thanks for the replies guys. it's gotten me quite close to the goal.

i found that using Tools>Global Set>Altitude in a number of steps with increasing altitude did help change the great sinkhole into an area of pretty rough terrain (say a given elevation +/- 1000 feet, all choppy and uneven). there didn't seem to be any settings that would actually flatten the area out.

some time with the "smoother" and a bit of tweaking more or less finished the job.

FT is pretty cool, sure fires the imagination. thanks again for the assistance.

t.