Middle Boggy Formation (Middle Pennsylvanian) Sedimentology and Sequence Stratigraphy: Implications for Arkoma Basin Tectonic Evolution

Dennis Kerr1,   Ernesto Puche2

¹University of Tulsa , ²University of Tulsa

A study of surface outcrops and subsurface well logs of the middle Boggy Formation in Eufaula Lake area indicates a previously unrecognized sequence boundary and a reversal in paleodispersal from into the Arkoma Basin for the lower Boggy (Bluejacket Sandstone) to out of the basin for middle Boggy (above the Inola Limestone). Below the sequence boundary, subunits of the lower Boggy are erosionally truncated, and above the sequence boundary middle Boggy stratigraphic units onlap the boundary. South of the city of Eufaula, middle Boggy braided fluvial deposits rest unconformably on phosphatic black shale associated with the Inola. The younger middle Boggy subunits are dominated by meandering fluvial deposits. Paleocurrent indicators related to facies consistently indicate northwest transport direction for the middle Boggy. Sandstone framework composition preliminary results indicate a contrast in provenance for the lower and middle Boggy. The lower Boggy had a mixed fine-grained sedimentary and plutonic basement source with minor contribution from metamorphic basement. Lower Boggy sandstones are sublitharenites with sparse, diverse heavy minerals. By contrast, middle Boggy sandstones are micaceous quartzarenites with very sparse, limited diversity heavy minerals. In addition, middle Boggy sandstones included recycled quartz detritus. Mineralogic maturity of middle Boggy suggests a recycled coarse sedimentary source likely influenced by intense chemical weathering. Past studies have suggested that a southern Ouachita source for clastics first appear in the basal Stuart Formation, which overlies the Boggy. Our results suggest that the Ouachitas were emergent and Arkoma Basin was over-filled by middle Boggy time.

AAPG Search and Discover Article #90097 © 2009 Tulsa Geological Society, Tulsa, Oklahoma

 

 

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