Solid-state nuclear magnetic resonance (NMR) techniques, combined with Fourier transform infrared (FT-IR) spectroscopy, were used to study synthetic AB-type carbonate hydroxylapatite (CHAp). 13C{1H} heteronuclear correlation (HetCor) experiments indicate that the two carbonate environments represented by the peaks at δC = 169.8 and 170.8 ppm are associated with three H environments with one environment represented by a peak centered about δH = 0.0 ppm and two additional peaks located at 1.3 and 5.5 ppm. The peaks near δH = 0.0 ppm correspond to hydroxyl environments within the channels of the CHAp, whereas those at 1.3 and 5.5 exhibit spectral characteristics consistent with bicarbonate ions that donate moderate to weak hydrogen bonds. Possible methods by which bicarbonate incorporation can be accommodated by the apatite structure are discussed. The Na/carbonate ratio and 23Na NMR spectroscopy indicate that Na plays an important role in the carbonate incorporation in these materials.

Thick, relatively homogeneous basal tills exposed in the drumlins and flutes of the Weedsport drumlin and flute field in New York State exhibit anisotropy of magnetic susceptibility (AMS) and pebble fabrics that are consistently oriented parallel to the streamlined bedforms. The pebble fabrics and AMS fabrics are concordant. In this study, six drumlins and five flutes were sampled. Thermally induced, incremental reduction of isothermal remanent magnetization indicates that AMS is caused by primarily elongate maghaemite grains. The orientations of principal axes of maximum susceptibility (k 1 ) are generally parallel to pebble long-axis orientations, and tend to plunge mildly up-glacier. Fabric directions are generally parallel to drumlin long-axis orientations, but deviate by 121-231 from flute directions. Fabrics of the flutes are stronger and more unidirectional than those of the drumlins. These results support the use of AMS as a fast and objective method for characterizing fabrics in tills, and suggest hypotheses about basal processes linked to glacially streamlined landforms.

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