Does the Holy Quran gives the concept of flat earth?

*This question is not related to these two verses only. These are just for reference.* Many searchers say Islams give the concept of flat earth which is contrary to what it is. > Sura An-Naziat (79:30) > > And after that He spread the earth; and > Sura Al-Kahf (18:86) > >Until, when he reached the setting place of the sun, he found it setting in a spring of black muddy (or hot) water. And he found near > it a people. We (Allâh) said (by inspiration): "O Dhul-Qarnain! Either > you punish them, or treat them with kindness." among many others. I have also come across Muslim brothers who believe the mountains act as pegs so that earth can not move. Is this a correct interpretation from Quran? Can we interpret from the Holy Quran, the earth is flat or it is round or it simply shed no light on it.