Roberta Rudnick
= Roberta Rudnick
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= Roberta L. Rudnick
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<Roberta Rudnick> is a <geologist> who investigates the composition and origin of <continental crust>. Much of the lower <continental crust> is inaccessible to direct sampling, so its composition must be inferred by combining <geochemistry>, <petrology> and <seismology>. Her 1995 synthesis with <David M. Fountain> linked laboratory measurements of elastic <wave speeds> in <rocks> to <seismic refraction surveys>, using <granulites> to constrain the composition of the deep <continental crust>.<Nature and composition of the continental crust: A lower crustal perspective by Roberta L. Rudnick and David M. Fountain>[Abstract and pp. 267–309: integration of seismic, petrological and geochemical constraints]{ref}
Their reconstruction distinguished a compositionally heterogeneous, on average <mafic> lower <continental crust> from an intermediate-composition middle <continental crust>. The distinction matters for <Earth>'s <heat> budget: the abundance of <potassium>, <thorium> and <uranium>, and hence <heat> production from <radioactive decay>, varies between <rock> types and with depth. Seismic <wave speeds> alone are not a unique chemical analysis; different <rocks> can have overlapping elastic properties, making independent constraints from <geochemistry> essential.<Nature and composition of the continental crust: A lower crustal perspective by Roberta L. Rudnick and David M. Fountain>[Abstract: overlapping rock velocities, lower-crustal heterogeneity and heat-producing elements]{ref}
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{title=Portrait of <Roberta Rudnick>}
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Research author of <Nature and composition of the continental crust: A lower crustal perspective by Roberta L. Rudnick and David M. Fountain>.