A NUMERICAL MODELING STUDY ON THE PROCESSES OF UPLIFT AND PLANATION OF THE TIBETAN PLATEAU

The Tibetan Plateau has experienced a number of processes of uplift an d planation alternately since about 45 Ma B. P. when it began to raise . A differential equation model for describing the Plateau altitude va riation with time is formulated on the basis of previous field studies and a theoretical hypothesis: ii palaeomagnetic polarity is positive, the convective activity in the earth is strong; orogenic movement is violent; and the raising velocity of the Plateau is high and vice vers a. The analytical solution of the equation is obtained. The altitude v ariation from the beginning of the Plateau uplift to present is comput ed through using the geomagnetic polarity reversals timing series and interstellar atomic hydrogen concentration data. A comparison between the model results and the field studies indicates that the former is q uite similar to the latter. The model results are able to basically re produce the alternating processes of uplift and planation of the plate geological history. In the present model, the influences of the denud ation and the geomagnetic polarity and interstellar atomic hydrogen co ncentration on the raising velocity of the Plateau altitude are mainly considered.