Journey to the perfect stir-fry!

The latest creation occurred quite a bit by chance. The simplicity was actually down to limited ingredients remaining in a depleted fridge and store cupboard. The result was texturally surprising with a great meld of flavours to top it off. Remarkably cheap at AUD$4 per serve, taking a leaf out of 'Save with Jamie'.

Here you go: Serves 4

1 x 250g pack of 4 slabs of extra firm tofu (Thai seasoned but patted dry) cut into wedges about 5 cm long, 1 cm wide; spray lightly with canola oil and sprinkle with salt.
3-4 Tbsp black bean and chilli mix (a variety that is quite salty and oily).
3 rings of soba noodles (about 200g).
2 small capsicum bell peppers (1 red, 1 green) or 1.5 large ones cut into wedged strips about 6 cm long, 0.5 cm.
1 large carrot cut into strips about 6 cm x 1 cm x 2 mm.
3 cloves garlic coarsely chopped
1 Thai red chilli coarsely chopped, including seeds.
1 Tbsp coarsely chopped ginger
1 small or 1/2 large brown onion cut into 1cm wide strips

Procedure [with notes]
Bring large wok to high heat and spray on a few squirts of canola oil. Add tofu and stir-fry using a after it starts to brown add 1 Tbsp of black bean-chilli mix. Continue to fry until crispy and set aside in a mid-sized metal bowl. [This puts a lot of oil into the room, so best to do this outside if possible...on a BBQ side-stove works well as they usually have high-flow gas burners.]

Start off the soba noodles boiling for 3 mins.

Add capsicum to the wok. Once fried add it to the metal bowl. [This allows most of the moisture to leave independently of the other ingredients so that they do not steam...it also allows the capsicum to fry down well themselves without steaming.]

Add onion, carrot and some more canola oil to the wok. After 1 min, add the chilli, garlic and ginger. After another minute add the rest of the black bean-chilli mix shortly followed by the contents of the metal bowl. Stir well and then allow flavours to meld while off the heat as you drain the noodles well. [Again noodles need to be drained well and then added immediately to the wok so as not to add moisture to the dish and also so as not to give them time to stick to each other.]

Add noodles and mix well while cutting down through some of the noodles to shorten their length to about half (i.e. about 10 cm). [The combination of these relatively short noodles and the wedge-shaped cuts in the veg, together with the overall dry and sticky nature of the dish makes it easy to pick up with chop sticks. The attention to texture really makes the flavour leap out in the mouth too.]

Serve in bowls, eat with chop sticks! Probably goes well with a lager but when you smell the food, that won't be high on the list of priorities.


A day in the life of Perth's summer heat waves and a climatic outlook

The above graph shows the temperature as measured in Perth (blue dots) every half hour over the last 4 days. The spiky one going up to nearly 45 C was today. The hottest two days show that the sun does its work in the mornings at a similar rate but starting at different night time temperatures (i.e. the slopes are the same). All the days show a marked drop off as soon as the sea breeze starts to hit whereby the wind direction flips from east to west and we get some cooler sea air affecting the temperature. There is often the sharpest shift of the day associated with this. The red line shows the Pearce Air Base today (5th Jan) which is currently experiencing thunderstorms. At 2 pm it had a huge hit whereby convection was initiated and clouds formed producing a massive 8 degree fall in just 30 mins. The overall trend in the evenings is one of gradual decline however and it shows how the sun's energy dissipates slower than it is received in the morning due to city concrete radiating it back into the air. We can also see that the nice cool evenings of last week have been superseded by 24C night time minima owing to a new air mass swinging in from the east. This is due to the precession of large air pressure gyres typically going from west to east, producing large-scale change in wind patterns.

The second of my weather-related musings involves a 120 year look at Perth's climate using average monthly data since 1876. See below:

Each dot represents an annual average from a 20 year period. The vertical scale is the same in both plots showing average monthly rainfall for each year in mm which varies considerably from over a metre down to around 40 mm in the most recent decade. The horizontal scale in the upper graph is the average minimum temperature for the year; the lower plot has the average max. The black line with grey dots shows the average of these statistics for a 10 year period, ending up towards the drier end in each case.

Clearly, a significant turning point is reached in the 1930s to 40s where a cooling max and warming min temp switches to a pulse in wet weather. Then the max temp just continues to rise and we get dryer. At the same time the min increases dramatically, then decreases dramatically and now we're on a slight increase again.

So its not a story of all doom and gloom but there we are in two decades of the hottest and driest times it has been since 1876. However it is conceivable that prior to 1876 it was also hotter and dryer, similar to today, according to an extrapolation on the lower graph. 2010 and 2006 were the driest two of the last 120 years. Therefore, if we are indeed entering a new age of global warming (i.e. beyond what can be explained by the early phase of the industrial revolution) then we are in for hot and dry times. The next few decades will be interesting in Perth because we may either see a return to the seemingly cyclical behaviour on a ~150 year scale...or we'll go off on a new path to uncharted and dry territory.

Understanding some odd mineral and rock combinations

Here I try to chat about and list some definitions (as I understand them at least) associated with some loose geological terminology revealed by various groupings of minerals and rocks used by geologists.

Firstly, there are processes whereby groups of minerals are formed, and these are given rock names. Secondly, there names given to groups of rocks, which require an interpretation about the way they formed. Thirdly, there are groups of groups of rocks, which stretch the bounds of what we can say reliably.

(1) Groups of minerals

As an intro 'exsolution' is where phases (usually 2-3) crystallize at the expense of a host crystal and form as lamellae. The exsolved products as a whole is the same composition as host. The geometry of exsolved phases is typically crystallographically controlled. e.g. Perthite: 'Rock' name for exsolved feldpars.

Symplectite: phases (usually 3 or more) crystallize as a corona around host crystal. Composition may vary slightly, involving originally adjacent phases.
Kelyphite: Type of symplectite formed around garnet, typically from kimberlite where it reacts with volcanic liquids to form fine-grained intergrown serpentine+phlogopite+oxides
Myrmekite: Type of symplectite formed within K-feldspar, cosnisting of intergrown quartz and plagioclase.

There are also other kind-of-symplectites which are alteration products of particular minerals involving partial oxidation and/or hydration:
Pinite: Hydrous alteration of cordierite yielding intergrown muscovite+illite+smectite+other clay minerals±oxides
Bastite: is a textural term for platy replacement along cleavage planes in orthopyroxene and rarely clinopyroxene.
Leucoxene: Oxidation of titanium-bearing minerals yielding intergrown rutile+clay minerals+Fe-oxides
Iddingsite: Oxidation ± hydration of olivine yielding intergrown smectite+hematite±Fe-hydroxides
Saussurite:  Oxidation + hydration of plagioclase yielding intergrown epidote+sericite±scapolite

Cancrinite: Single mineral formed as as result of hydration and cabronation of nepheline....countless other examples of hydration which forms single replacement minerals ...

(2) Groups of Rocks

On the other end of the spectrum there are many (often debatably used) rock names referring to groups of rocks. Typically the useage is process-oriented and hence interpretation rather than observation is implied:

Ophiolite: sequence of mafic-ultramafic volcanic and intrusive rocks produced as a result of sea-floor spreading, forming typical oceanic crust. This is then thrust onto continental crust and hence preserved resulting in 'ophiolite'.
Migmatite: literally 'mixed-rock' formed of host, melt and restite components. Strictly, melt is derived from in-situ melting of the host but term is also used generally for melts which are injected into hosts.
Amphibolite: a metamorphic facies describing all rocks that have been taken to medium pressure and temperature. Also, specifically referring to a metabasalt composed primarily of amphibole and plagioclase. Granulite, eclogite, blueschist also refer to facies.
Meteorite: wide compositional suite of extra-terrestrial rocks which have landed on earth.
Boninite/Komatiite/Kimberlite: (others): Suites of volcanic rocks defined by their geochemical composition and may easily be confused with similar rocks formed from very different tectonic processes.
Cataclasite/breccia/mylonite: fault/shear zone rocks of particular grain size and texture distributions.
Turbidite: sequence of greywackes and mudstones interlayered (may be formed of repeated 'Bouma sequences') as a result of turbidity currents in the middle depths of oceans.
Hyaloclastite: Volcaniclastic rock consisting of transported broken glass.
Biomicrite: Limestone made of shells set in carbonate mud.
Olistostrome/Olistolith/Melange: useage implying landslide/tectonic activity yielding a mixing of rocks.

(3) Groups of groups of rocks

Groups of groups of rocks are even more strange and interpretive leaving geoloists questioning such things as plate tectonics, plumes and long geological timescales. Some of these are:

Continental/oceanic arcs
Continental/oceanic plateaux
Coninental margins
Impactites/impact structures
Terranes (continent/microcontinent fragments)
Greenstone belt