Parting lineation, a term used to describe linear irregularities of low relief on bedding surfaces, is common in laminated sandstones. Its widespread occurrence and value in determining sediment transport directions makes it an important primary sedimentary structure. The data presented here show that parting lineation is related to an internal rock fabric. Thin-section data on quartz-grain orientation, summed in 10 degrees -class histograms, show that approximately 2/3 to 3/4 of grain long axes fall within 40 degrees of the parting lineation direction. The parallelism of grains to parting lineation is strikingly displayed in the Oakville (Miocene) Formation in Fayette County, Texas.

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