17 May 2024

Prof. Dr. Aral Okay’s Scientific Legacy

Prof. Dr. Aral Okay, one of the most prominent geoscientists in the field of geology of Türkiye, passed away on November 12, 2023. We asked his relatives, coworkers and students about our professor, who left lasting works in the history of geological science with his scientific contributions to our country and his studies that attracted international attention.

News: İTÜ Media and Communication Office
ur late faculty member Prof. Dr. Aral Okay, whom we lost last year, was one of our geoscientists that Turkish geology has raised in the last 30 years who stood out with his important studies in the international arena. Our esteemed professor conducted research in different geographies of Türkiye to understand the geological evolution of these regions and accomplished studies that will leave a mark in the history of science. Prof. Dr. Okay attracted great attention in the world with his publications on the geology of Türkiye, left lasting works in the field and was deemed worthy of international awards for his contributions to science.

In order to commemorate Prof. Dr. Okay’s memory, to convey his exemplary work habits to younger generations and to emphasize the scientific importance of his work, we, as ITU Directorate of Communication Media and Communication Office, asked his coworkers about Aral Okay Hoca.

Interview: Cüneyt Altındaş

News Editor: Fatih Çünkioğlu


“A curious mind that integrates fieldwork and advanced analytical techniques”

Prof. Dr. William Cavazza from the University of Bologna has worked with Aral Okay for the last 20 years. Prof. Dr. Cavazza answered our questions about the networks Aral Okay established with scientists from different countries, his interdisciplinary approach, and the importance of his fieldwork in China.

— What did Aral Okay pay attention to when carrying out joint scientific studies with colleagues from different countries or researchers from different disciplines?

During his career, Aral Okay often managed to work with foreign colleagues, always striving to bring added value and fresh stimuli to its own lines of research. He paid great attention to the promotion of the geology of Türkiye within the international scientific community and was able to cooperate efficiently with colleagues from different cultural backgrounds, whom he patiently introduced to the geology of his country. I have been one of the several foreign geologists whom Aral chaperoned, and it was quite characteristic of his personality that he never criticized me for the usual oversimplifications -or outright mistakes- of a newcomer. A synthetic mind, he was able to summarize diverse strands of geological information of different provenance and come out with appealing paradigms for the interpretation of several Turkish geological provinces. The trademark of Aral's research was the integration of traditional fieldwork and advanced analytical techniques. One of the defining features of a curious mind, he was equally at ease doing fieldwork or interpreting complex analytical results.

— What was the worldwide scientific significance of Professor Aral Okay's fieldwork in China? What kind of difficulties did he face as a geologist while conducting these studies?

The work of Aral Okay, Celâl Şengör and Shutong Xu on the geology of the Dabie Shan range of China was a game changer of wide scientific significance. Until then few geologists believed that the continental crust could be significantly subducted, i.e. brough to great depth below another plate during continental collisions. The discovery of the ultra-high-pressure minerals diamond and coesite in Dabie Shan proved beyond doubt that continental rocks can be subducted at depths in the order of 100 km and then rapidly brought to the Earth's surface. Aral's fieldwork and subsequent analytical research on Dabie Shan (1998–2000), at the time a poorly known mountain range, led to a series of high-impact papers published between 1989 and 1995 on what is arguably the largest ultra-high-pressure metamorphic terrain on Earth.


“Aral saw doing science in his own country as a mission”

Department of Geological Engineering faculty member Prof. Dr. Nilgün Okay shared her thoughts on field trips as part of Aral Okay’s research, his motivation, and the importance of scientific and technical studies in our country, both as his spouse and colleague.

Could you tell us about the reasons why Aral Okay cared about fieldwork during his scientific studies?

Aral thought that the lack of scientific curiosity in academics is an old and bad legacy. He would also point out that research in universities is seen as an endeavor to obtain academic titles. For Aral, it was extremely important to go to the field and make new discoveries driven by curiosity. One way to understand past geological events was to examine present-day structures. His main goal was to decipher the structures of these regions and to identify their place in the evolution of Anatolia. In this respect, being located on the plate boundary, Türkiye was in a very convenient position. His long-term work on geological mapping has provided a deep understanding of the interrelationships of geological structures and the importance of data based on fossil ages in understanding regional geological evolution.

He always emphasized the essential role of field studies in understanding the macro-scale processes of plate tectonics. The style of working he learned abroad did not have a broad perspective because this system consisted of very detailed mapping of a small area. While working in the Taurus Mountains, he was incredibly excited when he realized that he could look at a big mountain from afar and understand its structure.

During his field geology-based research in almost every corner of Türkiye, he has written 16 geological field guides, which he enriched with micro-scale observations and analyses.

The models he developed from different data sets obtained from field findings had an impact on the geological community and guided new researchers. Despite being retired, he has always felt the same excitement in the collecting, processing, interpreting and publishing of field data and continued to be a role model with his knowledge and constructive-positive attitude until the end of his life.

Aral Okay’s work is the product of a prolific geoscientist with a rigorous and broad imagination in different fields of geology. He was a scientist skilled at reaching solutions by synthesizing clusters of information from the field to the laboratory. His energy and enthusiasm made him tireless in publishing his research findings serially and disseminating them to the international scientific community. It was very important that the rocks found in Türkiye were described in an international journal by a researcher from Türkiye. Türkiye’s fossils, plants, birds and history had always been written by foreigners. He was very excited that Türkiye’s interesting rocks and evolution were described by a native researcher, not a foreigner. Also, while he was still a PhD student, he became an assistant at Cambridge University and published 5 single-authored articles.

— What was the biggest scientific motivation for Aral Hoca to create detailed maps in Türkiye, which has a complex geology?

İhsan Ketin’s oft-repeated sentence, “Geology is learned from nature, not from books; professors and books are temporary tools that make it easier for you to approach nature and understand its language!” shaped Aral Okay’s life. A significant part of his 40-45 years of professional life was spent in mountains, hills and valleys trying to understand the language of rocks. He examined rocks all over Anatolia to unravel the history of the world. His curiosity for looking at rocks in the mountains started as a child during geological excursions organized by his father Prof. Dr. Ahmet Can Okay for his students at Istanbul University. He never lost his love for geology and the pleasure and excitement of working in the field. His father was a pioneer in the field of palynology, and this had a significant influence on Aral’s career choice. As a curious person who loved nature, he believed that geology was one of the best professions. He was especially excited by the geology of Türkiye, which contains complex phenomena at every point and is full of mystery, as it pushes the scientist’s abilities and knowledge to the limit. While looking at the huge horizontal monotonous strata stretching for kilometers around the Grand Canyon in the USA for a year, he became even more convinced that Türkiye was one of the countries with the most complex geology in the world. He used to say that the first precondition for solving this complexity was to make detailed geological maps of Türkiye.

The most important aspect of Aral Okay as a geologist is that he not only produced detailed and reliable maps in the field, but also posed the problems with the right questions and expressed the data, which he produced with different methods and groups, by interpreting them based on solid foundations. When he returned home from England in 1980, his aim was to conduct international research in Türkiye and to contribute to the deciphering of the complex geology of Türkiye. 

— Could you tell us about the motivation behind Aral Hoca’s being a role model that researchers from Türkiye can conduct research at the international level on their own, without the support of western countries?

Like many of his works, Aral Okay’s most important work, which brought him international recognition, is his discovery of rocks containing diamond and coesite type minerals, spread over large areas in the Dabie Shan region of China, formed under very-high-pressure conditions. This study is also important in that it proved for the first time that in geosciences Turkish researchers can conduct research at the international level on their own, without the support of western countries. Thanks to these studies, Aral Okay became a Full Member of the Turkish Academy of Sciences (TÜBA) in 1996 and was awarded the TÜBİTAK Science Award in 2002.

Aral saw doing science in his own country as a mission. He felt it was his duty not only to conduct research, but also to show that this can be done at the highest level with Türkiye’s resources, and he was very excited about doing this. Today, Turkish geology competes with the world’s leading research groups, has even reached a level to surpass them, and gained a respectable place. The historical mission undertaken by Aral contributed a great deal to this.


“Aral will be remembered for his great contributions to the geology of Türkiye”

Prof. Dr. Demir Altıner from METU, as a colleague who worked closely with him for many years, evaluated Aral Okay’s perspective on scientific research.  

 — In your opinion, how and in what way will Aral Okay Hoca be remembered the most?

Dear Aral will of course be remembered for his great contributions to the geology of Türkiye. His studies and publications especially on the petrology, stratigraphy, structural geology and tectonic development of the Pontides and the formation and evolution of suture zones in Türkiye will always remain as valuable and useful works.

— How did he view the apparent differences of opinion among geoscientists?

I observed that Aral never looked at the differences of opinion among geoscientists in an impulsive way. What Aral always looked for and questioned in studies on geosciences was about which solid data were presented in which study. In Aral’s studies and publications, a precise production of data with the contributions of the people he works with can be clearly observed. Aral also thought that tectonic models were opinions and that there might be alternatives to them, and he had a moderate view of the different models and opinions he saw in the work of other geoscientists. Nevertheless, this pushed and encouraged him to conduct even more detailed studies.


“His scientific studies were always at the center of his life”

Prof. Dr. Gültekin Topuz, with whom he worked for 18 years and wrote 15 joint articles together, told Aral Hoca through the eyes of his colleagues and students. He presented sections of his thoughts on the working environment and academia at ITU.

— What kind of person was Prof. Dr. Aral Okay through the eyes of his colleagues and students?

I have known Aral Hoca closely since the end of 2004 as a colleague working in the same unit. In general, Aral Hoca’s scientific studies were at the center of his life. He worked in his room at the institute from 9 in the morning to 10-12 at night six days a week except Sundays. For me, he was one of the rare people at the institute whom I could ask for scientific opinion, talk about and discuss research findings, and who was also accessible. Similarly, he enjoyed sharing a finding he had just discovered, even if it was late at night. For example, the fact that the zircons in the sandstones in the Kastamonu region, which were formed in 120-100 million years, most probably came from the Ukranian Shield, and that 90% of the sediments in the Thrace basin were formed in a very short time interval of 5 million years…

He would not intervene in the occasional discussions and fights within the institute to the extent of breaking the ties. He would express his opinion clearly at meetings. However, if he felt that he was not being paid regard by the management or others, he would withdraw. In general, even if he did not agree with the decisions made by the management, he never quarreled with the management or his coworkers. On a few occasions, he even warned me not to get into conflict with coworkers and management. His main reason for this was that it was difficult to conduct research in a quarrelsome environment.

The main point that distinguished Aral Hoca from other faculty members was that he directly wrote down his findings. I guess he acquired this habit during his undergraduate education in England. When he made a scientific or touristic trip to a region, he would immediately write down his observations and have a thin section prepared to examine under the microscope even a few rock samples he had collected.

— How did Aral Hoca find the working environment and academic level at ITU?

Aral Hoca found the working environment at ITU generally comfortable. However, he was completely dependent on outside the country for analytical work. There is a mineral separation and sample preparation laboratory that he established at Eurasia Earth Sciences. However, he would occasionally go abroad for a week for microchemical analyzes and age determinations.

In our conversations, he complained that the quality of academics in geosciences has deteriorated in recent years. He frequently expressed that newly recruited faculty members could not collect enough points for incentive applications.


“To work with discipline and dedication and to produce under all circumstances”

Dr. Remziye Akdoğan, the last doctoral student who graduated under Prof. Dr. Aral Okay’s supervision, shared her thoughts on the scope and importance of his work and the example he set for his students.

— How does Aral Okay’s scientific method guide young researchers?

Türkiye has a complex geological structure as a natural result of its multi-phase orogenic history and deformation processes. Since Aral Okay knew that the best way to solve this complex geology was to make accurate geological maps, he participated in the production of geological maps in an area of many kilometers in the mapping camps of MTA, where he worked when he returned to Türkiye. After joining the academia, Aral Hoca first made detailed geological maps showing the settlement, distribution, properties and age relationships of rock units together with their structural features in the areas he worked. These maps have been and continue to be used as the main source for many geologists working in the region after him.

Aral Hoca has works in almost every part of Türkiye, from west to east, from north to south. If you look carefully, none of these studies were conducted in randomly selected areas. Each of them is about the elucidation of an important geological problem. Aral Hoca was a special geologist who knew very well that both the problems of geosciences and their solutions were actually found in the field. For this reason, he attached special importance to field studies and always encouraged his students to carry out detailed field studies. Such that he participated in the field studies of all of his master’s and doctoral students as a guide at the early stages, and then allowed them to proceed alone to do their original work. His observation skills in the field also found a place in the ordinary course of his life, and even the observations he made on limited rock outcrops during a walk with his wife Prof. Dr. Nilgün Okay on the ITU campus turned into a scientific article. He sometimes took his daughters with him to fieldwork and managed to instill in them a love of nature at a young age.

Although geological maps depict the rocks on the earth’s surface and their features, they actually depict records of events occurring deep within the earth as well. Aral Okay published his first paper, which was about rocks in northwestern Türkiye formed under high pressure/temperature conditions many kilometers below earth, as a single author in Contributions to Mineralogy and Petrology, a major international journal in geosciences, in 1978, when he was still pursuing his doctorate. He also published five single-author papers on high-pressure rocks around Tavşanlı in the same journal between 1980 and 1982. In addition, his publication in 1989, which showed for the first time that the coesite mineral, a high-pressure form of quartz, which he found in high-pressure rocks in the Dabie Shan region in China, was formed as a result of subduction at depths of >90 km and that it is widely observed in continental collision zones, contrary to what was known, brought him particular renown. These publications that contain important mineralogical findings, which also show Aral Okay’s mastery of the English language, have contributed greatly to Aral Okay’s worldwide recognition. In addition, the fact that a researcher from Türkiye makes successive publications in high-quality international journals independently has both contributed greatly to the visibility of Türkiye in the world geosciences community and has encouraged researchers in our country by setting an example for them. Aral Okay continued his publications without slowing down in the following years.

As students of Aral Hoca, the most important lesson we learned from him was to work with discipline and dedication and to produce under all circumstances. Even after his retirement, he would continue to work at the institute after working hours, and the light in his room would often stay on until midnight. We, too, would be motivated by his enthusiasm for work and continue working at the institute regardless of what time it was. While we are trying to go on with the work discipline he instilled in us, I would also like to point out that we still cannot accept his departure. We are waiting for him as if he went away for a short time for one of the field studies he loved so much and will soon return with his hammer in his hand and the rock samples he brought to show us… May his soul rest in peace…


“He paid attention to language usage and recommended to write with a simple and comprehensible Turkish”

Res. Asst. Sinan Yılmazer, one of the master’s students supervised by Aral Okay, shared his views on his guidance to young researchers and the importance he attached to Turkish as a scientific language.

— How does Aral Okay’s scientific method guide young researchers?

When we look at Prof. Dr. Aral Okay’s publications, we see that the scientific method he used was constantly evolving and changing. The first and I think the most important advice our professor gave to all geoscientists, from undergraduate students to his colleagues, was about the importance of identifying rocks and geological mapping in geosciences. He would build solutions to geological questions based on the data he obtained from field studies. In addition, he supported metamorphic petrology, which he focused on in the first years of his academic life, with research areas such as regional geology, paleontology and thermochronology over time. In recent years, he has put more emphasis on these research areas. He has integrated analytical methods, which have developed and diversified rapidly especially in the last 30 years, into his work through international collaborations. Another advice he gave us was to define the problems well, and to complete a planned field, laboratory and writing process by determining the objectives in advance. He wanted all findings, small or large, to be written down. This approach gave us both the habit of writing and the ability to master our work. He expected the studies to be conducted to necessarily contribute to the geology of the region and Türkiye. In summary, Aral Hoca demonstrated with his success the importance of basic geological studies, adapting to scientific development and interdisciplinary studies, and also provided us with an important perspective.

— What did Aral Okay think about preserving Turkish as a scientific language?

Aral Okay attached importance to his writings (articles, papers, reports, etc.) being simple and comprehensible, used short and concise sentences, and avoided flowery sentences and words. He also advised us to put our thoughts into writing in the shortest and most comprehensible way. He recommended undergraduate and graduate students to write their theses in Turkish, and he evaluated every manuscript sent to him with great care. He would carefully examine all elements such as the fluency of the language used in the writings, word choices and spelling rules, and make corrections. He meticulously applied the principle of making the language in his writings understandable, simple and fluent to his lectures and presentations as well. He wanted us to avoid indirect expression and convey our thoughts to the audience in a simple, understandable and fluent manner. Another characteristic of Aral Okay was that he would always write down the methods used and the usage of tools in the laboratories, send them to all his stakeholders and post them in the necessary places. He would prepare detailed booklets for his field trips and share them with the participants. These manners and behaviors show us his constructive attitude towards the preservation of Turkish as a scientific language.

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