When saltymud intrudes into the layer, the reduction of water layer is small, but the reduction of oil layer is great. This will form a low resistivity oil layer.
盐水泥浆侵入时,水层电阻率降低较小而油层电阻率大为降低,因此形成低阻油层。
So they collected mud from California's Mono Lake, where the waters are naturally salty, and laced with arsenic.