Today was a totally lazy day, in which I drove no more than
a 100 km. Too bad, because that means tomorrow I will have to go about 150 km,
but I had a late start and was not very motivated to cruise at high speed.
Rather I enjoyed the sights along the brand new road between Phan Ri and
Mui Ne. It is a beautiful coast, and in some places it looks like you could be
the only person in a 10-mile stretch of the beach.
The most memorable part of this leg of the trip was a vast
sand dune field that extended for good 25 km. I think the case can be done for
this being a very old sand dune field, because it has a distinctive
stratigraphy. The younger deposits are the standard cream or even white color,
but they rest over several hundred feet of older, slightly consolidated bright
brick orange (or brick red) deposits. The orange/red color is undoubtedly
linked to a coating of iron oxide around the individual grains, a feature that
has long be debated by geologists. The way I learnt it at school, red beds were
thought to be signs of arid climate. Not so, argued another group of
geologists, because the sands of Arabia are
cream colored, not red; rather, they suggested that red beds, like laterites,
indicate warm humid climate. But the young active dunes in Vietnam are cream/white in color, and nowadays Vietnam is the
poster child for warm and humid. Maybe I am just behind in my sedimentology, so
I am going to give the job of researching this subject to my students in
Sedimentary Rocks this coming fall semester.
Whatever the answer, I believe the red sand dunes were
formed under a different climatic regime than what we enjoy now. Perhaps the
results, at low latitudes, of the Pleistocene Ice Age?
I eventually made it to Mui Ne, which is getting ready to
become the next resort destination. At least six large resorts have been built
north of the town, and although they didn’t look like they were crawling with
guests, they look pleasant enough. Mui Ne is not like Puerto Vallarta , however, but a little town
with a couple of modest restaurants (in one of which I had an excellent lunch
of shrimp and pineapple stir-fry, and vegetables and seafood stir-fry) and a
couple of scooter repair shops.
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