Scientific Aspects

Dr. François Pujos

* Senior Researcher - Independent Researcher

E6-146, Argentine Institute of Nivology, Glaciology and Environmental Sciences (IANIGLA), CCT-CONICET-Mendoza, Avda.Ruiz Leal s / n, General San Martín Park, 5500 Mendoza, Argentina.

My father and I agree on the origin of these figures, they are also found in the fossil state (which is why I know them quite well) and indicate clearly a certain type of environment, called "ripple marks" (or wave marks).

The almost perfect shape of those ripple marks is probably random; however, we can try to give you more information about the sedimentation conditions in which they were formed.

The marks are small, symmetrical and rhomboidal; it is noted that the peaks are a few centimeters high. These structures were made by the ebb and flow of the tide in shallow water but strong dynamics, probably in the intertidal zone (at the breaking of the waves on the beach). The angles of these structures probably point to the flow of the current; They were formed during the "backwash" (return of the waves).

Professor Adam D. Switzer

Nanyang Associate Professor (NRF)

Associate Chair (Academic) | Asian School of the Environment (ASE) | Nanyang Technological University

Principal Investigator | Earth Observatory of Singapore (EOS) | Nanyang Technological University

Affiliated Researcher @ Complexity Institute (CI) and Institute for Catastrophic Risk Management (ICRM) | Nanyang Technological University

Singapore

I’ve never been there in that part of Mexico, but I assume like all beaches that particular beach is the product of the local geology.

You could see these figures anywhere where the geology contains what we call ‘heavy minerals’. I’ve seen similar patterns in India, Australia, Macau, Philippines and Vietnam.

The main commonality will be the presence of a diverse suite of minerals. The main heavy minerals are called zircon and ilmenite. Gold is possible but it will usually be pyrite (fools gold).

Your images are of the swash zone where waves sort the sediments out into their hydraulic equilibrium. The symmetry means the waves are likely washing straight up and down the beach. Unfortunately I have never documented photographically these sand patterns , since usually walk past them as my work relates to tsunami and storm deposits inland. The best of seen in India are near Cuddalore south of Chennai.

Profesor Francisco José Pérez Torrado

Geologist at the University of Las Palmas de Gran Canaria, Physics department. Basic Sciences Building. University Campus of Tafira., Spain

The pictures are of ripples, meaning, the way that seawater moves the sand generating small dunes. To be able to understand if they were climbing ripples or wave ripples we need a third dimension. we need to understand the internal lamination of the ripples.

Jesús Pineda

Senior Scientist

Biology Department

Woods Hole Oceanographic Institution

Massachusetts,USA

There are studies that indicate similar patterns to those that you have seen are due to a feedback effect between the characteristics of the micro-currents and the size of the sediment grains. I understand that repetitive patterns in nature are often associated with feedback phenomena.

Prof. Dr. Hans Jürgen Herrmann

Theoretical Physicist and Full Professor at the Institute of Building Materials

ETH Zurich

Switzerland

These patterns are a consequence of downstream water and also of the water that rises out of the ground, a phenomenon called seepage. Actually various effects overlap to give a variety of patterns depending on the sand composition, the slope of the beach, etc…

The water that flows downstream induces a phenomenon called segregation that separates the grains of sand according to their different weights or shapes, and colors, since almost all sand is a mixture of different types of grains. This segregation is carried out along lines that have a certain angle with respect to the slope. This explains the different color lines in the criss-cross form.

The seepage in turn forms patterns that look like rivers and also with a characteristic angle opening of pi / 3 and produce a pattern with more or less regular relief.