Factors Affecting the Horizontal Distribution of Vertical Worm Tubes in the Thorold Sandstone

Abstract

<p> 101 samples of Thorold sandstone were collected from 12 geographically distinct regions along the Niagara Escarpment. The average number of vertical worm tubes in each region was determined as was clay content, organic matter, burrow diameter, interburrow distance, mean grain size, sorting, quartz proportion, distance from shore, porosity, and the sandstone/shale ratio. Stepwise linear regression and principal component analysis were used to investigate relationships between the variables. The number of worm tubes can be predicted by clay content, organic matter, distance from the shore, and porosity, a model which explains 62% of the observed variation. All 11 variables accounted for 99. 9% of the variation. Distance from shore can be predicted by organic matter, burrow diameter, mean grain size, and the sandstone/shale ratio, a model which explains 94% of the variation. All 11 variables accounted for 99.9% of the variation. Organisms living in the Thorold evidently reacted to environmental parameters in a similar fashion to modern tidal flat organisms.</p>