Ann: NSE Presentation for Euroz Oil & Gas Confere, page-15

re: Ann: NSE Presentation for Euroz Oil & Gas... Hi Anatol,

The isostatic rebound I was referring to isn't really realated to the glaciogenic reservior plays you mention, however glaciation of course is. There's plenty of info on post glacial rebound on wiki here:

http://en.wikipedia.org/wiki/Post-glacial_rebound

I just think it's cool the rate at which nature responds to change and that these rebound effects could continue for another 10,000 years! And these are such short times on the geologic time scale. It's mind boggling!

Anyway, I read through your post and wish to contribute the following. I'll keep it as basic as possible as I don;t really have the time to go into huge detail and the detail isn't that relevant, it's the general concepts that are.

The Ordovician was a time of rising sea levels and warmer temperatures causing marine transgressions (flooding of the land surface) across glacial topography (as in the land forms were largely formed by previous glaciation during late cambrian/early ordovician).

we have two kinds of plays here:

Firstly - as the sea level rose, the land was progressively flooded. Swamps and estuaries were (as they are today) areas of high organic content and it is these zones which eventually form the sweet spots. They were in paleo-lows and are therefore patchy = hard to explore! Thus hitting the sweet spot could be huge.

Secondly - toward the end of the ordovician we have the late ordovician ice age and this was a huge extinction event for planktonic lifeforms. These all died and sank to the sea floor where they were subsequently buried and are another potential source.

So there are two possible plays - the smaller, patchier sweet spot, and the larger scale regional source. I'm not sure which or if both apply, but the Goldwyer is ordovician in age.

So yes the concept of glaciogenic reserviors applies!

In a broader sense we also had the following occur:

1. Cambrian-Ordovician - basin wide extension occuring = increased accommodation space = increased burial = less chance for organic matter to oxidise at surface. (Goldwyer formation)

2. Silurian-Devonian - basin wide compression = less accommodation space = less burial or uplift = oxidation at surface

3. Devonian-Carboniferous - basin wide extension again (Laurel formation)

4. Pretty much compression ever since

ps. Carboniferous period was named that as it means coal bearing as there are many coal beds formed globally during this period, and if you're getting coal formed from organic matter, why not some organic rich shale or some oil and gas that matter?

These two links are very good reads:

http://www.dmp.wa.gov.au/documents/1Canning_Basin_SRK_Report%282%29.pdf

http://www.geolsoc.org.uk/webdav/site/GSL/shared/pdfs/events/abstracts/Glaciogenic%20Reservoirs.pdf