I just weighted the Black Tarp on my postage scale....the tarp, the zipper carry pouch and all the cordage which goes on all loops including the outer center loop for creating shears or tying up to a limb. It weights 43 ounces.
I told you it isn't any super/ultra light weight tarp. But for wintertime I'll take the extra weight for the warmth and security. When training at 4500' elevation in the snow covered Cascades it works great. It isn't 100% spark resistant - I'm not sure what is these days but it is more resistant than my other nylon tarps.
I have no idea what a silnylon weighs in a 10' x 10' configuration as I don't own one. All I have is the Intergral Designs 5' x 7' that I use in the summer and it super lightweight.
I guess it weighs about what a tent weighs - I dunno cuz I don't use tents. I like the capacity to have a fire which a tent doesn't allow, and I can create seven or eight variations in the dark...when weather gets bad I change out to a configuration that puts it closer to the ground...when weather is fair to nice I go with a Whelan and still can have a fire. Also I like to be able to see out in case there is a problem and I can jet out quickly.