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Full-Text Articles in Physical Sciences and Mathematics
Building Arc Crust: Plutonic To Volcanic Connections In An Extensional Oceanic Arc, The Southern Alisitos Arc, Baja California, Rebecca A. Morris, Susan M. Debari, Cathy Busby, Sarah Medynski, Brian R. Jicha
Building Arc Crust: Plutonic To Volcanic Connections In An Extensional Oceanic Arc, The Southern Alisitos Arc, Baja California, Rebecca A. Morris, Susan M. Debari, Cathy Busby, Sarah Medynski, Brian R. Jicha
Geology Faculty Publications
The ~50 km long Rosario segment of the Cretaceous Alisitos oceanic arc terrane provides undeformed three-dimensional exposures of the upper 7 km of an oceanic extensional arc, where crustal generation processes are recorded in both the volcanic and underlying plutonic rocks. These exceptional exposures allow for the study of the physical and chemical links between the rock units and help constrain the differentiation processes active during the growth and evolution of arc crust. This study focuses on the southern third of the Rosario segment, previously referred to as the southern volcano-bounded basin, and its plutonic underpinnings. Upper crustal rocks in …
Subduction Initiation And Early Evolution Of The Easton Metamorphic Suite, Northwest Cascades, Washington, Jeremy L. Cordova, Sean R. Mulcahy, Elizabeth R. Schermer, Laura E. Webb
Subduction Initiation And Early Evolution Of The Easton Metamorphic Suite, Northwest Cascades, Washington, Jeremy L. Cordova, Sean R. Mulcahy, Elizabeth R. Schermer, Laura E. Webb
Geology Faculty Publications
The Easton metamorphic suite, in the northwest Cascades of Washington State, preserves an inverted metamorphic sequence with ultramafic rocks underlain by amphibolite and high-temperature blueschist juxtaposed above low-temperature blueschists. The sequence is interpreted as a metamorphic sole and younger accreted rocks that formed during and after the initiation of Farallon plate subduction beneath North America in Jurassic time. Two high-temperature deformation events are recorded in the metamorphic sole at ∼10 kbar and ∼760 °C to 590 °C between >167 and 164 Ma. High-temperature blueschist partly overprints the amphibolite but may have accreted separately at ∼530 °C between ca. 165 and …
Particle Size Specific Magnetic Properties Across The Norwegian‐Greenland Seas: Insights Into The Influence Of Sediment Source And Texture On Bulk Magnetic Records, Robert G. Hatfield, Benjamin H. Wheeler, Brendan T. Reilly, Joseph S. Stoner, Bernard A. Housen
Particle Size Specific Magnetic Properties Across The Norwegian‐Greenland Seas: Insights Into The Influence Of Sediment Source And Texture On Bulk Magnetic Records, Robert G. Hatfield, Benjamin H. Wheeler, Brendan T. Reilly, Joseph S. Stoner, Bernard A. Housen
Geology Faculty Publications
We make fundamental observations of the particle size variability of magnetic properties from 71 core tops that span the southern Greenland and Norwegian Seas. These data provide the first detailed regional characterization of how bulk magnetic properties vary with sediment texture, sediment source, and sediment transport. Magnetic susceptibility (MS) and hysteresis parameters were measured on the bulk sediment and the five constituent sediment particle size fractions (clay, fine silt, medium silt, coarse silt, and sand). The median MS value of the medium silt size fraction is ~3–5 times higher than that of the sand and clay size fractions and results …