Late Paleozoic  Chapter 11.


The late Paleozoic was the time of forming the supercontinent Pangea.


Laurentia and Baltica collided along a convergent plate boundary to form Laurasia during Silurian.  

This collision closed the Northern Iapetus ocean and is called Caledonian orogeny.

During Devonian Laurasia and Gondwana have started colliding as Southern Iapetus got narrower. This orogen is called Acadian orogeny.

Other tectonic events were in the Cordilleran, the Antler orogeny, the Ellesmere orogeny along the northern margin of Laurentia (collision between Laurentia and Siberia). There was an other mountain range forming, the Uralian which marked the collision between Baltica and Siberia.

Uniform climate


Gondwana moved over the south pole, resulting extensive continental glaciation. indicated by tillites. These icesheets spreaded and they well extended into the middle temperate latitudes during max. glaciation.

The advance and retreat of these glaciers resulted in global sea level changes, that affected sedimentation patterns on the cratons.

Gondwana moved north and collided with Laurasia, and it continued throughout the Carboniferous.

Siberia collided with Kazakhstania and moved toward the Uralian margin of Laurasia colliding with it during early Permian.

By the end of Carbonifeorus the various masses of the different continents were very close to each other, and Pangea the supercontinent of the Phanerozoic began taking shape.

Carboniferous is the time of formation of huge coal deposits on the earth. Plants on the land; 


The assembly of Pangea was essentially concluded during the Permian with the completition of many collisions (Hercynian, Alleghanian, Ouachita)

The supercontinent was moving northward during the Permian. The enormous single ocean is called Panthalassa, surrounded Pangea spanned from pole to pole. The water in this ocean circulated more freely than at the present which resulted more equal temperature.

Arid condition!!!!! Because of the super continent. The fact of supercontinent changed wind patterns, climate zones...... The climate pattern were troubled by the newly formed mountains.

Late Paleozoic history of North America

Kaskaskia sequence

The boundary between Tippeccanoe and Kaskaskia sequence is marked by a major  unconformity.

During the transgression of the Kaskaskia seawater in the early Devonian clean mature sandstone covered much of the craton as basal depositis. (Oriskany sandstone, NewYork, Pennsylvania). Their source area was the Appalachian mobile belt which is contained older sandstone facies.

After the sandstone basal sediment, the majority of kaskaskian rocks are carbonates including reefs, and associated evaporite deposits. In many other areas of the world same kind of sediments could be found. (England, Belgium, Central Europe, Australia, Russia).

 Reefs in Western Canada

Middle and Late Devonian reefs are very important in Western Canada (huge oil reservoar By the middle Devonian they had a huge barrier reef arrangement and the lagoonal areas behind them become restricted!!!!

Black shale

During Late Devonian the character of the sediment has changed from shallow water carbonates to black shales and coarser detrital rocks. The source of these sediments were the mountains formed by the Acadian orogeny in northern America.

In the Eastern Us. this black shale  is called Chattanooga shale. These shale deposits are the best developed along the Appalachian mobil belt to the Mississippi valley, they can be found elsewhere also.

          This shale usually thin bedded, non calcareous, less than 10 m thick, and rich in land plants. They sometimes are bitominous, containing mostly degraded algal material. (Source material for oil!!!!!!!)

          Presence of black shale indicate anaerobic bottom condition, reduced supply of coarse sediment and high organic productivity of the overlying oxigenated water layer.

The Late Kaskaskia

After the black shale formation, during Late Devonian early Mississippian, the carbonate deposition returned. Crinoideal limestone, oolitic limestone, dolomite were common. These carbonates display cross-bedding, ripple marks, and well sorted fossil fragments, all of which indicate shallow marine environment.

During the Late Mississippian regression of Kaskaskia sea from the craton resulted in deposition of detrital sedimentary rocks. Sandstone in the Illinois basin, (petroleum reservoar). These detrital sediments were followed by an unconformity because of the ongoing regression.

Absaroka sequence

Absaroka includes uppermost Missisipian through Lower Jurassic rocks.  The big unconformities between Kaskaskia abd Absaroka divides the Carboniferous into the Mississippian and Pennsylvanian sequence. These two system are equivalent to the Europian lower and upper Carboniferous.

The sequence contains a little bit different rocks, than what is characteristic to those in the Kaskaskia sequence.

Here we have a well developed foreland basin, behind the Caledonian, Acadian highland which is very deep fast subsiding basin on its east side, and become gentle sloping on its west side.

-Deposits in the foreland basin

Nonmarine detrital rocks with coal deposits on the east (Pennsilvanian           cyclothems)

          marine detrital rocks and limestone on the west


          The Pennsylvanian rock are characterized by cylical pattern. The cycles are alternating marine and nonmarine deltaic strata. (the formation of the cycles is the result of small scale sea level changes along the           shoreline.)

          Nonmarine unit:deltaic, fluvial sediment  regressive

          clay, coal (accumulation of plant material) transgressive

          Marine unit of limestone and shale with marine fauna.

          Modern examples for this:

          Mississippi delta

          Florida Everglades

Cratonic uplift - The ancestral Rockies

Although cratons are stable areas, in the Pennsylvanian period, there was some unusual deformation in the American craton and resulted in uplift and big part of the Precambrian rocks exposed. During this deformation arches and domes formed, and some older highlands became activated such as the Cincinnati arch, Nashwille dome, and Ozark dome.During the late Absaroka the area of greatest deformation was the southwestern part of North-America, where fault-bounded uplifted blocks formed the Ancestral rockies.

          As these mountains were uplifted and became source of large scale erosion, huge amount of coarse grained red arkosic sandstone and conglomerate were deposited in the surrounding basins. (Colorado Springs beautiful red sandstone, Denver’s red sandstones).


The Late Absaroka

The various basins bordering the ancestral Rockies contain extensive marine and nonmarine sediments.

Paradox basin and the four corners region (Arizona, New Mexico, Colorado, Utah) was covered by the Absaroka sea. During the Middle Pennsylvanian thick cyclical deposits of gypsum, anhydrite and salt formed in the central basin area.  Fossiliferous and oolitic limestones were deposited around the perimeter, with patch and barrier reefs grew along the western margin, further restricting the central basin. (oil reservoar).

During the Late Pennsylvanian, the whole Paradox basin was filled, by arkosic red sandstone.

Latest Absaroka

As the Absaroka sea started to retreat, it wes restricted to West Texas and Southern New Mexico, forming a complex of lagoonal, reef and open shelf environments. 

Massive reefs grew around the basin margins. While limestones, evaporites and red beds were deposited behind the reefs in the lagoonal areas.

Guadalupe Mountains of Texas and New Mexico where the Capitan limestone formed.

By the end of the Permian the Absaroka sea had retreated from the craton leaving continental red beds over most of it.

Mobil belts

Cordilleran mobile belt

During late Proterozoic and early Paleozoic this belt was passive continental margin along which extensive continental shelf sediments were deposited.

Beginning in the Middle Paleozoic an island arc (Klamath arc) formed on the western margin of the craton.

During the Late Devonian, early Mississippian there was a collision between this eastward moving island arc and the western border of the craton. As a result a highland have formed. This orogenic event  is the so called Antler orogeny.

The highland produced lots of sediment that were deposited toward the east  in an epiric sea covering the craton, and to the west into a deep sea.

Ouachita mobil belt

Texas, Arkansas.

This was also a passive margin, which became active convergent margin during the Mississippian. Volcanic arc to craton subduction hapeened to the south. Rapid sedimentation produced clastic vedge, which thickened to the south. 16,000 m of Mississippian and Pennsylvanian aged rocks crops out in the Ouachita mountains representing the really rapid sedimentation rate of this time. The collision of Gondwana and Laurasia is marked by a big mountain range.

The cratonic uplift most likely is also related to this compressional force.

Appalachian mobile belt

Caledonian orogeny

This mobile belt extends along the western border of Baltica.

During the Middle Ordovician, subduction along the boundary between Iapetus plate and Baltica began.

The most extensive phase of the Caledonian orogeny occured during the Late Silurian and Early Devonian with the formation of mountain range along the margin of Baltica. Red colored sediments deposited along the front of the Caledonian high-land forming a large clastic vedge. Old Red Sandstone.

Acadian Orogeny

The Acadian orogeny occured along an oceanic continental convergent plate boundary, and later during the Devonian Baltica finally collided with Laurentia forming a continental-continental convergent plate boundary along zone of collision.

Acadian was longer and more intensive, than Taconian. 360-400 million years ago.

Erosion and weathering of the Acadian highland produced a very thick clastic vedge, called Catskill delta. These sediments are composed of red, coarse conglomerates, sandstone, and shale, with much more sediment then the queenston delta.

Toward the west the red beds grade laterally into gray sandstones and shales containing fossil tree trunk, which indicate marsh and swampy environment.

Hercynian-Alleghany Orogeny

This is the collision of eastern Laurasia with Gondwana.

Initial collision began during Mississippian. The greatest deformation occured during Pennsylvanian and Permian. (Hercinian orogeny). The central and southern part of the Appalachian mobile belt were folded and thrust toward the craton as eastern Laurasia and Gondwana were sutured (Alleghanian orogeny)

These orogenesis represent the final joining of the supercontinent Pangea during Permian.

Mineral resources of the Late Paleozoic

Petroleum and natural gas

from Devonian to Permian rocks (Michigan basin, Illinois basin, Williston basin of Montana, South Dakota)

Permian reefs in the western US. Texas also important.



Appalachians and mid western US.

(Bituminous coal more than 80% C)

Some of the coal is metamorphosed and become antracite 98%C.


Zechstein evaporites in Europe

Delaware, New Mexico


Quartz sandstone

West Virginia, Maryland, Pennsylvania.


cement, and it is found everywhere


Copper, gold silver

Mississipi type lead and zink deposits in Missouri, Virginia, Tenessee.