CANADIAN AND WORLD MINERAL DEPOSIT DATABASES
Geological Survey of Canada


Deposit number Country Location Names Commodities
800 Canada (New Brunswick) 47.41.00 N -- 065.53.48 W Millstream; Millstream Cu-Fe skarn; Ellis Iron Mine Fe; Cu
 
Database name: World Fe-oxide+/-Cu-Au-U (IOCG) deposits
Compilers: Sunil S. Gandhi
Release date: 2015-03-04
   
Deposit name(s): Millstream; Millstream Cu-Fe skarn; Ellis Iron Mine
Political location(s): Canada; Province or state: New Brunswick; Nearest community: Bathurst (20 km 290°)
NTS map data: 021P12 (Bathurst)
Deposit clan (type): Iron Skarn-type
Deposit (sub) types: massive magnetite bodies, up to 12 m wide, occur in stratabound skarn lenses over strike length of 300 m; magnetite replaces the skarn minerals; locally garnet-magnetite bands; minor breccia-fillings; Reference: Lentz, D. R.; Walker, J. A.; Stirling, J. A. R., 1995: Millstream Cu-Fe Skarn Deposit: An Example of a Cu-bearing Magnetite-rich Skarn System in Northern New Brunswick; Exploration and Mining Geology, Volume 4, p. 15 - 31
Deposit status: prospect; Size category: 0.3 Mt
Geologic province: Appalachian
Geologic subprovince: Tobique-Chaleur Belt
Geologic district: Nigadoo River Synclinorium
Deposit object located: centre-deposit on surface
Commodities: Fe; Cu
Mineralization styles: stratiform magnetite layers and lenses; streaks; veins; breccia-fillings
Geological ages: Early Silurian - Late Silurian (host rocks)
Middle Devonian (related magmatics)
Middle Devonian (mineralization)
Tectonic setting: epicontinental deformation zone-fold belt; transpressive; Formal name: Nigadoo River synclinorium of Acadian orogen (host rocks)
Coincident features: intrusive contact (mineralization in contact metamorphic aureole on southeast side of the pluton); Coincident feature name: Nicolas Dénys pluton
fault zone (east-northeast trending fault zone parallels second generation folds in host strata); Coincident feature name: Rocky Brook- Millstream Faut Zone
host lithology (reactive limestone unit altered to skarn, which in turn was replaced by magnetite); Coincident feature name: La Vielle Formation
Regional tectonic structure: major fold (west-trending, doubly plunging synclinorium formed during the Acadian orogeny) Tectonic structure name: Nigadoo River synclinorium
second order folds (south limb of the Nigadoo River synclinorium folded into doubly plynging anticline-syncline pair) Tectonic structure name: east-northeast trending folds
major fault zone (100 m wide fault zone, dips steeply to the south; trends parallel to subvertical axial plane of the second-order anticline) Tectonic structure name: Rocky Brook-Millstream Fault Zone
Host rocks: (1) sedimentary; carbonate (Early Silurian Chaleurs Group; overlies basal conglomerate of the group); Depositional setting: carbonate platform; Metamorphic grade: greenschist
External host rock forms:well bedded
Host rock protoliths:carbonate (nodular to massive limestones, calcareous siltstones and sandstones); Host rock protolith name: La Vieille Formation
Internal host rock structures:variable,including bedded, laminated, nodular and
Individual lithologies:calc-silicate (thin-bedded limestone and intercalated mudstone-siltstone; contact metasomatic alteration near a granodiorite-quartz monzonite pluton)
Host rock stratigraphy:La Vieille Formation

(2) sedimentary; sandstone-conglomerate (basal unit of Early Silurian Chaleurs Group); Depositional setting: carbonate platform; Metamorphic grade: greenschist
External host rock forms:beds and lenses
Host rock protoliths:conglomerate-sandstone (pebble to cobble conglomerate; includes altered peridotite clasts of allochthonous Late Ordovician Belledune River Mélange); Host rock protolith name: Armsrong Brook Formation
Internal host rock structures:pebbles and cobbles in sandy matrix
Individual lithologies:conglomerate-sandstone (red to grey; unconformably overlies the Late Ordovician ultramafic peridotite/ophiolite mélange)
Host rock stratigraphy:Armsrong Brook Formation

(3) volcanic; ultramafic volcanic rocks (Ordovician ophiolite and peridotite); Depositional setting: deep marine; Metamorphic grade: greenschist
External host rock forms:flows, agglomerates, sills
Host rock protoliths:ultramafic flows and sills (allochthonous blocks of serpentinized mantle peridotites and ophiolites); Host rock protolith name: Belledune River Mélange
Internal host rock structures:massive, equigranular to porphyritic
Individual lithologies:ultrabasic (sepentinized ultramafic flows, sills and dykes)
Host rock stratigraphy:Belledune River Mélange

(4) sedimentary; sandstone-conglomerate (overlies the La Vieille Formation); Depositional setting: carbonate platform; Metamorphic grade: greenschist
External host rock forms:beds and lenses
Host rock protoliths:sandstone and conglomerate (fine grained micaceous sandstone, grades upward into coarse feldspathic wacke followed by red to grey, polymictic pebble-cobble conglomerate); Host rock protolith name: Simpson Field Formation
Internal host rock structures:fine grained to coarse pebbly
Individual lithologies:conglomerate-sandstone (sandstone forms the lower part of the formation; conglomerate contains clasts of mafic volcanic, jasper, chert and slate; unit locally magnetite-rich )
Host rock stratigraphy:Simpson Field Formation

(5) sedimentary; mudstone-carbonate-sandstone-siltstone (upper part of the Chaleurs Group); Depositional setting: carbonate platform; Metamorphic grade: greenschist
External host rock forms:well bedded
Host rock protoliths:calcareous shale-siltstone-sandstone
Internal host rock structures:fine to coarse grained
Individual lithologies:calcareous clastic sediments (calacareous slate, minor limestone, calcareous sandstone and siltstone)
Host rock stratigraphy:LaPlante and Free Grant Formations
Related igneous rocks: (1) intrusive; granodiorite-tonalite suite (Middle Devonian; nearly circular, 4.5 x 3.5 km pluton); Initials: Nicolas Dénys pluton; Magma series: calc-alkaline; Depositional setting: continental
Individual lithologies:granodiorite-quartz monzonite (pinkish grey, medium to coarse, seriate to equigranular granodiorite; locally quartz monzonitic; with related feldspar porphyry dykes)
Metallogenic signatures: Fe-Cu-Mo-W
Alteration signatures: skarn: grandite-diopside; What was altered: limestone-mudstone-siltstone
epidotization: epidote; What was altered: mafic silicates
albitization: albite, minor scapolite; What was altered: clay minerals
chloritization: chlorite; What was altered: mafic silicates
hematization: hematite; What was altered: magnetite
Mineralogy: (alteration): hematite
(gangue): garnet (andradite), diopside, actinolite/tremolite, epidote, albite, chlorite, calcite, scapolite
(mineralization): magnetite, sphalerite, pyrite, pyrrhotite, arsenopyrite, molybdenite, scheelite
Radiometric ages: Object dated: Related igneous rocks(1); Age - Ma: 381; +4; -4; Dating method: U-Pb; Concentrate: zircon; Source rock: granodiorite; Event dated: intrusive event; Interpretive comment: emplacement age of the pluton, which is regarded as the source of mineralizing hydrothermal fluids ; Reference: Walker, J.; Gower, S.; McCutcheon, S. R., 1991: Antinouri-Nicolas Project, Gloucester and Restigouche Counties, Northern New Brunswick (C-NBCAMD); in Project Summaries for 1991, Sixteenth Annual Review of Acivities, Edited by Abbott, S. A., Mineral Resources Circular, Review of Activities, New Brunswick Natural Resources and Energy, New Brunswick Department of Natural Resources and Energy, 912, p. 87 - 100
Deposit shape: tabular
Deposit dimensions:strike length: 300 metres
width: 12 metres
depth: 38 metres
Qualified comments: (Applies to: discovery and development) Discovered in 1890s; explored intermittently: edit driven in 1893; drilling 1949-1952; drilling in 1968 outlined a zone to 150 m depth with estimated 0.2 to 0.3 Mt averaging 1.2-1.5 % Cu, 22 g/t Ag.
Links to other databases: New Brunswick MINFILE; Key value: 425
References:
Davies, J. L.; Tupper, W. M.; Bachinski, D.; Boyle, R. W.; Martin, F., 1969
Geology and Mineral Deposits of the Nigadoo River-Millstream River Area, Gloucester County, New Brunswick
Paper, Geological Survey of Canada, Geological Survey of Canada, Department of Energy, Mines and Resources, Ottawa, Canada, Publication code 67-49, 70 p., 5 maps.

Lentz, D. R.; Walker, J. A.; Stirling, J. A. R., 1995
Millstream Cu-Fe Skarn Deposit: An Example of a Cu-bearing Magnetite-rich Skarn System in Northern New Brunswick
Exploration and Mining Geology, Volume 4, p. 15 - 31

Walker, J.; Gower, S.; McCutcheon, S. R., 1991
Antinouri-Nicolas Project, Gloucester and Restigouche Counties, Northern New Brunswick (C-NBCAMD)
in Project Summaries for 1991, Sixteenth Annual Review of Acivities, Edited by Abbott, S. A., Mineral Resources Circular, Review of Activities, New Brunswick Natural Resources and Energy, New Brunswick Department of Natural Resources and Energy, 912, p. 87 - 100


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