acquired the asset, which modernized the mine, mill, and smelter. The open-pit owners replaced an antiquated 1000-car railroad with conveyor belts and pipelines for transporting the ore and waste, which reduced costs by nearly 30% and returned the operation to profitability. Landslides At 9:30 pm on April 10, 2013, a landslide occurred at the mine. Around of dirt and rock thundered down the side of the pit. It is possibly the largest historic, non-volcanic landslide in North America. On the basis that the mine's steep walls made it a high risk for landslides, an interferometric radar system had been previously installed to monitor the ground's stability. As a result of warnings produced by this system, mining operations had been shut down the previous day in anticipation of the slide and there were no injuries. The massive slide was expected to cut production of mined copper by . A second slide caused an evacuation of 100 workers on September 11, 2013. Another, less severe slide occurred on May 31, 2021. Environmental history Similar to other industrial age mining operations, the mine historically had adverse environmental effects on the habitats of fish and wild animals as well as air and water pollution, creating health hazards to the surrounding public. Different federal agencies concerned with environmental conservation have used strict legal rules to pressure the subsidiary of Kennecott copper mine to comply with environmental regulations. Since the early 1990s, Kennecott has spent more than $400 million on clean-up efforts on the affected areas to avoid regulatory laws that would have placed them on the Superfund National Priorities List (NPL). The figure below shows a comparison of two satellite images used to identify the changes in the Bingham Canyon Mine between 1985 and 2016 JuxtaposeJS Embed Geology The Bingham Canyon ore deposits occur in the Bingham nappe. They are a porphyry copper deposit, formed by a quartz monzonite porphyry intruded into sedimentary rocks. They exhibit a concentric alteration pattern and mineralogic zonation around the Bingham stock. These zones include a central core containing magnetite, followed by "a molybdenite zone low in copper, a bornite-chalcopyrite-gold higher grade copper zone, a pyrite-chalcopyrite zone, a pyrite zone, and an outermost lead-zinc zone." Structurally, Late Paleozoic rocks were thrust faulted over the Precambrian craton during the Cretaceous Sevier orogeny. These rocks were later intruded and altered in the Tertiary by granitoid rocks. This igneous event was the source