The Geology of East Texas (Volume 1869) (Paperback)

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: EVENTS AT CLOSE OF COMANCHEAN While there is little evidence of deformation by faulting or folding in the Red river area at the close of the Comanchean, erosion was somewhat active and unconformities occur between the upper Denison beds, comprising the Mainstreet limestone and Grayson marls, and the succeeding Woodbine. This unconformity is clearly shown on the south side of Cedar Mills where the Buda has been entirely removed in places and,soft false- bedded sandstone of the Woodbine is in direct contact with the Arietina limestone. The basal clays of the Woodbine are present only occasionally and occur as thin wedges or lenticular masses. At other places the clays seem to lie upon the Buda blue limestone with perfect conformity. 9 While the erosion of the Lower Cretaceous of northeastern Texas was not extensive and while there may be in places apparent conformity between the Grayson marls and the basal elays and sands of the Woodbine in the Red river region, and the beds show but little evidence of discontinuity of deposition, the fact that there was a long interval of time between the last deposition of the Comanchean and the beginning of the Upper Cretaceous is clearly brought out in their relations as seen south of the Brazos. Here the Woodbine is absent and the Eagle Ford rests directly upon the Buda limestone and this condition continues through the whole sweep of the contact between Waco and Del Rio. They appear conformable everywhere, and yet we know that between the two we had the deposition of the Woodbine. In this area since no erosive action is discernible it is probable that during the interval between the deposition of the Buda and the Eagle Ford the former must have remained very near the water level if not below its surface, since even where very long contac...