subasurf said..
You're looking at the canyon carved out by the old swan river that was formed back when the water level was so low you could walk to Rotto (we're talking about it being formed before the dinosaurs were wiped out about 65mya). There are some REALLY steep sections, as in vertical, and the ROV today was checking out a particular section about about 650m depth. There is a load of sediment and 'marine snow' that falls down onto the rock so the run today started at the base of an underwater sand dune, which they followed to the vertical section of the cliff.
Different colour can be from different mineral composition, but it's just as likely that it is due to biological processes, either in the past or current. A section hosting a colony of anerobic bacteria for example might cause an increased rate of oxidation changing the chemical make up of the surface it's growing on, therefore changing the way it reflect light (ie, different colour). The footage wasn't exactly clear enough today to tell. Would love them to drill out some core samples. However it's a pretty solid bet that any horizontal stratified changes in colour are from the layering of different materials over a long geological age, no different than how you see stratified layers in canyons on land (ie: Kalbarri, Grand Canyon etc etc).
Oh, as a side note, those two laser beams are exactly 10 cm apart.
Thanks for that. I understand the Perth Canyon. I was just curious on the rock colours and the sand.
I understand they are looking for Corals? Are they trying to find something particular
Is this mission anything to do with getting or stopping deep water drilling in the Trench
Sorry one more, the laser beams are 10 cm apart at the point if impact on the rock face
If so that really through out my perception of scale..
I had a good chuckle.
