First results from a study into the abundance trends of oxygen in the Galactic thin and thick disks are presented .
Oxygen abundances for 21 thick disk and 42 thin disk F and G dwarf stars based on very high resolution spectra ( R \sim 215 000 ) and high signal-to-noise ( S / N > 400 ) of the faint forbidden oxygen line at 6300 Å have been determined .
We find that [ O / Fe ] for the thick disk stars show a turn-down , i.e .
the “ knee ” , at [ Fe/H ] between -0.4 and -0.3 dex indicating the onset of SNe type Ia .
The thin disk stars on the other hand show a shallow decrease going from [ Fe / H ] \sim - 0.7 to the highest metallicities with no apparent “ knee ” present indicating a slower star formation history .