Exploration of the Relationship Between Microbial Dendritic Shrub Structures and Formation of Aragonitic Botryoidal Cement
Testa, Maurice Philip
AdvisorKirkland, Brenda L.
CommitteeSchmitz, Darrel W.
Clary, Renee M.
The objective of this project was to test the hypothesis that micritic, microbial, dendritic shrub structures transition into aragonite botryoids by serving as an organic substrate that promotes the initiation of aragonite crystal precipitation. Samples for this study were taken from three sources: 1) a stalactite found in the Lighthouse Reef Blue Hole, Belize; 2) aragonite botryoids in the reef framework of the Permian Capitan Formation and 3) the Lower Permian Laborcita Formation found in the Sacramento Mountains, south-central New Mexico. Samples studied in thin section and with scanning electron microscopy (SEM) showed dendritic micrite within botryoids and spheroidal shapes associated with aragonite. Precipitation experiments were conducted to grow calcite crystals with organic molecules in solution. The textures formed were very similar to those found at the three sample sites. Despite the similarity, all evidence of an organic substrate promoting precipitation remains circumstantial and therefore inconclusive.