Adam and Harriet plus Richard William Girven were in Thames in 1870, this was during the 1867 to 1872 Goldrush, the goldfields having been proclaimed on 30th July 1967, but it was only companies that had the necessary machinery were able to process the quartz containing the gold. It looks like they had gone to Thames with J Moody the Manager of the Hikurangi Coalfield, J Moody along with Hannah's parents William and Jane Ball, all three families had gold mining claims.
To try to give dates for this, Richard William was born on 6th July 1868 in Kawakawa and Margaret Anne Girven was born in 1872 also Kawakawa, but Elizabeth Jane Girven their second child was born in Thames in 1870 during this Gold Mining time.
If you click on this link http://www.kaelewis.com and enter Girven in the search box, then you will find that Adam Girven had a gold claim at Karaka in the Thames area in November 1869, William Ball also had two claims registered in July 1969 and the Moody’s had two claims registered in August 1969. this implies that they went to Thames in about July 1969 when Richard William was about 1 year old.
I have found a description of those those exciting days in the following link, Theophilus Cooper’s Diary of his seven weeks from 1st November to the 20th December 1867 at the Thames Goldfield gives an intimate day by day picture of life on the northern goldfields.This says that by March 1868 Thames – at the time called the town of Shortland (which, joined with Grahamstown, was later renamed Thames) was beginning to enjoy a period of prosperity.
A Diggers Diary.
http://freepages.genealogy.rootsweb.ancestry.com/~babznz/diggerdairy.html
T P Moody Photo 1900
The Thames Area
THAMES Goldmining
Adam and the Thames Goldrush
A Diggers Diary
Thames Goldrush days
Adam Girven - Thames Goldminer