492 



SCIENCE 



[N. S. Vol. LI. No. 1324 



after a period of base leveling, when weathering 

 had been proceeding a long time. This long-eon- 

 tinued weathering is thought to have furnished 

 colloidal silica, iron, potash and alumina to the 

 sea water, where through the action of the saline 

 matter in the sea water the silica and alumina were 

 precipitated, while the iron was thrown down by 

 oxidation. These colloids mlingled in varying 

 amounts and then aibsorbed the potash from the 

 sea water, thus forming glauconite. 



A Mauch Chunlc Island in the Mississippian Seas 

 of eastern Keiitiichy: Willard R. Jillson, state 

 geologist of Kentucky, Frankfort, Kentucky. In 

 th© eastern Kentucky coal fields on the divide be- 

 tween the Licking Eliver and the Levisa Fork of the 

 Big Sandy River, there exists an elongated struc- 

 turally elevated area of ibeitween 700 and 1,000 

 square miles. This structural high has been called 

 the Paint Creek uplift and is located so as to 

 overlap parts of Magoffin, Morgan, Elliott, Law- 

 rence, Johnson and Floyd counties. The Paint 

 Creek upliit has a sight east of north major axis 

 as mapped structurally on the Pottsvdlle Fire-Clay 

 coal. The normal dip at the surface is slightly to 

 the south of east. The Paint Creek uplift cul- 

 minates in two pinnacles, the Paint Creek Dome 

 and the Laurel Creek Dome. There exists a 

 maximum reversal of a/bout 250 feet. The con- 

 siderable amount of oil and gas prospecting drill- 

 ing on these structures during the past two years 

 has resulted in defining two pronounced oil and 

 gas fields, one on either dome. Production is se- 

 cured principally from the Weir sand which corre- 

 lates with the Cuyahoga sandstone in the Waverley 

 group toward the base of the Mississippian system. 

 An examination of the well records of recent drill- 

 ings in this locality shows an increasing interval 

 between the Fire Clay coal of the Pottsville and 

 the Big Lime (St. Genevieve-St. Louis) of the 

 Mississipptian, as one proceeds away from the 

 highest structural points. 



A summary conception of the structure of the 

 Weir sand shows it to be much more steeply tilted 

 than the persistent coals of the surface Pottsville. 

 The absence of expected thicknesses of the Mauch 

 Chunk on the top of this structure and the thick- 

 ness of the Pottsville and Mauch Chunk on the 

 ^des coupled with the steeper inclinations of the 

 Weir sands suggests an anticlinal island in the 

 Mississippian seas at this point during the latter 

 part of the Mauch Chunk period with unconsoli- 

 dated Mauch Chunk sediments, subjected to sub- 

 aerial erosion. Following early Pottsville times, 



quiescent subsidence is conceived to have taken 

 place, which was followed during the time of the 

 Appalachian overthrusts by folding and faulting 

 along, and transverse to, the major axis of the 

 original Mississippian anticline. 



A Geological Section from St. Louis to Kansas 

 City: E. B. Branson. 



The Pre-Moenkopi unconformity of the Colorado 

 plateau: C. L. Dake. The area over which the 

 unconformity was studlied embraces the region 

 from the Zuni uplift in New Mexico west to the 

 Little Colorado River in Arizona, and northwest to 

 the vicinity of the Henry Mountains in Utah. Sud- 

 den changes in the thickness of the Moenkopi 

 ajuounting to two hundred feet or more, in short 

 distances, show local erosion of at least that mag- 

 nitude during the pre-Moenkopi erosion interval. 

 Data gathered by the writer tend strongly to con- 

 firm a hypothesis advanced by Cross that the Per- 

 mian rests on progressively younger beds as the 

 unconformity ds traced westwards, the erosion 

 amounting perhaps to all the Kaibalb, the Coconino 

 and the Supai formations. In other words the 

 Moenkopi Red beds rest on the Kaibab formation 

 in the area about the Grand Canyon and probably 

 west of the Henry Mountains, while farther east 

 they rest on the Goodridge (correlated by Girty 

 ,with the Redwall) dn the San Juan region, and 

 probably on equivalent beds near Moab. This 

 would involve the erosion of approximately two 

 thousand feet of Pennsylvanian strata in the east- 

 ern portion of the area under discussion, the equiv- 

 alents of which are present farther west. This 

 conclusion, lif true, would place the pre-Moenkopl 

 unconformity among those of larger significance in 

 geologic history. 



Notes on the geology of the Cove areas of east 

 Tennesese: C. H. Gordon, University of Tennessee, 

 Knoxville. Within the western foothills of the 

 Unaka or Great Smoky Mountains in east Tennes- 

 see are a number of firregular open valleys known 

 locally as ' ' coves. " The largest of these is 

 Tuokeleeehe Cove on Little River. Wear Cove to 

 the northeast and Cades Cove on the southwest are 

 about half as large. The coves are underlaid by 

 the Knox dolomite uplifted in broad irregular 

 domes with the overlying Wilhite slates outcrop- 

 ping in broad irregular bands around them. The 

 more fertile soils of the coves early attracted 

 settlers and each is now the locus of a prosperous 

 settlement. This and the region to the southwest 

 is the typical region of SafEord's Ocoee rocks con- 

 sisting of sandstones, conglomerates and slates 



