The other side of the log

[Bruce Williams]

Hi folks,

Not sure whether this is what Ken was asking for in my Microscope Forum posting Cell and ray detail in 48 million year old fossilised wood but here's a couple of pics showing the heavily (bubbly) agatized "other side of the log". I have also included a third one showing the fossilised bark (visible end is unpolished).

All three images are ~10 frame CombineZM stacks taken with Minolta A2 (underexposed by approx. 1 stop). The stacked results had a slightly "sharpened" look out of CombineZM so CS2 enhancement was just clean-up background and adjust levels only (ie, no USM).

Bruce

Log is approximately 10cm long and 5 cm diameter.

[Ken Ramos]

Perfect Bruce Exactly what I wanted to see but now what am I looking at? Could you please expound on the images a bit more, just exactly what are these...well, bubble like structures. These are outstanding I must say.

[Bruce Williams]

Hi Ken,

Those great looking bubbles are chalcedony, which is not a true agate but a form of waxy looking quartz.

The fossilisation process of wood from the Blue Forest Petrified Wood area is unique and quite well explained in this website:

http://www.thegemshop.com/eden_valley.htm

Bruce

[Ken Ramos]

Oh okay, so I see what I am looking at is actually part or all of an algal cast that has become filled in with quartz and other minerals after the wood dried and became petrified. I am supposing I am correct, eh? Interesting link and to think all this is about a four days drive from where I am currently at. Sheesh! That's almost two weeks round trip to go and look at petrified wood and maybe bring back a sample and a fossil or two.

Thanks for the follow up Bruce, a great and interesting post IMO.

[rjlittlefield]

These are beautifully clear photos, Bruce!

You commented that
Both stacked results had a slightly "sharpened" look out of CombineZM so CS2 enhancement was just clean-up background and adjust levels only (ie, no USM).

The standard CombineZM "Do Stack" macro has a sharpening step very near its end. Sounds like it worked perfectly in this case, but it's easy to delete that step or or it make less intense if necessary.

--Rik

[cactuspic]

Good sharp images, Bruce. The chalcedony is fascinating. Thanks for the follow up post.

Irwin

[beetleman]

Thanks Bruce for all the info on this specimen...very interesting reading

[Bruce Williams]

Thanks for your comments guys - your interest really is appreciated.

Ken - A four day drive eh. If I were to drive for more than 12 hours straight, in any direction, I'd be into serious underwater photography. Most ways and I'm treading water inside 3 hours.

Rik - Thanks for the information on CombineZM - I'll check out the various parameters tonight. I have to say that, with the exception of a couple of the more "difficult" stacks, I have generally been very pleased with the results out of CombineZM.

Irwin - I love this piece, it has something interesting from every possible angle and through the microscope too - and it looks good in the cabinet

Doug - When you have 5 minutes check out the following link (just the bit about digging for Blue Forest wood). It's a fun read and I think you'll enjoy it:

http://www.vgms.org/bt/vgms0002.htm#20

Bruce

ps The rest of you guys might enjoy the above link too