Editorial
October 2010
The UK has absolutely splendid
geology, we are all agreed, but apart from geomorphological processes and
sedimentation in our seas and water bodies, the greater glories of
actuo-geology (if I may be permitted to invent a new word) are largely denied
to us. By actuo-geology I mean glaciers, plate boundary phenomena (i.e.
volcanoes, earthquakes, thermally active areas), etc, actually doing their
thing before our very eyes, now, as we witness it. The most recent UK
volcanism, for example, took place 50-60 million years ago. However, the world
being a wonderful place, if one is prepared to travel, almost any geological
process can be seen happening right now. And nowhere, in my opinion, beats New
Zealand for sheer breadth of experiences available to the geo-tourist. What
this is leading up to of course, is an excuse for me to tell you about our
holiday to NZ for the month of September. Joanne was to deliver a talk at a
conference in Auckland, so we decided that if we were travelling all that way,
we might as well stay for a month, hire a car and see as much as we could. We
knew generally what to expect from background reading, but nothing prepared us
for the sheer spectacle and thrill of standing in front of the Franz Josef
Glacier (or the Fox Glacier for that matter) and getting an on-the-spot
tutorial of exactly how glaciation works. To see U-shaped valleys in the course
of formation, moraines being dumped, hanging valleys being created, outwash
gravels and sands being deposited at my feet, was an awe-inspiring experience
for any red-blooded geologist. Just the scale of it all is overwhelming, but
then it is realised that this is only one little glacier in a shrinking field.
I tried extrapolating it in mind’s eye to a glacial landscape from horizon to
horizon, and got just the merest glimpse of what the Pleistocene and other
periods of global ice really meant.
From that cold world it was possible only a day or so later to
experience quite the opposite, where it is heat and magma that drive the
landscape. As everyone knows, a major plate boundary runs along the western
side of the South Island and then dodges somewhat to the east of the North
Island, and the interraction between the two plates is responsible for the
creation of the Southern Alps and all the earthquake and volcanic activity. The
volcanoes are largely quiescent these days, and significant eruption has almost
ceased, but there is lots of other activity, particularly around Lake Taupo
(itself a magnificent example of a
crater lake on a vast scale) and Rotorua. You ain’t heard nothin’ until you’ve
listened to the contented plooping and plopping of a bubbling mud pool. And to
watch a geyser suddenly going off before your eyes, or see the wonderful
multicoloured terraces created by mineral-rich steaming streams and springs, is
a special experience.
But living near a plate boundary can have serious drawbacks, and we
received a salutory lesson in just how vulnerable NZ is when we heard about the
Christchurch earthquake as we woke on our second day in Auckland. The whole
country was buzzing and wondering what it could do to help. 7.1 is quite an
earthquake, but incredibly no-one was killed. It wasn’t expected, at least not
along the faultline whose movement was responsible, but aid was rapidly
mobilised and the dedication of the aid-teams was remarkable. We arrived in
Christchurch a week after the ‘quake hit, expecting devastation everywhere, but
the place appeared almost normal. That was deceptive, as much of the damage was
not immediately obvious, being in the form of insidious but structurally
significant cracking in superstructure, drains, sewers, etc. That’s not to say
there weren’t any collapsed buildings, there were, but the pattern tended to be
that vulnerable and old buildings were picked out for destruction, while all
around, the majority remained standing.
As if the glaciers and plate tectonic landscapes weren’t enough, there
is seemingly an endless supply of other ‘wow’ scenery and geology, far too much
to go into here. The west coast fjords for example and the wild almost deserted
coast further north, or the untouched primeval forest that covers large areas,
particularly in the wonderful South Island. Only 4.1 million people live in NZ,
and 1.4 million of them in Auckland, so it is very easy to imagine you are the
first person to set foot in some of these special landscapes. My favourite?
Well, none of the obvious choices, but a very remote, bewildering and beguiling
area known as the Rangipo Desert, north of Waiouru and south of Taupo. I’d
never seen anywhere like it, it is crossed by only one road, State Highway 1,
which is known there as the ‘Desert Road’. The area consists of hundreds of
square kilometres of plateau created by the activities of neighbouring
volcanoes, completely empty and wild with a spectral beauty. Not a tree, just
low scrub and barren volcanic soils for as far as the eye could see.
Turning briefly to other matters, the Section broke new ground, at least
in our recent history, by having a field excursion in October. That wasn’t as
intended, but bad weather earlier in the summer meant that our trip to the
Ancaster area had to be re-scheduled for October 9th. A report on
the day will appear in the next Charnia, also one for the Bradley Fen trip in
September.
Andrew Swift