White Cliffs Research Articles

Correlation of Pecan Gap Chalk in Texas

This paper presents the surface mapping of the Pecan Gap chalk from White Cliffs, Arkansas, across northeast Texas to the type locality of the Pecan Gap chalk in Delta County, then southward through Farmersville in Collin County, Rockwall in Rockwall County, Marlin and Lott in Falls County, Rogers in Bell County, Taylor in Williamson County, and into the Anacacho limestone as it occurs west of San Antonio. The Pecan Gap chalk is divided into three paleontological zones, Flabellammina compressa zone (basal), Diploschiza cretacea zone (middle zone), and Bolivina incrassata zone (upper) by means of the microfauna. These faunal zones reveal the fact that the variation in the width of outcrop of the chalk in northeast Texas is due to an unconformity at the base of the chalk ac oss Hunt, Delta, and western Red River counties and to a progressive overlap from Arkansas to Hunt County, where the upper Taylor clays rest unconformably on progressively older beds toward the west. Due to this overlap cutting out the upper chalk zone and the unconformity of the lower zone, the width of outcrop is very narrow in Delta County and western Red River County. The chalk exposed at the type locality at Pecan Gap, Delta County, is equivalent to the lower 50 feet of the chalk at White Cliffs, Arkansas. A subsurface section is given in which the Pecan Gap chalk is shown as a continuous chalk deposited east of the area where on the surface it is apparently missing due to some possible structural features, probably faulting.

The Age and Correlation of the Chalk at White Cliffs, Arkansas, with Notes on the Subsurface Correlations of Northeast Texas

The micro-fauna found in the chalk at White Cliffs, Sevier County, Arkansas, in the chalk at Rocky Comfort, Little River County, Arkansas, in the chalk at Clarksville, Red River County, Texas, and in the Pecan Gap chalk of Texas is the same and is Upper Taylor in age. Neither the Austin chalk nor Stephenson's Annona tongue of the Austin are present on the surface in northeast Texas east of Lamar County and in the wells east of Lamar and Hopkins counties. The sands which occur in the wells in northeast Texas below the Austin chalk and the Brownstown formation and which commonly have been called are Veatch's sub-Clarksville sands and are Upper Eagle Ford in age. The true Blossom sands, which are exposed at Blossom and Paris, Texas, are equivalent to the upper part of the Austin chalk.

Implements from Beer Head, S.E. Devon

These implements and flakes were collected during the past two years from the ploughed fields of Beer Head and the immediate vicinity.The white cliffs at Beer Head, S.E. Devon, are the last of the Chalk Cliffs to westward on the South Coast, but cretaceous beds appear inland further west at Haldon and Bovey Tracy.The cliff section shows greensand at the base, and chalk, with a thin capping of “clay with flints and chert,” above.The highest point of the Head is 475 ft. O.D. Early in last century gun-flints were made on this site. Occasional flakes from this factory are met with and are easily distinguished by their dull surface. The fields in which the implements were found are near the coastguard station, and from about 200 to 600 yards from the cliffs.

Opal pseudomorphs from White Cliffs, New South Wales

Opal pseudomorphs from White Cliffs, New South Wales

A second sauropterygian converted into opal, from the Upper Cretaceous of White Cliffs, New South Wales. With indications of ichthyopterygians at the same locality

A second sauropterygian converted into opal, from the Upper Cretaceous of White Cliffs, New South Wales. With indications of ichthyopterygians at the same locality

Mineralogical notes. 1. Precious opal from White Cliffs, N.S.W. 2. Basic sulphate of iron from Mount Morgan

1.Precious opal from White Cliffs, NSW. On examining a cut and polished specimen of a fossil-bearing ferruginous sandstone boulder from White Cliffs, N .S. Wales, I was struck by the appearance of the precious opal which had replaced the carbonate of lime of the shells. The rock is permeated with the opal, and particularly when polished has a very beautiful appearance. The minute surfaces in the interior of the opal which produce the play of color; when viewed with a lens, appear to be quite flat and terminated by perfectly straight edges often parallel.

The Light of Planets

A FEW facts relative to this subject may be interesting. At Plymouth on August 12, about 9 o'clock, favoured with a beautifully clear horizon, the brilliancy of Mars was so great that it cast a distinctly black shadow on a piece of white paper from an ordinary walking stick held at a distance of 4½ inches; the outline of the hand, under the same conditions, was also easily perceptible. A faint, yet decided, darkening of the white cliffs of the shore was caused by a person standing upright—the slope being about 45°. The point of observation was at the extreme north-west of the Sound, and the splendour of the planet's light reflected from three or four miles of water is perhaps unrivalled.