Mysterious Tufa Towers: Hercule Poirot Explains
By David Carle, Park Ranger, Mono Lake
Tufa State Reserve
(with apologies to Agatha Christie)
"Ah, Hastings, my good friend! Your comments,
as always, are a great help to me."
"Well, I do my best," I said, modestly, but
feeling pleased that Hercule Poirot, for once, had acknowledged
my contribution. A strange sort of puzzle now occupied
the attention of the famous detective's "little
"Er, what exactly did I say, Poirot, that was
"You could not help overhearing the perplexed
female tourist who wondered out loud about the tufa
towers here at Mono Lake. And, as usual, you gallantly
responded. (You can never resist the auburn hair, eh,
Hastings?) Eh bien, you repeated to the woman all the
facts regarding tufa towers as given in the so-helpful
park brochure we acquired at the parking lot upon our
"Well, perhaps I did mislead her a bit about my
level of expertise," I admitted. "But the
explanation seemed quite clear to me: Mono Lake contains
carbonates something like baking soda. And freshwater
springs under the lake have calcium."
"Something like milk, I suppose," Poirot
murmured. "Tcha! These culinary comparisons make
one hungry. Or perhaps it is just all this fresh air
"Really, Poirot, I don't believe it is at all
like milk. The springs seem to be pure and fresh, but
have a bit of calcium dissolved in them. And that joins
with the lakewater mineral, building up calcium carbonate
towers around the springs." I waved an arm toward
the formations nearby, pleased to be able to clarify
the topic so for my friend.
I turned to face Poirot, whose famous egg-shaped head
was wrapped several times in a large wool scarf. The
only features showing were bright eyes, a slightly red
nose and the mustaches, of which he was so vain.
"It seems quite straightforward, Poirot. Certainly
no great mystery," I concluded, wondering again
what it was about this place that could have attracted
the famous investigator and problem-solver. It was rare
to find Poirot out-of-doors on such an excursion.
"So far as it goes, your explanation is clear,
my friend. And, by presenting it so simply, as I have
remarked, you help me again to see the true dimensions
of the problem. Regard, mon ami, how much remains unanswered
in your oh-so-simple explanation."
The little Belgian detective gestured toward a 20-foot
tower nearby. "When did it form? Eh, Hastings?
"And a somewhat different problem: how long did
it take to achieve that size? You perceive the difference
in those two questions?"
I started to answer, but Poirot was walking over to
the tower now, gesturing excitedly. "This shelf,
Hastings? Does it indicate a period when the lake was
stable and the tower could no longer grow taller, but
had to build out sideways?
"And here and here and here again, my friend.
Notice the different colors and textures. White. Red.
Purple, even. Some is smooth. Some rough."
He spun around to face me. "But there is more.
These are scientific problems, eh, Hastings? The scientists
know that some of the tufa towers are 14,000 years old.
And that there is iron and potassium and manganese imparting
different colors. But the scientists have other questions
which remain unanswered.
"Chemical questions, for example: Does temperature
affect tufa formation? Does algae in the lake influence
the process, by altering concentrations of carbonates
as the plants undergo photosynthesis? And are there
"Yes, yes, Poirot," I interrupted, trying
to stem the tide of information. "I see."
Although, honestly, my understanding of such things
was too vague for me to keep up with my friend's line
"Are there please do not interrupt, my
friend are there other minerals in equilibrium
with the final product we see on these large towers?
What has become of the springs which formed these towers
that we see now on dry land? Would they begin flowing
inside these very towers once again, should the lake
rise to cover this spot?
"And, most of all," here, Poirot swung me
around to face the lake itself, "what is going
on right now, eh Hastings, under the lake? Divers have
recently seen tufa material forming. But they have done
no detailed studies yet. Are the present-day conditions
suitable for building big, stable towers, or is the
material the divers saw too fragile to persist and grow?
"You see, Hastings. There are many, many unanswered
questions. Mysteries still abound here at Mono Lake."
"I do see, certainly," I said, feeling a
bit chagrined by his display of knowledge on the subject.
"But is this really your kind of puzzle, Poirot?"
I had a momentary, absurd mental picture of Poirot in
SCUBA gear. "There's no crime here; nothing requiring
your special knowledge of human psychology and criminal
behavior, is there?"
"True. These are scientific questions. But there
is an important human element." I felt he was smiling
at me behind that scarf. "Hastings, my dear Hastings,
do you not ever wonder why anyone asks such questions?"
"I'm afraid you've lost me, Poirot." In truth,
I was beginning to wonder whether my old friend was
going a bit ga-ga, perhaps seeking new kinds of mysteries
because Scotland Yard had not called on his talents
in so long.
Poirot chuckled and startled me not for the
first time by seeming to read my mind. "You
wonder if I have lost too many of the little gray cells
to old age, eh? No. I only ask the philosophical questions:
Who cares about these things? Why do we care? Why do
we ask questions, seek answers, try to solve the mysteries?
"Why, Hastings, are all human beings scientists
and, yes, even detectives? None, of course, have the
talent of a Hercule Poirot" (Modesty has never
been one of my friend's talents, I'm afraid.)
"But from the moment of birth until the day they
die, all humans are compelled to investigate and try
to understand their particular portions of this mysterious
world. Why, Hastings?"
"Well, I suppose we can't help ourselves. It's
in our nature survival of the fittest, and all.
Keep on learning or the sabre-toothed tiger may eat
you, don't you know?"
"Superb, Hastings! And there is the solution to
the mystery which has been puzzling you ever since I
told you of my intention to visit Mono Lake.
"Why did I bring you here? Because this place
is so strange. So different. Always I wish to seek out
such places, to continue exercising my little gray cells.
They will only wear out, you comprehend, if they go
"I cannot solve the mysteries about tufa towers,
Hastings. That is for others. But, my friend, I am glad
to have seen them and to have seen Mono Lake."
"Me, too, Poirot. Er, what mysterious place calls
next for our attention?"
"Ah. There is an ancient coastal forest northwest
of here, Hastings, which presents many intriguing problems.
A type of owl is found there, I hear. With the polka-dots,
as they say."
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