | ⓘ Opal (var: Opal-AN) | SiO2 · nH2O |
| Si | ⓘ Quartz | SiO2 |
| Si | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn |
| Si | ⓘ Titanite | CaTi(SiO4)O |
| Si | ⓘ Zircon | Zr(SiO4) |
| S | Sulfur | |
| S | ⓘ Chalcopyrite | CuFeS2 |
| S | ⓘ Galena | PbS |
| S | ⓘ Pyrite | FeS2 |
| Cl | Chlorine | |
| Cl | ⓘ Amphibole Supergroup | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| Cl | ⓘ Amphibole Supergroup (var: Byssolite) | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| K | Potassium | |
| K | ⓘ Microcline | K(AlSi3O8) |
| Ca | Calcium | |
| Ca | ⓘ Babingtonite | Ca2(Fe,Mn)FeSi5O14(OH) |
| Ca | ⓘ Calcite | CaCO3 |
| Ca | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
| Ca | ⓘ Fluorite | CaF2 |
| Ca | ⓘ Titanite | CaTi(SiO4)O |
| Ti | Titanium | |
| Ti | ⓘ Amphibole Supergroup | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| Ti | ⓘ Anatase | TiO2 |
| Ti | ⓘ Amphibole Supergroup (var: Byssolite) | AX2Z5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| Ti | ⓘ Titanite | CaTi(SiO4)O |
| Mn | Manganese | |
| Mn | ⓘ Babingtonite | Ca2(Fe,Mn)FeSi5O14(OH) |
| Mn | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn |
| Fe | Iron | |
| Fe | ⓘ Babingtonite | Ca2(Fe,Mn)FeSi5O14(OH) |
| Fe | ⓘ Chalcopyrite | CuFeS2 |
| Fe | ⓘ Chamosite | (Fe2+,Mg,Al,Fe3+)6(Si,Al)4O10(OH,O)8 |
| Fe | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
| Fe | ⓘ Goethite | α-Fe3+O(OH) |
| Fe | ⓘ Hematite | Fe2O3 |
| Fe | ⓘ Pyrite | FeS2 |
| Fe | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn |
| Ni | Nickel | |
| Ni | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn |
| Cu | Copper | |
| Cu | ⓘ Chalcopyrite | CuFeS2 |
| Cu | ⓘ Cuprite | Cu2O |
| Cu | ⓘ Malachite | Cu2(CO3)(OH)2 |
| Zn | Zinc | |
| Zn | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn |
| Zr | Zirconium | |
| Zr | ⓘ Zircon | Zr(SiO4) |
| Pb | Lead | |
| Pb | ⓘ Galena | PbS |
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
| Pennsylvanian 298.9 - 323.2 Ma ID: 3184341 | Paleozoic sedimentary rocks Age: Pennsylvanian (298.9 - 323.2 Ma) Comments: Narragansett And Boston Basins Lithology: Sedimentary rocks Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. [154] |
| Ediacaran - Cryogenian 541 - 720 Ma ID: 2954814 | Dedham Granite Age: Neoproterozoic (541 - 720 Ma) Stratigraphic Name: Dedham Granite Description: Light grayish-pink to greenish-gray, equigranular to slightly porphyritic, variably altered, granite south and west of Boston. Includes dioritic rock near Scituate and Cohasset and Barefoot Hills Quartz Monzonite of Lyons (1969) and Lyons and Wolfe (1971). Intrudes Zdi, Zgb, Zb, Zv. Extensive calc-alkaline plutons separated by Boston basin have long been mapped as Dedham. Those to the north of Boston and studied in this report, are referred to as Dedham North. Crystallization ages for the Dedham North suite (based on titanites and zircons) have been determined at 607+/-4 Ma, while ages for the Lynn are slightly younger at 596+/-3 Ma. Both are clearly part of the Late Proterozoic magmatic event. Dates on two samples from Sheffield Heights indicate that the diorite and granite are part of the Dedham North suite. The Dedham south and west of Boston has been dated at 630+/15 Ma (Zartman and Naylor, 1984). Dedham North Granite has a compositionally highly variable suite ranging from leucogranites to granodiorites, tonalites, and quartz diorite. The granites originated by partial melting of a sedimentary protolith, while the intermediate members show a mixing of granitic magma and mafic magma (Hepburn and others, 1993). Comments: Part of Milford-Dedham Zone (Tertiary and Older Rocks). Secondary unit description per MA018. Proterozoic Z age of Dedham is based on the following isotopic dates: . 1. 630 +/-15 Ma by U/Pb methods on zircon (Zartman and Naylor, 1984) from Dedham Granite. 2. 595 +/-17 Ma by Rb/Sr whole rock methods (Kovach and others, 1977) from Dedham Granite north of Boston. 3. 640 +/-14 Ma by K/Ar methods on hornblende (Zartman and Naylor, 1984) per MA007. Original map source: Unpublished Digital Geologic Map of Massachusetts received from Rudi Hon of Boston College in 1998; based on the 1983 USGS paper version (MA002). Lithology: Major:{granite}, Minor:{dioritic,quartz monzonite} Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. [133] |
Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License
West Roxbury Crushed Stone Quarry, West Roxbury, Boston, Suffolk Co., Massachusetts, USA