Backed with positive cues from the global markets coupled with follow-up buying in early trades saw the Sensex opened with a positive gap of 42 points at 13,823. All-round buying in the market saw the index surge to a high of 13,977 - up 196 points.The index, thereafter, consolidated at higher levels before sliding into the negative zone in late noon trades. Agressive selling mainly in oil & gas stocks saw the index tumble to a low of 13,745 - down 232 points from the day's high.The Sensex finally settled with a marginal loss of 10 points at 13,771.