There is no better tool than a geologic hammer. MRI machines weigh tons, as rocks do, so there isn't any practical way to do field sampling. The only portable

There is no better tool than a geologic hammer. MRI machines weigh tons, as rocks do, so there isn't any practical way to do field sampling. The only portable tool available for field work is a ground penetrating radar, and it requires lots of power. Making even a moderately steep hike to these remote locations with just your survival gear is beyond exhausting, so lugging machines and rocks becomes a huge challenge: impossible. Transporting the equipment mechanically is an incredibly costly endeavor. An image from a GPR looks like this: http://mysite.du.edu/~lconyers/SERDP/figure1_pit_house.jpg http://mysite.du.edu/~lconyers/SERDP/figure1_pit_house.jpg - as you can see, the GPR can go through rock, but, what they're seeing is a pattern difference: signal pattern, that is. The GPR doesn't have an imaging resolution to be able to assemble an accurate point cloud, like you would with photographic imaging to make a 3D model. Instead, it's like watching spray from a water hose encounter an object - you can only really tell the water stream hit something, and its rough shape. I haven't used lasers for imaging in a decade, but they didn't make clean cuts: they burn right through what you're trying to image. I believe it's not a solution for sampling rocks. Though, a hammer can cleave right through a rock and be done with it.