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NARROW
GeoRef Subject
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all geography including DSDP/ODP Sites and Legs
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Atlantic Ocean
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North Atlantic
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Gulf of Mexico (1)
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-
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Canada
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Stikinia Terrane (3)
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Western Canada
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British Columbia
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Cariboo Mountains (1)
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Canadian Cordillera (4)
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Yukon Territory (3)
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Whitehorse Trough (1)
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Colorado River (10)
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Colorado River basin (3)
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Cortez Mountains (1)
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Coyote Lake (1)
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Mexico
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Chihuahua Mexico (1)
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North America
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Coast plutonic complex (1)
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North American Cordillera
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Canadian Cordillera (4)
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Omineca Belt (1)
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Rocky Mountains
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Sonoran Desert (2)
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Owens Valley (6)
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Pacific Ocean
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East Pacific
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Gulf of California (2)
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North Pacific
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Pinon Range (1)
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Quesnellia Terrane (1)
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Yuma County Arizona
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California
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Inyo County California
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Los Angeles Basin (1)
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Nevada
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Elko County Nevada
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Pershing County Nevada
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Oregon (2)
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Southwestern U.S. (3)
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U. S. Rocky Mountains
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Uinta Mountains (1)
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Utah
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Bingham mining district (1)
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Oquirrh Mountains (2)
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commodities
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elements, isotopes
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C-14 (4)
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halogens
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Cl-36 (1)
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isotope ratios (4)
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Pb-206/Pb-204 (1)
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Pb-207/Pb-204 (1)
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stable isotopes
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Pb-208/Pb-204 (1)
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Sr-87/Sr-86 (2)
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metals
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actinides
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thorium
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Th-230 (1)
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alkaline earth metals
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beryllium
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Be-10 (1)
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strontium
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Sr-87/Sr-86 (2)
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lead
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Pb-206/Pb-204 (1)
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Pb-207/Pb-204 (1)
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Pb-208/Pb-204 (1)
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rare earths
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neodymium
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Nd-144/Nd-143 (1)
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oxygen
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O-18/O-16 (2)
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-
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fossils
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Chordata
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Vertebrata
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Pisces
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Osteichthyes
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Tetrapoda
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Aves (1)
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Rodentia (1)
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Invertebrata
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Ostracoda (3)
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Mollusca
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Plantae
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upper Quaternary (1)
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Tertiary
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Muddy Creek Formation (1)
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Neogene
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Miocene
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Peach Springs Tuff (1)
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upper Miocene (5)
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Pliocene
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lower Pliocene (2)
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upper Pliocene (2)
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Salt Lake Formation (1)
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Paleogene
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Eocene
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upper Eocene (1)
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Oligocene
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lower Oligocene (1)
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Lake Bonneville (4)
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Mesozoic
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Cretaceous
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Aztec Sandstone (1)
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Middle Jurassic
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MIS 6 (1)
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upper Precambrian
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igneous rocks
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pyroclastics
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sheet silicates
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Primary terms
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absolute age (20)
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Atlantic Ocean
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Gulf of Mexico (1)
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biogeography (5)
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Canada
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Stikinia Terrane (3)
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Western Canada
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British Columbia
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Cariboo Mountains (1)
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Canadian Cordillera (4)
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Whitehorse Trough (1)
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carbon
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C-14 (4)
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Cenozoic
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Quaternary
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Holocene
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lower Holocene (1)
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Pleistocene
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Bishop Tuff (2)
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middle Pleistocene (1)
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upper Pleistocene
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Weichselian
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upper Weichselian
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Allerod (1)
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Bolling (1)
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Younger Dryas (1)
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upper Quaternary (1)
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Tertiary
-
Muddy Creek Formation (1)
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Neogene
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Bidahochi Formation (1)
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Miocene
-
Peach Springs Tuff (1)
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upper Miocene (5)
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Pliocene
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lower Pliocene (2)
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upper Pliocene (2)
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Salt Lake Formation (1)
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Paleogene
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Eocene
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upper Eocene (1)
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Oligocene
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lower Oligocene (1)
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-
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-
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Chordata
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Vertebrata
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Pisces
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Osteichthyes
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Actinopterygii
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Teleostei
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Cypriniformes
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Cyprinidae (1)
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Tetrapoda
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Aves (1)
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Mammalia
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Theria
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Rodentia (1)
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clay mineralogy (3)
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gabbros
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granites (3)
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granodiorites (2)
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monzonites (1)
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syenites
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shonkinite (1)
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ultramafics (1)
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volcanic rocks
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inclusions
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Invertebrata
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Mollusca
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Protista
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isotopes
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radioactive isotopes
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Cl-36 (1)
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Pb-206/Pb-204 (1)
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Pb-207/Pb-204 (1)
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stable isotopes
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Nd-144/Nd-143 (1)
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O-18/O-16 (2)
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Pb-206/Pb-204 (1)
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maps (1)
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Mesozoic
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Cretaceous
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Lower Cretaceous (1)
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Jurassic
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Aztec Sandstone (1)
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Carmel Formation (1)
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Lower Jurassic
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Laberge Group (1)
-
-
Middle Jurassic
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Page Sandstone (1)
-
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Upper Jurassic
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Kimmeridgian (1)
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-
-
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metal ores
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copper ores (1)
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gold ores (1)
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rare earth deposits (2)
-
-
metals
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actinides
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thorium
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Th-230 (1)
-
-
-
alkaline earth metals
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beryllium
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Be-10 (1)
-
-
strontium
-
Sr-87/Sr-86 (2)
-
-
-
lead
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Pb-206/Pb-204 (1)
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Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
-
rare earths
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neodymium
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Nd-144/Nd-143 (1)
-
-
-
-
metamorphic rocks
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amphibolites (1)
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gneisses (1)
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metasedimentary rocks
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metapelite (1)
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quartzites (1)
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schists
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greenstone (1)
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metamorphism (7)
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metasomatism (2)
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Mexico
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Chihuahua Mexico (1)
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mineral exploration (1)
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North America
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Basin and Range Province
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Great Basin (12)
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Coast plutonic complex (1)
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North American Cordillera
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Canadian Cordillera (4)
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Omineca Belt (1)
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Rocky Mountains
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San Juan Mountains (1)
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Uinta Mountains (1)
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Sonoran Desert (2)
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orogeny (3)
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oxygen
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O-18/O-16 (2)
-
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Pacific Ocean
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East Pacific
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Northeast Pacific
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Gulf of California (2)
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-
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North Pacific
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Northeast Pacific
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Gulf of California (2)
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paleoclimatology (12)
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paleoecology (10)
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paleogeography (6)
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paleomagnetism (3)
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paleontology (1)
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Paleozoic (2)
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Plantae
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algae
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Sphenolithus (1)
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plate tectonics (4)
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Precambrian
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upper Precambrian
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Proterozoic
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Mesoproterozoic (1)
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sea-level changes (1)
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sedimentary rocks
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chemically precipitated rocks
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sedimentary structures (1)
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Alaska (1)
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Mohave County Arizona (2)
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Yuma County Arizona
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Yuma Arizona (1)
-
-
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California
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Fresno County California
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Fresno California (1)
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Inyo County California
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Coso Range (1)
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Inyo Mountains (1)
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Owens Lake (4)
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Panamint Range (1)
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Los Angeles Basin (1)
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Northern California (1)
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Salton Trough (2)
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San Bernardino County California
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Avawatz Mountains (1)
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Old Woman Mountains (1)
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Southern California (4)
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Colorado (1)
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Colorado Plateau (3)
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Gila River (1)
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Great Basin (12)
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Idaho (1)
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Klamath Mountains (1)
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Mojave Desert (12)
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Nevada
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Elko County Nevada
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Pequop Mountains (1)
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Pershing County Nevada
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Humboldt Range (2)
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Oregon (2)
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Pilot Range (2)
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Sevier orogenic belt (1)
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Southwestern U.S. (3)
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U. S. Rocky Mountains
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San Juan Mountains (1)
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Uinta Mountains (1)
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Utah
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Bingham mining district (1)
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Box Elder County Utah (4)
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Juab County Utah (1)
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Oquirrh Mountains (2)
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Tooele County Utah (1)
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Virgin River valley (1)
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Western U.S. (1)
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rock formations
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sedimentary rocks
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sedimentary rocks
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carbonate rocks
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limestone (3)
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chemically precipitated rocks
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clastic rocks
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conglomerate (1)
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marl (1)
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mudstone (2)
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sandstone (2)
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volcaniclastics (1)
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sediments
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sand (1)
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volcaniclastics (1)
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soils
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soils
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Desert soils (1)
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Volcanism and tectonics of young basaltic fields in the eastern California shear zone, California, USA
ABSTRACT Circa 12 Ma, there was a fundamental reorganization of magmatism and tectonics in the Mojave Desert, California, USA, from basaltic to rhyolitic fields associated with extensional tectonics to dispersed basaltic monogenetic fields associated with the northwest- or east-striking strike-slip faults. The broad zone of strike-slip faults associated with the San Andreas transform margin stretched east to Arizona, but the high slip-rate central part that is known as the Quaternary eastern California shear zone is the locus of the post–12 Ma volcanism. We compiled a literature review of 29 basaltic fields, conducted detailed and reconnaissance study of several fields, and conducted geochemistry on many. Most of the volcanic fields are near or cut by the long fault systems, but more importantly, in nearly two-thirds of the fields that have scoria cones, the cones are <1 km from one of these faults. Eighteen volcanic fields have geochemistry data, and of the 441 analyses of major elements, 286 are new U.S. Geological Survey data that include comprehensive trace elements. The data are used to compare fields and determine the compositional variations during the formation of each field. Comparisons between fields show that several nearby volcanic fields have similar geochemical compositions and trends compared to distant fields; we suggest that six magmatic clusters formed, some with 200–300 k.y. duration. Spatial patterns change over the 12 m.y. span, with early fields forming in the north and south and the youngest in a central area from Pisgah to Amboy fields. The volume of magma also changed, most notably with a sixfold increase ca. 4 Ma followed by a 2–3 m.y. quiescence. In addition to the fracture control provided by strike-slip faults as magma conduits, we advance arguments for shear melting in the mantle along the most active faults, with secondary controls of local tectonic interactions, to explain spatial and temporal patterns in the fields.
Ibex Hollow Tuff from ca. 12 Ma supereruption, southern Idaho, identified across North America, eastern Pacific Ocean, and Gulf of Mexico
Temporal and Petrogenetic Links Between Mesoproterozoic Alkaline and Carbonatite Magmas at Mountain Pass, California
ABSTRACT Lake Coyote, California, which formed in one of five basins along the Mojave River, acted both as a part of the Lake Manix basin and, after the formation of Afton Canyon and draining of Lake Manix ca. 24.5 calibrated (cal) ka, a side basin that was filled episodically for the next 10,000 yr. As such, its record of lake level is an important counterpart to the record of the other terminal basin, Lake Mojave, following the draining of Lake Manix. We studied lake and fluvial deposits and their geomorphology and identified five principal periods of recurring lakes in the Coyote basin by dating mollusks. Several of these periods in detail consist of multiple lake-rise pulses, for which we identified specific fluvial deposits that represent the Mojave River entering the basin. The pulsed record of rapid lake rise and decline is interpreted as switching of the Mojave River between Lake Coyote and Lake Mojave. A composite lake record for both basins shows nearly continuous lake maintenance by the Mojave River from 24.5 cal ka to ca. 14 cal ka. One potential gap in the lake record, ca. 22.7–21.8 cal ka, may indicate either temporary river routing to yet another basin or a dry climatic period. The Mojave River discharge was sufficient to maintain at least one terminal lake throughout most of the Last Glacial Maximum and deglacial periods, indicating that paleoclimate was moist and/or cool well into the Bølling-Allerød and that the lake records may not be sensitive to variations from moderate to high discharge. Nuances of lake-level changes in both the Coyote and Mojave basins are difficult to interpret as paleoclimatic events because the current chronologic control on lake levels from nearshore deposits does not provide the necessary precision. Mojave River avulsion leading to flow to Coyote basin may have been influenced by rupture on a dextral-oblique fault. Earliest post–Lake Manix stream deposits of the Mojave River leading to the Coyote basin are faulted, and most subsequent streams were confined to the downthrown fault block. This fault rupture and possible enhanced river routes to Lake Coyote, rather than Lake Mojave, are bracketed by dated beach deposits to the period ca. 20–19 cal ka. Later, headward erosion through the fluvial plain by the Mojave River eliminated flow to Coyote basin after ca. 14 cal ka and completed incision of the plain after ca. 12 cal ka.
Geophysical characterization of a Proterozoic REE terrane at Mountain Pass, eastern Mojave Desert, California, USA
Paleodischarge of the Mojave River, southwestern United States, investigated with single-pebble measurements of 10 Be
Bouse Formation in the Bristol basin near Amboy, California, USA
Chronology, sedimentology, and microfauna of groundwater discharge deposits in the central Mojave Desert, Valley Wells, California
Hydrologic Characterization of Desert Soils with Varying Degrees of Pedogenesis: 1. Field Experiments Evaluating Plant-Relevant Soil Water Behavior All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher.
Controls on alluvial fan long-profiles
Dedication
During glacial (pluvial) climatic periods, Death Valley is hypothesized to have episodically been the terminus for the Amargosa, Owens, and Mojave Rivers. Geological and biological studies have tended to support this hypothesis and a hydrological link that included the Colorado River, allowing dispersal of pupfish throughout southeastern California and western Nevada. Recent mitochondrial deoxyribonucleic acid (mtDNA) studies show a common pupfish (Cyprinodontidae) ancestry in this region with divergence beginning 3–2 Ma. We present tephrochronologic and paleomagnetic data in the context of testing the paleohydrologic connections with respect to the common collection point of the Amargosa, Owens, and Mojave Rivers in Death Valley during successive time periods: (1) the late Pliocene to early Pleistocene (3–2 Ma), (2) early to middle Pleistocene (1.2–0.5 Ma), and (3) middle to late Pleistocene (<0.7–0.03 Ma; paleolakes Manly and Mojave). Using the 3.35 Ma Zabriskie Wash tuff and 3.28 Ma Nomlaki Tuff Member of the Tuscan and Tehama Formations, which are prominent marker beds in the region, we conclude that at 3–2 Ma, a narrow lake occupied the ancient Furnace Creek Basin and that Death Valley was not hydrologically connected with the Amargosa or Mojave Rivers. A paucity of data for Panamint Valley does not allow us to evaluate an Owens River connection to Death Valley ca. 3–2 Ma. Studies by others have shown that Death Valley was not hydrologically linked to the Amargosa, Owens, or Mojave Rivers from 1.2 to 0.5 Ma. We found no evidence that Lake Manly flooded back up the Mojave River to pluvial Lake Mojave between 0.18 and 0.12 Ma, although surface water flowed from the Amargosa and Owens Rivers to Death Valley at this time. There is also no evidence for a connection of the Owens, Amargosa, or Mojave Rivers to the Colorado River in the last 3–2 m.y. Therefore, the hypothesis that pupfish dispersed or were isolated in basins throughout southeastern California and western Nevada by such a connection is not supported. Beyond the biologically predicted time frame, however, sparse and disputed data suggest that a fluvial system connected Panamint (Owens River), Death, and Amargosa Valleys, which could account for the dispersal and isolation before 3 Ma.
The western North American pupfish clade (Cyprinodontidae: Cyprinodon ): Mitochondrial DNA divergence and drainage history
The western pupfish clade (Cyprinodontidae: Cyprinodon ) consists of nine species that occur primarily in isolation from one another in the large area extending from the Guzmán Basin, northwestern Chihuahua, Mexico, to the Death Valley region of southeastern California and southwestern Nevada. This paper presents a reassessment of estimated divergence times based on a compilation of previously published mitochondrial DNA sequences (ND2, cyt b, and control region). The results agree with previous estimates, which state that the western pupfish clade originated in the late Miocene or early Pliocene and that Cyprinodon was present in the Death Valley region by at least the middle Pliocene and possibly earlier. Enigmatically, there is little geologic evidence of late Neogene surface-water connections among the Guzmán, Lower Colorado River, and Death Valley regions. This indicates that either our knowledge of such connections is incomplete or pupfish dispersal across basin divides via small, relatively transient, surface-water connections has been more common than expected based on the low-gradient, valley-floor habitats generally occupied by this group.
Multistage late Cenozoic evolution of the Amargosa River drainage, southwestern Nevada and eastern California
Stratigraphic and geomorphic analyses reveal that the regional drainage basin of the modern Amargosa River formed via multistage linkage of formerly isolated basins in a diachronous series of integration events between late Miocene and latest Pleistocene–Holocene time. The 275-km-long Amargosa River system drains generally southward across a large (15,540 km 2 ) watershed in southwestern Nevada and eastern California to its terminus in central Death Valley. This drainage basin is divided into four major subbasins along the main channel and several minor subbasins on tributaries; these subbasins contain features, including central valley lowlands surrounded by highlands that form external divides or internal paleodivides, which suggest relict individual physiographic-hydrologic basins. From north to south, the main subbasins along the main channel are: (1) an upper headwaters subbasin, which is deeply incised into mostly Tertiary sediments and volcanic rocks; (2) an unincised low-gradient section within the Amargosa Desert; (3) a mostly incised section centered on Tecopa Valley and tributary drainages; and (4) a west- to northwest-oriented mostly aggrading lower section along the axis of southern Death Valley. Adjoining subbasins are hydrologically linked by interconnecting narrows or canyon reaches that are variably incised into formerly continuous paleodivides. The most important linkages along the main channel include: (1) the Beatty narrows, which developed across a Tertiary bedrock paleodivide between the upper and Amargosa Desert subbasins during a latest Miocene–early Pliocene to middle Pleistocene interval (ca. 4–0.5 Ma); (2) the Eagle Mountain narrows, which cut into a mostly alluvial paleodivide between the Amargosa Desert and Tecopa subbasins in middle to late Pleistocene (ca. 150–100 ka) time; and (3) the Amargosa Canyon, which formed in late middle Pleistocene (ca. 200–140 ka) time through a breached, actively uplifting paleodivide between the Tecopa and southern Death Valley subbasins. Collectively, the interconnecting reaches represent discrete integration events that incrementally produced the modern drainage basin starting near Beatty sometime after 4 Ma and ending in the Salt Creek tributary in the latest Pleistocene to Holocene (post–30 ka). Potential mechanisms for drainage integration across paleodivides include basin overtopping from sedimentary infilling above paleodivide elevations, paleolake spillover, groundwater sapping, and (or) headward erosion of dissecting channels in lower-altitude subbasins. These processes are complexly influenced by fluvial responses to factors such as climatic change, local base-level differences across divides, and (or) tectonic activity (the latter only recognized in Amargosa Canyon).
The Death Valley system (southeastern California and southwestern Nevada) contains a locally endemic aquatic biota that has long been the subject of compelling biogeographic speculation, yet it remains little studied phylogenetically. Springsnails (Hydrobiidae: Pyrgulopsis ) are one of the most diverse elements of this fauna, and they are thought to have evolved in association with late Tertiary rearrangements of landscape and drainage. We assembled a molecular phylogeny for this fauna to investigate its evolutionary development in relation to regional geological history. Sequences for two mitochondrial genes were obtained from 80 populations representing 13 of the 14 Death Valley system springsnail species, and 31 extralimital congeners. Combined analyses of the 1188 base-pair data set consistently depicted the Death Valley system fauna as a polyphyletic assemblage of eight or nine lineages. Based on a molecular clock, the six lineages endemic to the Death Valley system were estimated to be minimally Pliocene in age, which is concordant with inception of regional topographic closure during this time period. The single endemic lineage with a well-resolved sister relationship was closest to a species from the upperGila Riverbasin, which also suggests an old divergence event. Three other lineages shared a pattern of shallow structuring (divergence events youngerthan 0.7 Ma) across multiple drainage basins, some of which have long been isolated. This suggests that, contrary to previous thought, regional springsnail biogeography has been shaped in part by geologically recent (Pleistocene) dispersal, and, in some places, it has occurred by means other than spread through continuous reaches of aquatic habitat.
The North American Great Basin is a useful venue for the study of dispersal, vicariance, and rates of molecular evolution among aquatic organisms because its Pleistocene hydrogeographic history is relatively well known. This study examines regional molecular variation in the amphipod Hyalella azteca using mitochondrial (mt) gene sequence (deoxyribonucleic acid [DNA]) data. Populations within several endorheic drainages in the southern Great Basin were analyzed to determine if they represent a monophyletic assemblage with respect to populations from the pluvial Lake Bonneville drainage in the northern Great Basin. We also tested whether the patterns of molecular diversification among populations in the southern Great Basin were consistent with a Pleistocene vicariance hypothesis, and if the magnitude of observed sequence divergence was concordant with standard molecular clock calibrations. Our results show that diversity and endemism among Hyalella populations in the southern Great Basin are high with respect to those in the Lake Bonneville Basin. We further demonstrate that hyalellid populations in the southern Great Basin are a polyphyletic assemblage with respect to their counterparts in the Bonneville Basin, suggesting that dispersal events have been partially responsible for the enigmatic relationships within this assemblage. The relationships among lineages within the southern Great Basin are largely enigmatic and are not concordant with Pleistocene hydrographic history. Our data also indicate that rates of molecular evolution have been heterogeneous; there is a 2.8-fold disparity in relative rates of mtDNA divergence among closely allied lineages. The magnitude of sequence divergence among lineages is inconsistent with standard molecular clock calibrations, and evidence indicates that accelerated rates of divergence may have contributed to the high diversity and endemism among Great Basin hyalellids, complicating reconstruction of the temporal sequence of biogeographic events.
Geological and hydrological history of the paleo–Owens River drainage since the late Miocene
From the late Miocene to the middle Pliocene, the current drainage basin of the Owens River probably consisted of a broad, moderate-elevation, low-relief plateau with radiating drainage toward the Pacific Ocean, the northwestern Great Basin (now Lahontan drainages), and the Mojave and Colorado drainages. This plateau probably contained shallow basins, created by an extensional pulse at 12–11 Ma, at the present locations of major valleys. Between 4 and 3 Ma, this plateau was disrupted by a rapid westward step of extensional Basin and Range Province tectonism, which reactivated the Miocene faults and resulted in a linear north-south valley (the Owens Valley) with high mountain ranges on each side. This tectonic event resulted in geographic isolation and fragmentation of aquatic habitats and may have been a critical driver for speciation of aquatic organisms. Subsequent to this remarkable transformation of the landscape, the predominant influence on aquatic habitats has been very large, climate-driven fluctuations in the regional water balance that have resulted in the repeated interconnection and disconnection of the various basins that make up the paleo–Owens system. The magnitude of these fluctuations appears to have increased markedly since the early Pleistocene. Searles Lake has generally been the terminus of the Owens River, but at least once, probably at ca. 150 and/or ca. 70 ka, the system overflowed into Death Valley. During the last interglacial (marine isotope stage 5) and the Holocene, Owens Lake has been the terminus, but apparently not frequently before. These very large fluctuations in the water balance undoubtedly produced large shifts in the nature and distribution of aquatic habitats over geologically short periods of time, as well as repeatedly creating and severing connections between various parts of the larger drainage basin. This dynamic hydrological system provided the setting, and no doubt much of the impetus, for speciation, extinction, and distribution of aquatic species within the paleo–Owens system, but any paleohydrological causes will have to be extracted from a complex history.
Late Pleistocene lakes and wetlands, Panamint Valley, Inyo County, California
Pleistocene deposits in Panamint Valley, California, document the changes in pluvial lake level, source water, and elevation of the regional groundwater table associated with climate change. The oxygen isotope stage (OIS) 2 and 6 lacustrine record is well preserved in surficial deposits, whereas the OIS 3–5 lacustrine-paludal and lacustrine record is mainly derived from an archived core sample. Amino acid racemization ratios in ostracodes and gastropods suggest that the shoreline and groundwater-discharge features that lie between ∼600 and 550 m elevation formed during one highstand, probably during OIS 6. A fossiliferous part of the ∼100-m-deep core DH-1, which was drilled in the Ballarat Basin during the late 1950s, was resampled in this study. Comparison of DH-1 with core DH-3 from Panamint Valley and core OL-92 from Owens Lake suggests the 34–78-m-depth interval of DH-1 may span all or much of OIS 4. The microfauna from this depth interval indicate a saline marsh or shallow lacustrine environment, but not a large lake. The ostracode assemblage requires low ratios of alkalinity to calcium (alk/Ca) water likely indicative of solutes in deep regional groundwater sources rather than the high alk/Ca solutes common to the Owens River system. OIS 2–aged sediment from surficial deposits, a shallow auger hole, and core DH-1 contain faunas, including the ostracode Limnocythere sappaensis , which require the high alk/Ca evolved solutes common to the Owens River. The elevation of the lacustrine sediments further indicates a moderate-sized saline lake around 180–200 m depth. In the northern Lake Hill basin, a saline lake persisted until at least 16 ka, and it was succeeded by fresh, groundwater-supported wetlands, which were fully developed by ca. 12,575 14 C yr B.P. and which persisted until around 10,500 14 C yr B.P., when the basin became a dry playa.
Late Quaternary MIS 6–8 shoreline features of pluvial Owens Lake, Owens Valley, eastern California
The chronologic history of pluvial Owens Lake along the eastern Sierra Nevada in Owens Valley, California, has previously been reported for the interval of time from ca. 25 calibrated ka to the present. However, the age, distribution, and paleoclimatic context of higher-elevation shoreline features have not been formally documented. We describe the location and characteristics of wave-formed erosional and depositional features, as well as fluvial strath terraces that grade into an older shoreline of pluvial Owens Lake. These pluvial-lacustrine features are described between the Olancha area to the south and Poverty Hills area to the north, and they appear to be vertically deformed ∼20 ± 4 m across the active oblique-dextral Owens Valley fault zone. They occur at elevations from 1176 to 1182 m along the lower flanks of the Inyo Mountains and Coso Range east of the fault zone to as high as ∼1204 m west of the fault zone. This relict shoreline, referred to as the 1180 m shoreline, lies ∼20–40 m higher than the previously documented Last Glacial Maximum shoreline at ∼1160 m, which occupied the valley during marine isotope stage 2 (MIS 2). Crosscutting relations of wave-formed platforms, notches, and sandy beach deposits, as well as strath terraces on lava flows of the Big Pine volcanic field, bracket the age of the 1180 m shoreline to the time interval between ca. 340 ∼ 60 ka and ca. 130 ∼ 50 ka. This interval includes marine oxygen isotope stages 8–6 (MIS 8–6), corresponding to 260–240 ka and 185–130 ka, respectively. An additional age estimate for this shoreline is provided by a cosmogenic 36 Cl model age of ca. 160 ∼ 32 ka on reefal tufa at ∼1170 m elevation from the southeastern margin of the valley. This 36 Cl model age corroborates the constraining ages based on dated lava flows and refines the lake age to the MIS 6 interval. Documentation of this larger pluvial Owens Lake offers insight to the hydrologic balance along the east side of the southern Sierra Nevada and will assist with future regional paleoclimatic models within the western Basin and Range.