scholarly journals Quantifying capital versus income breeding: New promise with stable isotope measurements of individual amino acids

Author(s):  
John P. Whiteman ◽  
Seth D. Newsome ◽  
Paco Bustamante ◽  
Yves Cherel ◽  
Keith A. Hobson
1984 ◽  
Vol 48 (348) ◽  
pp. 311-322 ◽  
Author(s):  
A. P. Dickin ◽  
C. M. B. Henderson ◽  
F. G. F. Gibb

Abstract The Dippin sill, which is emplaced into the Triassic sediments of SE Arran, is an alkaline basic sheet which displays pronounced hydrothermal alteration. The 40-m-thick sill has suffered pervasive contamination with radiogenic Sr, introduced from the Triassic sediments by hydrothermal fluids. Stable isotope measurements suggest that fluids were of meteoric origin, but were restricted to a small closed-system circulation. Initial 87Sr/86Sr ratios in the sill were raised from an original value of 0.7032 to a maximum of 0.7091, contamination being especially pronounced near the contacts at Dippin Head itself (localities 12 and 14) and in a drill core section through the sill above Dippin. Hydrothermal Sr was incorporated into an early-formed high-CaO, high-Sr analcime, which replaced unstable high-silica nepheline in interstitial patches. However, this high-CaO analcime, along with plagioclase, was later replaced by a low-CaO, low-Sr analcime, allowing Sr leaching from the margins of the sill. Hydrothermal fluids are thought to have migrated up to 1 km laterally, up the dip of the sill, mainly via tension joints forming in the cooling intrusion. Pooling of hot fluids at the upper end of the sill probably raised water/rock ratios in this region and allowed greater Sr contamination during mineralogical alteration. The undersaturated mineralogy of the sill accounts for its pervasive hydrothermal Sr contamination, which contrasts markedly with the relatively undisturbed Sr isotope compositions of Hebridean granites involved in hydrothermal systems.


2009 ◽  
Vol 285 (9) ◽  
pp. 6285-6297 ◽  
Author(s):  
Ming Li ◽  
Jason M. Aliotta ◽  
John M. Asara ◽  
Qian Wu ◽  
Mark S. Dooner ◽  
...  

2017 ◽  
pp. 239-256
Author(s):  
Emad Ehtesham ◽  
Federica Camin ◽  
Luana Bontempo ◽  
Russell D. Frew

Radiocarbon ◽  
2002 ◽  
Vol 44 (1) ◽  
pp. 59-62 ◽  
Author(s):  
C M Takahashi ◽  
D E Nelson ◽  
J S Southon

We tested a simple method for removing a collagen-based glue preservative from bone destined for radiocarbon and stable isotope analyses. The method is sufficient for bone samples from which only stable isotope measurements are required. For 14C dating, such samples of age less than about 10 ka can be adequately dated, but for older samples, the circumstances must be carefully evaluated.


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