GIBRALTAR'S WATERFALL                               9 I

   As Ryan listened, Sturani elaborated his interpretation that the eel had
 entered into a lagoon filled with brine except for a thin cap of less dense
 freshwater.  It had perished there, settled onto the oxygen-depleted sterile
 bottom, and been pickled.  The brine had sucked all the water from the
 tissues inside the eel through its skin via the well-known osmotic process,
 thus causing the body to shrink and the backbone to compress into the
 contorted skeleton so vivid on the screen.
   Ryan's thoughts raced back to his expedition to the Mediterranean aboard
 the Cbain a dozen years earlier when he had stood watch during an echo-
 sounding survey of the Strait of Gibraltar.  He remembered vividly that at the
 entrance to the Mediterranean Sea there had been hundreds of small, color-
 ful Moroccan boats fishing for eels.  It had been explained to him at the time
 that this was the eels' breeding ground.  Now Ryan realized why.  The dam,
 which five million years ago had kept the Atlantic water out of the Mediterra-
 nean, had been located at Gibraltar. it had also been a barrier to the eels.
 The high wall had effectively prevented the Mediterranean eels from joining
 their Atlantic relatives.
   It is well known that eels living today in European rivers that flow into
 the Baltic Sea and the Atlantic Ocean migrate to a breeding ground in the
 Sargasso Sea South of Bermuda, whereas those in European and North Afri-
 can rivers that flow into the Mediterranean reproduce east of Gibraltar.  Their
 copulation takes place at the foot of the long-destroyed dam in the Gibraltar
 Strait.  Ryan wondered if the memory of their former isolation had been
 stored genetically for millions of years.
   Dick Benson, a specialist in tiny aquatic Crustaceans at the National Mu-
 seum of Natural History at the Smithsonian Institution in Washington, D.C.,
 had his turn at the podium on the final day of the conference.  For him "the
 evidence for shallow seas or sea-lakes of rapidly changing salinity during
 the Messinian [a stratigraphic name for the time interval between 7.2 and 5.4
 million years ago during which the Mediterranean became separated from
 the Atlantic] appeared very convincing." in fact, the news was a bit anticli-
 mactic.  For Benson the greatest excitement was not from the anhydrite and
 desert sands but from the microscopic creatures in the marine oozes below
 and above the salt.  In his analyses of the Glomar Challenger cores, he had
 found tiny aquatic crustaceans belonging to species without eyesight that
 generally live in the cold abyssal waters of the deep ocean.  These he had
    discovered in the marine sediments, which like two pieces of bread form a
    sandwich bracketing the time between the initial evaporation of the Mediter-
    ranean and its reflooding.  These faunas could have returned to the Mediter-
    ranean within a few thousand years after the floodgate was opened in only
    one way.
       The Gibraltar dam must have collapsed catastrophically.  Salt water from
    the "bathyal realm" of the Atlantic had inundated the Mediterranean desert
    at the pace of thousands of Niagara Falls.  In the process the raging torrent
    had eroded the former barrier, incising the breach to perhaps one thousand
    feet below the level of the inrushing Atlantic.  Such a deep opening was
    considered necessary to siphon in the blind crustaceans from the abyss of
    the North Atlantic and deliver them, enveloped in salt water no warmer than
    40 degrees Fahrenheit, to the rapidly filling basins of the Mediterranean.  Had
    the portal not been wide open, Benson argued, an entirely different set of
    tiny crustaceans would have been found in the Glomar Cballenger cores.
       Although no humans lived five million years ago, had any been present,
    they would have witnessed the Mediterranean desert disappearing pernia-
    nently beneath a mile of salt water in a matter of a single human lifetime.

   In fact, as soon as the Mediterranean had been shut off from the Atlantic,
  the hundreds of specialized species populating its vast colorful coral reefs
  were rapidly annihilated.  Only one, Porites, was able to hang on as a reef
  builder-a feat achieved with tenacity and only for a relatively short time.
  Although perhaps not intuitive, stability is indeed the handmaiden of diver-
  sity in the long march through the corridors of planetary evolution.  Global
  change provides the punctuation for the Earth's story.
    At this point Pitman proposed that they consider an episode of aridity in
  the relatively recent past.  "How about sometime since the melting of the last
  continental ice sheets?" he asked.  Then without waiting for the reactions of
  the others, he volunteered: "I bet you would see caves and campsites aban-
  doned as hunters and gatherers were induced to migrate elsewhere for
  survival."
    Pitman was well informed about the Ice Age caves of France and Spain
  with their glorious wall paintings.  He continued, "When excavating the
  interiors of an ancient tell, perhaps you would come across a gap in settle-
  ment sandwiched between overlying and underlying floors of occupation."
  Such a period of total sterility had occurred a number of times in the severe
  desert conditions that had occupied the Mediterranean for several hundred
  thousand years during its isolation from the Atlantic.
    "All right," said Dewey.  "You look for seas turned into deserts.  You find
  deep river valleys and perhaps some weird inhabitants with strange behav-
  ior.  But how do you find the flood itseIP"
    Ryan replied, "By the same sudden replacement of the fauna I just told
  you about!" The floodgate that had opened at Gibraltar five million years
  ago allowed the entry of marine plankton, fish, and sea mammals to replace
  completely the desert vagabonds and squatters.  The filling of this huge
  depression may have taken less than a century.  The creatures that inhabited
  the new seabed took a bit longer to reach their final destinations than those
  that could swim or float passively.  But the replacement was essentially ac-
  complished in a flash of geological time.  Ryan added, "Of course, those
  species in the outside ocean that became extinct after the dam had been
  erected were no longer around to celebrate the good old times once the
  barrier came tumbling down."
    "And what became of those in the way of the flood?" asked Dewey.
    Ryan thought for a minute.  He then responded, "Charles Lyell reported
  a whole bunch of mammals suddenly appearing out of nowhere on the
  Mediterranean islands, such as Sicily, Sardinia, and Malta.  Maria Cita men-

    tioned this to me on the Glomar Challenger.  There are elephants and hippos
    in Cyprus and Crete.  In scrambling to high ground in response to the flood
    they arrived in places they had never been before."
      To the three scientists gathered around their languishing reconstruction
    of the Alps, the most useful clue for identifying Noah's Flood had emerged.
    It was to look for human refugees driven into exile by the water reclaiming
    the territory they had formerly occupied.

                   Pontus Axenus


BILL Ryan had been giving considerable thought to the subject of
   faunal replacement.  Not only had he discussed it with Maria Cita on
   the Glomar Challenger, but he had also started to read about it in
   scientific journals.  Somehow, however, he missed the very story he was
   hoping to find.
     In early October 1970, Thee New York Times reported under a four-column
   headline that the Mediterranean Sea had been "a land-locked basin where,
   through evaporation, little was left but a salt plain." Ryan had been so
   absorbed in this announcement of the results of his drilling expedition that
   he failed to see an article published simultaneously in the journal Science,
   the prestigious weekly publication of the American Association for the Ad-
   vancement of Science.  It concerned the recent sedimentary history of the
   Black Sea.  Beyond lacking a catchy title, any reader would have had to
   probe deep into its jargon-filled text to learn that something remarkable had
   been discovered.  Yet there in both words and pictures lay a finding as
   significant as the great Mediterranean flood.
     A replacement of fauna had indeed happened.  And it had transpired not
   five million years ago but as recently as the last ice age when modern man
   roamed widely throughout both Europe and southwest Asia.  The reported
   metamorphosis was not of a sea becoming a desert and then returning to a
   sea, however.  It was instead of a former sea that had turned into the world's
   largest freshwater lake and then back to a sea.  Its fish, plankton, crustaceans,
   mollusks, and coastal plants had all been affected.  Those species that had
   formerly colonized a saltwater habitat were replaced species by species by
   those adapted to freshwater.  Then the freshwater species had disappeared,
   and in their place the saltwater ones had returned.

        The lake had persisted for thousands of years.  It vanished once it re-
     connected with the Aegean arm of its neighboring Mediterranean Sea.  The
     Science article noted that the reentry of salt water had occurred sometime
     between twelve and seven thousand years ago.  Apparently not a single
     species of the earlier freshwater environment survived the transition back to
     a sea.  Most of the lake inhabitants were annihilated as the salt content rose.
     Those that survived were able to hang on only by seeking refuge in the
     Black Sea rivers.
       The increase in salinity created the Black Sea that we know today-the
     body of water explored during the mythical voyage of Jason and his
     Argonaut crew in their quest for the golden fleece.  Until this era of the epic
     hero, the land surrounding the Black Sea had remained essentially terra
     incognita.  Historical records date the foundation of the earliest seaports to
     the mid-eighth century B.c. These and other frontier trading posts estab-

  lished in the course of the following century gave the merchants from the
  Aegean and Ionian seas access to rich granaries, nearly endless stands of
  timber, and hoards of precious metals.
     In his Natural History, Pliny the Elder described the Black Sea as "having
  swallowed up a large area of land which retreated before it." He gave it
  the name Pontus Axenus (from the Greek axenos, meaning inhospitable),
  mentioning that without abundant islands to shelter sailors in the notoriously
  brutal storms, an open crossing of such a vast body of water would almost
  certainly have brought peril.  The Turks of the Middle Ages, in similar fright
  of being shipwrecked on its wave-tossed surface, called it Karadeniz, the
  black sea, harbinger of death.
     The research announced in Science had developed quite by mischance.
  A team of geologists and chemists at the renowned Woods Hole Oceano-
  graphic Institution on Cape Cod, Massachusetts, had hoped to return to the
  Red Sea in the summer of 1967 to follow up some earlier discoveries.  But
  the scientists' plans were canceled when war broke out between Egypt and
  Israel.  So the researchers decided, after steaming into the eastern Mediterra-
  nean Sea, that instead of turning right to Port Said and the Suez Canal, they
  would go left into the Aegean and on to the Black Sea.  The Woods Hole
  team was led by David Ross and Egon Degens.  Their ship, Atlantis II, was
  commanded by Captain Edmund Hiller, the same skipper who had directed
  the Cbain when it sailed into the Black Sea in 1961 with Bill Ryan aboard.
    In place of a greeting from a Soviet escort destroyer after passage through
  the Bosporus, Atlantis ligained the attention of a Soviet four-engine bomber
  that leveled off at masthead height on the first of a dozen or more terrifying
  passes.  When the roar of its turbine engines at last faded away, the sky
  darkened, and the wind began to whip the sea into a tempest.  By nightfall a
  gale had intensified to near hurricane strength.
    With characteristic impatience Ross and Degens had already stopped
  Atlantis II for a first attempt to sample the bottom sediments, even while still
  being buzzed from the sky.  The coring tube had reached the seabed when
  Captain Hiller decided that the exercise should be aborted.  However, with
  the ship heaving in the mounting swell, bringing the heavy gear aboard was
  fraught with serious risk.  The forward thruster alone, unassisted by the
  action of water flowing past the ship's rudder, was slowly losing its ability to
  keep the bow of the ship pointed into the wind.  Hiller was sure that if
  Atlantis II fell off her heading and slipped into the trough of the sea, they
  would then roll at the mercy of the storm.
    Fortunately, after an arduous struggle, the seasoned deckhands delivered
  the coring device back on board and lashed the mud-filled tube to the deck.

   By mid-morning the next day, when Degens strolled out on the afterdeck,
   the sky had cleared and the surrounding sea was subsiding.  Wandering over
   to the coring device, immobile in wood chocks and chains, he noticed jet
   black mud oozing from the end of the tube despite a valve installed to
   prevent such an incident.  A sizable puddle of the soft gelatinous material
   had accumulated on the deck.  Disheartened, Degens checked whether the
   valve had properly closed.  It was indeed shut, but the gunk was still leaking
   out; something was forcefully extruding it!
      A sniff of the air solved the mystery.  An invisible gas, a poisonous combi-
   nation of hydrogen sulfide and methane, slowly vaporizing from a former
   icelike state in the abyssal graveyard of the sea, was expelling the core
   material.  To disassemble the core tube safely in the open air Degens used
   an electric-powered screwdriver.  He removed the twenty-foot metal sheath
   and scraped the exposed face of the recovered sediment with a clean spatula
   to expose its internal layering.  The top forty inches was a dark black, jellylike
   mud.  Below the material was a light gray clay.  The black mud revealed
   hair-thin white bands at a density of approximately one hundred stripes per
   inch, stacked one upon the other.
      Everywhere Atlantis II went to recover additional cores the sequence of
   black mud overlying light gray clay was the same.  The black mud was
   gorged with plant and animal remains.  At some levels its content of organic
   carbon reached an astonishing 50 percent of the bulk dry weight of the
   sediment, whereas in typical sediment from oceans like the Atlantic or Pa-
   cific the enrichment is only a tiny fraction of 1 percent.  When viewed
   through a microscope at high magnification, the thin white bands turned out
   to be composed entirely of the skeletal framework of a single species of
   plankton that lived near the sea surface where it could be bathed in sunlight.
      More powerful magnification of the organic soup revealed membranes of
   proteinlike structures.  No one expected that the long-dead tissue and its
   amino acid building blocks could be preserved in such exquisite detail.  The
   organic residues were thousands of times more enriched in the gelatinous
   black mud than in the underlying light gray clay.
      At first glance the older clay deposit below the black mud had no visual
   treasures.  When the clay was put in a press to squeeze out its pore fluids,
   however, the extracted water was fresh.  In fact, it was so low in dissolved
   salts that had there been enough to drink, it might have tasted like mineral
   water from a mountain spring.
      Ross and Degens composed a compelling story.  In the past the Black Sea
   had transformed itself into a lake; it was linked to the Mediterranean only
   by a narrow outlet not deep enough to permit the continued entry of marine

  water from outside.  This condition had been established more than twenty
  thousand years ago when ice sheets covered Scandinavia, northern Europe,
  and all of Canada.  The building of continent-sized glaciers to a mile or more
  in thickness, as first envisioned by Louis Agassiz, had caused the withdrawal
  of global sea level below the level of the floor of the Dardanelles and
  Bosporus Straits.  When the ice over Russia eventually began to thaw, much
  of its meltwater was delivered into the Black Sea's Ice Age lake.  The light
  gray clay in Ross and Degens's cores came with the meltwater as a milky
  suspension via the Danube, Dnieper, Dniester, and Don rivers.
    Eventually there came a time when the giant lake turned back into a
  saltwater sea.  This event was marked in the Atlantis II sediment cores by the
  abrupt change from light gray clay to black mud and by the simultaneous
  disappearance of the skeletal remains of freshwater organisms and their
  replacement by creatures that lived only in brackish water or salt water.  Ross
  and Degens had clearly detected a recent rapid faunal replacement.  But
  these scientists had no reason to suspect any catastrophic inflow of the salt
  water.  Their expedition was completed a full year ahead of the Glomar
  Cballenger's discovery of the Gibraltar waterfall that refilled the Mediterra-
  nean.  The potential drying out of isolated inland seas was an idea that had
  not yet fermented.
    Unbeknownst to Ross and Degens the Soviets had stumbled on a clue
  that the Black Sea's lake may have indeed partially dried out and shrunk to
  a size two-thirds its Ice Age extent near the end of the great thaw.  In plan-
  ning a railroad bridge across the strategic Kerch Strait, a four-mile-wide and
  twenty-mile-long passage into the Sea of Azov on the north coast of the
  Black Sea, Russian engineers had drilled a series of holes to learn the depth
  of the bedrock.  They suspected the riverbed sediments were thin, as was
  discovered by the Soviet drilling beneath the Nile River at Aswan, directed
  by 1. S. Chumakov.  However, another chasm appeared that reached to more
  than two hundred feet beneath the strait's bottom.  The deposits in the axis
  of this gorge were the sand, gravel, and snails diagnostic of a terrestrial
  streambed.  There was no doubt about it.  The entire Sea of Azov to the north
  had once been a tract of dry land across which a river (probably the ancient
  Don River) had cut its valley for a distance of more than one hundred miles
  in order the reach the shoreline of the shrinking lake.
     This vast landscape had then drowned.  The Soviet scientists found in the
  soft mud accumulating on top of the streambed deposits tiny mollusks with
  both halves of their seashells still attached by their hinge.  Had these speci-
  mens been washed out of older nearby strata as contaminants rather than
  having been living dwellers of a new and deep estuarian environment, their

     delicate valves would have been scattered long e re.        ese crea re
     have lived in a substantial depth of water so as to have been sheltered from
     the disturbance of storm waves and surface currents.  In examining the pore
     water in the mud containing the mollusks, the researchers realized that not
     only had the passage from a flowing river to a deep estuary been rather
     sudden, but the water that had invaded the land was of a different composi-
     tion-enriched sodium, chlorine, and magnesium.  The mollusks themselves
     were a replacement fauna carried in from the Mediterranean.  It did not take
     long for the Soviets to recognize that the sediment cores from the Black
     Sea's perimeter contained the same abrupt transition from fresh to salty, just
     as Atlantis II had found in the central abyss of the Black Sea.
      Keeping track of the sequence of sediments in the boreholes, the inquisi-
     tive researchers from Moscow State University began to investigate a large
     number of sediment cores recovered from the now-submerged seabed south
     of the Kerch Strait and reaching westward around the Crimea along the
     Black Sea coasts of Ukraine, Romania, and Bulgaria.  A similar picture ap-
     peared.  Outward from the shore for ten to more than a hundred miles the
     cores brought up a dark-colored mud layer, three or so feet thick and overly-
     ing a former terrestrial landscape consisting of river channels, steppe grass-
     lands, and desert sand.  Along the outer edge of the continental shelf the
     university scientists soon discovered beach deposits at 350 feet below to-
     day's sea level.
       The Soviets added some important embellishments to the history tale
     initiated by Ross and Degens.  They could demonstrate that when the Black
     Sea was a lake, its shoreline had migrated far beyond the present coast.
     Rivers flowing into the falling surface of this body of water had deepened
     and lengthened their pathways to maintain a steady downstream gradient
     all the way to their deltas.  In the process of traversing the emerging terrestrial
     landscape, the Don River, in particular, had incised the valley encountered
     by the astonished civil engineers beneath Kerch Strait.
       The Soviet scientists could also demonstrate that the arrival of the replace-
     ment marine fauna and flora was accompanied by a submergence of the
     Black Sea margin.  Although they were not able to tell exactly when and how
     fast this flooding had occurred, they described it as rapid and said it had
     produced a rather impressive covering of a former terrestrial landscape.  The
     big unknown in the case of the Black Sea was whether the surface of the Ice
     Age lake had ever lain below its outlet.  Such a condition-the necessary
     precursor for a catastrophic flood-could only have happened under a re-
     gional aridity of the type that contributed to the desiccation of the Mediterra-
     nean.  In other words, the lake would have had to shrivel in response to a

 regional drying out.  Unfortunately, the past climate of the Black Sea periph-
 ery was poorly known.  Its prehistoric record, retained in the soils of the
 coastal nations, was just then being unraveled.  Sharing those secrets with
 the West would be the next step in putting the full puzzle together.

The first of the rapid pulses was dated by Fairbanks and Bard as beginning 12,500 B.C. It was expressed as well the the Aquanaut's cores from the Black Sea by a deposit of light gray clay that Kazimieras Shimkus called "New Euxine" (the Russian name for the Black Sea lake at its greatest expanse late in the last glacial cycle). . . .

The second meltwater spike beginning in 9,400 B.C., and seen vividly in the Barbados coral growth, never reached the Black Sea . . . Pitman could tell that already by 10,000 B.C., the Black Sea dropped below the level of the external ocean just as Petko Dimitrov had confirmed in his fax from Bulgaria. By 5,600 B.C., its shoreline lay 350 feet below the top of the Bosporus dam. It was then, with the glogal ocean at 50 feet below today's sea level, according to Fairbanks's corals, that the trickle of salt water started, carrying the larvae that would become the Black Sea's first immigrants. This period of post-glacial warming was interrupted by a precipitous and brief shift back to near-glacial condiitons. Called the Younger Dryas in Europe, it lasted from 10,500 to 9400 B.C. The continental ice sheets ceased melting and in some localities (such as Scotland and Norway) began once more to expand, sending long tongues of glacial ice down mountain valleys and back into coastal fjords. The word Dryas comes from the name of an Arctic plant that is a member of the rose family and which appeared across northern Europe at the onset of the abrupt refrigeration. In the Barbados coral sequence, the Younger Dryas's cold and dry climate produced a drastic slowing of the rise of global sea level. Ryan and Pitman 1998:171-172

                          CHAPTER TWENTY



           On a Golden Pond



    It was delightfully cool and fresh on the patio.  From points across and
     down the near slope came the call to morning prayer.  Two hundred
   -and fifty feet below, the Bosporus flowed gently, glittering in the re-
 flected light from the European side.  In the night a warship had made
 passage, a reminder of the many armies and traders and wandering tribes
 that had crossed and recrossed this channel between Europe and Asia, the
 Black Sea and the Aegean, over thousands of years.
   At the Marmara end there is always a queue of ships anchored below the
 walls of the old city, above which loom the minarets of several mosques and
 the dome of Hagia Sophia.  They wait to go north, upstream, to ports on the
 rim of the Black Sea.  Once in the Bosporus strait they fight a gentle but
 constant southerly flow of water from the Black Sea and often hug the
 easterly shore, seeking the easy water.  But this current against which even
 Jason and his Argonauts had to struggle is only at the surface, the upper fifty
 feet or so.  On the bottom a dense salty layer flows northward from the
 Aegean through the Dardanelles, Sea of Marmara, and Bosporus, bringing
 Mediterranean water to the Black Sea.  In a sense this countercurrent is a last
 vestige of the Great Flood.  Before the age of motorboats, fishermen and
 others wishing to move upstream would lower a basket weighted with rocks
 into this bottom current and be towed northward toward the Black Sea by
 the hidden river.
   The Bosporus is almost two miles wide in the south, and narrows to half
 a mile in its middle course where it is bounded by steep slopes that reach to
 a plateau three hundred feet above.  A layer of sediment of varying thickness
 masks the deep bedrock channel that was cut by the flood and is in places
 over four hundred feet deep.  Below the patio on the Asian side of the strait

      2 3 0                    NOAH' s FLO OD

      lies the town of Anadoluhisari and across Rumelihisari, the remains of two
      forts built by Sultan Mehmet 11 during the siege of Constantinople.  Darius is
      reputed to have bridged the Bosporus at this point.
       Ships ease by heading north and south, and at dawn the first of the
      ferryboats appear.  In a few hours they will grow to a swarm plying back and
      forth and up and down.  This gentle awakening to a new day belies the
      dramatic events that occurred there over seventy-six hundred years ago,
      drastically altering the landscape of the Bosporus and the entire area of the
      Black Sea and forcing a diaspora that changed the course of human history.
        But the story begins long before, back at the beginning of the last glacial
      cycle, 120,000 years ago when the Earth's climate and the level of the seas
      was about the same as today.  From that point in tii-ne and for the next
      100,000 years waters evaporated from the oceans and, transported by the
      winds, fell as snow on the near Arctic regions, gradually accreting and
      compressing into sheets of ice that were in some places up to two miles
      thick.  Twenty thousand years ago at the zenith of this accumulation so much
      water had been withdrawn from the oceans that sea level was four hundred
      feet lower than today.  Massive glaciers covered the entire northern half of
      North America, all of Scandinavia and northern Europe, and the northern
      edge of Eurasia.  All the high mountains of Europe, Asia, North America, and
      South America were sheeted with ice down to their lowermost valleys.
        Modern man was there in Europe and Asia to witness and survive the
      extremity of this glacial episode.  Having emerged from Africa about one 
hundred thousand years ago, the Moderns spread across Asia, rafted over to
      Australia, and finally entered Europe about thirty-five thousand years ago.
      Hunter-gatherers, they made stone tools and lived in temporary shelters and
      caves much like their very distant cousins the Neanderthals.  But they
      brought with them qualities that their predecessors lacked, in particular an
      extraordinary ability to adapt and innovate.  Their inventiveness is reflected
      in the rapid evolution of their hunting and survival skills.
         Twenty thousand years ago the great glacial meltdown began.  Torrents
      of frigid waters raced to the sea, which slowly began to rise.  Gradually the
      huge icy burden was removed from the land.  In northern Russia rivers
      choked with meltwater flowed southward across the steppes and eventually
      spilled into the Black Sea's Ice Age lake.  The icewater filled this lake to a
      level where it entered the Sakarya River, formed an estuary and advanced
      into the interior of Anatolia.  Fifty miles in from the coast, this narrow and
      winding arm of the expanding lake found an outlet to the Sea of Marmara,
      having intercepted a cleft in the bedrock wrenched open through the grind-
      ing action of the North Anatolian fault (the locus of numerous large-

                         ON A GOLDEN POND                                       2 3 1

   magnitude deadly earthquakes delineating a zone of shear along which two
   of the earth's plates still slide past each other at the rate of inches per year).
   Exploiting the crushed and permeable rock in this crack, the meltwater
   passed through to the Mediterranean Sea.  In the process, the Ice Age lake
   freshened and became potable for humans and animals.
     Those Moderns who lived in the north followed the great herds of mam-
   moth, reindeer, and other large herbivores as they migrated across the tundra
   in front of the retreating glaciers.  They lived in hunting camps for several
   months a year.  On the Russian steppes where wood was scarce, they framed
   their lodges with mammoth bones, interlocked, tied together, and covered
   with skins.  Meat was stored in pits dug into the frozen ground.  They sewed
   skins into pants and boots, and made jackets with hoods.
     In the more temperate areas of Europe and Asia, the Moderns lived in
   round and oval huts of reeds or poles and skins sometimes built over a
   shallow pit.  Fish were caught with hook and line and in traps and nets.  They
   invented the bow and arrow, and the throwing stick that doubled the range
   of their hunting spears.  Some may even have smoked and salted meat and
   fish.  But life remained a day-to-day struggle for survival.
     As they met the challenge of this most difficult and demanding environ-
   ment, there emerged from their creative impulses a most remarkable prolifer-
   ation of art objects, often rendered with astonishing skill and finesse.
   Frequently quite decorative, many of these objects may have been created
   for aesthetic reasons only.  But most seem to have been made for mystic and
   cultic purposes.  Beads and amulets were carved of ivory, stone, and shells,
   and used to decorate clothes and to make necklaces and bracelets.  Marvel-
   ous statuettes were Sculpted of ivory, bone, and stone.  Throwing sticks were
   carved into stylized images of horses, deer, and other animals they preyed
   upon.  Weapons for the hunt, tools, and decorative objects such as bracelets
   and necklaces are found in graves with the body of the deceased as if these
   would be needed in some afterlife.
     The most spectacular of this "primitive" work are the cave paintings
   found for the most part in France and Spain.  Usually rendered on the walls
   of chambers deep underground, they have been painted and scratched into
   the rock with extraordinary grace and skill.  There are striking monochrome
   and multicolored paintings and line drawings of buffalo, deer, mammoths,
   horses, lions, hyena, and other animals and birds.  Painted dots, chevrons,
   and silhouettes of hands are often interspersed among the figures of the
   animals.  There are a few human portraits and several graceful drawings of
   the female figure.  In many cases pictures have been superimposed on one
   another as if the act of drawing was important rather than the drawing itself.

  2 3 2                      NOAH's FLO OD

  This artwork, sometimes quite realistic and at other times very abstract, has
  been found on the walls of caves and on cliffs, and even in a cave along the
  shore of the Mediterranean, long submerged by the rising sea level, and
  everywhere the Moderns roamed.
    A very clear and persistent manifestation of the spiritual and mystical
  nature of the Moderns are statuettes of women, interpreted almost univer-
  sally as a symbol of fertility cult, found at sites throughout Europe, the
  Middle East, North Africa, and as far east as Lake Baikal in Siberia.


  FlFTEEN thousand years ago the glaciers were in full retreat, pouring
  millions of gallons of frigid meltwater into the rivers across North America
  and Eurasia.  The colossal weight of these ice sheets impressed itself on the
  Earth's surface like a heavy object placed on a soft mattress.  The weight on
  the mattress does not fill the dent entirely but is surrounded by a moat.
  Likewise the glaciers are often bordered by moats that trap meltwater, debris,
  and large chunks of ice that have broken away.  Because in the northern
  hemisphere it was always warmer to the south, the glaciers melted mostly
  along their southern edge.  As they retreated, the moat followed northward,
  across the steppes, trapping water and diverting flow to follow the channel
  parallel to the glacier front.  By 13,000 B.C. the ice had withdrawn so far north
  that the flow of meltwater to the Black Sea had almost ceased.
     Europe was gripped by a return to the rigors of the glacial climate 12,500
  years ago, an event known as the Younger Dryas, which lasted for a thou-
  sand years.  Temperatures fell and the rains became scarce throughout south-
  west Asia, Europe, and Africa.  Glaciers advanced in the high mountains.
  Lakes in Africa and Anatolia dried up.  Precipitation in and around the Black
  Sea was low, so inflow was reduced to the point that the loss of water by
  evaporation from its surface exceeded the water received from the rivers
  and rainfall.  The water level began to drop until it had fallen below the
  Sakarya outlet.  Outflow ceased, and the Black Sea became an isolated lake.
    The Sakarya channel, no longer connected to either the lake or the sea,
  slowly collected mud and debris brought in by torrential seasonal rains and
  the flooding of its several streams.  This debris built up slowly, forming a
  natural earthen dam.  As the lake slowly drew down, it exposed an old shelf,
  a thick accumulation of the remains of marine organisms and rich sediments
  brought by the many rivers.  The retreating waters, driven by winds and
  tides, sloshed back and forth, removing the silt from the uppermost layers
  of the sediments, leaving only the fragile shells of the delta mollusks, broken
  and bleaching in the sun.  Sunbaked cracks filled with sand and seed of the

                       ON A GOLDEN POND                                    233

 wild wheats native to the area, some of which took root-especially in the
 more moist depressions and valleys.  New sinuous valleys were cut right out
 to the shoreline, and detritus carried by the rivers in these valleys was
 deposited at the newly lowered lake edge, building new deltas that were
 bordered by the natural levees created during the occasional overflow.
 These valleys and deltas-with their rich soils, nurtured by the constant, if
 sluggish, flow of water and with abundant fish life in the rivers and at the
 edge of the sea-became an ideal refuge for man and beast.
    In the Near East many bands of hunter-gatherers had adopted a more
 sedentary way of life, constructing permanent villages, hunting and fishing
 locally, and gathering fruits, nuts, and wild wheat and barley, which they
 later learned to cultivate.  With the coming of the Younger Dryas, however,
 and the sudden change to a cooler and and climate, these resources disap-
 peared.  Jericho was deserted, as were many other villages.  The plains of
 Ukraine and southern Russia reverted to steppe desert.  Tribes crowded near
 oases where game and water were plentiful, such as at the rim of the Black
 Sea lake.  There on the deltas and the river terraces, at the edges of the
 lagoons-perhaps due to the accidental scattering of some of the wild seeds
 they had harvested-they learned the lessons of sowing grains, the first step
 in farming.  They also traded food, goods, and ideas with others around the
 lake.
    The Younger Dryas ended 11,400 years ago, as abruptly as it had begun.
 Warmth and rain softened the harshness of the surrounding countryside, and
 over a period of a few hundred years the landscape was revitalized as game
 and the wild fruits, nuts, and grasses returned.  People began to move away
 from the oases, taking with them the newly acquired skill of farming.  They
 spread into Anatolia, the Levant, and northern Mesopotamia, flourishing in
 the valleys that were well watered again and along the shores of lakes.
    In 6200 B.C. this tranquil existence was once again disturbed by another
 mini Ice Age that seized the Northern Hemisphere.  Temperatures dropped
 and rains were meager.  A wave of aridity again swept across southeast
 Europe, Ukraine, and southern Russia.  The lakes and rivers of Anatolia,
 southwest Asia, and southeast Europe shrank.  Many farming villages in Ana-
 tolia and along the Fertile Crescent were abandoned, while others dwindled.
 Communities of people, many of whom were now farmers, retreated to
 the watery patches, to the few rivers that still flowed and to the rim of the
 Black Sea.
    Sea level was still below the level of the divide that separated the
 Bosporus valley from Marmara.  The Black Sea remained an isolated lake.
 Most of the people who came to the lake edge this time were farmers who

    2 3 4                       NOAH's FLO OD

    cultivated the river valleys and deltas.  Here again they traded around the
    lake edge, now using small boats, speaking different languages-Proto-
    Semitic, Proto-Indo-European, Proto-Kartvalian, and others-exchanging
    goods, obsidian, leather, pottery, herbs and essences, and borrowing words
    for new things and ideas.  Some on the edge of being hunter-gatherers and
    herders adopted a new way of life and learned to farm from their agrarian
    neighbors.  A Sumerian myth declares that they were given their knowledge
    and culti-ire by "seven wise men who came from the sea." Eventually on one
    of the deltas someone may have diverted the water through a natural levee
    and invented irrigation.
       Relief came around 5800 B.C. as the rains and warmth returned and some
    of the lakeside dwellers, such as people called Halaf, left the basin and
    reoccupied a few of the abandoned sites to the south.  By 5600 B.C. the ocean
    had risen to a height where it stood poised to invade the Bosporus valley,
    and plunge to the Black Sea lake five hundred feet below.  Driven by the
    wind and tide, the waters must have repeatedly washed up onto the top of
    the divide to fall back, leaving damp patches on the soil, until a final surge
    began to flow continuously across and down the slope toward the lake,
    finding old gullies and dried streambeds in the rough ground between the
    trees and around the litter of boulders.
       Reaching the ancient shelf below, the water meandered across its flat
    surface, trickling into old channels long dry, formed small lagoons, and
    gradually cut its own course, at last flowing over the edge and down the
    gentle slope to the lake below.  The rivulet became a gentle brook, flowing
    ever more swiftly, scouring and tugging more forcefully at the bottom and
    walls of its channel.  Within days its gentle murmur would have grown to a
    roar as the stream became a wildly turbulent river, cutting into its banks,
    pulling trees and large chunks of earth into the maelstrom.
       The soil and debris that had once dammed the valley were quickly swept
    away, and the water, now several tens of feet deep, was a thundering flume
    twisting and churning with 1-u]3ble as it clawed at the soft rock walls that
    now and then collapsed.  The debris-laden water ground into the bottom
    like a rasp, cutting deeply into the bedrock itself.  The deeper it cut, the faster
    it flowed, and the faster it flowed, the faster it cut until it had gouged a flume
    at least 280 feet and up to 475 feet deep.  Ten cubic miles of water poured
    through each day, two hundred times what flows over Niagara Falls, enough
    to cover Manhattan Island each day to a depth of over half a mile.
       Most if not all the fish life in the lake died in the strange salty water.  New
    life that flushed in from the Mediterranean at first perished in the maelstrom,

                       ON A GOLDEN POND                                     2 3 5

 but after some days, when the torrent had abated, it made it through and
 quickly took over.
   The level of the lake began to rise six inches a day, immediately inundat-
 ing the deltas and invading the flat river valleys-moving upstream at as
 much as a mile each day, without pause hour after hour, day after day,
 drowning the less agile, forcing all else upriver or up onto the desertlike
 plateau through which the valley had been cut.
   It is hard to imagine the terror of those fari-ners, forced from their fields
 by an event they could not understand, a force of such incredible violence
 that it was as if the collected fury of all the gods was being hurled at them.
 They fled with family, the old and the young, carrying what they could,
 along with fragments of the other languages, new ideas, and new technolo-
 gies gathered from around the lake.
   Farmers, called Vin@a, makers of lovely wattle-and-daub houses and fine
 incised pottery, appeared abruptly on the plains of Bulgaria and up along
 the valley of the Danube.  Other refugees crossed from the Black Sea to the
 Aegean to settle on some of the islands such as Samothrace, crossing over
 as far as the Dalmatian coast.  Some Linearbandkeramik fled up the Dniester
 River and then rapidly to the west across northern Europe as far as the Paris
 basin, displacing peaceably or by force the indigent hunter-gatherers.  They
 brought with them their longhouse building style, their ceramic pottery dec-
 orated with linear bands of incised grooves, and their agrarian ways.  They
 may have been Indo-European speakers, but others who certainly were
 moved out to the north, up through the river valleys of the Dnieper, the Don,
 and the Volga, spreading in an arc from southeast Europe to the Caspian
 Sea and beyond.  It was around the northern Caspian Sea that they first
 domesticated the horse, on the backs of which they stormed into eastern
 Europe sixteen hundred years later.
  The speakers of the Semitic tongues climbed through the hills to the
 south, up creeks and streams and over the Anatolian plateau, scattered wide
 by the complex of deep valleys and mountains.  In Anatolia some of these
 desperate peoples laid siege to a few small villages, which were then burned
 to the ground.  Many deserted farm villages of the Levant were suddenly
 reoccupied, and strangers with an advanced farming technology and domes-
 ticates of foreign origin settled in Egypt on the Nile Delta.  Many more of the
 Halaf appeared along the northern fringes of Mesopotamia and ventured
 outl'lward into its and valleys farther than any farmers had dared before.
  Some of the Semitic peoples who crossed southward through eastern
  atolia and speakers of Caucasian languages who fled from the eastern

      @- 3 6                    NOAH' s FLO OD

      end of the Black Sea to the south or up the Rioni Valley and around to the
      south, drifted down along the eastern side of Mesopotamia, and settled in
      the foothills of the Zagros Mountains.  They, too, were farmers.
        A few of these, called Ubaid, speakers of a tongue later to be known as
      Sumerian, ventured to the middle of the southern Mesopotamian alluvium,
      a region where the rainfall was only four inches a year and where the
      only natural resources were the extraordinarily rich soil and the Tigris and
      Euphrates rivers that bound the plain.  These people, who knew how to
      irrigate and may even have used a light plow, flourished.  Irrigation here
      required canals and, hence, social organization was needed to design, plan,
      and maintain the canals.
        The exceptional fertility, the presence of a limitless supply of water for
      irrigation, and the growing web of canals for transport meant that the few
      could provide for the many.  Prosperity led to more prosperity, and soon one
      of the world's great civilizations emerged as a people and culture known as
      Sumerian succeeded from their ancestors, the Ubaids.  There flowered
      among them an amazing pantheon of gods, one for every need.  A very
      superstitious and fatalistic people, they believed in predestination but also
      that the future could be revealed by divination.  They sought a cause for all
      events among the gods.  Small wonder that their entire history was recorded
      in myth.  By 3000 B.C. these people had invented writing.  Using wedge-
      shaped styli to inscribe symbols on tablets of wet clay, they recorded the
      everyday events of their lives and immortalized their myths, religious beliefs,
      and practices.
        The flood continued long after the human population had fled.  Nvith
      awesome unabated violence the waters poured through the Bosporus day
      after day.  The rising waters filled the river valleys and dry channels of many
      old streams and brooks of the old shelf to the north, forming a glittering
      web of canals.  For twelve months the tumultuous rush of water continued
      undiminished until the level of the lake had risen 180 feet, to the lower
      surface of the flume.  As it continued to rise, the rate of flow slowly began to
      diminish.  Still, during the next twelve months it would rise another hundred
      feet.  It crested the old shelf edge and began its race toward the present
      shoreline, pushing all life before it.  Rolling over the scrub bushes, desert
      grasses, and small trees, it inundated the sparse vegetation, sand, dirt, and
      fragments of shells left behind eons before to bleach in the sun.  Everywhere
      the encroachment of the floodwaters was so rapid that whole regions that
      had been dry were covered by ten or more feet of water within days.  There
      was no continual wash of waves to form sandy beaches, but in this suddenly
      deep and quiet water, the sediments, shells, and skeletal structures of very

                            ON A GOLDEN POND                                      2 3 7

    small sea creatures and particles suspended in the water floated down like
    dust, covering everything with a uniform layer without regard to the underly-
    ing topography.
       With these foreign waters came migrant species from the Mediterranean,
    now able to colonize in the newly saline water and on the shelly bottom.  On
    one of these newly flooded muddy shallows the immigrant cockle, Cardium
    editle, having survived the rush at the Bosporus, proliferated, lived, and
    died.  The delicate shells of these first colonizers settled on the bleached
    shelly surface of the old shelf, to be picked by tweezers from sediment cores
    7600 years later.
       All around the lake the tentacles of salty water reached up the rivers and
    creeks, pushing farther and farther inland each day.  Along the south edge of
    the lake the waters quickly swamped the deltas and followed the valleys
    into the fringing mountains of Anatolia, chasing life up into the hills.
       After two years, when the lake level had risen 330 feet, the waters entered
    the Kerch strait and shortly thereafter reached the Azov plain, which had
    been abandoned long before by humans.  It would be several more years
    before the basin was completely filled, creating the Sea of Azov, so that its
    surface, like that of the Black Sea, was at the same level as the Aegean
    and Mediterranean seas, beyond.  Sometime afterward the flow through the
    Bosporus slowly changed to its present state with fresher, lighter Black Sea
    water flowing out at the surface and the heavier Mediterranean water flow-
    ing in along the bottom.  Once this change had occurred it would be impossi-
    ble for surface-dwelling creatures to travel northward into the Black Sea
    except as stowaways in the bilgewater of ships.  And most vessels could not
    have made this journey until the discovery of the northward-flowing bottom
    current.
      To those who fled to Mesopotamia, in particular, the mythic and oral
    tradition of the event would have been reinforced by the frequent if irregular
    floods that occur there.  The myth lived on, sung and chanted at ceremonies
    and around caravan campfires by generations of guslars and storytellers.
    Each year that the floods came was probably the occasion to retell the story
    of that ancient time when the Great Flood destroyed all people but one
    single family from whom all were descended.  Elaborated and modified to
    conform to the more familiar geography of Mesopotamia, it still retained its
    basic theme: a warning, a violent flooding, the escape of a family, the
    apparent inundation of the entire world, the apparent retreat of these waters,
    and the landing and salvation of these people.