Translator Disclaimer
1 July 2010 ENVIRONMENTAL CONTROLS ON SHELL-RICH FACIES IN TROPICAL LACUSTRINE RIFTS: A VIEW FROM LAKE TANGANYIKA'S LITTORAL
MICHAEL M. MCGLUE, MICHAEL J. SOREGHAN, ELLINOR MICHEL, JONATHAN A. TODD, ANDREW S. COHEN, JOHN MISCHLER, CHRISTINE S. O'CONNELL, OCEANA S. CASTAÑEDA, RICHARD J. HARTWELL, KIRAM E. LEZZAR, HUDSON H. NKOTAGU
Author Affiliations +
Abstract

Lake Tanganyika, the world's largest tropical rift lake, is unique among its counterparts in East Africa for the remarkable diversity of mollusk-rich sediments in its littoral zone. Molluscan shell beds are, however, a common feature of ancient lacustrine rift deposits and thus a better understanding of their spatial and temporal development is important. Targeted surveys across the littoral region of the Kigoma Basin reveal three surficial shell-rich facies that differ widely in depositional style and geometry. A unifying characteristic of these deposits is the volume of shells of Neothauma tanganyicense, a large, viviparous gastropod endemic to the lake. Reservoir-corrected radiocarbon dating indicates that Neothauma deposits in these surficial sediments are time averaged over at least the last ∼1600 calendar years BP. Preservation of fossil Neothauma shells in the littoral zone depends on both environmental conditions and on post-mortem shell modifications. Interaction between shells and mobile siliciclastic grains, facilitated by wave action and storms, represents a particularly destructive taphonomic process in the study area. Rank scoring of damage to Neothauma suggests that stromatolitic encrustations or early calcite coatings may help mitigate shell destruction caused by hydraulic fragmentation and abrasion. Persistence of Neothauma in littoral beds has important implications for the structuring of specialized communities of shallow-water benthos, as well as for improving analog models for hydrocarbon reservoirs in lacustrine carbonates.

MICHAEL M. MCGLUE, MICHAEL J. SOREGHAN, ELLINOR MICHEL, JONATHAN A. TODD, ANDREW S. COHEN, JOHN MISCHLER, CHRISTINE S. O'CONNELL, OCEANA S. CASTAÑEDA, RICHARD J. HARTWELL, KIRAM E. LEZZAR, and HUDSON H. NKOTAGU "ENVIRONMENTAL CONTROLS ON SHELL-RICH FACIES IN TROPICAL LACUSTRINE RIFTS: A VIEW FROM LAKE TANGANYIKA'S LITTORAL," Palaios 25(7), 426-438, (1 July 2010). https://doi.org/10.2110/palo.2009.p09-160r
Accepted: 1 April 2010; Published: 1 July 2010
JOURNAL ARTICLE
13 PAGES

This article is only available to subscribers.
It is not available for individual sale.
+ SAVE TO MY LIBRARY

Share
SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top