# Talk:Silverthrone Caldera

This article has really transformed.  Great job by Black Tusk!

Images
A little expansion
3 or 4 References
--Meldshal (§peak to me) 11:43, 18 July 2008 (UTC)

Expanded and added more references and photos. There's very little known about this volcano because of its remoteness so I would say this article is almost complete... Black Tusk (talk) 20:12, 18 July 2008 (UTC)

I don't think there's a source mentioning the Silverthrone Caldera as a VEI-7 volcano given the fact it's remote and poorly studied, but it's size appears to be quite similar to other VEI-7 calderas per Category:VEI-7 volcanoes which are mostly at least 16 kilometers wide. It's most likely explosive in nature and not mainly effusive since rhyolite, dacite and andesite lava have high viscosity and are commonly associated with violent explosive volcanism. Not a highly accurate observation but the larger the caldera is the larger the eruption must have been. It's also larger than the Crater Lake caldera in Oregon (another Cascade volcano) which also formed by a VEI-7 eruption. Black Tusk (talk) 04:53, 14 July 2008 (UTC)

I readded this infomation because Silverthrone appears to be subduction-related based on chemistry. I also deleted the bit about its elevation not definitely known because there appears to be no source to support it. References I seen for the Silverthrone Caldera show an elevation of 3,160 m (10,367 ft). Black Tusk (talk) 03:59, 18 July 2008 (UTC)

This review is transcluded from Talk:Silverthrone Caldera/GA1. The edit link for this section can be used to add comments to the review.
I have read through this article, and have found it satisfactory. It is well written, engaging, and free from grammatical errors and typos. It catches the readers attention, though it is at times rather technical. However, this level of technicality is acceptable from a "research point of view". It is thoroughly referenced, and in all the right places. The article and its sections are also illustrated by images and a map. There is no history of recent edit warring. All-in-all, this is an article of excellent quality, and a definite Good Article. J.T Pearson (talk) 12:38, 13 August 2008 (UTC)

I've made many small edits, working as an editor who's not a geologist: see this diff. They're intended to make the article clearer, emphasising salient facts. I also added some invisible commented-out queries that only you-all can respond to: some things need to be given explanatory phrases to keep the general reader on board. The date of the "most recent ice age" didn't seem indicated by the rest of the paragraph: do please check that the link I made is right. I de-forced the px of images: now we get to select our own preferences, according to the MoS. --Wetman (talk) 17:28, 7 September 2008 (UTC)

The bit about the last ice age appears to be from a non-reliable website so I deleted and reworded the infomation. "choss" is just a term for dirty or loose rock, so I changed that as well. However, I don't understand your note about the Cascadia subduction zone theory being doubted. Black Tusk (talk) 16:10, 8 September 2008 (UTC)
To the unnecessarily hesitant phrase "However, it may be a product of the Cascadia subduction zone" my commented-out note meant "could this possibly be doubted?" Is there any doubt in any quarter that the volcano belt is a product of crustal subduction? The conditional hesitancy should be cleared from the thought. Yes?--Wetman (talk) 16:37, 8 September 2008 (UTC)
Not really, unless there's solid evidence. Andesite, dacite, and rhyolite are usually found together at subduction zones as mentioned in the article and that's why scientists consider Silverthrone as a subduction-related volcano. Other tectonic environments usually have different magma types, for example, hotspot volcanoes are usually made of basalt, which contrast significantly because basalt is fluid and andesite, rhyolite, and dacite magma is thick. Black Tusk (talk) 17:18, 8 September 2008 (UTC)

Hey editors, this article is using two of my photos without proper attributon
pic of the icefall and rockfall on Kingcome Glacier is from https://www.flickr.com/photos/druclimb/299665900
pic of the andesite columns in Charnaud Creek is from https://www.flickr.com/photos/druclimb/404125808
Anyways the licenses for these are both Creative Commons 2.0 Attribution Non-commercial, so it's fine for Wikipedia to use them, but you absolutely must do so with the appropriate attribution and CC license when you do so. 50.67.165.104 (talk) 17:24, 8 February 2024 (UTC)

@50.67.165.104: Please upload them on Wikimedia Commons and then we can delete the ones with without proper attribution. Volcanoguy 17:39, 8 February 2024 (UTC)


### Silverthrone Caldera
Hi there, I've just expanded and refurbished this old GA from 2008 so I would like someone to have a look at this article to see if it still meets GA. I would also like some feed back on improving this article since I plan on bringing it to FA at some point in the future. 
Thanks, Volcanoguy 20:23, 8 August 2025 (UTC)

Hey Volcanoguy, are you still interested in comments, or can this be closed? —TechnoSquirrel69 (sigh) 16:51, 24 September 2025 (UTC)
@TechnoSquirrel69: I'm still waiting for comments. Volcanoguy 17:16, 24 September 2025 (UTC)
@Volcanoguy For the other name of the mountain you can use: occasionally referred to sit amet, commonly referred sit amet, also referred to as sit amet, locally referred to as sit amet, formally called sit amet, currently called sit amet, Lorem ipsum dolor (or sit amet) and locally referred to as sit amet Work? Tokeamour (talk) 03:41, 11 October 2025 (UTC)
lorem imposum dummy text if your asking. Tokeamour (talk) 03:43, 11 October 2025 (UTC)
Used "also referred to as". Volcanoguy 20:08, 11 October 2025 (UTC)
I'm pinging Jo-Jo Eumerus and GeoWriter in case they want to provide some input. Volcanoguy 20:12, 11 October 2025 (UTC)

Putting this on my watchlist, but with real life I don't promise anything. Jo-Jo Eumerus (talk) 07:46, 12 October 2025 (UTC)


#### Comments by GeoWriter
Lead

"The caldera mainly poses a threat to air traffic from renewed explosive eruptions since there are no communities nearby, but lahars or debris flows could be produced from the melting of glacial ice."
I suggest changing this sentence to something along the lines of "Lahars and debris flows on the ground could be produced from the melting of glacial ice but they pose little threat because there are no nearby communities. The main potential hazard would be to air traffic if explosive eruptions were to occur." 

"The Silverthrone Caldera was a source of obsidian for indigenous peoples during the pre-contact era and was studied in the 1970s as a potential source of geothermal energy."
To avoid giving readers the impression that the obsidian was studied for geothermal energy, I suggest that it should be clarified that it is the caldera that was studied in the 1970s.
Names and etymology

""the caldera whose name has been identified in Canadian Alpine Journal articles"
I suggest changing "identified" to "used", "quoted" or "reported".
Geography
Location and climate

"massive icefields"
Massive compared to what? I think that "massive" is uninformative and unnecessary and it should be removed.
Geology
Tectonic setting

"very little geological studies"
Change to "very few geological studies".

"Immediately north of the Juan de Fuca Plate is the Explorer Plate, both of which are separated by the Nootka Fault"
"both of" should be removed.

"they have a volume of at least twice as much as that of the Mount Meager complex"
I suggest changing to "they have a volume at least twice that of the Mount Meager complex".
Structure
Multiple image of caldera formation - caption text - I recommend that the caption should clarify that this is actually for Mount Mazama not Silverthrone, but the same general processes apply at both.   
Geothermal potential

"silicious"
Spelling error. Change to "siliceous".
Eruptive history

"each of which have been radiometrically dated"
Change to "each of which has been radiometrically dated".

"between 100,000 and 900,000 years ago"
I recommend that the order of the ages should be swapped - geology/history is complicated enough if describing events in the order in which they occurred; going backwards adds unnecessary complications. 
First stage

"which contains a white to light grey matrix"
Change to "which has a white to light grey matrix" - the matrix is the thing doing the containing of fragments.

"then quickly covered and compressed by overlying volcanic rocks while still in a hot, plastic state"
- I think the overlying material does not necessarily have to be volcanic rock. I recommend changing "volcanic rocks" to "rocks". 
Third stage

"the eruption of basaltic andesite lava flows and pyroclastic cones"
I think this could give some readers the misleading impression that pyroclastic cones spring out of the ground fully formed. I recommend changing "pyroclastic cones" to "the formation of pyroclastic cones"

"vents around the parameter of the caldera"
Spelling error. Change to "vents around the perimeter of the caldera".

"Most of the lava flows issued from vents around the parameter of the caldera, the largest of which is continuously exposed for more than 25 km"
I suggest changing to "Most of the lava flows issued from vents around the perimeter of the caldera; the largest of these flows is continuously exposed for more than 25 km".
Mineral exploration

"clay and silica minerals such as opal, malachite, pyrolusite and celadonite"
Opal is not a "mineral" but it could be described as being an "industrial mineral", which has a looser definition; malachite is a carbonate mineral, pyrolusite is an oxide mineral and celadonite is a mica phyllosilicate mineral.
Conservation

"a group of geomorphological features known as “the paint pots”""
A brief description of what these "paint pots" actually are would be helpful. I think the inclusion of this text without informing readers of what these features are seems pointless. 
Notes 

"Xenoliths are rock fragments that become enveloped in a larger rock during the latter's development and solidification"
I suggest that "a larger rock" should be changed to "a larger mass of originally molten rock" (because in this case the xenoliths are in a specific basaltic andesite lava flow).
References
Scott et al. (2001) is downloadable as a pdf file at https://pubs.usgs.gov/pp/1630/report.pdf
GeoWriter (talk) 22:00, 16 October 2025 (UTC)


#### Scattered comments by JJE
"The relationship of the Silverthrone Caldera to other volcanoes in southwestern British Columbia remains unclear due to there having been very little geological studies conducted at the caldera" is a bit syntactically weird. "The Silverthrone and Franklin Glacier complexes lie inboard of the Explorer Plate which is subducting under the North American Plate at a rate of about 2 centimetres (0.79 inches) per year.[37][47] However, both tectonic plates are currently locked to some degree in the Cascadia subduction zone" my understanding that "locking" in the context of plate tectonics usually implies a temporary standstill between the actual megathrust earthquakes - and the Explorer Plate is something different than the Juan de Fuca Plate? Jo-Jo Eumerus (talk) 08:57, 17 October 2025 (UTC)