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New outcrops created during the 1983 draining of Watauga Lake within the Mountain City window exposed the Little Pond Mountain thrust zone, marked by more than 200 m of Max Meadows-type carbonate breccia. The breccias are derived from the lower Rome Formation of the hanging wall, which is thrust 12 km over younger Rome beds. The upper boundary of the fault zone is gradational, beginning with intact shales and dolostones that become progressively disaggregated by boudinage and disharmonie folding, grading into a thick zone of polymict breccia in contact with Rome shales in the footwall. The brecciation is thrust related and tied to a particular stratigraphie horizon. Extreme competency contrast between brittlely deformed dolostones and shales, and interlayered, plastically deformed calcitic laminites is inconsistent with the current mineralogy and suggests the presence of weak evaporite-rich layers during deformation. Within the fault zone, these weak beds grade into the breccia matrix. Boudinaged dolostones and shales form clasts in a breccia mixed by mesoscopic isoclinal folding.

Raindrop prints, ubiquitous mudcracks, and evaporite crystal molds in the lower Rome Formation are consistent with evaporative depositional environments. The breccias also exhibit features of evaporite solution-collapse breccias, including sedimentary cavity fillings. Pétrographie evidence for vanished evaporites includes anhydrite inclusions, evaporite crystal molds, and chert nodules pseudomorphous after anhydrite. A sparry calcite mosaic that apparently replaced evaporite laminites also forms the breccia matrix. The evaporite hypothesis is supported by interbedded dolostone and anhydrite discovered in the subsurface at the base of the Rome. The Watauga Lake breccias are postulated to be the result of décollement thrusting within a dolostone-anhydrite sequence at the base of the Rome Formation, producing a polymict evaporite-matrix breccia, which after deformation, underwent local solution collapse and widespread replacement of anhydrite by calcite.

The Max Meadows breccias have long been considered unique, but a review of published work shows that these rocks and occurrences at Watauga Lake are identical in many ways to Rauhwacken (cornieules) of Europe and similar carbonate breccias in Nevada, the northern U.S. and Canadian Rockies, Ireland, and southern England, all of which have been interpreted as deformed carbonate-evaporite sequences. There are also similarities to carbonate breccias in Nova Scotia, northern Michigan, and the foreland of the Canadian Rockies that are purely the result of evaporite dissolution. These comparisons show that, in a given occurrence, thick carbonate breccias with similar diagenetic histories may originate from either décollement thrusting, evaporite dissolution, or a combination of the two processes.

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