Diverse would seem to be an appropriate description: from most research, the Gulf & surrounding area was an extensive region of river valley and wetlands particularly during the transition between the end of the Last Glacial Maximum and the start of the Holocene period.
Human settlement flourished in northern Oman & the Persian Gulf as it was less arid (transitory) than other regions in the peninsular.
David A Lockwood 
I wonder what the climate was so long ago….like the Sahara, green? Interesting. thanks.
Diverse would seem to be an appropriate description: from most research, the Gulf & surrounding area was an extensive region of river valley and wetlands particularly during the transition between the end of the Last Glacial Maximum and the start of the Holocene period.
Human settlement flourished in northern Oman & the Persian Gulf as it was less arid (transitory) than other regions in the peninsular.
David.