Ontario Geological Survey
Permanent Link to this Record:
MDI42E11NE00005
| Record Name(s) | Tombill Main Central Porphyry - 1940, Main Group Central - 1940 |
|---|---|
| Related Record Type | Partial |
| Related Record(s) | |
| Record Status | Occurrence |
| Date Created | 1980-Feb-13 |
| Date Last Modified | 2022-May-09 |
| Created By | |
| Revised By |
Primary Commodities: Gold
Township or Area: Errington
Latitude: 49° 41' .35" Longitude: -87° 0' 21.56"
UTM Zone: 16 Easting: 499568 Northing: 5503434 UTM Datum: NAD83
Resident Geologist District: Thunder Bay North
NTS Grid: 42E11NE
Point Location Description: DDH and trenching on map M1951-07 and description in ARV60 part 6 p. 133
Location Method: Data Compilation
Access Description: The property is located in south central Errington Township. The claims are easily accessible by Trans Canada Highway 11 which passes through the two claims approximately 4.5 km west of the turn-off to Geraldton (Highway 584).
Showings are located on claims TB10112 and TB10115, so the history of both is given though it should be noted that they are part of a much larger claim block held by Tombill Mines Limited. 1931: Claim TB10112 was staked by Alex Gillies and claim TB10115 was staked by Pat Barry. Both applied for Mining Operation Permits. 1932-33: Permits were obtained and surface work was performed. 1935: Surface exploration and 6553.2 m of diamond drilling were done on the claim block by the Oro Plata Mining Co., which managed Longlac Lagoon Mines Ltd. 1936: Elmos Gold Mines Ltd. was incorporated to take over Longlac Lagoon Gold Mines Ltd. and performed surface work on the claims. 1937: Both claims were patented by T.A. Johnson. 1940: Tombill Gold Mines acquired the assets of Elmos Gold Mines Ltd. No work was performed on the property. 1940s: Diamond drilling and geophysics were performed by Tombill. 1959: Tombill Gold Mines Ltd. changed its name to Tombill Mines Ltd. 1974: Tombill Mines Limited conducted VLF, mag, geological and geochemical (soil) surveys on the claim block. 1979: Airborne mag and EM surveys were conducted by Tombill Mines Ltd. 1980: Diamond drilling was conducted elsewhere on the claim block.
| Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
|---|---|---|
| 63.3224 | 42E10NW0180 | 42E10NW0180 |
Province: Superior
Subprovince: Wabigoon
Belt: Beardmore-Geraldton
Geological Age: Archean
| Rock Type | Rank | Composition | Texture | Relationship | Conglomerate | 1 | Near |
|---|---|---|---|---|
| Sandstone | 2 | Greywacke | Near | |
| Claystone | 3 | Argillite | Near | |
| Schist-Unsubdivided | 4 | Chlorite | Near | |
| Ironstone-unsubdivided | 5 | Near | ||
| Diorite | 6 | Hornblende Diorite | Near | |
| Porphyry-unsubdivided | 7 | Albite | Sheared, Brecciated | Host |
| Quartz Diabase | 8 | Quartz Diabase | Near |
Dec 04, 2018 (B Nelson) - The Main Tombill Group is underlain principally by Early Precambrian clastic metasediments but also by metavolcanic and metaintrusive rocks. Conglomerate, greywacke, argillite, and chlorite schist strike N75-90 degrees E. Narrow iron formation is interbedded with the schist and the argillite. Intrusive into the clastic and pyroclastic sediments are hornblended diorite, albite porphyry and quartz diabase. Aside from the Ellis syncline, the most important structural feature on the property is the Bankfield-Tombill Fault. The fault is represented by a zone up to 110 feet in thickness of silicified and carbonatized rock material. It strikes N75 degrees W and dips to to south at 60 to 70 degrees. The first movements along the fault were pre-ore. The structure, however, appears to have been the locus of adjustments offsetting two north-south diabase dykes a distance of 2200 feet. The most important mineralization is located in a sheared, brecciated zone along the north contact of a narrow sill-like body of albite porphyry which has intruded greywacke. Diorite occurs to the north of the porphyry. The sheared, brecciated porphyry is impregnated with small amounts of pyrite and arsenopyrite and is cut by numerous narrow and discontinuous quartz stringers.
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 1 | Arsenopyrite | Economic | Ore | ||||
| 2 | Pyrite | Economic | Ore | ||||
| Quartz | Alteration | Silicification | 1 | Unknown | Disseminated | ||
| Sericite | Alteration | Sericitization | 2 | Unknown | Disseminated | ||
| Unspecified | Alteration | Carbonatization | 3 | Unknown | Disseminated |
Dec 07, 2005 (B Nelson) - Surface trenching showed the porphyry to have a length of 152.4 m and a width of 6.1 to 24.3 m. Diamond drilling extended the length and additional 304.8 m to the west. Scattered values were obtained in the porphyry proper while more interesting values were obtained along the north contact. The best intersection noted was 0.26 oz/ton Au over 0.76 m. This hole was located near the boundary between the two claims.
Dec 04, 2018 (Therese Pettigrew) - The most important mineralization is located in a sheared, brecciated zone along the north contact of a narrow sill-like body of albite porphyry which has intruded greywacke (Pye, 1951). Diorite occurs to the north of the porphyry. The sheared, brecciated porphyry is impregnated with small amounts of pyrite and arsenopyrite and is cut by numerous, narrow and discontinuous quartz stringers. The wall rock adjacent to stringers of quartz has been sericitized and locally carbonatized (Pye, 1951).
Dec 07, 2005 (B Nelson) - The wall rock adjacent to stringers of quartz has been sericitized and locally carbonatized.
Map - Little Long Lac gold area, District of Thunder Bay, Ontario
Publication Number: ARM44D Scale: 1:31,680 Date: 1997
Author: Bruce E.L.
Publisher Name: Ontario Dept. of Mines
Location:
Mono - Gold occurrences, prospects, and deposits of the Beardmore-Geraldton area, districts of Thunder Bay and Cochrane
Publication Number: OFR5630 Page: 587-589 Date: 1986
Author: Mason J.K., White G.D.
Publisher Name: Ontario Geological Survey
Location:
Map - Compilation series, Geraldton sheet, Thunder Bay and Cochrane districts
Publication Number: P0241 Scale: 1:126,720 Date: 1984
Author: Stott G.M., McConnell C.D., Mason J.K.
Publisher Name: Ontario Geological Survey
Location:
Map - Mineral deposits series, Ontario mineral potential, Longlac sheet, districts of Thunder Bay and Cochrane
Publication Number: P1527 Scale: 1:250,000 Date: 1978
Author: Springer J.S.
Publisher Name: Ontario Geological Survey
Location:
Part - Geology of Errington Township, Little Long Lac area
Publication Number: ARV60-06 Date: 1997
Author: Pye E.G.
Publisher Name: Ontario Dept. of Mines
Location:
File - Resident Geologist Mineral Deposit Files
Publication Number: Min Dep Date:
Author:
Publisher Name:
Location: Thunder Bay RGP
Map - Township of Errington, District of Thunder Bay, Ontario
Publication Number: M1951-07 Scale: 1:12,000 Date: 1997
Author: Horwood H.C., Pye E.G.
Publisher Name: Ontario Dept. of Mines
Location:
Map - Tashota-Geraldton sheet, geological compilation series, Thunder Bay and Cochrane districts
Publication Number: M2102 Date: 1997
Author: Pye E.G., Harris F.R., Fenwick K.G., Baillie J.
Publisher Name: Ontario Dept. of Mines
Location:
Part - Mines of Ontario in 1940
Publication Number: ARV50-01.001 Date: 1997
Author: Tower W.O., Cave A.E., Taylor J.B., Little E.S., Hargrave W.G., Bayne A.S., Cooper D.F., Weir E.B., Douglass D.P.
Publisher Name: Ontario Dept. of Mines
Location:
Map - Thunder Bay data series, Geraldton area, Thunder Bay District
Publication Number: P2520 Scale: 1:15,840 Date: 1982
Author: Love W.D.
Publisher Name: Ontario Geological Survey
Location:
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