Arrowheads made from white, gray, pink, and black chert. (Courtesy of Mr. A. A. Jeffrey, Columbia, Mo.)
Sedimentary rocks are those whose particles settled down through the air or water to form rocks in layers or beds; hence layered, bedded, or so-called stratified rocks are sedimentary rocks. For instance, the sand and mud settling out of the Gulf of Mexico (or ocean) after being brought in by the Mississippi River is on its way toward becoming sandstone and shale. Limestone is forming off the coast of Florida now. All of these rocks are accumulating in layers. Where one sees regularly-layered or stratified rocks in streams, road cuts, quarries, bluffs or hillsides, he expects them to be sedimentary rocks. The sedimentary rocks that have been described herein include:
Diaspore and Burley clay
Igneous rocks are those which solidified from a hot liquid which was either forced into older surrounding rocks (intrusive) or discharged on the earth’s surface as a lava flow or products from a volcano (extrusive).
The examples given below illustrate the two types. Everyone knows about the extrusive forms from accounts of present-day volcanoes and occasional lava flows, like those of Vesuvius, Paricutin, and Mauna Loa. An intrusion was injected beneath the Yellowstone Park area years ago, and its heat, with steam and gases, is contributing to the unusual natural features which are found in the park and which make it famous.
Igneous rocks in Missouri are:
Metamorphic rocks are rocks which have been changed through the effects of tremendous pressure (enough to raise mountains) and high temperature while in the solid state. In most cases a banded rock results. The metamorphic rocks mentioned in this booklet are:
No doubt it has become apparent to the reader that rocks ordinarily occur in great quantities, that they are composed of multitudes of grains (mineral grains), and that their properties and compositions vary with the different minerals which are present in the grains of the rock. A rock can, therefore, be different from a mineral. In fact, a rock may be defined as “an aggregate of mineral particles,” or more broadly “a typical part of the earth.” To focus closer attention on minerals we may discuss them for their own sake below.
MINERALS OF MISSOURI
A mineral is characterized by a constancy of composition and of properties which sets it apart from rocks which vary widely. Minerals may be metallic, like pyrite, or non-metallic, like barite; they may be ore, like galena, or rock-forming, like quartz or feldspar; they may show crystal faces, or they may be fragments with rounded or broken surfaces. A favored definition teaches that “a mineral is a naturally occurring, inorganic substance having a definite chemical composition and definite physical properties, within limits.” The Missouri minerals listed herein include:
GEOLOGIC VALUES
Although the emphasis in this pamphlet has been on the recognition of Missouri rocks and minerals, it is not out of order to consider the broad values that they contribute to our civilization. Their use as building materials has been noted, but it should be further recognized that as our timber is being rapidly depleted more and more structures will be built out of earth materials. Missouri possesses a wealth of beautiful limestone that is serviceable and readily quarried. Where limestone is not near, there is usually shale or glacial clay which can be used in the manufacture of brick and tile. Permanency will be the keynote of the rock and ceramic structures. Gravel and sand are abundant in Missouri for concrete and other varied uses.
The soil is Missouri’s most valuable earth material. Hundreds to thousands of years of normal weathering are required to develop the rocks and minerals and texture of the inorganic fraction of the soil. We should preserve it and prevent disastrous soil erosion.
Aside from these more tangible values, a fascinating and instructive hobby can be made of collecting, arranging, and studying rocks and minerals. One gains a fuller understanding and appreciation of nature from their study. The orderliness, constancy, and interrelation within the rock and mineral “world” is a restful contrast to the one which man often keeps in turmoil. The beauty of a glistening crystal or a polished mineral or stone is as inspiring as a lovely flower, yet it lasts and lasts through centuries, a veritable “rock of ages.”
Suggested Collateral Reading Material
Books on Rocks and Minerals
How to Know the Minerals and Rocks, by Pearl; publisher, McGraw-Hill Book Co., New York.
A Field Guide to Rocks and Minerals, by Pough; publisher, Houghton, Mifflin Co., Boston.
Gemstones and Minerals: How and Where To Find Them, by Sinkankas; publisher, Van Nostrand, Princeton, New Jersey.
Look for paper back editions of these and other books which may be widely available.
Fossils
The Common Fossils of Missouri, by A. G. Unklesbay, Missouri Handbook No. 4.
Magazines on Rocks, Minerals, and Fossils
Rocks and Minerals, Box, 29, Peekskill, N.Y.
Gems and Minerals, P.O. Box 687, Mentone, Calif.
The Mineralogist, P.O. Box 808, Mentone, Calif.
American Mineralogist, technical official publication of the American Mineralogical Society, Ann Arbor, Michigan, editorial office, Dept. of Mineralogy, University of Michigan.
Books on Mineralogy and Rocks (Technical)
Dana’s Manual of Mineralogy, by Hurlbut; publisher, John Wiley & Sons, New York.
Dana’s Textbook of Mineralogy, by Ford; publisher, John Wiley & Sons, New York.
Mineralogy, by Berry and Mason; publisher, Freeman & Co., San Francisco.
Rocks and Rock Minerals, by Knopf; publisher John Wiley & Sons, New York.
Guide to the Study of Rocks, by Spock; publisher, Harper & Co., New York.
Books on General Geology
Introduction to Geology, by Branson, Tarr, and Keller; publisher, McGraw-Hill Book Co., New York City.
Introduction to College Geology, by Holmes; publisher, Macmillan, New York.
Books on Physical Geology
Geology, by Emmons, Thiel, Stauffer and Allison; publisher McGraw-Hill Book Co., New York.
Principles of Geology, by Gilluly, Woodford, and Waters; publisher, Freeman & Co., San Francisco.
Physical Geology, by Leet and Judson; publisher, Prentice-Hall & Co., New York.
Books on Historical Geology
The Geological Evolution of North America, by Clark and Stearn; publisher, Ronald Press Co., New York.
Time, Life, and Man, by Stirton; publisher, John Wiley & Sons, New York.
These books may be borrowed from public libraries, or purchased from the publishers and retail book stores. At Columbia, the University Book Store, and the Missouri Store Co., sell most of them from shelf stock.
Missouri Geology Publications
Missouri has an excellent State Geological Survey which has published numerous volumes on various geologic topics and areas within the State. Inquiry about these bulletins, circulars, maps, and individually handled correspondence, should be addressed to the:
State Geologist
Missouri Geological Survey
Rolla, Mo.
FOOTNOTES
INDEX
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- A
- Acid, testing, muriatic, hydrochloric, storage battery, sulphuric 10
- Agate 37
- Alabaster gypsum 63
- Aluminum 23
- Amethyst 42
- Aragonite 17
- Arrow heads 34, 71, 72
- Artifacts 71, 72
- Asphaltic sandstone 32
- Audrain County 26
- B
- Barite 19, 61, 74
- Barton County 32
- Basalt 13, 44, 46, 47, 48, 71, 73
- Bauxite 23, 29
- Biotite mica 44, 54
- Black jack zinc ore 60
- Bloodstone 42
- Blossom rock 42
- Boone County 26
- Brick 22, 74
- Burley clay 29, 66, 73
- Burlington limestone 12
- Burned shale 21, 54
- C
- Calcite 12, 16, 37, 49, 61, 62, 63, 65, 66, 68, 74
- Calcium carbonate 12, 16, 37, 67
- Callaway County 26, 27
- Cannel Coal 51
- Carnelian 42
- Carnotite 65
- Carter County 58
- Carthage marble 15
- Cave deposits 16
- Chalcedony 37, 68
- Chats 35, 43, 60
- Chert 14, 34, 37, 42, 59, 62, 66, 71, 73
- Clinton 33
- Coal 20, 49, 53, 63, 73
- Cole County 62
- Conchoidal fracture 26, 34, 51
- Concretion 66, 68
- Conglomerate 54
- Copper 40, 66
- Cotton rock 15
- Crawford County 27
- Crinoids 12
- Cross-bedding 30, 31
- Crystal City 33, 41
- D
- Definition, rock and mineral 5, 73, 74
- Developing mineral deposit 24, 59
- Diabase 44, 48, 49, 73
- Diamonds 40, 65
- Diaspore clay 27, 58, 66, 73
- Dike 46, 47, 48
- Dolomite 10, 11, 18, 59, 60, 73, 74
- Dolomite chemical composition 12, 20
- Double refraction 18
- Drusy quartz 42
- F
- Feldspar 38, 39, 43, 45, 46, 54, 74
- Festus 33
- Fire clay 19, 24, 73
- Flat River 60
- Flint 14, 34
- Flint fire clay 26, 73
- Fool’s gold 14, 51
- Fossils 12, 22, 35, 36, 52, 53, 69
- Franklin County 27
- Fredericktown 60
- G
- Gabbro 13, 38, 44, 48, 73
- Galena 59, 65, 74
- Gasconade County 26, 27
- Geiger Counter 66
- Geode 42, 67
- Geological Survey, Missouri 6
- Glacial boulders and deposits 40, 48, 55, 65, 74
- Glass “tiff,” barite 61
- Gneiss 54, 73
- Gold 51, 53, 65
- Granite 16, 31, 38, 43, 46, 47, 49, 53, 54, 73
- Graniteville 39, 43
- Gypsum 19, 49, 61, 62, 63, 74
- I
- Igneous rock 73
- Iron band diaspore 58
- Iron County 39, 45, 58
- Iron Mountain 56
- Iron ore 56, 57
- Isinglass 44
- L
- Lafayette County 32
- La Grange 37
- Lava flow 46, 73
- Lead ore 59
- Lexington 33
- Lime 13
- Limestone 10, 22, 53, 55, 59, 62, 66, 73, 74
- Limestone, chemical, composition 12, 23
- Limonite 53, 56, 57, 66, 74
- Lincoln County 27
- Loess dolls, -kinder 66
- M
- Madison County 39, 45, 58
- Magnesium carbonate 12
- Manganese ore 58
- Marble 15, 55, 73
- Marcasite 49, 51, 53, 57, 74
- Maries County 27
- Mark of mineral 6, 56
- Metamorphic rock 15, 21, 55, 73
- Metatorbernite 65
- Meteorites 64
- Mica 38, 39, 44, 53, 74
- Microcline feldspar 44, 74
- Miller County 62
- Millerite 68
- Mineral, definition 5, 74
- Missouri Geological Survey 6, 59
- Missouri School of Mines and Metallurgy 6
- Moberly 33
- Moniteau County 62
- Morgan County 62
- Muriatic acid 10
- Muscovite mica 44
- O
- Ochre 58
- Olivine 65
- Onyx 16, 42
- Oolites 27, 29, 66
- Orthoclase feldspar 44, 74
- Osage County 26, 27
- Ozora marble 15
- P
- Pacific 33, 41
- Paint ore 58
- Paleontology 71
- Paris 33
- Petrified wood 35, 43, 69
- Petroleum 71
- Phelps County 26, 27
- Phenocrysts 46
- Pilot Knob 56
- Plagioclase feldspar 44, 49, 74
- Plaster of paris 63
- Plastic fire clay 26
- Polish on marble and granite 16
- Pop-corn flint fire clay 26
- Porphyry 31, 40, 44, 45, 53, 73
- Porphyry, chemical composition 40
- Potosi 37
- Pyrite 14, 49, 51, 52, 53, 57, 58, 63, 66, 74
- Pyroxene 49, 74
- R
- Radioactivity 66
- Reynolds County 58
- Rhyolite, rhyolite porphyry 45, 71, 73
- Ripple marks 33
- Rock crystal 42
- Rock, definition 5, 73
- Rock wool 13
- Rose quartz 42
- Rosin jack zinc ore 60
- Rosin spar zinc ore 60
- Ruby jack zinc ore 60
- S
- Sampling rock or ore 15, 59
- Sand 14, 30
- Sandstone 30, 41, 43, 53, 55, 66, 73
- Sandstone, chemical composition 23
- Satinspar gypsum 63
- Sedimentary rock 72, 73
- Selenite gypsum 63
- Shale 19, 20, 24, 50, 53, 55, 66, 73, 74
- Shale, chemical composition 23
- Shannon County 58
- Silica 35, 43, 66
- Silver 59, 65
- Silver Mines 65
- Six-sided crystals 16, 41
- Slate 21, 50, 55
- Soapstone 21
- Soil sweetening 13, 14, 20
- Sphalerite 60, 74
- “Sponge” limestone rock 13
- Stalactites 16
- Stalagmites 16
- State Geologist, Geological Survey 6, 24, 51, 59
- St. Francois County 39, 45
- St. Louis County 26
- St. Peter sandstone formation 41
- Ste. Genevieve 65
- Streak of mineral 6, 56
- Sulphur 51
- Sulphuric acid 10, 53, 63
- W
- Warren County 27
- Warrensburg 33
- Washington County 62
- Weathered chert 19, 35, 36, 37
- Widmanstatten figure 64
- Z
- Zinc ore 60