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D Gunther

Publications and source records attributed to D Gunther.

6 recordsLinked to original sources
PubMed1999

Hafnium isotope stratigraphy of ferromanganese crusts

A Cenozoic record of hafnium isotopic compositions of central Pacific deep water has been obtained from two ferromanganese crusts. The crusts are separated by more than 3000 kilometers but display similar secular variations. Significant fluctuations in hafnium isotopic composition occurred in the Eocene and Oligocene, possibly related to direct advection from the Indian and Atlantic oceans. Hafnium isotopic compositions have remained approximately uniform for the past 20 million years, probably reflecting increased isolation of the central Pacific. The mechanisms responsible for the increase in (87)Sr/(86)Sr in seawater through the Cenozoic apparently had no effect on central Pacific deep-water hafnium.

Journal Article↗
PubMed1999

Turner syndrome: a pattern of early growth failure.

The purpose of this study was to determine the pattern of early growth in girls with Turner syndrome. Analysis was performed on a total of 464 longitudinal measurements of height, obtained from birth to 8 years of age from 37 girls with Turner syndrome who did not have significant cardiac disease or autosomal abnormalities. All data were obtained prior to the initiation of any hormonal therapy. Mean height SDS fell from -0.5 at birth to -1.5 at age 1 year and -1.8 at age 1.5 years. Growth curves fitted using the first two components of the infancy-childhood-puberty model of growth revealed that growth failure was due to (a) mild growth retardation in utero, (b) slow growth during infancy, (c) delayed onset of the childhood component of growth and (d) slow growth during childhood. Physicians should consider the diagnosis of Turner syndrome in any girl with an unexplained failure to thrive or with short stature, even during the first 2 years of life.

Body Height↗
PubMed1998

Formation of a magmatic-hydrothermal ore deposit: insights with LA-ICP-MS analysis of fluid inclusions

The physical and chemical mechanism of ore precipitation in the Yankee Lode tin deposit (Mole Granite, Australia) was quantified by direct trace-element microanalysis of fluid inclusions. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to measure element concentrations in a series of fluid inclusions representing the fluid before, during, and after the deposition of cassiterite (SnO2). Tin precipitation was driven by mixing of hot magmatic brine with cooler meteoric water. At the same time, a separate magmatic vapor phase selectively transported copper and boron into the liquid mixture.

Journal Article↗