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Filters: Tags: Volcanic breccia (X) > partyWithName: U.S. Geological Survey - ScienceBase (X)

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This geologic database is a digitized version of the 1:24,000-scale original analog geologic map titled "Geologic map of the Parker NW, Parker, and parts of the Whipple Mountains SW and Whipple Wash quadrangles, California and Arizona", published by the U.S. Geological Survey (USGS) in 1980. The map area straddles the Arizona-California border and includes the community of Parker, AZ, and the southeastern part of the Whipple Mountains, where the prominent Whipple Mountains Detachment Fault separates lower plate Cretaceous and older gneisses from upper plate crystalline, volcanic, and sedimentary rocks. The Whipple Mountains are surrounded by numerous Neogene sedimentary units that record the arrival and subsequent...
Tags: Alluvium, Andesite, Arizona, Basalt, California, All tags...
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This geodatabase contains all the geologic map information for the Geologic Map of the San Juan caldera cluster, southwestern Colorado and is part of U.S. Geological Survey Geologic Investigations Map Series I-2799. The San Juan Mountains are the largest erosional remnant of a composite volcanic field that covered much of the southern Rocky Mountains in middle Tertiary time. The San Juan field consists mainly of intermediate-composition lavas and breccias, erupted about 35-30 Ma from scattered central volcanoes (Conejos Formation) and overlain by voluminous ash-flow sheets erupted from caldera sources. In the central San Juan Mountains, eruption of at least 8,800 km3 of dacitic-rhyolitic magma as nine major ash...
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This 1:50,000-scale geologic map represents a compilation of the most recent geologic studies of the upper Arkansas River valley, between Leadville and Salida, Colorado. The valley is structurally controlled by an extensional fault system that forms part of the prominent northern Rio Grande rift, an intra-continental region of crustal extension. This work also incorporates new detailed geologic mapping of poorly understood areas within the map area and reinterprets previously studied areas, aided by lidar data that covers 59 percent of the map area. The mapped region extends into the Proterozoic metamorphic and intrusive rocks in the Sawatch Range west of the valley and the Mosquito Range to the east. Paleozoic...
Categories: Data; Tags: 207Pb/206Pb zircon age, 40Ar/39Ar age, Arkansas River, Balltown, Balltown placer gold mining areas, All tags...


    map background search result map search result map Data release for the geologic map of the upper Arkansas River valley region, north-central Colorado Database for the geologic map of the central San Juan caldera cluster, southwestern Colorado Digital database for the geologic map of the Parker NW, Parker, and parts of the Whipple Mountains SW and Whipple Wash quadrangles, California and Arizona Digital database for the geologic map of the Parker NW, Parker, and parts of the Whipple Mountains SW and Whipple Wash quadrangles, California and Arizona Data release for the geologic map of the upper Arkansas River valley region, north-central Colorado Database for the geologic map of the central San Juan caldera cluster, southwestern Colorado