...intrusion, some being simply micaceous, others more indurated and with the characters of mica slate and gneiss, while others again appear converted into a hard zoned rock strongly impregnated with felspar. The alteration of the rocks in this case is of very easy explanation. The grauwackc, which...

...surrounding Dartmoor have been changed," says De la Beche, " by the intrusion of granite; some being simply micaceous, others more indurated and with the characters...converted into a hard zoned rock strongly impregnated with felspar. The alteration of the rocks in this case is of very easy explanation. The greywacke, which...

...granite, says Mr. De la Beche, of Dartmoor, in Devonshire, has intruded itself into the greywacke: twisting and contorting the strata, and sending veins...gneiss, while others again appear converted into a hard-zoned rock strongly impregnated with felspar." f We learn from the investigations of M. Dufrenoy,...

...granite, says Mr. De la Beche, of Dartmoor, in Devonshire, has intruded itself into the greywacke', twisting and contorting the strata, and sending veins...gneiss, while others again appear converted into a hard-zoned rock strongly impregnated with felspar.":): We learn from the investigations of M. Dufrenoy,...

...GKANITE. 245 Mr. De la Beche, has intruded itself into the slate and slaty sandstone called grey wacke, twisting and contorting the strata, and sending veins...gneiss, while others again appear converted into a hard-zoned rock strongly impregnated with felspar." * We learn from the investigations of M. Dufrenoy,...

...Devonshire, says Mr. De la Beche, has intruded itself into the slate and slaty sandstone called greywacke, twisting and contorting the strata, and sending veins...gneiss, while others again appear converted into a hard-zoned rock strongly impregnated with felspar." * We learn from the investigations of M. Dufrenoy,...

...Devonshire, says Mr. De la Beche, has intruded itself into the slate and slaty sandstone called greywacke, twisting and contorting the strata, and sending veins...gneiss, while others again appear converted into a hard-zoned rock strongly impregnated with felspar."* We learn from the investigations of M. Dufrenoy,...

...Devonshire, says Mr. De la Bêche, has intruded itself into the slate and slaty sandstone called greywacké, twisting and contorting the strata, and sending veins...gneiss; while others again appear converted into a hard-zoned rock strongly impregnated with felspar."* We learn from the investigations of M. Dufrénoy,...

...Devonshire, says Mr. De la Beche, has intruded itself into the slate and slaty sandstone called greywacké, twisting and contorting the strata, and sending veins...gneiss, while others again appear converted into a hard-zoned rock strongly impregnated with felspar."* We learn from the investigations of M. Dufrénoy,...

...Devonshire, says Mr. De la Beche, has intruded itself into the slate and slaty sandstone called greywacké, twisting and contorting the strata, and sending veins...gneiss, while others again appear converted into a hard-zoned rock strongly impregnated with felspar."* Now the alterations above described as superinduced...