. Additional notes on the Grinnell ice-cap. Ice -- Nunavut Baffin Island. 108 Field Museum of Natural History—Geology, Vol. VII addition to being fine-grained to granular, have retained traces of taenite particles or lamellae, indicating incomplete separation. Grain boundaries in kamacite bands (fig. 40) are common, more common in one part of the section than in another. Taenite lamellae bounding the kamacite bands and plessite fields can be distinguished easily by the naked eye. They are not. Fig. 42. Enlarged plessite fields. Right: A dense field. X25. Left: The tri- angular field with taeni
. Additional notes on the Grinnell ice-cap. Ice -- Nunavut Baffin Island. 108 Field Museum of Natural History—Geology, Vol. VII addition to being fine-grained to granular, have retained traces of taenite particles or lamellae, indicating incomplete separation. Grain boundaries in kamacite bands (fig. 40) are common, more common in one part of the section than in another. Taenite lamellae bounding the kamacite bands and plessite fields can be distinguished easily by the naked eye. They are not. Fig. 42. Enlarged plessite fields. Right: A dense field. X25. Left: The tri- angular field with taenite lamellae and kamacite bands running in three directions shows the general octahedral structure. X14. uniform in width and are generally wavy. They occur in various forms, as long or short threads, as needles, and as particles. Some, particularly in plessite fields, appear thickened at the ends, near or at the junction of kamacite bands (fig. 41). Under high magnifica- tion, many of these are found to be looped at the thickened ends, some having dark cores, very similar to those observed in Seneca Township, Bethany, and others. Plessite fields consisting of taenite and kamacite are abundant and show an unusual variety of shapes (fig. 42). These fields are both light and dark, the former type predominating. The dark fields, however, are not typical, being not as dark, nor the texture as visibly dense. In some of the fields the kamacite bands bounded by taenite lamellae have three systems, reproducing on a small scale the general octahedral structure. The taenite lamellae in these fields are not always continuous but are often hachured (fig. 43).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Roy, Sharat Kumar, 1897-1962. Chicago : Field Museum of Natural History
Size: 2149px × 1163px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookpublisherchicagofieldmuseumofnaturalhistor
