The oldest geological era is the Precambrian period. It is the period of Earth's formation, as well as the origin of the first single and multi-celled organisms.
The geologically oldest mountains in North America are the Laurentian Mountains located in eastern Canada. They formed over a billion years ago and are part of the Canadian Shield, a large geological province that also includes some of the oldest rocks on Earth.
Geologically speaking, we are in the Quaternary Period.
Which is the oldest era christian or Saka or Hijri or Vikrami?
Its Archeozoic.
I am not sure which particular parts, but I think I recall an exhibit at the Scottish National Gallery showing the west coast islands of Scotland as the oldest land surface in Europe.
The oldest ocean, geologically, is the Panthalassa Ocean which was around 220 million years ago in the Triassic era. It encompassed the whole Earth except the land mass Pangea. See related link for more information.
triassic
An era is a time period of indeterminate length, or, geologically speaking, a unit of time, smaller than aeons and greater than periods.
The Vikrama Era is the earlier/oldest of the two. The Vikrama Era began about 56 BC, whereas the Saka Era started about 78 AD, roughly 135 years after the Vikrama Era.Please see the related links below for more information.
The oldest named Era was the Eoarchean Era from 4 to 3.6 billion years ago. This was preceeded by the Hadean Eon (4,576.2 to 4,000 Ma) but this so far is not subdivided into eras.
An anticline is a convex fold in the landscape. It has the freshest part at the top with the oldest part in its centre. It looks like a ripple in the sea but is on land.
Deimos is not geologically active.