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Dated subsurface cores, 40 m, 100 m, and 200 m in length, from the Salar de Atacama, Chile, record changes in climate and tectonics over the past 325 ka. These cores were used to assess completeness of the stratigraphic record and how that record was influenced by faulting and climate change. The same basic facies, efflorescent halite crust and cement (subaerial halite), and chevron halite (saline lake) occur in each core. The dominant facies is efflorescent halite formed in a subaerial environment like that in the Atacama basin today. Thick, well-preserved efflorescent crusts in the Salar de Atacama cores illustrate that major sediment aggradation occurred in subaerial environments by growth of efflorescent halite from evaporation of groundwater brines. Similar pedogenically formed evaporites may be preserved in the geologic record.The N-S trending Salar Fault System has downdropped the eastern block of the Salar de Atacama (core 2002) relative to the western block (cores 2005 and 2031). Relative faulting rates over the past 60 ka were determined from stratigraphic offset and uranium-series ages from core 2005. Major faulting along the Salar Fault System occurred between 16.5 and 5.4 ka, with offset of 26.5 m and faulting rates of 2.4 m/kyr. Aggradation of efflorescent halite crusts on the downdropped eastern block served to smooth out topographic variations created by faulting. Although stratigraphic units in core 2002 shifted down Ͼ 30 m over the past 60 ka, the thickness and sedimentary features are similar for all but one equivalent stratigraphic unit in all three cores. Faulting along the Salar Fault System, despite significant offset, did not alter the basic stratigraphic record.Temporal completeness of the stratigraphic record, within the limits of the age dates and their errors of greater than ؎ 3 ka, was examined qualitatively by comparing long-term sedimentation rates (0.6-0.9 m/ kyr) and shorter-term sedimentation rates (0.3-3.6 m/kyr). The similarity of sedimentation rates on the 10 kyr scale and the longer 100 to 300 kyr scale suggests temporal completeness of Salar de Atacama sediments, at least at the 10 kyr scale.Although hiatuses, long periods of subaerial exposure, and dissolution of evaporites may have occurred, the main climate fluctuations at Salar de Atacama over the last 100 ka are recorded in all three subsurface cores. Paleoclimate records obtained from such cores are therefore representative of basin-wide climate change and are valid for regional paleoclimate reconstructions.

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Beaver‐mimicry stream restoration (BMR) involves the alteration of a stream channel to approximate the effects of beaver activity. Project objectives often include increasing groundwater storage and dry‐season streamflow, but limited data are available to understand the nature of its effects on groundwater dynamics. We developed generic groundwater models of mountain headwater streams to investigate the effects of installing a single beaver‐mimicry structure (BMS) using different restoration designs in varied hydrogeologic settings. The magnitude of changes in dry‐season net stream gains from a single BMS was always a minor component of the channel water balance, and would be too small to measure in the field; however, the modeled patterns of change caused by a single BMS help to understand the underlying mechanisms. All tested scenarios caused increases in groundwater recharge from the stream, which resulted in increased groundwater levels, and groundwater outflow from the model domain. For scenarios that did not include evapotranspiration, most treatments in gaining and losing settings caused slight increases in dry‐season net stream gains, but in strongly losing settings net stream gains were reduced. The addition of simulated evapotranspiration often resulted in decreased dry‐season net stream gains, since evapotranspiration increased with groundwater elevations. BMR design and siting influence the types of hydrologic effects that should be anticipated.