From time to time, I will do field work involving recovery of fossils and paleontological materials. Usually these excursions involve a fair amount of hiking, such that versatile tools not too heavy, are a real advantage. I have been using a small (7 in) pry bar roughly similar to this: http://www.2daydeliver.com/product_detail.php?id=SKUB00002X1XS#.Vuw4CUe2Elk

It is reasonably light weight, probably about 2 oz, and I find it very versatile for digging and prying. I will be carrying it more frequently as part of my general outdoor gear, primarily for those situations where one might use a large, really tough (and fairly heavy!) knife. It will work together with a 4 inch blade that will do all the cutting and slicing. If I ever felt I would need to, I could grind an edge on the pry bar and baton with it.

Google "pry bar" and you will find a lot of variations on the crow bar, many of which would be useful in various emergency situations. Some just might be suitable for your circumstances.