Saturday, March 10, 2012

Notes: Week of March 9

We humans tend to make patterns where there are none - this is a normal quartz intrusion

Photos this week are a collection representing the artistry to be found in rocks...Each rock has a story to tell, as well as beauty in itself. These rock were once sedimentary sand and gravel, then compressed and heated deep in the earth. The Sierra Mts. are mostly composed of granite, but this is typical of the older cap rock found above the granite... these are all metamorphic rocks from over 10000 ft. in Tuolumne.

Quartz veins injected into fractured granite rock

Under great pressure, the rock mass was super heated so that liquified quartz could be injected into rock cracks. The metamorphic rock was heated to a softened condition but keeping some of its original sedimentary character… At some later time conditions changed and it was able to cool.

A metamorphosed sedimentarty rock heated and contorted to produce folds

Later the rocks were raised over long periods of time by the shifting earth crust to elevate it to its present height… then erosion by water and ice have exposed it… Last, the surfaces were cut and polished by the action of glaciers into the surfaces we today…

Iron compounds leached out of parent rock and deposited on metamorphic rock


I am a gambler this time of year – We may still have cold nights with light frost – but maybe not… So I think its time to plant tomatoes!

Metamorphosed sedimentary rock, cut and smoothed by glacier action - note striations

I know the common wisdom to wit until late April or early May – but we have a south-facing wall with great heat even now – and my early tomatoes take off.

Metamorphosed sedimentary rock with quartz intrusions, then folded to form striations

Starting tomatoes is all about preparing the soil! I dig a hole for each plant at more than a foot deep and a foot wide and refill with a rich blend of organic material mixed with soil. I use compost, horse manure but you can add any good organic material.

Quartz intrusions through granitic rock, then iron compounds added

Small plants are available in the nursery now – For several years I have grown Ace and Early Girl varieties… Here in the bay area we just don’t have the heat for a good crop of most of the “heirloom varieties –

Granite was fractured, then large heated quartz intrusions added

I have tried them and while I get a few tomatoes – its just not a good crop. I can count on lots of tomatoes over the entire season. Ace tomatoes are about tennis ball size and Early Girls are a bit smaller.

Rhyolitic flow: Obsidian with a lot of ash suspended in the liquid rock, cooled at surface

I plant the small plants deep so that at least two inches of the stem above the original soil line is covered with my soil. As you plant them, create a watering ring around each one. Then soak well.

Higher quality obsidian

With my dogs I also surround each plant with 4 vertical sticks to prevent them “accidentally” lying on top of them.

The bottom end of a small glacier - Ice causes much faster shaping of rock than flowing water

And don’t forget to treat each plant with snail pellets!

Now should it be that a frost wipes them out – I’ll just do it again!

Sedimentary metamorphic rock turned 90 degrees and then cut and by glacieral action