Newer Pages dropped from Google Index

What's going on?

[Baraccus]

I've noticed that recently that nearly half of my pages that were cached and indexed as of late July, have now been dropped from the Google index entirely.

My pages are well-linked, included in my sitemaps, and my overall site is #1 for almost all of it's keywords, and has a PR4. The pages are new, original content, are not duplicated anywhere.

Now all these pages seem to have been dropped entirely from the index. There are now only 87 pages indexed, out of about 178 total pages on the website, all of which were indexed as of late July.

I am not using directory structures - all are in the first tier and all are linked from several other pages in the website. It appears that the pages I added more recently got hit a lot harder than pages that are older.

What is happening? Does anyone have any insight?

[F_Rose]

Thier must be a technical issue with your site..

Do you have only one url pointing to each page?

Have you done something recently that could of caused your pages dropping out of Google index?

[kidmercury]

pretty much the same thing happened to me, and i think it had to do with the sitemap that i was submitting.