软流圈气体压力和洋板自重驱动海底扩张

基于地幔软流圈不断产生高温气体的事实和气体压力随密度和温度而变的特性，提出：洋板（海洋岩石圈部分）随其下高温气体积聚增压而逐渐上隆，最后会从弯张应力最大的中部断裂并弹性回缩；熔岩随气体喷出楔入裂缝，使洋板保持拱隆状并使其下气体压力骤降；洋板因自重下沉并产生巨大推力，使相邻大陆向两旁分离或将洋板边缘推入软流圈而熔融；楔入的熔岩形成新洋板和密闭条件使高能气体又重新积聚，旧洋板向两旁推移。这一过程的往复进行即形成海底扩张和大陆漂移。并认为陆板（大陆岩石圈部分）薄化是使其分裂而开始海底扩张的原因。由概化力学模型进行验算所得的洋脊隆起高度、洋脊隆起形状、洋脊在水平面上的分布规律和海底扩张的运动规律等，都与实际情况相符。

OCEAN-FLOOR SPREAD DRIVEN BY GAS PRESSURE IN ASTHENOSPHERE AND THE DEAD WEIGHT OF OCEANIC CRUST

Based on the fact that high-temperature gas is continuously produced in the asthenosphere and that the gas pressure varies with the density and temperature,the author points out :oceanic crust rises gradually with the accumulation of high-energy gas and the increase of pressure,finally, it will break at the centre where the spread bending stress is maximum and shrink;as a result of the lavas of spurting with gas pour into the fault,the oceanic crust is still in arch and the gas pressure decrease rapidly;the oceanic crust will subside for its dead weight, which causes a huge thrust so that both of vicinal continents will be thrust aside or that the end of the oceanic crust will be thrust into asthenosphere to melt ; high-energy gas will accumulate again because the lavas jetting into the fault form the new oceanic crust,and the old will be thrust away;the repeats of this process cause ocean-floor to spread and continents to drift;the reason of breakaway of continent lithosphere and the spread of ocean-floor is that the continent lithosphere is thinning out.The upheaval height and shape of oceanic ridge and the distributional characters of oceanic ridge and oceanic floor spread calculated by use of a simple mechanics model are corresponding to real.