Scientists do not think the mare basalts in the basins are the source of the gravity anomalies ; individual lava flows appear to be quite thin ? from a few meters to a few tens of meters ? and total accumulations are typically 200 meters or less 科学家不认为盆地中的月海玄武岩是这些重力异常的来源,因为个别的岩浆流似乎相当薄(从数公尺到数十公尺) ,且累积总计通常少于200公尺。