Part 8

+-------------+------------------+------------------+-------------------+ |=Life Ages | =Rock Systems= | =Series of | =Characteristic | |of the Earth=| | Rock Strata= | Rocks= | +-------------+------------------+------------------+-------------------+ | | |Recent, or Human. |Alluvium, sand, | | | | |gravel, mud, clay, | | | | |marl, loess. | | | | | | | | |=Pleistocene= |Drift, boulder | | | |(_plīs´tŏ-sēn_), |clay, gravel, | | |=Quaternary= |or “most recent.” |loess, silt, gla- | | |(_kwa-ter´na-ri_) |Glacial Period. |cial deposits and | | |or “fourth.” Once | |other formations | | |supposed to be the| |formed during | | |_fourth_ sedimen- | |glacial period. | | |tary system. Age | | | | |of man. |=Pliocene= |In East and West, | | | |(_plī´ō-sēn_), or |land deposits pre- | | | |“more recent.” |dominate. Marine | | | | |sands, clays, marls| | | | |on Atlantic and | | | | |Pacific coasts. | | | | |Igneous rocks in | | | | |West. | | +------------------+------------------+-------------------+ | | |=Miocene= (_mī´ō- |On Atlantic coast: | |=Cenozoic= | |sēn_), or “less |sand, clay, shell | |(_se´nō-zō´- | |recent.” |marl, diatomaceous | |ik_), or | | |earth. In West: | |“Recent | | |sandstone, shale, | |life.” | | |and diatomaceous | | | | |material. Extensive| |_Estimated | | |volcanic formations| |Age of | | |in Rocky Mountains | |Period_, | | |and Great Basin | |=3,000,000= | | |region. | |_years_. | | | | | | |=Oligocene= |Limestone in | | | |(_ŏl´ĕ-gō-sēn_), |Caribbean region, | | |=Tertiary= (_ter´-|or “a little more |and deposits in | | |shi-a-ri_), or |recent.” |West. Marine and | | |“third”. Once | |fresh water beds on| | |supposed to be the| |west coast. Many | | |_third_ sedimen- | |coal beds in Puget | | |tary system, or | |Sound. | | |Age of mammals. | | | | | |=Eocene= (_ē´-ō- |In Eastern States: | | | |sēn_), or “dawn of|clays, sands, | | | |recent.” |greensand marls. | | | | |In West: conglom- | | | | |erate, sandstone, | | | | |shale, diatomaceous| | | | |shale and igneous | | | | |formations are de- | | | | |veloped. Many coal | | | | |beds in Puget | | | | |Sound. Fresh water | | | | |beds in western | | | | |interior. | +-------------+------------------+------------------+-------------------+ | | |{Upper. |In East: sand, | | | |{ |clay, and greensand| | | |{ |marl. In West: | | | |{ |sandstone, shale, | | | |{ |limestone, chalk, | | | |{ |extensive coal | | |=Cretaceous= |{ |beds, various | | |(_krē-ta´-she-us_)|{ |igneous rocks. | | |or “bearing |{ | | | |chalk.” |{Lower. |Clay, sand, gravel | | | |{ |on Atlantic coast | | | |{ |and Gulf. Sedi- | | | |{ |mentary and igneous| | | |{ |rocks on west | |=Mesozoic= | |{ |coast. Some non- | |(_mĕs-ō-zō´- | |{ |marine beds in | |ic_), or | |{ |Texas. | |“Middle +------------------+------------------+-------------------+ |life.” | |{Upper. |Probably not repre-| | |=Jurassic= (_jȯȯ- |{ |sented in East. | |_Estimated |ras´sik_), or like|{ |Sandstones, lime- | |Age of |the mass of the |{Middle. |stones and shales | |Period_, |Jura Mountains. |{ |in West. Some “red | |=9,000,000= |Age of Reptiles. |{ |beds” in western | |_years_. | |{Lower. |interior. | | | | | | | | |{Upper. |In East sediments | | | |{ |formed in shallow | | | |{ |troughs between re-| | | |{ |cently formed moun-| | |=Triassic= |{ |tains. Considerable| | |(_trĭăs´ĭk_), or |{ |bodies of igneous | | |in a triple |{Middle. |rock, traps, and | | |series. |{ |other flows and | | | |{ |dikes. “Red beds” | | | |{ |in West with salt | | | |{ |and gypsum. Some | | | |{ |igneous rocks on | | | |{Lower. |west coast. | +-------------+------------------+------------------+-------------------+ | | |=Permian= (_per´- |In East fresh water| | | |mē-ăn_), like |sediments including| | | |those at Perm, |coal; in West “red | | | |Russia. |beds” probably of | | | | |continental origin.| | | | |Some marine sedi- | | | | |ments; salt and | | | | |gypsum in red beds | | | | |in Kansas. | | | | | | | |=Carboniferous= |=Pennsylvanian=, |In Eastern States | | |(_kăr-bŏn-if´-er- |like those of |grits, sandstones, | | |us_), or coal- |Pennsylvania. |shales, limestone | | |bearing. Age of | |and coal. In | | |Amphibians. | |Western States much| | | | |limestone; no coal.| | | | |Igneous rocks on | | | | |west coast. | | | | | | | | |=Mississippian=, |Limestones pre- | | | |or Lower Carboni- |dominate with sand-| | | |ferous. |stones near base | | | | |and shales near top| | | | |of series. Igneous | | | | |rocks in | | | | |California. | | +------------------+------------------+-------------------+ | |=Devonian= (_de- |{Upper. |Sedimentary rocks, | |=Paleozoic= |vō´ni-an_) like |{ |limestones, sand- | |(_pāl-æ-ô- |those of Devon- |{Middle. |stones, shales; | |zō´ic_), or |shire, England. |{ |igneous rocks in | |“Old life.” |Age of Fishes. |{Lower. |Maine, Nova Scotia,| | | |{ |and New Brunswick. | |_Estimated +------------------+------------------+-------------------+ |Age of | |{ |Sedimentary rocks | |Period_, | |{=Ontarian= (_on- |predominate; con- | |=24,000,000= |=Silurian= (_si- |{tā´rē-ăn_), place|glomerates, sand- | |_years_. |lū´ri-an_), in the|{name. |stones, shales, | | |land of the |{ |limestones, salt, | | |Silures, England. |{=Champlainian= |gypsum. Igneous | | |Age of In- |{(_shăm-plān´ē- |rocks in Nova | | |vertebrates. |{ăn_), place name.|Scotia, New Bruns- | | | |{ |wick, and Maine. | | +------------------+------------------+-------------------+ | | |{=Cincinnatian= |Chiefly limestone | | |=Ordovician= (_ŏr-|{(_sĭn-sĭn-năt´-ē-|with subordinate | | |dŏ-vīsh´ăn_), a |{ăn_), place name.|sandstone and | | |place name in | |shale. Rocks great-| | |Wales. |{=Mohawkian= (_mō-|ly folded in New | | | |{hŏk´ē-ăn_), place|York, in Taconic | | | |{name. |Mountain region. | | +------------------+------------------+-------------------+ | | |{ |Mainly sandstones | | | |{=Saratogan= |with some shales, | | | |{(_săr-ă-tō´găn_),|and in Western | | | |{place name. |States considerable| | |=Cambrian= (_kam´-|{ |limestone. At some | | |bri-an_), from |{=Acadian= (_ä- |places rocks are | | |Cambria, the old |{kād´ē-ăn_), place|changed by pres- | | |name for Wales. |{name. |sure, especially in| | | |{ |the Appalachian | | | |{=Georgian= (_jōr´|Mountains. Upper | | | |{gē-ăn_), place |Cambrian covered | | | |{name. |larger area than | | | |{ |lower Cambrian. | +-------------+------------------+------------------+-------------------+ | | |{=Keweenawan=, |A great series of | | | |{(_kē´wē-năh- |sandstones, lime- | | | |{wān_), pertaining|stones and shales, | | | |{to Keweenaw Pen- |in middle portion | | | |{insula, Michigan.|of which are many | |=Proterozoic=| |{ |enormous flows of | |(_prō-ter-ō- | |{ |lava. | |zō´ik_) or |=Algonkian= (_ăl- |{ | | |“Former |gŏn´kē-ăn_), from |{=Huronian= (_hu- |Three great series | |life.” |district of |{rō´nē-ăn_), |of sedimentary | | |Algonquin |{rocks on borders |rocks, sandstone, | |_Estimated |Indians, north of |{of Lake Huron. |shale and lime- | |Age of |St. Lawrence. |{ |stone, and iron | |Period_, | |{ |formation. Contains| |=18,000,000= | |{ |also many great | |_years_. | |{ |igneous bodies, | | | |{ |acidic and basic. | | | |{ |Lower members much | | | |{ |metamorphosed by | | | |{ |pressure. | +-------------+------------------+------------------+-------------------+ | | |{=Laurentian= |Granitic rocks and | | | |{(_law-ren´shi- |gneisses that are | | | |{an_), pertaining |believed to be | | | |{to rocks along |granitic rocks | | | |{the St. Lawrence |metamorphosed by | | | |{River. |pressure. Formerly | | | |{ |supposed to be | | | |{ |older than Keewatin| |=Archaeozoic=| |{ |and regarded as the| |(_ar´kē-o-zō´| |{ |“original crust of | |ic_), “With- | |{ |the earth.” | |out life.” |=Archean= (_är- |{ | | | |kē´-ăn_), |{=Keewatin= (_kē- |A great schist | |_Estimated |“oldest.” |{wā´tĭn_), rocks |series made up of | |Age of | |{in a district of |lava flows, tuffs, | |Period_, | |{Manitoba, Canada.|and volcanic ashes.| |=18,000,000= | |{ |With these are sub-| |_years_. | |{ |ordinate sedimenta-| | | |{ |ry rocks; sand- | | | |{ |stone, shale, lime-| | | |{ |stone, and iron ore| | | |{ |formations nearly | | | |{ |everywhere greatly | | | |{ |metamorphosed by | | | |{ |pressure. Includes | | | |{ |the oldest rocks | | | |{ |known. | +-------------+------------------+------------------+-------------------+