The plate tectonic theory requires a rigid lithosphere floating over a weak asthenosphere, separated by the lithosphere-asthenosphere boundary, which has been sometimes interpreted as the Gutenberg discontinuity. Using a deep seismic reflection technique, we report the presence of two continuous reflections covering 27 Ma to 58 Ma oceanic lithosphere in the Atlantic Ocean. We find that the upper reflection deepens with age and follows the ~1250°C isotherm, whereas the deeper reflection lies at a constant depth of ~75 km. We suggest that the upper reflection represents the thermally controlled lithosphere-asthenosphere boundary, whereas the lower reflection is the Gutenberg discontinuity, a frozen-in dehydration boundary separating the dry mantle melting region above from the hydrated mantle below formed at the ridge axis. We also find that thermal mantle anomalies rejuvenate the lithosphere, uplift the lithosphere-asthenosphere boundary, and destroy the Gutenberg discontinuity.

中文翻译：

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发现明显的岩石圈-软流圈边界和大西洋中的古腾堡不连续面

板块构造理论要求刚性岩石圈漂浮在弱软流圈之上，由岩石圈-软流圈边界隔开，有时被解释为古腾堡不连续面。使用深层地震反射技术，我们报告了覆盖大西洋 27 Ma 至 58 Ma 海洋岩石圈的两个连续反射的存在。我们发现上部反射随着年龄的增长而加深并遵循~1250°C 等温线，而更深的反射位于~75 公里的恒定深度。我们认为上部反射代表热控制的岩石圈-软流圈边界，而下部反射是古腾堡不连续面，这是一个冻结脱水边界，将上方的干燥地幔熔化区与下方的水合地幔分开，形成于脊轴处。