EARTH SCI RECITATION Flashcards
its an important tool for geologists and paleontologists to study the rocks , fossil and other evidences for studying history and development of earth.
WHY DO WE NEED TO STUDY GEOLOGIC TIME SCALE
what is geologic time scale?
CHRONOLOGICAL MEASUREMENT THAT RELATES STRATIGRAPHY TO TIME
how are geologic time scale divided?
EON
ERAS
PERIODS
EPOCHS
AGE
what are eons?
LARGEST MEASUREMENT OF TIME CONSISTING OF HADEANS, ARCHEANS , PRETOROZOIC
describe hadean
INITIAL FORMATION OF EARTH ( METEORITES AND VOLCANIC ACTIVITIES )
describe archean
TRANSFORMATION OF EARTH ATMOSPHERE THROUGH THE RELEASE OF OXYGEN BY EARLY PHOTOSYNTHETHIC ORGANISMS ALGAE AND BACTERIA
describe proterozoic
INCREASE IN THE AMOUNT OF FREE OXYGEN IN THE ATMOSPHERE
what are eras
UNIT OF TIME SHORTER THAN EON
( 100 milion years ) PALEOZOIC, MESOZOIC , CENOZOIC
describe paleozoic
OLD LIFE
describe mesozoic
MIDDLE LIFE
describe cenozoic
RECENT LIFE
what are period?
UNIT OF TIME THAT IS LONGER THAN EPOCH
Cambrian period
AGE OF TRILLOBITES ( INVERTEBRAES ANIMALS )
devonian period
AGE OF FISHES
mississpians period
AGE OF ABUNDANT PLANTS AND ANIMALS