 | 1873 - 562 דפים
...surfaces. On careful consideration of these raised impressions, I have arrived at the conclusion that they have been left by denudation of the surrounding material,...pressure being better able to resist the denuding agency. Such markings in relief on the upper surfaces of beds are, however, I believe, altogether exceptional.... | |
 | Elkanah Billings, Bernard James Harrington, James Thomas Donald - 1875 - 498 דפים
...surfaces. On careful consideration of these raised impressions, I have arrived at the conclusion that they have been left by denudation of the surrounding material,...pressure being better able to resist the denuding agency. Such markings in relief on the upper surfaces of beds are, however, I believe, altogether exceptional.... | |
 | Henry Alleyne Nicholson - 1879 - 540 דפים
...specimens ; especially as some elevated impressions, supposed to be tracks, do really occur on the upper surfaces of the strata. Such impressions, in the opinion...being better able to resist the denuding agency." Before leaving this obscure subject finally, it may be well to notice briefly one or two considerations... | |
 | Sir John William Dawson - 1888 - 370 דפים
...arched upward on top, or castings of worms thrown up upon the surface. Sometimes, however, they may have been left by denudation of the surrounding material, just as footprints on dry snow remain in relief after the surrounding loose material has been drifted away by the wind; the portion... | |
 | Sir John William Dawson - 1888 - 322 דפים
...upward on top, or castings of worms thrown up upon the surface. Sometimes, however, they may have beeu left by denudation of the surrounding material, just as footprints on dry snow remain in relief after the surrounding loose material has been drifted away by the wind; the portion... | |
 | William Miller, III - 2011 - 632 דפים
...arched upwards on top, or castings of worms thrown up upon the surface. Sometimes, however, they may have been left by denudation of the surrounding material, just as footprints on dry snow remain in relief after the surrounding loose material has been drifted away by the wind; the portion... | |
 | 1873 - 1024 דפים
...surfaces On careful consideration of these raised impressions, I have arrived at the conclusion that they have been left by denudation of the surrounding material,...pressure being better able to resist the denuding agency. Such markings in relief on the upper surfaces of beds are, however, I believe, altogether exceptional.... | |
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As might be expected, the markings above referred to, when in relief, occur on the under sides of the beds. A few instances may, however, be found where they exist on the upper surfaces. On careful consideration of these raised impressions, I have arrived... 