1. 1 THE EARTH THROUGH TIME TENTH EDITION H A R O L D L. L E V I N © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

2. Late Paleozoic Events 2 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

3. 3 FIGURE 10-1 Major events of the Paleozoic Era.

4. Paleozoic can be divided into:  Early Paleozoic = Cambrian, Ordovician and Silurian  Late Paleozoic = Devonian, Mississippian, Pennsylvanian, and Permian  160 million years long   Mississippian & Pennsylvanian Periods are also referred to with one name - Carboniferous Period. 4 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

5.  The supercontinent Pangea assembled as the continents collided during Late Paleozoic.  Larger continents grew by addition of island arcs and microcontinents around their edges. 5 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-1 Paleogeography of the Late Paleozoic.

6. Continental collisions caused several orogenies or mountain-building events in eastern North America. Acadian orogeny and Caledonian orogeny Laurentia + Baltica  Laurasia and A volcanic island arc (Avalon terrane or Carolina terrane) collides with eastern North America. Alleghanian orogeny (eastern North America) and Hercynian orogeny (central Europe) Laurasia + Gondwana  Pangea 6 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

7.  The Acadian and Alleghanian orogenies were the result of the closure of the Iapetus Ocean and continental collisions which resulted in the formation of the supercontinent Pangea. 7 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

8. 8 FIGURE 11-27 Eastern U.S. physiographic provinces.

9.  Shallow epicontinental seas transgressed and regressed across Laurasia (North America) during Late Paleozoic as the glaciers melted and enlarged.  These sequences are bounded by (or separated by) unconformities. 9 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

10.  Two major transgressions occurred in North America during Late Paleozoic:  Kaskaskia (Devonian-Mississippian)  Absaroka (Pennsylvanian-Permian)  During regressions, such as the one between Mississippian and Pennsylvanian, the former seafloor was exposed to erosion, creating one of the most widespread regional unconformities in the world. 10 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

11. Green = sedimentary deposits Yellow = missing strata associated with unconformities 11 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

12.  As Late Paleozoic began, the continents were fairly fragmented and separate, particularly in the Northern Hemisphere. (After C. R. Scotese, et al., 1979, Jour. Geol. 83(3):217–277) 12 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

13.  There is an extensive sedimentary record for Devonian.  Note that North America sat on the equator, with warm, tropical climatic conditions. (After C. R. Scotese, et al., 1979, Jour. Geol. 83(3):217–277) 13 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

14.  A large continental landmass named Gondwana (composed of South America, Africa, India, Antarctica, and Australia) was present in the southern hemisphere, on or near the South Pole. (After C. R. Scotese, et al., 1979, Jour. Geol. 83(3):217–277) 14 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

15.  Laurentia and Baltica collided to form Laurasia in the Caledonian orogeny affecting northeastern Canada, Greenland, and Europe). (After C. R. Scotese, et al., 1979, Jour. Geol. 83(3):217–277) 15 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

16.  A volcanic island arc or exotic terrane, called the Avalon terrane (or Carolina terrane), collided with Eastern North America in the Acadian orogeny. A thick sequences of sedimentary rocks are interbedded with rhyolitic volcanic rocks and granitic intrusions. (After C. R. Scotese, et al., 1979, Jour. Geol. 83(3):217–277) 16 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

17.  The Acadian highlands in eastern North America (orange), form a continuous belt with the Caledonian Mountains adjacent to Greenland and Europe.  Erosion of these mountains resulted in the deposition of the Catskill Red beds in the Appalachian area, and the Old Red Sandstone in Europe. 17 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-4

18.  Sea levels were high worldwide during Devonian (indicating that there were no glaciers).  Much of the North American continent was flooded by shallow seas. 18 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-4

19.  The seas regressed from the continents at the end of Early Paleozoic as a result of the Ordovician-Silurian glaciation.  Gradual flooding of the North American craton occurred during Late Paleozoic, reaching its maximum extent during Mississippian Period. This new inland sea was called the Kaskaskia sea. 19 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

20.  In eastern North America, initial deposits of the Kaskaskia sea were clean quartz sands, such as the Devonian Oriskany Sandstone, used for glass making because of its purity.  As the sea continued to transgress, shales, and then limestones with reef-forming coral were deposited over the sands.  In areas where water circulation was more restricted, evaporites were deposited.  Reefs and carbonates indicate a warm climate.  Evaporites suggest dry conditions. 20 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

21.  After the Acadian orogeny, carbonate sedimentation was followed by deposition of clastic sediments.  Clastic sediments are thicker and coarser to the east, nearer their source area in the Acadian highlands.  Primarily continental red beds (stream deposits).  Wedge-shaped deposit called the Catskill clastic wedge or Catskill delta (although these are not deltaic deposits). 21 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

22.  Similar Devonian red beds are also present in Europe, such as the Old Red Sandstone.  The red color of the sandstone indicates deposition under oxidizing conditions in continental or non-marine environments. 22 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

23. 23 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-20 Upper Devonian sedimentary rocks in the northeastern U.S.; Catskill clastic wedge in New York. FIGURE 11-21 Panorama of the Catskill clastic wedge viewed from a point above southcentral Pennsylvania.

24.  Isopach (sediment thickness) and lithofacies map of Upper Devonian in the eastern U.S.  The Catskill clastic wedge sediments are thicker and coarser in the east.  The sediments become finer-grained westward, away from the Acadian highland source area. Catskill clastic wedge deposits 24 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

25.  Farther west, black shales were deposited in a thin unit (less than about 10-20 m thick) over a wide area (Chattanooga Shale) during Late Devonian and Early Mississippian.  Offshore equivalent of the 3000 m thick Catskill clastic wedge.  An important marker bed for regional correlation.  High organic carbon content, along with finely disseminated pyrite, and uranium.  Chattanooga Shale was deposited in stagnant, oxygen-deficient water. 25 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

26.  In the Williston Basin area (South Dakota, Montana, and adjacent Canada), extensive reefs formed.  Restricted circulation within the reef- encircled basin led to the deposition of thick evaporite deposits.  The reefs of the Williston Basin provided permeable structures into which petroleum migrated, forming rich oil fields. 26 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

27. In North America, Carboniferous consists of two periods: Mississippian and Pennsylvanian.  Mississippian is Early Carboniferous.  Pennsylvanian is Late Carboniferous. 27 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

28.  The name "Mississippian" is derived from exposures of rock in the valley region of the Mississippi River.  Mississippian sedimentary deposits contain abundant limestone with fossils of crinoids, blastoids, bryozoans, and fusulinid foraminifera. 28 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

29.  Pennsylvanian rocks are dominated by coal- rich sediments that were deposited in swamps and deltas.  Coal deposits are particularly well developed in Pennsylvania. 29 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

30. Landmass in eastern North America and Europe (yellow), formed as the mountains (orange) eroded after Caledonian and Acadian orogenies. 30 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-8 Mississippian Period paleogeography.

31.  Although a large mountain range was present in the Appalachian area, another orogeny was soon to occur, as indicated by the arrows and the words "Africa approaching" along the right side of the map. 31 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

32.  Much of North America was covered by a shallow epicontinental sea.  North America sat on the equator, so temperatures were warm.  Note the Antler highlands in the western U.S. 32 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

33.  By Mississippian, the Acadian highlands were reduced in size by erosion, and were no longer releasing large quantities of sediment.  In the east, near the remaining highlands, non- marine shales, sandstones, and conglomerates were deposited.  These sediments belong to the Pocono Group. 33 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

34.  As muddy sediment from the eroding highlands decreased, carbonate deposition became widespread in the warm, shallow Kaskaskia sea.  Mississippian limestones contain abundant crinoids, blastoids, bryozoans, and fusulinid foraminifera.  The widespread blanket of carbonate rocks deposited during this time is called the great Mississippian lime bank.  In places, Mississippian limestones are more than 700 m thick. 34 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

35. (top) National Museum of Natural History/ Smithsonian Institution; (right) Harold Levin) 35 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

36.  Sands, clays, and thin layers of carbonates were deposited during Late Mississippian time as the Kaskaskia sea regressed.  These rocks are a source of petroleum in Illinois.  They appear to have been deposited in stream valleys developed on the former seafloor.   Farther west, the Williston basin (South Dakota, Montana, and part of Canada) continued to have extensive reefs developed around. 36 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

37.  In the Gulf Coast area, slow deposition continued from Early Devonian to Late Mississippian.  Carbonates predominated in the more northerly shelf zone.  Cherty rocks called novaculites were deposited in deeper waters to the south. Novaculites are composed of microcrystalline quartz, which has been subjected to heat and pressure.  Arkansas novaculite is used as a whetstone to sharpen steel knives and tools. Harold Levin 37 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

38.  Graywackes and shales spread into the depositional basin near the end of Mississippian, forming a clastic wedge more than 8000 m thick, that thickened and coarsened to the south, where a new mountain range had formed and was eroding.  The remnants of this mountain range are the Ouachita Mountains of Arkansas and Oklahoma, and the Marathon Mountains of southwestern Texas. 38 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

39.  The Kaskaskia sea retreated from the craton at the end of Mississippian.  This event is marked by one of the most widespread unconformities in the world. This unconformity separates Mississippian from Pennsylvanian.  The overlying Pennsylvanian rocks were deposited under very different conditions. 39 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

40.  During Late Paleozoic, northwestern Africa collided with southeastern North America, causing the Alleghanian orogeny, and building the Appalachian mountains.  The orogeny began during Mississippian and continued through Pennsylvanian and Permian. 40 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-1

41. South America collided with the Gulf Coast region of North America, forming the Ouachita Mountains, a southwestern continuation of the Alleghanian orogenic belt. 41 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

42. The Alleghanian orogeny produced folds in the Appalachian Valley and Ridge province, and large thrust faults in the southern Appalachians. Many folds are asymmetrically overturned to the northwest, and surfaces of thrust faults dip to the southeast. 42 FIGURE 11-27 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

43. Blue Ridge and Piedmont metamorphic and igneous rocks form a sheet ranging from 6-15 km thick, overlying relatively flat-lying lower Paleozoic sedimentary rocks. This type of tectonic deformation is called "thin-skinned tectonics." 43 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

44. 44 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-26 Plate tectonic model for late Paleozoic continental collisions.

45.  By Late Carboniferous, a large continental landmass called Pangea, had formed by the collision of Laurasia (North America plus Europe) with Gondwana (the southern continents of Africa, South America, Australia, Antarctica, and India). 45 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

46.  In the western part of North America, the Antler orogeny began during Devonian with the subduction of oceanic lithosphere beneath the western margin of the continent.  The Antler Orogeny continued into Mississippian and Pennsylvanian. 46 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-32 Interpretation of the Cordilleran orogenic belt shortly after the Antler orogeny.

47.  A volcanic island arc collided with the western margin of North America, crushing sediments and causing thrust faulting (Roberts Mountains Thrust Fault of Nevada).  Continental rise and slope deposits were thrust as much as 80 km over shallow water sediments of the former continental shelf. 47 FIGURE 11-32 Interpretation of the Cordilleran orogenic belt shortly after the Antler orogeny. © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

48.  The supercontinent, Pangea, sat over the South Pole. When a continent is over a pole, conditions are right for a glaciation, if the climate is cold and if sufficient moisture is present. 48 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

49.  The Iapetus Ocean (or Proto-Atlantic), completely closed by Late Carboniferous.  Closure of the Iapetus Ocean disrupted global ocean circulation and caused currents to be diverted from the tropics to more polar areas, contributing to glaciation. 49 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

50.  The presence of evaporites (E) indicates that the climate was at least locally dry.  This was probably due in part to changes in global oceanic and atmospheric circulation induced by the closure of the Iapetus, as well as by orogeny. 50 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

51.  Glacial deposits are present in the southern hemisphere, indicating that a glaciation occurred during Carboniferous and Permian. 51 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

52.  Large landmass in the east, with extensive lowlands (yellow).  Appalachian Mountains (orange) have formed as a result of the Alleghanian orogeny. 52 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-9 Pennsylvanian Period paleogeography

53.  Sediment eroding from the Appalachian Mountains was transported to the west into the epicontinental sea that covered much of North America during Mississippian.  These sedimentary deposits have built a broad plain to the west, with alternating non- marine and marine deposits, as the sea transgressed and regressed. 53 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

54.  Coal swamps formed along the western edge of the Appalachian Mountains, in what was basically a tropical rainforest setting. 54 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

55.  Uplifts in the southern and southwestern North America (Uncompahgre mountains or ancestral Rockies, and others), and the Antler Mountains in the western U.S. 55 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

56.  The erosion of the Antler Mountains provided detrital sediment that was transported into adjacent basins.  Thick sequences of Pennsylvanian and Permian shelf sediments accumulated in the area now occupied by the Wasatch and Oquirrh Mountains in Utah. 56 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

57.  The Absaroka sea began to transgress upon the North American craton near the beginning of Middle Pennsylvanian.  The rocks in the eastern half of the U.S. are predominantly interbedded marine and nonmarine sediments, indicating the advance and retreat of the sea.  Each nonmarine-marine sequence is called a cyclothem. 57 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

58.  A typical Pennsylvanian cyclothem contains 10 units.  The lower half consist of nonmarine sediments, topped by a coal deposit.  The coal is overlain by marine deposits, indicating the advance of the sea into the swampy, vegetated area. 58 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-11 Coal-bearing cyclothems.

59.  The repetitious interbedding of non-marine and marine sedimentary deposits indicates either:  Episodic regional subsidence and uplift OR  Eustatic (worldwide) sea level changes related to Carboniferous-Permian glaciation in Gondwana. 59 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

60.  Pennsylvanian coal deposits are mined extensively in the Appalachian area, the Illinois basin, and in Europe.  They are commonly associated with rocks containing plant fossils. 60 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

61.  SW part of the North American craton experienced mountain building during Pennsylvanian.  The highlands are called the Uncompahgre Mountains (or ancestral Rockies) in southwestern Colorado, and the Oklahoma Mountains of western Oklahoma.   These mountains and related uplifts resulted from movement along large, nearly vertical faults. 61 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-12 Principal highland areas, southwestern part of the craton, Pennsylvanian time.

62.  The Colorado Front Range-Pedernal uplifts extending north-south through central Colorado formed at this time.  Precambrian igneous and metamorphic rocks are now exposed in the cores of these eroded mountain ranges. 62 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

63.  Erosion produced great wedge-shaped deposits of red arkosic sandstone during Pennsylvanian and Permian, some of which is exposed in Colorado as:  The "flatirons" near Boulder  The rocks at Red Rocks Amphitheatre near Morrison, west of Denver  The Garden of the Gods, near Colorado Springs 63 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-13

64.  Other uplifts also formed, including the Zuni-Fort Defiance uplift, the Amarillo mountains, and the Oklahoma mountains (represented today by the Arbuckle and Wichita mountains).  The origin of these mountains may be related to the collision of Gondwana along the southern edge of the North American craton in the Ouachita orogenic belt. 64 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

65. Crustal adjustments to relieve stress may have resulted in the deformation that produced the highlands and associated basins (such as the Early Pennsylvanian Paradox basin, which contains evaporites and petroleum deposits). 65 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-15 Generalized cross-section through the Paradox basin in Utah/Colorado.

66.  The Paradox basin lies southwest of the Uncompahgre mountains.  Clastic sediments from the mountains were deposited along the northeastern side of the basin. 66 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

67. The Paradox basin was flooded by the Absaroka sea during Early Pennsylvanian. Shales were deposited over Mississippian limestone. The basin became restricted and thick beds of evaporites (salt, gypsum and anhydrite) were deposited. 67 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

68. Reef-like algal mounds, associated with fossiliferous and oolitic limestones, developed along the western rim of the basin. The reefs serve as petroleum reservoirs. Near the end of Pennsylvanian, the basin filled with arkosic sediments eroded from the Uncompahgre highlands. 68 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

69.  The Absaroka sea, which began its transgression at the beginning of Pennsylvanian, began a slow and irregular regression before the end of Pennsylvanian, which continued into Permian. 69 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

70.  During Permian, the continents collided and joined to form the supercontinent, Pangea.  Pangea was surrounded by a huge ocean called Panthalassa.  The oceanic area east of Pangea, and between Africa and Europe was called the Tethys Sea. 70 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

71.  Continental collision was accompanied by orogeny, and the Appalachian mountain chain reached its peak during the Alleghanian orogeny. 71 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

72.  Late Permian was a time of widespread regression of the seas.  The global map above indicates that sea levels were low worldwide.  The vast epicontinental seas that once covered North America and parts of other continents were gone. 72 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

73.  The Gondwana part of Pangea continued to sit atop the South Pole, and glaciation continued into Permian. 73 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

74. Red circles are coal deposits (humid climates during interglacial periods, possibly associated with glacial meltwaters). Blue triangles are glacial tillites. Irregular green areas are evaporites (arid climates). 74 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

75. Cold air holds less moisture than warm air, and the climate became arid during Permian. Evaporite deposits (gypsum and salt) accumulated in the green areas on the map. There are more Permian salt deposits than any other age. 75 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

76.  Drying of climates at low latitudes led to contraction of coal swamps and extinctions among spore-bearing plants and amphibians that required moist conditions.  Because of the drying, gymnosperms (seed plants, including conifers) replaced many spore-bearing plants, which require moist conditions. 76 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

77.  Orogenies probably also affected the climate.  Locations of mountains can affect climate and control precipitation (rain-shadow effect).  Deserts form on the downwind side of mountain ranges. 77 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

78.  The eastern 2/3 of North America consisted of lowlands, undergoing erosion.  Continental red beds were deposited locally. 78 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

79.  Appalachian mountains in the east.  Ouachita mountains in the southeast.  Farther west are the "Ancestral Rockies."  Antler Mountains have been eroded, and are called uplands.  Subduction and volcanism continue in the far west. 79 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

80.  The Absaroka sea continued its regression during Permian.  Fossiliferous limestones were deposited in the Absaroka sea, overlain in places by shales, red beds, and evaporites.  The Kaibab Limestone, which forms the cliffs along the rim of the Grand Canyon, is a Permian carbonate deposit. 80 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

81.  Deep marine basin in the Wyoming, Montana, and Idaho area filled with cherts, sandstones, and mudstones of the Phosphoria Formation.  Formation named for layers of dark phosphatic sediments and phosphorites.  Phosphorite = dark gray variety of calcium phosphate. May have formed by upwelling of phosphorus-rich sea water from deeper parts of basin.  Phosphate is mined for fertilizers and other products. 81 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

82.  Several irregularly subsiding basins (such as the Delaware basin) developed between shallow submerged carbonate platforms. 82 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED. FIGURE 11-16

83.  Reefs formed along the basin edges (Capitan Limestone).  The ancient reef forms the steep El Capitan promontory in the Guadalupe Mountains. 83 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

84.  In the shallow water lagoons behind the reefs, thin limestones, evaporites, and red beds were deposited. 84 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

85. 85 © 2013 JOHN WILEY & SONS, INC. ALL RIGHTS RESERVED.

86. 86 FIGURE 11-27 Eastern U.S. physiographic provinces. Source: After F. A. Cook et al., 1979, Geology 7:563–567. FIGURE 11-4 Devonian Period paleography. Source: Harold Levin. FIGURE 11-20 Upper Devonian sedimentary rocks in the northeastern U.S.; Catskill clastic wedge in New York. Source: (A) After W. D. Sevon, 1985, Geol. Soc. Amer. Special Paper ZOI: 71–90, and W.G. Ayrton, 1963, Pennsylvania Geol. Survey Report. 39(4):3–6. (B) Based on Classic Studies by G. H. Chadwick and G. A. Cooper Completed between 1924 and 1942. FIGURE 11-21 Panorama of the Catskill clastic wedge viewed from a point above southcentral Pennsylvania. Modified from Woodrow, D.L. and Sevon, W.D., eds., The Catskill Delta: Geological Society of America Special Paper 201:51-63. FIGURE 11-8 Mississippian Period paleogeography. Source: Harold Levin. FIGURE 11-26 Plate tectonic model for late Paleozoic continental collisions. Source: After P. E. Socks and D. T. Secor Jr. 1990, Science 25:1702–1705. FIGURE 11-32 Interpretation of the Cordilleran orogenic belt shortly after the Antler orogeny. Source: Harold Levin. FIGURE 11-9 Pennsylvanian Period paleogeography. Source: Harold Levin. FIGURE 11-11 Coal-bearing cyclothems. Source: Harold Levin. FIGURE 11-12 Principal highland areas, southwestern part of the craton, Pennsylvanian time. Source: Harold Levin. FIGURE 11-13 The Pennsylvanian Period across eastern Colorado and New Mexico. Source: Harold Levin. FIGURE 11-15 Generalized cross-section through the Paradox basin in Utah/Colorado. Source: After D.L. Baars et al., 1988, Basins of the Rocky Mountain region, in Sloss, L.L., ed., Sedimentary Cover of North American Craton. Geological Society of America. FIGURE 11-16 Division of the Permian Period into four stages in North America. Source: After P. B. King, 1948, U.S. Geol. Survey, Professional Paper 215. IMAGE CREDITS