Structural Development of the Walker Lane: Neotectonics and Geodesy

Geodesy shows the Walker Lane currently accounts for upwards of 20-25% of relative Pacific-North America plate motion across the San Andreas plate boundary. Cumulative right-lateral offset across the Lane ranges from about 30 to >60 km. Yet, at latitudes between the northern end of Walker Lake and Reno, there exist no well-developed strike-slip faults oriented to accommodate the motion. Rather, deformation currently and in the past appears to be expressed in the development of a set of major left-stepping normal faults and basins extending from Walker Lake in the south to Lake Tahoe in the north. In this sense, the basins may be viewed as an en-echelon arrangement of crustal scale tension gashes. We report on our ongoing effort to resolve the relationship of geodetic patterns of strain accumulation to the pattern of strain release as expressed in the development of the basins and the implications of this relationship to the tectonic development of the Walker Lane.