The middle Eocene Seeb Formation represents deposition on one of the earliest ''modern'' style carbonate platforms, i.e., influenced by seagrasses and mangroves, and presents an opportunity to explore controls on the preservation of Cenozoic carbonate lithofacies. In the study area, the Seeb Fm. is dominated by an anomalously thick (approximately 250 m) and uniform package of shallow marine, platform-interior sediments. These nodular, indistinctly bedded shallow-subtidal sediments display no evidence for relative sea-level change (such as subaerial exposure features), and lack the shallowingupwards cyclothems that have characterized carbonate sediments deposited in platform-interior settings throughout much of the rock record (particularly during greenhouse periods). We conclude that this is a consequence of thorough bio-retexturing of the sediment by burrowing organisms and the roots of marine vegetation, which destroyed primary fabrics, facies diversity, evidence for cyclicity, and '