Stratigraphy of lower to middle Paleozoic rocks of northern Nevada and the Antler orogeny

Abstract

COVER. Lower Silurian Cherry Spring chert at the stratigraphic top of the Valmy and Vinini Formations regionally. This conspicuous white chert unit is invariably underlain by thick-bedded black chert of Late Ordovician age. The outcrop shown on the left is in Sonora, Mexico; that on the right is in northern Nevada. Sporadically, throughout its range, parts of the Cherry Spring chert are mineralized with iron, lead, and zinc sulfides resulting in intense colors as shown by the hand specimen from Nevada.

Phanerozoic Large Igneous Province, Petroleum System, and Source Rock Links

“…Barnes (2004) and Lefebvre et al (2010) suggested a Katian superplume induced the Late Ordovician glaciation. The Late Ordovician Mass Extinction event temporally coincides with the Gondwana glaciation (see Youbi et al,Chapter 8 this volume) and several major HSR events, for example, Tayyarat Formation (Qusaiba Member: Hayton et al, 2017); Mudawwara Formation (Batra Mudstone Member: Amireh et al, 2001); Vinini Formation, USA (Ketner , 2013); Upper Yangtze black shales, China (Wu et al, 2019); and was followed by abundant lowermost Silurian black shales associated with a postglaciation global transgression.…”