关键词: 大陆岩石圈, 塑性流动网络, 延性剪切网带, 热异常网带, 大地热流正异常

Abstract: Based on the “Netlike plastic-flow” model for continental dynamics and the distribution of terrestrial heat flow in the China continent, the balanced state of viscous shear-heating effect of plastic-flow belts (PFBs) is analyzed in the paper, involving the establishment of the equations of PFB-induced temperature-anomalies by solving the energy equations of thermal dynamics and the determination of the relevant parameters by fitting the positive heat-flow-anomalies of PFBs. It is shown that the viscous shear-heating of PFB provides a thermal energy source for positive temperature-anomalies and results in the enlargement of PFB-affected width by heat conduction. It is indicated as an estimation of the average situation for the Central-Eastern Asia (CEAs) plastic-flow network system that the thermal-anomaly width of PFB is identical with the average apparent-width of PFBs manifested by seismic belts, being approximate to 65km; the shear width of PFB is equal to 44km, about 2/3 of the thermal-anomaly width; the form of the positive temperature-anomaly distribution curve as a result of the analysis is consistent with that of the positive heat-flow anomaly “peak” controlled by PFBs; the positive temperature anomalies at the mid line and boundary of PFB are about 210K and 67K respectively and decrease to zero at the boundary of the thermal-anomaly belt affected by PFB. The results of this study give a theoretical verification for the existence of plastic-flow network in the lower lithosphere and the effect of PFB on the positive anomalies of terrestrial heat-flow.

Key words: continental lithosphere, plastic-flow network, ductile shear belt, thermal-anomaly belt, positive heat-flow anomaly