Why does Nevada own huge lithium mines?

In Clayton Valley, a vast basin in Nevada’s Esmeralda County, turquoise lakes are nestled among brown mountains. Similar basins and mountain ranges stretch from the west to the east of the state. However, the still water lake in Clayton is man-made and is rich in lithium.

Silver Peak, a small former silver mining town in this remote valley, became Nevada’s first lithium production facility in 1966, decades before lithium became the key energy metal. renewable energy and national security. The facility operated by the Albemarle group produces 5,000 tons of lithium carbonate annually, according to Live Science.

Historically, lithium had little economic importance, but skyrocketing demand for lithium-ion batteries has shifted the focus toward mines. According to the US Geological Survey, lithium-ion batteries are mainly for electric vehicles, accounting for 87% of global lithium demand. Analysts predict the market share will increase to 95% by 2030. The US produces 0.5% of global lithium, but Nevada could change that figure. “Nevada has more lithium than any other state,” said Christopher Henry, emeritus geologist with the Nevada Bureau of Mines and Geology (NBMG).

According to James Faulds, a geologist at NBMG, the cause lies in tectonic conditions. Nevada’s lithium mines are the result of a geological windfall. Nearly everything has to do with the stretched crust: steep terrain, abundant volcanic rocks, high heat flow, arid climate, and hydrologically closed basins.

The tectonic history of the North American Great Basin, which includes much of the western United States including the entire state of Nevada, is complex. About 17 million years ago, the Earth’s crust, which had thickened due to ancient tectonic collisions, began to stretch and thin, spreading like candy. The crustal blocks tilt like a game of dominoes, forming basins where sediment and water flow into shallow lakes. Magma surged up too large a thin shell, spewing volcanic rock onto the ground and mixing it with pebbles, sand and clay. Most of Nevada’s basin is now dry, with only cracked mud and salt remaining. The process of shell stretching continues today and is key to the state’s vast lithium reserves.

According to Simon Jowitt, an economic geologist at the University of Nevada, Reno, the formation of lithium begins with igneous rocks. Much of the world’s mined lithium is mined directly from this hard rock, including the world’s largest lithium mine in pegmatite in Australia’s Greenbushes. But the source of lithium in Nevada is rhyolite rock (an eruption form of granite), which only contains a very small amount of lithium, not enough for direct exploitation on an economic scale. Instead, geologists are interested in volcanic deposits, when soluble metals are concentrated in nearby basins after the rock has weathered.

Streams often carry rainwater over the land and into the ocean, as Nevada’s arid climate and topography make most of the basin hydrologically closed. Streams carry water into basins and form small lakes. Rainwater extracts lithium from rhyolite rock deep underground or on steep mountain slopes. This lithium-rich rainwater accumulates in the basin and slowly accumulates into brine.

In the Clayton Valley, lithium-rich brine is pumped to the surface for evaporation or processed through direct lithium mining techniques. Besides the brine, what has geologists excited is the potential of lithium clay in Nevada.

The McDermitt caldera, which crosses the states of Nevada and Oregon, forms a chain of volcanoes when the North American plate moves above a fixed heat source. When McDermitt erupted 16.3 million years ago, a lake inside the caldera was filled with ash and smectite clay. As the lake evaporated, hydrothermal flows transformed the lithium-rich smectite into illite clay, especially Thacker Pass on the south side of the caldera. Today, McDermitt is one of the largest lithium mines in the world. Technology startup Lithium Americas Corp estimates the Thacker Pass project contains 217.3 million tons of lithium. The company plans to begin production in 2028.

Some 431 kilometers south, the Rhyolite Ridge tilts along the Silver Peak range, Neavada’s next lithium clay deposit. Rhyolite Ridge once sat above a caldera like McDermitt. Initially, geologists thought that lithium-rich rhyolitic deposits accumulated in the tectonically active basin of Rhyolite Ridge. As the basin developed, a lake formed, depositing clay-rich silt above the volcanic rocks. Hydrothermal fluid seeps through cracks, causing silt in the lake bed to leach lithium from the rhyolite rock layer below. Later fracking lifted those deposits, exposing the valuable clay. Ioneer USA Corporation is planning to exploit a lithium – boron mine and build a chemical processing plant at Rhyolite Ridge, expected to begin production in 2028. When production at McDermitt and Rhyolite Ridge begins, production Nevada’s lithium reserves will increase.