Nash Dome was the first oil field to be found through the use of any geophysical technique. Its discovery in 1924, in Fort Bend and Brazoria Counties, Texas, demonstrated the capability of torsionbalance surveying to define subsurface features. Barton ((1949) reports that considerable luck was involved in the discovery and that similar salt domes would not be found by the reconnaissance methods in use in the late 1930s. This dome is also a classic example of the gravity signature of a salt dome with a cap rock. A fairly broad low contains a relatively sharp high within it. The broad low is the anomaly caused by low-density salt, and the sharp high is caused by dense cap rock (e.g., limestone, anhydrite) at shallow depth. A generalized profile of this classic salt-dome anomaly is given here.