The Moine Thrust zone (MTZ) marks the Caledonian foreland-to-hinterland transition zone at the base of the Scandian (c. 430 Ma) orogenic wedge. In the Loch Eriboll region, the upper ductile part of the MTZ is composed in ascending order of two regionally extensive thrust sheets (Upper Arnaboll-Creag na Faoilin and Creagan) and is overlain by the Moine Nappe. Quartz crystal fabrics, kinematic vorticity (Wm), and strain estimates from the ductile thrust sheets in this region are used to determine how pure and simple shear components of deformation are partitioned, and indicate that these processes may be thermally, structurally, and lithologically dependent. At the lowest structural levels, quartzite and gneiss in the Upper Arnaboll-Creag na Faoilin (UA-CNF) thrust sheet yield rigid grain-based arithmetic mean minimum (Wmmin) and mean maximum (Wmmax) vorticity estimates of 0.57 and 0.67, respectively (60–53% pure shear). Creagan thrust sheet mylonites yield Wmmin and Wmmax estimates of 0.59 and 0.72 (59–48% pure shear). At the highest structural levels, Moine Nappe mylonites yield Wmmin and Wmmax estimates of 0.59 and 0.71 (59–49% pure shear). Quartz c- and a-axis fabrics qualitatively indicate an increase in non-coaxial deformation (top-to-the-west) traced towards structurally higher levels, which is accompanied by increases in deformation temperature (c. 370 °C to c. 550 °C). Integrated strain and vorticity estimates indicate that significant sub-vertical foliation normal shortening has occurred as nappe stacking progressed.

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The dramatic relief of the Teton Range in northwestern Wyoming results from motion along the Teton normal fault. New apatite (U‐Th)/He (AHe) and fission track (AFT) ages of samples collected in the footwall yield fundamental constraints on contrasting models of Teton fault activity and consequent relative footwall uplift. Low‐elevation samples in the immediate footwall of the fault range from 12.5 to 6.5 Ma. AHe ages of samples from subvertical transects range from 57.8 to 6.5 Ma (Rendezvous), 54.0 to 6.8 Ma (Grand), and 20.5 to 7.1 Ma (Moran), with all three transects yielding an expected trend of decreasing age with decreasing elevation. AFT ages obtained from the three transects range from 55.4 to 45.7 Ma (Rendezvous), 43.2 to 13.3 Ma (Grand), and 38.0 to 11.7 Ma (Moran). Inverse thermal history modeling indicates that the onset of relatively rapid cooling, as a proxy for relative footwall uplift, initiated first in the northern part of the range (15–13 Ma) and then migrated south as fault displacement continued (7 Ma to present at Rendezvous). Thus, this work suggests that although the Teton fault likely initiated due to Basin and Range extension, this structure remains active. Normal fault displacement models also suggest a minimum of ~6 km displacement for footwall uplift of ~2 km. If evaluated in the context of established normal fault length‐displacement relationships, this yields a length of ~180 km, substantially longer than current estimates of Teton fault length and putting the northern end of the fault well into, and potentially beyond, the bounds of Yellowstone National Park.

Classically held mechanisms for removing mountain topography (e.g., erosion and gravitational collapse) require 10-100 Myr or more to completely remove tectonically generated relief. Here, we propose that mountain ranges can be completely and rapidly (<2 Myr) removed by a migrating hotspot. In western North America, multiple mountain ranges, including the Teton Range, terminate at the boundary with the relatively low relief track of the Yellowstone hotspot. This abrupt transition leads to a previously untested hypothesis that preexisting mountainous topography along the track has been erased. We integrate thermochronologic data collected from the footwall of the Teton fault with flexural-kinematic modeling and length-displacement scaling to show that the paleo-Teton fault and associated Teton Range was much longer (min. original length 190-210 km) than the present topographic expression of the range front (~65 km) and extended across the modern-day Yellowstone hotspot track. These analyses also indicate that the majority of fault displacement (min. 11.4-12.6 km) and the associated footwall mountain range growth had accumulated prior to Yellowstone encroachment at ~2 Ma, leading us to interpret that eastward migration of the Yellowstone hotspot relative to stable North America led to removal of the paleo-Teton mountain topography via posteruptive collapse of the range following multiple supercaldera (VEI 8) eruptions from 2.0 Ma to 600 ka and/or an isostatic collapse response, similar to ranges north of the Snake River plain. While this extremely rapid removal of mountain ranges and adjoining basins is probably relatively infrequent in the geologic record, it has important implications for continental physiography and topography over very short time spans.

Dam installation on a deep hydrologically open lake provides the experimental framework necessary to study the influence of outlet engineering and changing base levels on limnogeological processes. Here, high-resolution seismic reflection profiles, sediment cores, and historical water level elevation datasets were employed to assess the recent depositional history of Jackson Lake, a dammed glacial lake located adjacent to the Teton fault in western Wyoming (USA). Prograding clinoforms imaged in the shallow stratigraphy indicate a recent lake-wide episode of delta abandonment. Submerged ∼11–12 m below the lake surface, these Gilbert-type paleo-deltas represent extensive submerged coarse-grained deposits along the axial and lateral margins of Jackson Lake that resulted from shoreline transgression following dam construction in the early 20th century. Other paleo-lake margin environments, including delta plain, shoreline, and glacial (drumlins, moraines) landforms were likewise inundated following dam installation, and now form prominent features on the lake floor. In deepwater, a detailed chronology was established using 137Cs, 210Pb, and reservoir-corrected 14C for a sediment core that spans ∼1654–2019 Common Era (CE). Dam emplacement (1908–1916 CE) correlates with a nearly five-fold acceleration in accumulation rates and a depositional shift towards carbonaceous sediments. Interbedded organic-rich black diatomaceous oozes and tan silts track changes in reservoir water level elevation, which oscillated in response to regional climate and downstream water needs between 1908 and 2019 CE. Chemostratigraphic patterns of carbon, phosphorus, and sulfur are consistent with a change in nutrient status and productivity, controlled initially by transgression-driven flooding of supralittoral soils and vegetation, and subsequently with water level changes. A thin gravity flow deposit punctuates the deepwater strata and provides a benchmark for turbidite characterization driven by hydroclimate change. Because the Teton fault is a major seismic hazard, end-member characterization of turbidites is a critical first step for accurate discrimination of mass transport deposits controlled by earthquakes in more ancient Jackson Lake strata. Results from this study illustrate the influence of dam installation on sublacustrine geomorphology and sedimentation, which has implications for lake management and ecosystem services. Further, this study demonstrates that Jackson Lake contains an expanded, untapped sedimentary archive recording environmental changes in the American West.