Document Type

Article

Publication Date

2-1990

Publication Title

PALAIOS

Keywords

Lithoherms, Florida

ISSN

0883-1351

Volume

5

Issue/No.

1

First Page

15

Last Page

33

Abstract

Elongated carbonate mounds ("lithoherms") oriented parallel to prevailing northerly bottom currents at moderate depths (500-700 m) along the western margin of the Little Bahama Bank exhibit a consistent faunal zonation characterized by attached, suspension-feeding invertebrates. The four most abundant macroepibenthic groups (alcyonarians, crinoids, sponges and stylasterid hydrocorals) dominate all hard substrates examined except upcurrent ends and crests of lithoherms. We recognize three faunal zones on these mounds: a Coral Zone (Lophelia prolifera) restricted to the upcurrent end; a Zoanthid Zone (?Gerardia sp.) along upcurrent crests, and a Crinoid/Alcyonarian Zone along lithoherm flanks and downstream crests. Taxa characteristic of the latter also occur on surrounding, low-relief hardgrounds but are accompanied by additional taxa usually absent from mounds. Intervening unconsolidated sediment is largely barren. Biozonation appears chiefly dependent on current flow regime and secondarily on substrate. The observed zonation occurs over a much smaller areal scale than previously reported for deep-water (non-hydrothermal) hard bottoms. Abrupt, small-scale faunal zonation can no longer automatically be considered as evidence of a shallow-water environment in interpreting fossil assemblages.

Comments

©1990, SEPM

Additional Comments

NSF grant #: OCE-8315203; National Cancer Institute contract #: N01-CM-67919

DOI

http://www.jstor.org/stable/3514994