Geological magazine . been determined before the period when the plateau gravel bedswere being accumulated. Isle of Wight: Evidence of an Ancient Sea-margin.—Some fewyears ago, when on a visit to this island, with the aid of an aneroidI spent my time in making observations of level, and, amongst otherplaces, I took the level of a gravel-bed at the summit of the cliffoverlooking Alum Bay, and also of the remarkable gravel terracesouth of Newport known as St. Georges Down. My interest wasgreatly aroused on discovering that the aneroid readings were verynearly the same in both, cases—approximatin
Geological magazine . been determined before the period when the plateau gravel bedswere being accumulated. Isle of Wight: Evidence of an Ancient Sea-margin.—Some fewyears ago, when on a visit to this island, with the aid of an aneroidI spent my time in making observations of level, and, amongst otherplaces, I took the level of a gravel-bed at the summit of the cliffoverlooking Alum Bay, and also of the remarkable gravel terracesouth of Newport known as St. Georges Down. My interest wasgreatly aroused on discovering that the aneroid readings were verynearly the same in both, cases—approximating to 400 feet above thesea, or a little under. It then occurred to me that we had in thesereadings evidence of the existence of an ancient sea-margin. Onascending to the top of the St. Georges gravel-pit, I found myselfon a nearly level terrace extending far westwards, and breakingoff in an abrupt cliff on the north and Avest sides. The beds werefound to consist mainly of rolled chalk-flints, rudely but distinctly. Soundings ut-fathotTvn Len^Or uCiuhm^i^^ed iTuiJutf? iL*-a/-iy>300 ENGLISH CHANNEL RIVER-VALLEY (TO ILLUSTRATE PROF. HULLS PAPER). 102 Professor Edward Hull—Gravel Beds, Isle of Wujht, etc. stratified. The section of the gravel cliff is fully described in theSurvey Memoir. The gravel-bed on the summit of the cliff above Alum Bay isdistinctly visible from the deck of the ship anchored in the bay below ;and its horizontal stiatification, resting on the nearl}^ vertical strata ofthe Tertiary Series, forms one of the most interesting geologicalfeatures of the country. Its presence there is easily explained. Itonce extended westwards to an undefined distance, but with theunderlying Tertiaries it has been worn back along the side of theridge of the Chalk, which now stretches to the Needles, but onceextended to a greater distance towards the Isle of Purbeck. TheChalk ridge at the Tennyson Monument rises to a level of 483 feet, orsomewhat under 100 feet above
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectgeology, bookyear1864
