The record of Cain's genealogy is halted— Eve has given birth to another son:
Adam had relations with his wife again; and she gave birth to a son, and named him Seth, for, she said, "God has appointed me another offspring in place of Abel, for Cain killed him." (Genesis 4:25)Since Seth was Abel's replacement, it is reasonable to assume that Seth was the first son that Eve bore since Abel. There is, however, some question as to when the birth of Seth took place. Is the account of Seth's birth in chronological order with the previous passage (Genesis 4:17-24)? Was Seth born after Lamech's three famous sons (Jabal, Jubal, and Tubal-cain)? Or did Seth's birth occur around the time when Cain's son Enoch was born?
No definite answer can be given. If the account of Seth's birth is in chronological order with the account of Cain's descendants, then no more than 130 years could have elapsed between the the creation of Adam and the birth of Lamech's famous sons (it is definitely known that Adam was 130 years old when became the father of Seth (Genesis 5:3)— if the people mentioned in the account of Cain's early descendants were born before Seth, then all of Cain's lineage mentioned in Genesis 4:17-22 must have been born within 130 years of the creation of Adam).
Several generations of people were born (originating from Cain) in the passage prior to the account of Seth's birth (see The City of Enoch for more information on Cain's descendants). It is important to piece the years together in order to demonstrate the plausibility of only 130 years elapsing between Adam's creation and the birth of Lamech's famous sons. If Adam was 5 years of age when he gave birth to Cain— and if 20 years passed between the birth of each of Cain's descendants— and if it took an additional 25 years for Lamech to become the father his three famous sons— then when these years are added together, the number of elapsed years is equal to 130 (which is equal to the number of years Seth was born after creation). Below is a diagram which should restore your sanity if none of the above numbers made sense (take note that the blue numbers represent the amount of time since creation — for instance, according to this diagram Enoch was born 25 years after creation).
And so while it is certainly possible to know when Seth was born (130 years from creation), it is not possible to determine how many years elapsed in Genesis 4:17-22. However, it has been demonstrated that if Seth's birth is in chronological order with the previous passage, then it is possible for all of the people in Cain's genealogy to have been born within 130 years of creation. Whether Seth was born after Lamech's sons or not— clearly both scenarios are plausible.
The Birth of Seth - Genesis 4:25
Righteous Men of the Pre-Flood World - Genesis 4:26
Lamech's Song - Genesis 4:23-24
The Genealogy Introduced - Genesis 5:1-2
Enoch: A Prophet in the Pre-Flood World - Genesis 5:21-24