Field Notebook: Texas 1957a
Page 246
Image from the Biodiversity Heritage Library. Contributed by Yale Peabody Museum of Natural History. | www.biodiversitylibrary.org
Transcription
PG. 116 The Kings did not recognize the complicated structure of the Gap Tank area. I believe this #4 and #5 Gaptank limestone are the same bed, faulted into 2 portions. The N75-74°W faults do this, and the N-S faults tend to make the units appear thicker than they are normally. The conglomerate in the eastern most “upper” Wolfcamp contains Tenus (+Haymond) and Dimple, the Dimple in very dark limestone, the Tenus and Haymond are quartzite. The massive limestone member of the Wolfcamp seems to grade laterally into bed 3, section 17, but faulting may make the picture more complicated. Fossils look like the only answer to the question of just were to place there “upper” Wolfcamp beds in Section 17. The conglomerate would suggest it should all be called Hess, but the lithology is similar to the upper Wolfcamp. The fossils suggest an environment similar to the Uddenites interval. These beds are slightly more coarse than the type section of Wolfcamp, but PG. 117 we are about 12 miles? away too - There is no typical conglomerate of the Hess before we get into the silty quartz Hess beds here. Problems! It will pay to investigate the outcrops in the Canyon south of the Allison Ranch. The “Wolfcamp” may be exposed there, but I really wonder! PG. 118 7/19/57 Mr. Moore wasn’t at home (Ranch); lives in Midland. Decie Ranch The conglomerate lithology C.O.D. pointed out as Wolfcamp pinch the shale interval out to the southwest. The biohermal horizons Jarvey mentioned near the road, I believe are southwest extensions of the lower Hess ledge. The lower Hess ledge 1/2 mile northeast of the first stop contain “Wolfcamp” lith conglomerate high into the unit. The lower Hess ledge is in beds of 1’ to 3’ limestone at this southwest locality but the lower beds become massive to the northeast and the upper limestone of this interval gradual thin out within 1.5 miles to the northeast. The conglomerates below look like those {note: illustration followed} within the Hess (lower) ledge. At this southwest locality I believe Jarvis has mistaken the upper Hess ledge for the lower Hess ledge. PG. 119 Collection 7/19/57/1 - a limestone cobble in the Wolfcamp conglomerate. From a free back, but apparently from lower 1/2 of exposed conglomerate section about halfway between Wind Mill and stop 1. PG. 120 7/20/57