This dissertation addresses the resolution and reliability of paleomagnetic recoreds obtained from oceanic and marine sediments, with a particular focus on records of relative geomagnetic paleointensity. It shows the methods used to recover such signals by constructing a high-resolution paleomagnetic record from the Ocean Drilling Program (ODP) Site 1101, which covers the interval 0.7-2.1 Ma. The reliability of individual paleointensity records can be further tested with time series analysis techniques such as wavelets. This point is illustratred by a spectral analysis of a record of relative geomagnetic paleointensity from ODP Site 983, covering the time interval 0-1.1 Ma. The use of wavelets made it possible to demarcate the intervals over which Earth's orbital frequencies are present in the record. Results of this investigation suggest that the orbital frequencies embedded in the paleointensity record are the expression of lithologic variations, although they have a minor effect on the record. (mod. auth. abst.)