Requires training, and each seismic sounding takes 30-60 minutes to do. An electronic instrument for mapping soil or rock anomalies in the ground. The process involves placement of 4 or 5 electrodes in the ground and passing an electric current between them, measuring the voltage drop per unit of distance of ground covered. Can be used to identify old foundations, buried river valleys, plumes of pollution in the ground water, or changes in the soil or water table. Magnetometer Another electronic instrument for measuring anomalies in the ground based on the ground's magnetic susceptibility.
Uses are similar to the resistivity meter.
Rock Drill Gasoline powered drill for getting an oriented core of a rock unit in the field. The cores are about an inch in diameter and up to several inches long. Can be backpacked if you are energetic, and is somewhat temperamental to use. Dissolved Oxygen Meter For assessing the oxygen content of water in lakes and streams. For assessing the level of dissolved solids in lakes and rivers.