Refuting Creationism - How 70% of the Mediterranean Sea Was Lost 5.5 Million Years Before 'Creation Week'

Artistic representation of the Gibraltar sill rupture at the end of the Messinian Salinity Crisis. In the final moments of this crisis, the level of the Mediterranean Sea was around 1 km lower than that of the Atlantic Ocean.

© Pibernat & Garcia-Castellanos

How 70% of the Mediterranean Sea was lost 5.5 million years ago | CNRS

The two accumulation phases of the Mediterranean salt layer during the Messinian Salinity Crisis.
In the first phase, salt accumulated in a Mediterranean Basin filled with brine; in the second phase, salt accumulated in a Mediterranean completely isolated from the Atlantic Ocean, as a result of the significant drop in sea level in the western and eastern Mediterranean sub-basins.

© Giovanni Aloisi

Despite living not a stone's throw from it, the authors of Genesis appear to have known next to nothing about the Mediterranean, and, having guessed that Earth was created about 4,000 earlier they blundered on with their preposterous, counterfactual mythology. Had they been away of real history they might have made a better fist of it, but there was no way they could have known that about 5.5 million years earlier there was no sea to speak of; instead there was a salt-filled depression due to what is now called, The Messinian Salinity Crisis.

This event was caused by land rising up under the straights of Gibraltar restricting inflow from the Atlantic and eventually closing it altogether, and, as water levels fell, the ridge between Sicily and the North African coast formed another barrier, effectively dividing the Mediterranean into two seas.

Scientists have worked out that the Messinian Salinity Crisis had two phases by analysing the isotopes ³⁷Cl and ³⁵Cl in the salt deposits* How does this show that there were two phases to the crisis? The discovery of two phases in the Messinian Salinity Crisis (MSC) through the analysis of chlorine isotopes ³⁷Cl and ³⁵Cl stems from the way these isotopes are fractionated during different processes of salt formation.

Key Points of Isotope Analysis:

1. Isotopic Fractionation in Salt Precipitation:
   • During the evaporation of seawater and the subsequent precipitation of salts (e.g., halite, gypsum), lighter isotopes (³⁵Cl) are preferentially incorporated into the crystalline structure of the salts.
   • This leaves the residual brine enriched in the heavier isotope (³⁷Cl).
   • By analyzing the isotopic composition of chlorine in salt deposits, scientists can infer the conditions under which the salts formed.
2. Two Distinct Isotopic Trends:
   • Researchers found that the chlorine isotopic signatures in the salt deposits show two distinct phases:
     1. First Phase: Relatively consistent ³⁷Cl/³⁵Cl ratios indicative of a gradual process where seawater input was restricted but not entirely cut off. This phase aligns with moderate salinity increases as seawater continued to flow intermittently into the Mediterranean.
     2. Second Phase: A sharp increase in the ³⁷Cl-enriched signal, suggesting extreme salinity conditions due to a near-complete isolation of the Mediterranean from the Atlantic. This corresponds to massive evaporation and the formation of thick salt layers.
3. Geochemical Evidence of Environmental Shifts:
   • The isotopic variations correlate with geochemical and sedimentological evidence, such as the types of evaporites and the stratigraphic layering.
   • The first phase is associated with gypsum and other less extreme evaporites, while the second phase shows deposits of halite and other minerals that form under extreme hypersaline conditions.

Conclusion:
The two-phase nature of the MSC is reflected in the chlorine isotopic record because the isotopic composition of chlorine in the salts directly records the degree of seawater restriction and the intensity of evaporation. These data, combined with sedimentological and stratigraphic evidence, reveal the transition from a moderately restricted Mediterranean to one undergoing severe desiccation.

Now a team from Centre national de la recherche scientifique (CNRS) investigating the event which produced a million cubic kilometres salt deposit, have analysed two stable isotopes of chlorine in the deposits and shown that there were two phases to the salinity crisis.

These correspond to a restriction at the Straits of Gibraltar which lasted about 35,000 years which caused salt to be deposited in the Eastern Mediterranean, and a rapid phase of evaporation lasting less than 10,000 years when the straight closed completely. This latter phase resulted in salt being deposited across the whole basin and the Mediterranean losing 70% of its water volume.

During this phase, the sea level dropped between 1.7 and 2.1 km in the Eastern Mediterranean and about .85 km in the Western Mediterranean.

The CNRS team have recently published their findings in Nature Communications and in a press release from CNRS:

How 70% of the Mediterranean Sea was lost 5.5 million years ago

---

A new study, led by a CNRS researcher^1.1 , has highlighted just how significantly the level of the Mediterranean Sea dropped during the Messinian Salinity Crisis – a major geological event that transformed the Mediterranean into a gigantic salt basin between 5.97 and 5.33 million years ago^2.1

---

Until now, the process by which a million cubic kilometres of salt accumulated in the Mediterranean basin over such a short period of time remained unknown. Thanks to analysis of the chlorine isotopes^3.1 contained in salt extracted from the Mediterranean seabed, scientists have been able to identify the two phases of this extreme evaporation event. During the first phase, lasting approximately 35 thousand years, salt deposition occurred only in the eastern Mediterranean, triggered by the restriction of Mediterranean outflow to the Atlantic, in an otherwise brine-filled Mediterranean basin. During the second phase, salt accumulation occurred across the entire Mediterranean, driven by a rapid (< 10 thousand years) evaporative drawdown event during which sea-level dropped 1.7-2.1 km and ~0.85 km in the eastern and western Mediterranean, respectively. As a result, the Mediterranean Basin lost up to 70% of its water volume.

This spectacular fall in sea level is thought to have had consequences for both terrestrial fauna and the Mediterranean landscape – triggering localised volcanic eruptions due to unloading of Earth's crust, as well as generating global climatic effects due to the huge depression caused by the sea-level drawdown.

These results, published in Nature Communications on November 18, provide a better understanding of past extreme geological phenomena, the evolution of the Mediterranean region and successive global repercussions.

Abstract
Hydrological restriction from the Atlantic Ocean transformed the Mediterranean Sea into a giant saline basin during the Messinian Salinity Crisis (5.97–5.33 million years ago). It is still unclear if the deposition of nearly one million km3 of evaporite salts during this event was triggered by a major (≥1 km) evaporative drawdown, or if it took place in a brine-filled Mediterranean connected to the Atlantic. Here we present evidence for a two-phase accumulation of the Mediterranean salt layer based on the chlorine stable isotope composition of halite. During the first phase, lasting approximately 35 kyr, halite deposition occurred only in the eastern Mediterranean, triggered by the restriction of Mediterranean outflow to the Atlantic, in an otherwise brine-filled Mediterranean basin. During the second phase, halite accumulation occurred across the entire Mediterranean, driven by a rapid (<10 kyr) evaporative drawdown event during which sea-level dropped 1.7–2.1 km and ~ 0.85 km in the eastern and western Mediterranean, respectively. During this extreme drawdown event, the eastern Mediterranean basin lost up to 83% of its water volume, and large parts of its margins were desiccated, while its deep Ionian and Herodotus sub-basins remained filled with >1 km-deep brine.

Introduction
Today, more freshwater is extracted from the Mediterranean Sea by evaporation than is added by continental runoff¹. Blocking the net import of Atlantic Ocean waters through the Gibraltar sill would result in a Mediterranean sea level fall at a rate of about 0.5 m yr⁻¹ (ref. ²). During the Messinian Salinity Crisis (MSC), the deposition of nearly one million km³ of evaporite salts^3,4 (mainly gypsum, CaSO₄.2H₂O, and halite, NaCl) is a testimony of highly restricted hydrological exchange with the Atlantic Ocean. Whether or not evaporite deposition was accompanied by a major (≥1 km) sea level drawdown, however, is still debated. Estimates of the magnitude of the base-level fall during the MSC rely on geological indicators such as deeply incised canyons onland^5,6,7,8,9, widespread erosional surfaces on the margins^10,11,12,13 and in the basins^14,15,16 and evaporite facies from drilled cores17,18,19,20. However, these indicators are not interpreted unequivocally^21,22,23,24 and drawdown estimates range from ~ 200 m to ~ 2 km^{9,11,14,21,25,26,27}. Existing hydro-chemical models cannot solve the controversy because they show that the complete MSC halite body can be deposited in scenarios that include periods of Mediterranean isolation and sea level drawdown²⁸, but also in scenarios involving exclusively a partially restricted, brine-filled Mediterranean^9,10,29.

We use the chlorine stable isotope composition of halite to estimate the volumetric halite precipitation rate in the Mediterranean basins during the MSC. Compared to other geochemical tracers such as strontium isotopes^30,31, chloride has the advantage of being a major constituent of halite and, for all practical purposes, is derived solely from inflowing seawater. Laboratory contamination issues are also minimal for this reason. At the basis of our approach is the chloride isotope reservoir effect which results from the preferential incorporation of the heavy isotope ³⁷Cl (as opposed to the lighter isotope ³⁵Cl) into precipitating halite³². The extent of the isotope reservoir effect depends on the balance between the rate of halite precipitation, which tends to decrease the ³⁷Cl/³⁵Cl ratio of dissolved chloride, and the rate of addition of dissolved chloride from the Atlantic Ocean, that tends to push Mediterranean ³⁷Cl/³⁵Cl towards heavier global ocean values. The faster the precipitation, the stronger the ³⁷Cl-depletion of the precipitating halite. Evaporative drawdown of a halite-saturated water column³³ results in very high rates of halite precipitation, and in the most extreme dissolved Cl, and thus halite, ³⁷Cl-depletion.

Fig. 1: The Messinian Salt Giant of the Mediterranean sea.

a Study area showing data and on-land and offshore Messinian evaporite thickness distribution⁴ over a Mediterranean Basin map (background relief and bathymetry maps taken from https://www.geomapapp.org/). Chloride isotope data included in this work comes from the hydrocarbon industry well Aphrodite (AP2) located in the Levantine basin (eastern Mediterranean) and from Deep Sea Drilling Project (DSDP) sites 134 (western Mediterranean), 374 (Ionian Basin, eastern Mediterranean) and 376 (Florence rise, eastern Mediterranean). b location of the seismic section (red dashed line) shown in d. c Petrophysics and associated lithologic log of the Aphrodite well. GR-Gamma Ray (graph ranges between 0 – left - and 100 API) and RES-Resistivity (graph ranges between 0 – left - and 1000 Ωm; logarithmic scale) logs; d Composite seismic section (d-d’) in the Levantine basin showing the Messinian evaporites composed of seven seismo-stratigraphic units³⁴. Notes: in a, symbols are as follows: RB, Rhodes Basin; FB, Finike Basin; AB, Antalya Basin; CB, Cilicia Basin; LRB, Larnaca Basin; LTB, Latakia Basin; LEB, Levant Basin; HB, Herodotus Basin; CYB, Cyrenaica Basin; SB, Sirte Basin; IB Ionian Basin; TB, Tyrrhenian Basin; L-PB, Liguro-Provençal Basin; ALB, Algerian Basin; in the lithological log of c, orange layers represent clastic inclusions. Black horizon in seismic section of d is a high-amplitude continuous reflection corresponding to a layer of clastics encased in halite; in d, vertical distance is in km below sea level.

Aloisi, G., Moneron, J., Guibourdenche, L. et al.
Chlorine isotopes constrain a major drawdown of the Mediterranean Sea during the Messinian Salinity Crisis Nat Commun 15, 9671 (2024). https://doi.org/10.1038/s41467-024-53781-6

Copyright: © 2024 The authors.
Published by Springer Nature Ltd. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

When did the Mediterranean refill after the MSC? The Mediterranean refilled rapidly at the end of the Messinian Salinity Crisis (MSC) during an event known as the Zanclean Flood, which occurred approximately 5.33 million years ago at the beginning of the Pliocene Epoch. This dramatic event marked the end of the MSC, which had lasted from about 5.96 to 5.33 million years ago.

Evidence for the Refill:

1. Erosional Features:
   • Submarine canyons, such as the Ebro, Rhône, and Nile Canyons, were carved deeply into continental shelves during the MSC when the Mediterranean was partially or nearly desiccated. These features indicate significant drops in sea level and subsequent rapid inundation.
2. Sedimentological Evidence:
   • The deposition of marine sediments overlying the thick evaporites from the MSC suggests a sudden return of normal marine conditions.
3. Geophysical Evidence:
   • Seismic studies have identified a large erosional surface, known as the M-reflector, beneath the Zanclean marine deposits. This surface is interpreted as the result of massive erosion during the refill.
4. Isotopic Data:
   • Oxygen isotopic records from marine fossils show a shift consistent with a dramatic change in the water mass and salinity of the Mediterranean.

The Zanclean Flood:

The refill likely occurred through a catastrophic breach of the Gibraltar Strait. Water from the Atlantic Ocean poured into the Mediterranean, rapidly filling the basin in what is hypothesized to have been a flood of immense proportions. Some estimates suggest the Mediterranean may have refilled within a few months to a couple of years, with water flow rates potentially exceeding 100 times the discharge of the Amazon River.

This event restored the Mediterranean's connection to the global oceans, transforming it back into a normal marine environment.

Just one more piece of evidence that creationism is based on the naïve and ignorant guesses of Bronze Age pastoralists who weren't even away of recent history in their own part of the world, so got their childish guesses hopelessly wrong.

Before creationists default to their traditional excuse and claim, without any evidence to support it, that these dating methods are all wrong because radioactive decay rates have changed by several orders of magnitude in the last 6-10,000 years, this wasn't a radiometric method. It was based on an analysis of the stable isotopes of chlorine ³⁷Cl and ³⁵Cl, neither of which is radioactive.

---

Advertisement

Refuting Creationism: Why Creationism Fails In Both Its Science And Its Theology

A systematic refutation of creationism, exposing the childish parodies, fallacies and pseudo-science that underpins it. This book takes the reader through the major themes of creationism from the Big Bang, through abiogenesis and the origin of the genetic code, the evidence for evolution, falsifying the claims of creationism with scientific evidence. Also exposed is the deliberate disinformation to be found on creationist websites and publications and the absurdity of the belief that the Bible, particularly the origin myths in Genesis, is real science and genuine history, written or inspired by an omniscient, inerrant creator god

Available in Hardcover, Paperback or ebook for Kindle

Advertisement

The Failure of Creationism: The Theory That Never Was

An exposé of the failure of creationism and especially the Discovery Institute's Wedge Strategy, showing that the Theory of Evolution is as central to biomedical science today as it was when the DI launched it's disinformation campaign in 1991. Creationism is not a science; it is religious fundamentalism and, as was shown in the Kitzmiller case, Intelligent design is creationism dressed in a lab coat.

Available in paperback, hardcover or ebook for Kindle

Advertisement

Thank you for sharing!

Tweet Link