From Tuffeau to Turonian Oil: A Geologist’s Toast to Tours, Terroir, and Time

By Marcel Chin-A-Lien, 23th May 2025.

Some chase petroleum buried deep in ancient Turonian-age shales, such in offshore Guiana-Suriname Basin and now also in NE offshore Switi Sranan.

Others chase the perfect glass of Chenin Blanc, nurtured by the same epoch’s sun-bleached limestone.

Both are noble quests, but only one ends in foie gras, floral minerality, and the soft clink of wine glasses on a summer terrace in La Douce France.

The Turonian Stage: Oilfield to Wineglass

The Turonian Stage of the Late Cretaceous is a familiar friend to both petroleum geoscientists and Loire Valley vignerons.

Offshore Suriname, especially in Block 64 and its stratigaphic-structural and porcellanite siblings, Goliath Voltzberg North-1, Araku-1, and Macaw-1, the Turonian is a deep, dark enigma.

Rich in source rock potential, but risky, silent, and stubborn.

You probe it with seismic waves and AVO curves and AI aided reprocessing chasing subsurface Petroleum ghosts.

You map it, log it, and hope it flows.

Meanwhile, in the Touraine region of central France, the Turonian literally flows and feeds the table.

Here, exposed as chalky tuffeau limestone, the Turonian stage does not trap oil.

It expresses terroir.

It nurtures the roots of Chenin Blanc in Vouvray, Cabernet Franc in Chinon, and Sauvignon Blanc in Touraine.

Its porous structure stores just the right moisture, its mineral content infuses just the right flintiness.

It gives structure, acidity, and aging power, not to reserves in metal barrels with petroleum.

But in oak barrels and to bottles on the shelf.

A Tale of Two Turonians

Turonian in Offshore Suriname	Turonian in Touraine, France
Deepwater, subsurface, seismic and AVO-guided	Outcropping limestone hills of the Loire Valley
Holds potential hydrocarbons, elusive targets	Holds vines, limestone minerality, exquisite wine
Processed with AI, ML, and seismic reprocessing	Processed with wild yeast, bâtonnage, and oak barrels
Drilled and logged — with risk of dry holes	Sipped and savored — never dry in spirit

A Personal Stratigraphy

My first encounter with the sacred Turonian of Tours wasn’t in a lab or an AI reprocessed seismic cube.

It was from behind the wheel of a grey Citroën 2CV, bouncing across France with my dear friend and study buddy Willem V. (R.I.P.), en route to geology fieldwork in Riaño and Cremenés, Cantabria, España, oléeee.

The year was pre-digital, most fortunately not yet guided by GPS, TomTom and Google.

But by the fat Het Beste Boek van de Weg of the Dutch ANWB, and mainly by intuition and looking at the position of the sun or moon…the gut feeling and our simple geological compass.

We overnighted near Tours, surprised by the summer evening and full moon, in our tents.

Somewhere in an unknown field, just along the road, clueless to the chalk beneath, only aware of the charm above.

Later I would come to realize: that chalk, that Turonian tuffeau, was not just picturesque.

It was foundational, to wines, to landscapes, and to memory.

A Different Kind of Exploration

So I invite you, fellow explorers, of oil, of wine, of life, to visit this corner of La Douce France.

Walk among vineyards rooted in Turonian limestone.

Dine in Saumur or Montlouis.

Sip Bourgueil with confit duck.

And raise your glass not just to terroir, but to time.

For while the Turonian beneath Block 64 may remain untouched by our own hands, its secrets kept in the dark?

The Turonian of Touraine is open, bright, and generously poured.

À vôtre Santé!

And if?

Black Polluting Smoke on Quatorze Juillet 2025.

Habemus Petroleum?

Petroleum found in Macaw-1?

In, above or below the Turonian.

I will certainly bring a big toast

With a big Turonian wine.

Chinon (no…no, not yet Chinalien) “ Le Clos Guillot “ 2021, Domaine Bernard Baudry (Organic).

Marcel Chin-A-Lien

Petroleum and Energy Advisor

48 Years of Global, in-depth expertise, knowhow and insights.

That have generated transformative, multi billion giant fields discoveries, iconic first capitalistic new ventures in the USSR, bid rounds, added value and long term cash flow generating offshore exploration and production activities on Dutch North Sea, M&A, PSC designs, Contract negotiations.

Combined with a cross & trans discipline background of 4 petroleum post grad degrees, that fuse technical, business, commercial and management disciplines, accompanied by fluency in 7 languages in a variety of geographical, socio-cultural and business landscapes. 

“ Exploration & Production integrated with Business & Commercial Development “

Drs – Petroleum Geology
Engineering Geologist – Petroleum Geology

Executive MBA International Business – Petroleum – M&A
MSc International Management – Petroleum

Energy Negotiator Association of International Negotiators (AIEN)

Certified Petroleum Geologist # 5201 – American Association Petroleum Geologists – Gold standard Certification
Chartered European Geologist # 92    – European Federation of Geologists – Gold standard Certification

Cambridge Award  “ 2000 Outstanding Scientists of the 20th Century ”, UK – Gold standard Award
Paris Awards  “ Innovative New Business Projects “, GDF-Suez, France – Two Gold standard Awards, Paris, 2003.

Public Profile: nl.linkedin.com/pub/marcel-chin-a-lien/9/a73/547/

Email: marcelchinalien@gmail.com