A very quiet part of section in this London area (7)
I believe the answer is:
wapping
'london area' is the definition.
(Wapping is a district of London)
'a very quiet part of section in' is the wordplay.
'very quiet' becomes 'pp' (musical abbreviation for pianissimo).
'part of section' becomes 'wing' (I can't explain this - if you can you should give a lot more credence to this answer).
'in' indicates putting letters inside.
'a'+'pp'='app'
'app' inserted inside 'wing' is 'WAPPING'.
'this' acts as a link.
Can you help me to learn more?
(Other definitions for wapping that I've seen before include "London Docklands district" , "using mobile technology?" , "part of our capital" , "London area" , "Murdoch HQ" .)