1. Geologic map of the Mare Acidalium quadrangle of Mars (including the potential Viking landing site Cydonia) / [cartographic material] Yale Public content 1978. 2014-01-23T19:27:22Z. 2014-02-04T23:15:48Z. Geological Survey (U.S.). U.S. Geological Survey. English. Public. Mare Acidalium (Mars), Cydonia (Mars), and Mars (Planet).