BEMBRIDGE BEDS

bembridge beds, in geology, strata forming part of the fluvio-marine series of deposits of oligocene age, in the isle of wight and hampshire, england. they lie between the hamstead beds above and the osborne beds below. the bembridge marls, freshwater, estuarine and marine clays and marls (70-120 ft.) rest upon the bembridge limestone, a freshwater pool deposit (15-25 ft.), with large land snails (_amphidromus_ and _helices_), freshwater snails (_planorbis, limnaea_), and the fruits of _chara_. the marls contain, besides the freshwater _limnaea_ and _unio_, such forms as _meretrix, ostrea_ and _melanopsis_. a thin calcareous sandy layer in this division has yielded the remains of many insects and fossil leaves. see "geology of the isle of wight," _mem. geol. survey_, 2nd ed. 1889.