Coast Geological Society

Ventura, California


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The Coast Geological Society would like to invite you to the third meeting of the 2017-2018 season!

The third meeting will be on Tuesday, November 21st 2017

Yannick Wirtz will present his talk titled:

Variation in Strain and Deformational Style Between the Monterey and Sisquoc Formations, Santa Maria Basin, California

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CGS would like to thank Numeric Solutions for sponsoring the November meeting!

Numeric Solutions has provided tailored consulting services and advisory for the energy and water management industry since 1999.

Numeric Solutions’ founding staff have professional experience in upstream oil and gas development, energy finance, water management, water well design, well field optimization, and environmental regulatory support and compliance. Their body of work includes development of geologic maps and models that have served as the foundation for entire basins and regions.

November 21st 2017 Talk:

Variation in Strain and Deformational Style Between the Monterey and Sisquoc Formations, Santa Maria Basin, California



Balanced cross-sections test geometric and kinematic models of fold and thrust belts, unravel their deformational histories, and define structural traps for petroleum prospects in basin exploration at map scales. Yet, this method has limitations because of assumptions of constant volume and bed thickness and consistent mechanical behavior and strain between major lithostratigraphic units. These problems are amplified in the analysis of the diagenetically distinct siliceous sedimentary rocks of the Monterey and Sisquoc formations in the Lompoc-Santa Rosa, and Lompoc-Purisima Anticline fold belts of the southern Santa Maria basin, California. Structural analysis at map-scale shows significant variation along fold strike in shortening ( 5.5 % to 21.1 %), in the axial lengths of folds, and in fold angles and amplitudes. Apparent shortening in the thin-bedded and mechanically contrasting Monterey Formation is twice as high as in the overlying, thick-bedded, and mechanically homogeneous and highly porous Sisquoc Formation, suggesting that the same amount of actual strain was accommodated by tight folding and faulting in the brittle diagenetic rocks of the Monterey, but by compaction and open to gentle folding in the diatomaceous Sisquoc Formation. Sub-map-scale structures exhibit complex deformational styles. Parasitic Z- and S-type folds and limb-thrusts along the limbs of map-scale folds are common and consistent with being coeval with the map-scale folding. At map-scale, a tectonic wedge-model ties shortening in the Monterey Formation to deeper convergent structures via slip along larger thrusts. 

Yannick Wirtz
Speaker's Bio:

Yannick Wirtz is a California geologist. His research interest focuses on structural geology, petroleum systems, and active tectonics in Southern California. Yannick is currently working for Earth Consultants International (ECI), a geologic consulting firm based in Santa Ana, CA. He completed an MS in Geology at California State University, Long Beach under the guidance of Richard Behl, Nate Onderdonk, Thom Davis, and Jay Namson after completing a BS degree in Applied Geology at RWTH Aachen University of Technology in Germany. Yannick originally came to California in the spring of 2011 to go surfing and to conduct climate research at UC Irvine as part of his BS degree thesis. He then went on to work as an intern for ECI. At ECI he gained experience in southern California geology and engineering geology practice. In Fall 2013, Yannick started an MS program in geology at California State University, Long Beach where he worked with the Monterey and Related Sediments (MARS) research group, an industry affiliates program on the Monterey Formation incorporating field methods, structural geology, sedimentology, and tectonics in his research. His research project was sponsored by grants received from AAPG, GSA, and the MARS industry affiliates. Yannick was on the Long Beach team at the 2014 AAPG Imperial Barrel Award competition where he and his colleagues utilized petroleum industry software, and an understanding of petroleum systems to analyze the prospectivity of a frontier region and present their findings and recommendations to a panel of industry experts. In 2016, Yannick returned to ECI as a full time consultant. He has been active in professional societies throughout his academic and professional career and presented, and lead field trips at several science symposiums at California State University Long Beach, local geological societies, the National GSA Conference in Baltimore (2015), Pacific Section AAPG conferences (Bakersfield 2014, Oxnard 2015, Las Vegas 2016), and the Tectonic Studies Group conference in London (2016).

Future Sponsors for the 2017-2018 Season!
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The California Wine Club

(800) 777-4443 

Treat yourself, friends, family and business associates to award-winning wines handcrafted in quantities too limited to be found in stores. Since 1990, we've been helping small family wineries introduce their small-batch wines to appreciative wine lovers. Holiday wine gifts include an insider's look into each winery with our guide, Uncorked®, plus a fun cork coaster set, a $25 wine credit and a VIP Tour and Tasting invitation. Send as many gift months as you wish.

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Panaro Brothers Winery, Ventura, California

Taste, Passion, Tradition -- A Taste of Italy in every bottle

Panaro Brothers wines are inspired by place, history, and Italian Old-World wine-making methods.

Experience the adventure of sharing a bottle of Panaro Brothers wine with friends or family.  Experiment and explore new wine styles and tastes.  We push boundaries and dare to be original.  So sip and savor because wine moments create fine memories and everlasting friendships.  

If you’re really daring, ask for a “Suicidio(a suicide wine blend).


Experiencing wines made Sicilian Style!

(805) 654-1577  ---

Open: Thursday & Friday 3-7, Saturday & Sunday 11–7

Address: 4517 Market Street, Suite 7, Ventura, CA 93003

“Every bottle begins with geology.”  ---  David J. Panaro, P.G.

CGS is proud to be affiliated with the PSAAPG