Sequence stratigraphy and depositional environment of the Cambro-Ordovician bliss sandstone, Franklin mountains of El Paso, Texas
Abstract
The Bliss Formation formed along the Southwestern continental shelf of Laurentia during the Late Cambrian and records the craton]wide Cambrian transgression previously described by Sloss. This study divides the Bliss into five facies associations which were used to determine the depositional environments: 1) The Basal Transgressive Lag (BTL) was interpreted to be a high energy fluvial deposit the top of which has been reworked and winnowed during transgression. 2) The Lower Cyclic Sandstones and Silty Sandstones (LCSS) were interpreted to be be tidal delta or tidal estuary deposits composed of delta deposits, slackwater deposits, and tidal dunes within tidal channels. 3) The Glauconitic Cyclic Sandstones (GCSS) were also interpreted to be intertidal with tidal estuary deposits, tidal channel deposits, and lightly winnowed mixed flats. 4) The Hematitic Cross-bedded Sandstones (HCSS) were interpreted to be intertidal with the exception of the northernmost section, measured section (TRSM) where the depositional environment was interpreted to be fluvial. 5) The Cross]bedded Transition Sandstones (CTS) were interpreted to be a high]energy prograding tidal delta to shallow marine deposit. At TRSM the energy was higher and this was interpreted to be a braided stream deposit. By analyzing six measured sections, it was determined that the Bliss Sandstone is composed of seven systems tracts: LST1, HST1, HST2, TST3, TST4, HST4, and TST5. Together these progradational and retrogradational sequences record an overall retrogradation of the shoreline from shallow intertidal/supratidal to intertidal to a shallow intertidal environment. The influence of a PreCambrian topographic high can be seen in the increase in grain size, and decrease in overall energy of deposition from North to South.
Subject Area
Geology
Recommended Citation
Chenoweth, Drew, "Sequence stratigraphy and depositional environment of the Cambro-Ordovician bliss sandstone, Franklin mountains of El Paso, Texas" (2015). ETD Collection for University of Texas, El Paso. AAI1592352.
https://scholarworks.utep.edu/dissertations/AAI1592352