Early Proterozoic ophiolite, central Arizona
- Washington Univ., St. Louis, MO (USA)
The 1.73 Ga Payson ophiolite is a pseudostratigraphic sequence of mafic plutons, dike swarms, sheeted dikes, and submarine basalts that intruded and erupted upon a 1.75-1.76 Ga magmatic-arc complex. The composition of the sheeted dikes is tholeiitic basalt (minor andesite) with island-arc affinities. The submarine basalts are overlain by dacitic breccias and a thick section of turbidites with ca. 1.72 Ga ash beds. The entire sequence was deformed, intruded by ca. 1.70 Ga granites, and unconformably overlain by fluvial to shallow-shelf sediments. Although most of the 1.8-1.6 Ga juvenile crust of Arizona consists of magmatic-arc rocks, the Payson ophiolite is unique and is interpreted to have formed the floor of an intra-arc basin. The ophiolite developed in situ on the older arc basement, as opposed to being thrust over it. The basin was accreted to the continent by ca. 1.70 Ga.
- OSTI ID:
- 5667528
- Journal Information:
- Geology; (USA), Vol. 19:6; ISSN 0091-7613
- Country of Publication:
- United States
- Language:
- English
Similar Records
Highly extended oceanic lithosphere: The basement and wallrocks for the Late Jurassic Rogue-Chetco oceanic arc, Oregon Klamath Mountains
Preston Peak ophiolite, Klamath mountains, California, an immature island arc: petrochemical evidence
Related Subjects
ARIZONA
VOLCANIC REGIONS
GEOLOGIC MODELS
AGE ESTIMATION
BASALT
BASEMENT ROCK
CONTINENTAL CRUST
CONTINENTAL SHELF
DIKES
DIORITES
GABBROS
GEOCHEMISTRY
GEOLOGIC HISTORY
ORIGIN
PLUTONIC ROCKS
PRECAMBRIAN ERA
SEDIMENTS
STRATIGRAPHY
VOLCANIC ROCKS
CHEMISTRY
CONTINENTAL MARGIN
DEVELOPED COUNTRIES
EARTH CRUST
FEDERAL REGION IX
GEOLOGIC AGES
GEOLOGIC STRUCTURES
GEOLOGY
IGNEOUS ROCKS
NORTH AMERICA
ROCKS
USA
580000* - Geosciences