Pennsylvanian Period

Pennsylvanian Period

It’s old. It’s gone. WHO CARES?

(The Pennsylvanian Dutch do)

It’s only half of the carboniferous.

StephanieBontorin

KonstantinosPapadimitrios

Description of time period• Pennsylvanian time period• The Pennsylvanian is the youngest

sub period of the Carboniferous period

• It lasted from approximately 318-299 million years ago

• The Pennsylvanian period has been subdivided into four stages– The bashkirian (Oldest)– The Moskovian – The Kasimovian– The Gzhelian (Youngest)

• During this time period equatorial swamps had large amounts of organic beds laid down

• These eventually turned into the coal deposits which many countries now use for fuel.

• The tem Pennsylvanian is of American origin while late Carboniferous Period or Silesian Period are preferred internationally.

System Subsystem/Series Stage Age

(Ma)

Permian Cisuralian Asselian younger

Carboniferous

Pennsylvanian

Gzhelian 299.0–303.9

Kasimovian 303.9–306.5

Moscovian 306.5–311.7

Bashkirian 311.7–318.1

Mississippian

Serpukhovian 318.1–328.3

Viséan 328.3–345.3

Tournaisian 345.3–359.2

Devonian Upper Famennian older

Subdivision of the Carboniferous system according to the ICS.[1]

SubdivisionsThe Bashkirin

• Named after the Bashkirs, who lived in the Bashkortosan republic in the southern Ural Mountains

• This Sub period was first introduced in 1934 by Sofia Semikhatova

• The end of the Bashkirin marked the first emergence of the condont; eel like creatures.

• During this time the first fusulinids began to appear, eventually they would form a vast limestone layers due to the composition of their shells.

The Moscovian

• The Moscovian stage was introduced by Sergei Nikitin in 1890

• He defined this stage by the types of brachiopods found in the Moscow basin

• The end of the Moscovian is marked by the appearance of the first ammonite genus (parashumardites)

• The beginning of the Moscovian is difficult to pinpoint but as a generality the appearance of the condonts is considered the start.

Sub divisions cont.The Kasimovian

• The Kasimovian • The name is taken from the russian

city of Kasimov• Witch lies eastern of Moscow• The stage is defined by its deposits of

limestone, dolomite mudstones, and some siltstones

• The beginning of this stage is usually marked by the first apperance of advanced fusilinids

The Gzhelian

• Gzhelian• Its named after the Russian city Of

Gzhel the beginning of the Gzhelian is marked by the first apperance of the conodont (Streptognathodus zethus)

• The beginning of the Permian or the end of the stage is marked by the first apperance of streptognathodus isolatus

Landforms and Continent Positions• During the Pennsylvanian period the continent of the world were

split in to two large land masses called Pangaea and Gondwanaland.

• At this time Pangea was in formation and did not look like the models which show all of the continents melded together as in latter stages.

• Modern North America was located around the equator while South America, India, Africa, and Australia were at the south pole covered in ice

• The Paleo-Tethys sea was nestled between bits of modern China, Russia, North America and the Indian sub-continent

• Much of the world was dominated by a huge body of water known as the Panthalasic Ocean (Panthalasic translates roughly to covering everything ocean everywhere)

Climate • With Gondwanaland shifting around the south pole there were many

period of freezing and thawing• Because of this the ocean was prone to recede and then again cover costal

lowlands• Repeating layers of sedimentary layers are common in the Pennsylvanian

period• sandstone, shale, coal, limestone, and sandstone again are the common

cyclothems of rock formations• Formation

– Ice in Gondwanaland melted causing sea levels to rise. Rivers and streams deposited sediemnts in lowland areas in order to return to equilibrium(sandstone + shale)

– As the rising of the seas began to settle in specific locations rich costal swamps formed and took in organic matter rich in carbon (coal)

– The sea completely moves in and forms a shallow marine enviroment. Shelled creatures begin to move in and form limestone layers.

– Eventually ice would form again causing the process to start over

More Climate• As the Pennsylvanian period drew to a close the

swamps that characterised its equatorial regions began to dry out

• Gondwanaland remained relatively cold for the most part while the land situated around the equator continued to be warm and wet

• At this time many of the giant plants so common to the Pennsylvanian began to die out

• The Pennsylvanian atmosphere contained much more oxygen than today, about 35% rather than 21%, which lead to the growth or larger plants and animals.

Flora-It was big• Large trees and ferns grew in the warm moist equatorial

regions during the Pennsylvanian• They produced so much oxygen that all life forms were able to

grow to sizes never seen before or after the Pennsylvanian• Giant ferns, club mosses, tree ferns, and conifers dominated

the landscape• When these enormous plants died they became the coal beds

of the Pennsylvanian• The Pennsylvanian was also the time where seed bearing

plants began to flourish after their fist appearance in the Devonian

Fauna

Bryozoa• Bryozoa are small (5mm)

aquatic invertibrates • They feed using small

retractable cillia by filtering water

• Bryozoa date back to the ordovician period but were prominet sea creatures during the Pennsylvanian

Brachiopods• Small bivalve animals • They have survived through

millions of years• The most diverse current

groups of brachiopods stemmd from those in the carboniferous

• Their shells now compose many of the limestone deposits which are characteristic of the Pennsylvanian

A Carboniferous brachiopod Neospirifer condor, from Bolivia. The specimen is 7 cm across.

Amphibians

• During the Pennsylvanian Amphibians were the dominant predators

• They ate the huge insects of the land and also the fish of the sea

• During this time period amphibians also began to move onto land and form early reptiles

Reptiles

• Compared to their aquatic counterparts reptiles were fairly small and insignificant

• The first reptiles were not much larger than 10-20 cm

Hylonomus

Insects

• Meganeura- HUGE dragonfly. Largest hexapod ever.

• Its wingspan could reach 75 cm

• Arthropleura- was a big millipede, from one to two meters long and with up to 30 pairs of legs

Major Happenings

• During the Pennsylvanian many mountains were formed as conbtinental plates came together at subduction boundries

• The applalacian mountains whiuch still exist today were formed during this period

• Huge limestone layers were formed when the crinoids and shelled creatures of the period died

• Coal beds which are indicative of the period were laid down during the Mississippian and Pennsylvanian periods