ABSTRACT

Sabine Lake, a lake estuary, and the adjacent parts of the Gulf of Mexico, a nearshore neritic environment, were cored and clam-shell sampled to determine if certain physical characteristics of their sediments could be used to differentiate between the two sedimentary environments. Megascopically, in the wet state, the sediments of the two environments appear mainly as grayish to blackish, very fine sandy and silty mud or silty and clayey mud. Some very fine sand and fine sand occur in the northern part of Sabine Lake; very fine sand also occurs along the western part of the Gulf of Mexico shoreline. The sediments of the two environments are usually soft with a high water content and contain variable amounts of shell and plant materials. In the dry state, megascopically, the sediments are seen to be sand, silt or clay, or admixtures of these types and exhibit lighter shades of gray or black color.

Analysis of laboratory data shows that the dominant sedimentary type in the two environments, based on mean grain size, is silt with the secondary occurrence of very fine sand and fine sand. Poor sorting is usually characteristic of the sediments of both environments. Comparison of all data indicates that the described sedimentary characteristics would make poor criteria in differentiating between the two sedimentary environments.