Westward to Houston and southward to about 32° 48' on the Alabama boundary and occupying a much larger area than the other Cretaceous formations, is the Selma chalk, called "Rotten Limestone" by Hilgard; it is made up of a material of great uniformity, - a soft chalky rock, white or pale blue, composed chiefly of tenacious clay, and white carbonate of lime in minute crystals.
On the island of Andros there is an extremely fine white marl almost resembling a chalky ooze.
Therein two eggs, with white, chalky shells, are commonly laid.
It includes chalky limestones, siliceous earths, red clay, and, at the top, a layer of mudstone composed mainly of volcanic dust.
Within a recent geological period, central Aragon was undoubtedly submerged by the sea, and the parched chalky soil remains saturated with salt, while many of the smaller streams run brackish.
The Cretaceous system includes the Waipara series, a belt of chalky limestones with some phosphate beds at Clarendon in eastern Otago.
The soil varies greatly according to the district, being in some cases a rich loam, in others a chalky marl, and elsewhere showing a coating of peat.
The town lies low, flanked by two chalky eminences, called East and West Hills.
From a careful series of experiments made in the Horticultural Society's Garden at Chiswick, it was found that where the soil is loamy, or light and slightly enriched with decayed vegetable matter, the apple succeeds best on the doucin stock, and the pear on the quince; and where it is chalky it is preferable to graft the apple on the crab, and the pear on the wild pear.
For the plum on loamy soils the plum, and on chalky and light soils the almond, are the most desirable stocks, and for the cherry on loamy or light rich soils the wild cherry, and on chalk the " mahaleb " stock.
On the top is a shallow cup for the reception of the one or two eggs, which have a bluish-white shell with chalky incrustation.
The colour of mahogany is reddish brown, and in the Cuban wood the pores are often filled with a white chalky substance which is usually absent in the Honduras variety; the latter, however, may be obtained in larger sizes, and is straighter in the grain and easier to work.
Erectus is a useful forage grass on dry chalky soil.
The Southdown, from the short close pastures upon the chalky soils of the South Downs in Sussex, was formerly known as the Sussex Down.
Two chalky white or greenish eggs are laid.
The trees seemed to have flourished on neighbouring chalky heights.
We know little or nothing at present of the upland plants, or of those of dry or chalky soils.