+-------------+------------------+------------------+-------------------+ |=Life Ages | =Rock Systems= | =Series of | =Chief Economic | |of the Earth=| | Rock Strata= | Products= | +-------------+------------------+------------------+-------------------+ | | |Recent, or Human. |Clay, peat, bog | | | | |iron ore, marl, | | | | |gold placers. | | |=Quaternary= | | | | |(_kwa-ter´na-ri_) |=Pleistocene= |Clay, gravel, | | |or “fourth.” Once |(_plīs´tŏ-sēn_), |gold placers. | | |supposed to be the|or “most recent.” | | |=Cenozoic= |_fourth_ sedimen- |Glacial Period. | | |(_se´nō-zō´- |tary system. Age | | | |ik_), or |of man. |=Pliocene= |Gold (in part | |“Recent | |(_plī´ō-sēn_), or |placers), coal, | |life.” | |“more recent.” |oil, gas. | | +------------------+------------------+-------------------+ |_Estimated | |=Miocene= (_mī´ō- |Silver, gold, coal,| |Age of | |sēn_), or “less |oil, gas, phosphate| |Period_, | |recent.” |rock, diatomaceous | |=3,000,000= |=Tertiary= (_ter´-| |earth. | |_years_. |shi-a-ri_), or | | | | |“third”. Once |=Oligocene= |Copper, silver. | | |supposed to be the|(_ōl´ĕ-gō-sēn_), | | | |_third_ sedimen- |or “a little more | | | |tary system, or |recent.” | | | |Age of mammals. | | | | | |=Eocene= (_ē´-ō- |Gold, zinc, lead, | | | |sēn_), or “dawn of|coal, oil, gas. | | | |recent.” | | +-------------+------------------+------------------+-------------------+ | |=Cretaceous= |{ |Coal, oil, gas, | | |(_krē-ta´-she-us_)|{ Upper. |copper, gold, china| | |or “bearing |{ |clay, fire clay, | | |chalk.” |{ Lower. |cement building | |=Mesozoic= | |{ |stone. | |(_mĕs-ō-zō´- | |{ | | |ic_), or | |{ | | |“Middle +------------------+------------------+-------------------+ |Life.” |=Jurassic= (_jȯȯ- |{ Upper. |Oil, gold. | | |ras´sik_), or like|{ | | |_Estimated |the mass of the |{ Middle. | | |Age of |Jura Mountains. |{ | | |Period_, |Age of Reptiles. |{ Lower. | | |=5,000,000= | | | | |_years_. | |{ Upper. |Salt, gypsum, a | | |=Triassic= |{ |little coal in | | |(_trĭ-ăs´ĭk_), or |{ Middle. |Virginia, copper, | | |in a triple |{ |building stone. | | |series. |{ Lower. | | +-------------+------------------+------------------+-------------------+ | | |=Permian= (_per´- |Salt and gypsum; | | | |mē-ăn_), like |some coal in | | | |those at Perm, |Eastern States. | | | |Russia. | | | | | | | | |=Carboniferous= |=Pennsylvanian=, |Coal, oil, gas, | | |(_kăr-bŏn-if´-er- |like those of |iron ore, fire | | |us_), or coal- |Pennsylvania. |clay, phosphate | | |bearing. Age of | |rock. | | |Amphibians. | | | | | | | | | | |=Mississippian=, |Oil, gas, lead, | | | |or Lower Carboni- |zinc, building | | | |ferous. |stone, cement rock.| | +------------------+------------------+-------------------+ | |=Devonian= (_de- |{ Upper. | | | |vō´ni-an_) like |{ |Gas, oil, iron ore,| | |those of Devon- |{ Middle. |phosphate rock. | |=Paleozoic= |shire, England. |{ | | |(_pāl-œ-ô- |Age of Fishes. |{ Lower. | | |zō´ic_), or +------------------+------------------+-------------------+ | “Old Life.” | |{ =Ontarian= (_on- |Iron ore, gas, | | |=Silurian= (_si- |{ tā´rē-ăn_), place|salt, gypsum, | |_Estimated |lū´ri-an_), in the|{ name. |cement rock. | |Age of |land of the |{ | | |Period_, |Silures, England. |{ =Champlainian= | | |=24,000,000= |Age of In- |{ (_shăm-plān´ē- | | |_years_. |vertebrates. |{ ăn_), place name.| | | +------------------+------------------+-------------------+ | | |{ =Cincinnatian= |Oil, gas, lead, | | |=Ordovician= (_ŏr-|{ (_sĭn-sĭn-năt´-ē-|zinc, phosphate | | |dŏ-vīsh´ăn_), a |{ ăn_), place name.|rock, manganese, | | |place name in |{ |marble. | | |Wales. |{ =Mohawkian= (_mō-| | | | |{ hŏk´ē-ăn_), place| | | | |{ name. | | | +------------------+------------------+-------------------+ | | |{ =Saratogan= |Lead, zinc, barite,| | | |{ (_săr-ă-tō´găn_),|copper. | | | |{ place name. | | | |=Cambrian= (_kam´-|{ | | | |bri-an_) from |{ =Acadian= (_ä- | | | |Cambria, the old |{ kād´ē-ăn_), place| | | |name for Wales. |{ name. | | | | |{ | | | | |{ =Georgian= (_jōr´| | | | |{ gē-ăn_), place | | | | |{ name. | | +-------------+------------------+------------------+-------------------+ | | |{ =Keweenawan=, |Copper, silver. | |=Proterozoic=| |{ (_kē´wē-năh- | | |(_prō-ter-ō- | |{ wān_), pertaining| | |zō´ik_) or | |{ to Keweenaw Pen- | | |“Former |=Algonkian= (_ăl- |{ insula, Michigan.| | |Life.” |gŏn´kē-ăn_), from |{ | | | |district of |{ =Huronian= (_hu- |Principal iron ores| |_Estimated |Algonquin |{ rō´nē-ăn,_), |of Lake Superior | |Age of |Indians, north of |{ rocks on borders |region; also | |Period_, |St. Lawrence. |{ of Lake Huron. |copper, nickel, | |=18,000,000= | |{ |silver, cobalt, | |_years_. | |{ |gold. Building | | | |{ |stone and ornamen- | | | |{ |tal stone.