Unlikely that you had a volcano. Was there lava or any volcanic material on the ground? This just talks about "daada baleko" means that the side of the hill was burning. In the present geologic setting of Nepal, volcanism would be difficult to explain!

Not at all. I think the written text in this pic is referring to something else, not the volcano.

Indeed it is unlikely to have a typical volcanic setting as mentioned ('Jwalamukhi') in the text written on stone shown in the picture.

However, I like to add that some glassy material was reported from sine locality in the Garhwal Himalayas. But it was only limited to a few very small pockets. That time I was in Wadia Institute of Himalayan Geology, Dehradun. I tried to search through literature and at best what I recall now, there were interpretations that such glassy material may be due to lightening during thunderstorm. Another opinion was possibility of heating under electrical pillars as in few cases those glassy material were found near electric lines.

Anyways it was not my main project there, so I didn't follow it much. Just from the memories of 2007. I guess Dr V C Thakur submitted a small report on this.

As I know it is impossible to have a Volcano with present-day Himalayan crustal thickness. And about the picture, tells about the combination of landslide and electric discharge(?) ( I remember in some earthquakes because of electric discharge some sparkling light can be observed. For example, I read one news during the Mexico earthquake.) https://www.nationalgeographic.co.uk/environment/2019/04/earthquake-lights-explained

https://www.newscientist.com/article/2147401-mysterious-lights-in-the-sky-seen-after-mexicos-huge-earthquake/

For me the volcanic activity is not possible. I just checked the coordinate, which falls exactly on MCT, where rocks are highly crushed and frazile, where Landslide activity is very common. The lightening during land slide is caused by several reason such as lightening caused by forest fire or burning because of spark generated by huge amount of friction generated during mass movement. I negate the possibility of fire caused by heating under electrical pillars because there is no electric line.

I am unaware about volcanic activity duting 7.8 Mw Gorkha Earthquake. Dear researcher, we have performered one work related to ionospheric TEC variation during Gorkha earthquake 2015 (though not related to your qustion) please have a read, if you are interested. Hope you will like this. https://www.researchgate.net/publication/346063036_GPS_Observations_of_Ionospheric_TEC_Variations_during_2015_Mw_78_Nepal_Earthquake

It's unlikely as far as presence of an active volcano in Nepal's present geological setting is concerned. Further, no volcanic eruption was reported during M7.8 Gorkha Eq.

Thank you resp. Sir for your insightful reply.

Atul Kohli , Sujan Prasad Gautam , Ratnamani Gupta , Ajit Singh , Girish Ch. Kothyari , Shiba Subedi , Malay Mukul

Remember Jwalamukhi Devi Temple in Kangra district Himachal Pradesh where continuous flames come out from the faults/fractures in Siwalik sandstone. The location of this so called volcano (actually dozen of spots with small flames) is on the Jwalamukhi Thrust, a fault within the Siwalik belt. The fault/fracture within the Siwalik rocks facilitates flow of trapped inflammable hydrocarbon gas. Similar situation could have followed the 2015 Gorkha earthquake along some nearby fault in Nepal.