NJDEP - NJGS - First Annual Report of the Geological Survey of the ...

10• amino into the causes of these changes, and chemistry revealsto us the laws by which they are governed. It has been saidby Bischof_4. the celebrated chemical geolo_st, that our earth_as far as we know it_ is a'grcat chemical laboratory, in whichsinc_ the period of its creation uninterrupted chemical processeshave been in operation, and will continue so long as itdescribes its course around the sun. The soil, the atmosphere,animals, and plants, arc constantly undergoing changes ; andeach performs its part in the great and uninterrupted circle oftransmutations.:Rocks arc composed of one or more distinct substancescalled simple minerals, such as quartz (silica), feldspar: mica_hornblende, carbonate of lime, tale, oxide of iron, &c. Thesesimple minerals are composed of elementary substances 2such"as oxygen, hydrogen_ carbon, silioium_ aluminum: potassium,sodium, calcium_ &c., which uniting together in twos form binarycompounds ; and it is in this latter state that they occurin minerals.• The most common binary compounds are silica, composedof oxygen and silicium; alumina_ of oxygen and aluminum;llme, of oxygen and calcium ; potash_ of oxygen and potassium,&c.Reeks are sometimes classified according to the prcdomi-* _ nancc of some one of the above bilmry coinpounds---as a siliciouSor arenaceous rock: one in which quartz predominates;an argilIasoous rock, one in which alumina or clay predomi-0nares; a calcareous rock, one of which lime is the principalconstituent; and a carbonaccous rock, one in which carbonprevails.Almost all the changes that take'place in the rocks andmaterials, organic or inorganic, which constitute the crust o_the oarth_ or grow upon its surface, have their origin in thetransformations of the simple elementary bodies. Having aknowledge of the laws by which these transformations aregoverned, we are able to apply them to the various usefulpurposes of life.* BiBehof'BGeologic--_IntroduetloD.NEW JERSEY GEOLOGICAL SURVEY