Drillers Hit Magma Chamber

You know hamburger, you've had a darn good life. I envy you.

If molten rock went several meters up the borehole, then solidified, how are they studying anything except the surface of what solidified....or a little way int it?

The term "Dacite" is an igneous rock classification based on a system called the QAPF system. Igneous rocks are classified , simply, based on the percentages of free silica(Q) they contain (IE quartz), the chemical makeup of the feldspars (AP)within the mix (plagioclase is a calcium rich and high temperature feldspar, while orthoclase is a sodium rich and hence, COOLER feldspar), and lastly the amount of fwldspathoids (F) , the F, or Foid minerals are similar to feldspars but contain much less silica and more of things like aluminum and magnesium. Then on top, each of the rocks are classed according to grain size (Small grains are explosives and large grains are deep rocks).
SO the classification of a dacite, by the QAPF system ,means that this rock has a small grain appearance and a chemical makeup similar to granites and diorites, except, unlike granites, these are mostly primary melted rocks .

What the petrologist is looking at is the chemical and physical makeup of these rock types in a mantle mix. That can tell us how deep it was emplaced or its methodof crystrallization.

Dacites are often good metal ore producing zones so we often look for them as a princip[al ore carrier, especially if these rocks are emplaced right along side a sedimentary rock body.


anybody awake yet?

dlowan asked :



i wonder if they dip their little pinky in ?
a poor joke - i really don't know what they did .
i just remembered seeing that molten rock sliding into the pacific like some kind of a waterfall .

this website by the U.S. geological survey has quite a bit of interesting info - including video clips and web cameras .

http://hvo.wr.usgs.gov/

we had a local guide who told us that picking up and taking home lava pieces would surely invite bad luck (the volcano god would punish us) .
i slipped the piece of lava i had picked up and put in my pocket back onto the island soil before re-boarding the ship !!!
the guide also mentioned that plenty of envelopes and small parcels arrive from the mainland sending back lava rock <GRIN> .
hbg (i am NOT superstitious !!!)

gee hb you should come back to the Big Island. it is anticipated that we are going to have a major eruption in the near future. small earthquake acitivity has picked up.

merry andrew and I will be moving into a house april 1 in the golf course subdivision which is across the highway from Volcano Nationall Park.

always got a bedroom for you and mrs hb, actually bring your daughter and that fellow she hangs out with.

actually there is a sizable lava tube on our property which will make a great home for Claws our awesome black cat.

Yes and Madam Pele gets real upset when people take home pieces of her without leaving a donation. she is very fond of cigaretts and vodka.

Send back that rock HB, it's for your own good.

sglass :
while i had picked up a piece of lava rock , i did put it down again before re-boarding the bus !
mrs h still questions our sanity of walking across the fields when she sees the pictures with the staem rising - did not go off the marked trail , though .
we sure had a great time visiting hawaii - especially when enjoying a "lava cocktail" while sitting near the beach and seeing the sun set .
hbg