were thrust upward. For the most part, the Antler Orogeny occurred in the Devonian and Mississippian, although it may have continued longer. One terrane that may have driven the orogeny is the Nolan Belt, an intensely folded mass of quartzite, schist and slate extending from Esmeralda County to the north, through central Nevada as far as the Mountain City and Bull Run Mountain area near Idaho. Hinterland and foreland basins filled with sediments as the Antler highland eroded. Sea levels rose over the eroded mountains in the late Paleozoic, although uneven rock surfaces remain as the Antler overlap sequence, which includes conglomerate, siltstone, limestone and sandstone deposited from the Pennsylvanian into the early Triassic. High concentrations of the rare element iridium and jumbled mega-breccia deposits in the Guilmette Formation, made up of shattered limestone that re-cemented in deep water, has led geologists to infer the Alamo meteorite impact even around 382 million years ago in the Devonian. Distinct gravel rubble is common in late Devonian rocks in the area, suggesting large tsunamis. Although an exact impact site has not been found, geologists have suggested a possible location in the Timpahute Range in southern Lincoln County, near Rachel, Nevada. Based on the distribution of debris, estimates suggest a crater one mile deep and 30 miles in diameter. Terranes continued to accrete, driving the Humboldt orogeny, first recognized in rocks in the Pinon Range in 1977, and Permian-Triassic Sonoma orogeny. During the Sonomo orogeny, the Golconda allochthon, a thick sequence of metamorphosed basalt, siltstone, shale, chert and limestone, was thrust on top of the Antler overlap sequence. It is named for the Golcondo Summit, where US Interstate 80 crosses Edna Mountain. Sonomia, the superterrane added to the region, includes several smaller terranes, including Walker Lake, Pine Nut and Paradise. Mesozoic (251-66 million years ago) Plate convergence continued through the Mesozoic, with the addition of the Black Rock-Jackson terrane in the Jurassic and Cretaceous now present in northwest Nevada. The terrane rocks are volcanic or sedimentary and originated offshore in the Paleozoic and Triassic. By the end of the Mesozoic, dry land conditions prevailed across Nevada. The Farallon Plate transported the terranes and subducted under North America in the Cretaceous. Numerous thrust faults developed due to compressional strain, placing older rocks on top of younger units. In the northwest, the Luning-Fencemaker thrust fault developed in the Jurassic and thrust the Jungo terrane to