الفهرس 
Diatoms as unique microorganisms
SYSTEMATIC PALEONTOLOGYOnly 14 pages are availabe for public view
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Abstract
The present work is concerned with the detailed study of fossil diatom assemblages that recognized from the recent and late Holocene sediments of the Manzala Lake. The study is based on 21 surface samples gathered from the bottom sediments of the lake and 120 subsurface samples obtained from six short cores recovered from the Lake at depth interval varying from 85 cm to 110 cm. The sites of the studied cores and surface samples were selected to cover various environmental variables that may be important to water qualit(e.g. from lesser to more highly polluted sites).The surface sediment samples were taken from the upper 5 cm of the bottom sediments using a Van Veen
grab sampler. The cores were taken using a small local made gravity corer on board of a large boat. The core samples were longitudinally sub sectioned at
5 cm intervals. The sediment samples were dried and weighed to determine
their total dry weight. Lithologically,the investigated surface sediments are composed mainly of dark blue to greenish gray mud and sandy mud with common mollusk shells in some localities. The core samples are consisted mainly of dark greenish-gray to olive-gray and dark gray silty clays rich in organic matter with common mollusc shells at the topmost part 20-30 cm. The rest of the section in most cores is composed mainly of dark gray silty mud with few mollusca shell fragments and sometimes sandy layers interbeds.