Bryozoan Nodules as a Frame-Builder of Bryozoan- Microreef, Middle Miocene Sediments, Egypt

Journal Article

El-Sorogy, Abdelbaset . 2015

• المجلة \ الصحيفة: Journal of Earth Science
• رقم العدد: 2
• رقم الإصدار السنوي: 26
• الصفحات: 251–258

مستخلص المنشور

Bryozoan nodules, coralline algae, scleractinian corals and oysters form an important organic
buildup, 1.2–4.5 m thick in the Langhian-Serravaliann sediments of Egypt. Based on type, shape
and size of the substrate, bryozoan nodules take tree-like and globular morphologies. Tree-like specimens
reach 10 cm in maximum height and 3 cm in diameter, while Globular ones attain 9 cm in maximum
diameter. Most tree-like nodules are perforated with wide or narrow pores, few are
non-perforated. Globulars and few tree-like forms are with mamelon-like structures. Perforations on the
outer surfaces may indicate a symbiotic relationship between bryozoans and a live plant substrate. Nodules
from Homiera and Gharra areas of the Cairo-Suez District with wider perforations may indicate
growth in slightly lighter or turbid areas of the continental shelf than those of North Western Desert of
narrower perforations. Non-perforated nodules may assume an incrustation on ephemeral substrate.