A FORTRAN IV program for comparing ranking algorithms in quantitative biostratigraphy

Volatile fatty acids (VFAs) are key intermediates in the anaerobic mineralization of organic matter in marine sediments. We studied the role of VFAs in the carbon and energy turnover in the sulfate reduction zone of sediments from the sub-arctic Godthabsfjord (SW Greenland) and the adjacent continental shelf in the NE Labrador Sea. VFA porewater concentrations were measured by a new two-dimensional ion chromatography-mass spectrometry method that enabled the direct analysis of VFAs without sample pretreatment. VFA concentrations were low and surprisingly constant (4-6 µmol L-1 for formate and acetate, and 0.5 µmol L-1 for propionate) throughout the sulfate reduction zone. Hence, VFAs are turned over while maintaining a stable concentration that is suggested to be under a strong microbial control. Estimated mean diffusion times of acetate between neighboring cells were <1 second, whereas VFA turnover times increased from several hours at the sediment surface to several years at the bottom of the sulfate reduction zone. Thus, diffusion was not limiting the VFA turnover. Despite constant VFA concentrations, the Gibbs energies (Gr) of VFA-dependent sulfate reduction decreased downcore, from -28 to -16 kJ (mol formate)-1, -68 to -31 kJ (mol acetate)-1, and -124 to -65 kJ (mol propionate)-1. Thus, Gr is

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Formate, acetate, and propionate as substrates for sulfate reduction in sub-arctic sediments of Southwest Greenland.

Multivariate analysis of stratigraphic data in geology: A review

The biostratigraphic utility of Permo-Carboniferous Ostracoda in Central and North-Central Texas is demonstrated by the establishment of six new interval-zones: the Bairdia whitesidei, Kegelites dattonensis, Bairdiacypris acetalata, Waylandella spinosa, Cryptobairdiaforakerensis, and Kindlella aff. K fissiloba zones. All of these zones have good or adequate reliability in offshore, very shallow marine, and (except K fissiloba) deltaic paleoenvironments. The species defining and characterizing these zones have good to high scores on a proposed Index of Biostratigraphic Utility, which measures vertical stratigraphic range, facies independence, biostratigraphic constancy, and ease of recognition of the species. Stratigraphic ranges and position on an independently derived coenocline are presented for 226 species.

Ostracode biostratigraphy of the Permo-Carboniferous of central and north-central Texas; Part II; Ostracode zonation

Steven A. Millendorf

Papers

A comparison of methods for the quantification of assemblage zones

Methods for the quantification of assemblage zones based on multivariate analysis of weighted and unweighted data

Biostratigraphic correlation within IGCP Project 148

FORTRAN program for lateral tracing of time-stratigraphic units based on faunal assemblage zones

A FORTRAN program for calculating binary similarity coefficients