Post by
diabase1 on Mar 20, 2023 9:20am
Seguin-Challies Twps.
The Seguin-Challies Property is located within the Case Batholith, about 25 km northwest of the Power Metals' cesium-lithium discovery area and approximately 65 km east northeast of Cochrane, Ontario.
In general, the rocks of the Case Batholith have been described as being granodiorite, along with pegmatites, but there may also be patches of quartz monzonite in some areas as well. However, the exact rock types in the immediate area of the Property are not known at this time. Perhaps they can be either granodiorite, tonalite, diorite or quartz monzonite.
As stated in Power Metals' August 19, 2022 press release, "Drill hole PWM-22-131 intersected biotite-rich metasedimentary host rock with elevated Li, Rb and Cs contents from 45.89-47.30 m, 1.41m interval with 0.49 % Li2O, 3094 ppm Rb and 0.47 % Cs2O. This metasomatized host rock can be used as a pathfinder to locate blind pegmatites on the property". This is an impotant bit of information. As it turns out, the metasedimentary rocks are magnetic and therefore can be traced on the ground. The pegmatites, although not magnetic, will be found in contact with the metasediments. This no doubt may be the case near the margins of the Case Batholith, but the scenario within the interior of the batholith is still being explored.
In the Recommendations for Explorations 2021-2022, page 28 "The Case pegmatite system is hosted in the southeastern part of the Case batholith, an extensive 50 by 85 km, ovoid granitic complex that is apparently part of the Opatica Subprovince (Jackson and Fyon 1991). The immediate host rocks of the pegmatite dikes consist of massive to subtly foliated, biotite tonalite that is characterized by biotite-rich orbicules that range in diameter from 1 to 7 cm. The foliation of the biotite in the tonalite is perpendicular to the contact with the pegmatite". Peter Chadwick, the author, calls the host rock tonalite, while others call it a granodiorite. Also, as mentioned above, Power Metals calls the host rock a biotite rich metasedimentary rock. So who's right, Power Metals or Peter Chadwick, an OGS geologist?
The Seguin-Challies claims contain an arcuate shaped topographic ridge that is about 20m -30m high, over a width of approximately 350m. Referring to the Quaternary Map 2555, it shows 'Bedrock: undifferentiated igneous and metamorphosed rock, exposed at surface or covered by a discontinuous, thin layer of drift'. As well, Google Earth shows a lot of outcrop. To have a substantial ridge that extensive, it would seem that there will probably is a lot of quartz. And to have an arcuate ridge, must there have been a pluton, on the east side, that formed the curved ridge? Another thought about the ridge and its possible makeup: "Some rare metal granites display pegmatitic cupolas (bubbles-my term) that suggest an origin from pegmatitic melts that did not separate from their plutonic parent (Cerny, 1992)".
Referring to Map 82826, the Second Vertical Gradient shows the arcuate formation has been broken up into 3 sections, a north zone, a west zone and a south zone. Each is estimated to be about 75m wide. A couple of weak north-south diabase dykes are running through the middle of the arcuate formation.
There is no discernible Ternary anomaly associated with the magnetic anomaly.
There are a number of logging roads in the immediate area of the Property, so access to most areas of the Property will not be a problem.
Referring to Map 2586, the magnetic total field background in this area is quite high, suggesting a more mafic phase to the Case Batholith. It is interesting to note that the location of the Power Metals' cesium-lithium discovery is just outside of this extensive magnetic high, but still within the Case Batholith. Whether or not this is an important point to consider, I'm not sure!! As I've mentioned in a previous post, the Power Metals' discovery area is located in an area of intense gravity low, suggesting a more felsic intrusive.
On a more local level, Map 82815 shows the arcuate shaped magnetic feature, jammed between a cluster of north-south diabase dykes. However, there are several other east-west trending magnetic features, both north and south of the Property, so I don't know why this one, in particular, was staked.
There were no gravity readings taken in the area of the Property.
Google Earth: there should be lots of outcrop on this ridge.
As far I know, there was no historical work carried out on the Property.