2002 Chevy Trailblazer oil pressure gauge

When driving during acceleration or idling the check gauges light displays and the oil pressure gauge dives to 0 pressure for a few seconds then fluctuates back to the proper reading as the check guages light goes back out and now it's a bit more routine than when it initially started approx. 2 weeks ago. What do you feel could be the problem and the solution to repairing the problem?