Do you know that how was Earth before billions of years ago? Are you interested to know the rich facts which contributed to the evolutionary process of the Earth? Billions of years ago the Earth was not like the present time we are living. There were no or a fewer life. Different significant changes and developments occurred and Earth began to gain its new form full of lives. Those days of ancient time are divided into several eras and each era has its own periods. These periods have also their respective epochs. Hence divisions of those ancient days are really interesting. The Calymmian period is also one of such ancient periods and is a subdivision of the Mesoproterozoic Era.

Calymmian period: the first period of the Mesoproterozoic Era
Time and geological factors of the Calymmian period
Known as the first period of the Mesoproterozoic Era this period lasted from 1.6 billion to 1.4 billion years ago and contributed to develop several features of the era. The name of the period indicates that it stands for that time when development and expansion of platform covers occurred. These covers are the layers or deposits of the sedimentary or the igneous which accumulated over the cratons.

Continental building events by expansion of the sedimentary depositions
Do you know that these developments and expansions of sediments and igneous are the major parts of the continental building? How this process gave birth to continents? As crust of the Earth thickened rocks began to deposit on the older rock's top which led to the continental building. Expansion of these plates also took place when sediments were deposited along the coast of the seas and made the seas shallower. Due to continental movements landmasses were created between the shallow seas and finally these landmasses were filled up by sedimentary depositions and new land formed.

The first continent breakup during the Calymmian period

Have you heard about the first continent? Do you know how it broken up into several margins and when it was broken?
The first continent was Columbia. This started its breaking process in the Calymmian period and continued till the Ectasian, the second period of the Mesoproterozoic Era. This process taken place due to rifting along the eastern margin of India, western margin of Laurentia, southeastern margin of Siberia, southern margin of Baltica, northern margin of the South China Block, and the northwestern margin of South Africa. Igneous deposition of rocks also took place in all these regions as volcanic activities accompanied rifting.

So, let us recall the features and the major developments of this period of the Mesoproterozoic Era:

• The first period of the Mesoproterozoic Era
• Major developments and expansion of platform covers
• These platform covers are mainly the igneous and sedimentary deposits
• Breaking up of the first continent, Columbia

This period ends with the starting of Ectasian period when the Earth had some major developments which contributed to change its geological features. Hence all of these periods devoid of life or a fewer trace of life had contributed to the making of the modern day world.