My recent fieldwork has been somewhat limited by the fact that most of my outcrops are totally encrusted with lichen and moss. Scrub as I may, a toothbrush and a bottle of water just won't shift enough of it for me to see the rock in any detail. Extensive hammering for fresh exposure is impractical, impossible or illegal* in varying degrees, so I really need a way to clean my exposures. Can anyone reccomend any techniques? The rock is limestone if it matters.
*I have permission to hammer, but questions may be asked if I knocked large chunks off of every outcrop I come to.
Lichen is a different matter. It hardly ever comes off cleanly. Another question is: should you remove it? It took a few (50-100?) years to grow there.
If it really needs removing, try sandpaper and acid (?).
As Jon have said, lichens could have decens to hundreds years in age. But if you really need to see the outcrops, you can use bleach dissolved in a bit of water and rubbing with a brush. We remove them so, when it´s really necesary.
cheers!
Javi
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Lucky man whose destiny is to know the Earth´s secrets. Eurípides (480-405)
Rank: Topaz
Joined: 18/12/2006
Points: 3499
Moss should come off easy enough.
Lichen is a different matter. It hardly ever comes off cleanly. Another question is: should you remove it? It took a few (50-100?) years to grow there.
If it really needs removing, try sandpaper and acid (?).
Geologists are gneiss!!
Rank: Talc
Joined: 12/07/2007
Points: 46
try a steel brush and mild soap water. acid might rather dissolve your rocks than remove the lichen in any reasonable time i believe.
Rank: Fluorite
Joined: 20/04/2005
Points: 385
As Jon have said, lichens could have decens to hundreds years in age. But if you really need to see the outcrops, you can use bleach dissolved in a bit of water and rubbing with a brush. We remove them so, when it´s really necesary.
cheers!
Javi
Lucky man whose destiny is to know the Earth´s secrets. Eurípides (480-405)
Rank: Calcite
Joined: 29/01/2006
Points: 228
Thanks guys. I'm planning on removing the minimum i can get away with.