"astonished about" is a correct and usable phrase in written English.
It can be used to express surprise or amazement about something. Example: I was astonished about how quickly the storm moved in.
In his typically unaffected fashion, Cade was astonished about the fuss.
I was astonished about the gap that existed between the patriotism surrounding British football and the scepticism about continental football.
"I am endlessly astonished about the rigid and hostile views and arguments over nothing," he said to me in an e-mail about the photography forums he visits.
And I am still astonished about the number of women in their 30s, 40s and beyond who care about what their mothers or sisters think of their housekeeping.
The result is simultaneously astonishment, and the sort of synaptic buzzing that comes with having to recap and untangle what it is you're astonished about.
What astonishes about his designs (you can see them online) is just how thoroughly childlike, in shape and detail, they were.
The jazz-centered bassist, singer and songwriter ESPERANZA SPALDING astonished just about everyone, probably including herself, when she won the Grammy this year for best new artist.
But what astonished me about Tokyo, on visiting it for the first time, in the fall of 1975, was how much it resembled a Tenjo Sajiki theatre set.
Members of other remote tribes occasionally visited Bakairí Post, and Jack and Raleigh soon saw something that astonished them: "about eight wild Indians, absolutely stark naked," as Jack wrote to his mother.
During four years of wonderment, one of the things that astonished me about the house was the extent to which politicians, once they are established in it, are capable of leaving their common sense behind.
What astonished scientists about the original artwork was not just the age – the Chauvet paintings were twice as old as those in Lascaux, in the Dordogne – but the artistic virtuosity.
