Curious if this could indicate an underground river feeding water, and debris to a pool the volcanic activity heats to the point of eruption.
Enough of a current could move even the concrete block. In other words it might not be debris from the vicinity of the geyser itself, but from even a landfill many miles away. I can’t understand the concept of anyone taking a concrete block to a geyser.
No. Not reasonable.
Some of the “stuff” clearly was likely to have been “innocently” (ignorantly more accurately) dropped. Cell phone, pacifier, a few other things.)
Some are “accidently” dropped - but by “researchers” who screwed up their own hole! (The clamp and the funnel, the block (to anchor it in place for the sample), a few others).
The beer cans? The glass bottle? All of the coins? Yeah. Ignorant tourists.