The Çakallar Volcanism and Human Foot Prints on the Bottom of Pyroclastic Layers (Western Anatolia)

Yıl 1992, Cilt: 6 Sayı: 1, - , 01.06.1992

İlhan Kayan

Öz

The Çakallar volcanism and human foot prints on the bottom of pyroclastic layers (Western Anatolia) Western Anatolia has many features of a recent rift tectonism such as graben systems mostly in the west-east directions and block faulte mountain ridges between them. One of the most distinguished grabens is the Gediz valley and its eastern branches, to the SE the Alaşehir plain and to NE the continuation of main Gediz valley (Fig. 1). Between them, a 500-600 m high erosional surface occurs, with a relatively low undulated surface on the crystalline basement and its Neogene cover of limy-marly formations. This surface was formed at the end of the Neogene period and the present river system was Incised during the latest tectonic uplifting of the area. Finally the surface was covered by volcanic formations such as pyroclastic deposits and cones, lava flows and other smaller volcanism features, of volcanism. This area Is known by the name of largest nearby town of Kula (Fig. 2).

The Kula area is mostly characterized by very recent volcanic landforms. Strabo mentions this area as "Katakekaumene (Burnt land)”. However volcanic activity was not noticed in his time. The Kula volcanism occured over many periods of time. In general, it is accepted that the three phases are dominant. During the last activity, which occured in the Holocene epoch, eruptions concentrated in four majör centres on a NW-SE line. Only the Çakallar eruption occured on the western side of the Gedlz valley (Fig. 2). Although a small area, the Çakallar volcanism shows a poligenetic formation and a varied set of a very recent volcanic features including a widespread tephra cover, a pyroclastic cone 100 m high, explosion features and many small lava How features (Fig. 3 and Photo 1). Before the main formation of the Çakallar cone, an agglomeratic-basaltic lava eruption occured as seen especially In the north base of the Çakallar cone. Further, the Küçükdivlit cone to the east must have formed earlier than the Çakallar cone.

The Çakallar volcanism started with relatively small eruptions, initially covering the area with a thin tephra layer. Perhaps the most interesting characteristic of this area is the occurance of fossil human bare foot prints on the fine tephra layer (Photos 2 and 3). The foot prints, which belong at least two persons walking from west to east

toward the valley bottom can be clearly followed (Fig. 3). There are also foot prints of animals (perhaps dogs) walking together with the humans. The human foot prints are different, the larger is about shoe size 40-41 (7-7.5). The distance between the prints averages 75-80 cm. The foot prints are slightly deformed because of the inclination of the surface. Many speculations have been made related to the persons who left the foot prints, especially on their behavior during the volcanism. However, there Is no direct relation between the walking direction and the eruption centre.

Not much later, following the walking of the persons. Çakallar volcanism started repeated new explosions. During this activity a scoria layer with dark, very light vesicular lapilli (about 1-2 cm at the bottom and gradually larger sizes toward up) and small bombs of basic composition covered the foot prints and nearby area (Figs. 4 and 5, Photos 2 and 3). The pyroclastic scoria layer did not have a baking and hardening effect on the first ash layer, on which the foot prints had been formed. However, this porous cover prevented erosion the foot prints by surficlal running waters.

During the following active phases of the Çakallar volcanism, explosions became increasingly more severe and sizes of the piroclastic material became gradually larger. As the newer material accumulated, in the explosion centre, the Çakallar pyroclastic cone formed. However, the eastern part of the cone finally exploded and a basaltic lava flowed toward the east covering the area between the chimney and the Gedlz valley at that time. Therefore, the present shape of the cone is a cresent at about 500 m diameter in its outer circle (Fig 3).

The Çakallar volcanism caused some changes on the drainage of the area because it occured at the junction of tributaries at the Gedlz river. There, it formed a volcanic dam with small alluvial plains behind the cone, in the west. Ultimately, the tributaries cut the volcanic barrier and Incised small overflowing gorges (Fig. 3).

Today the basaltic scoria cover has an economic value. It is used as a mixture for cement and brick production, and as insulation material in some instances. Therefore this material has been quarried for many years. When the excavation reached the bottom of the scoria cover, the foot prints were first seen in 1968. Initially, the Mineral Research and Exploration Institute of Türkiye researched the subject in 1969, followed by many scientific and popular papers. However, to date, a satisfactorily complete scientific research has not been published on this matter. During the time since the finding of the foot prints, no one has been able to save the foot prints from the attack of modem people. Some of the foot prints were taken for the museums, others as personal curiosities. Most of the prints have been destroyed. The Council for Protecting of Cultural and Natural Values (Kültür ve Tabiat Varlıklarım Komma Kurulu) decided to reserve this area and stopped the activity of quarries of pyroclastics in this area. It is thought that more prints may be found under the remaining scoria cover; but. Today only a few destroyed prints can be seen on the surface.

Present curiosity is concentrated mostly on the age of the Çakallar volcanism and especially the foot prints and their owners. Research on the age of the foot prints varies greatly from one another. Ozansoy (1969) suggests that the foot prints occured at least 250.000 years ago according to his studies based on river terrace deposits. But some radiometric studies on the volcanics and geomorphologic research of the area give much later dates such as 10.000 years before present (Sanver 1968, Erinç 1970). Thus, the age of the foot prints remains controversial.

We suggest that the area must be stricktly preserved and new interdisciplinary research must be done, especially on details of prehistory, antropology, and environmental sciences. Only after decisions have been made on how the foot prints will be preserved or saved, can new excavations be made to find additional foot prints. The Çakallar area provides considerable advantages, to be used as an area for both touristic and scientific purposes. It is close to the main Ankara-lzmlr highway, connected with a fairly good road, and is only 130 km from Izmir. Also, the nearby Demirköprü dam adds an excellent recreational setting (Fig. 1 and Photo 1)

Anahtar Kelimeler

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DEMİRKÖPRÜ BARAJ GÖLÜ BATI KIYISINDA ÇAKALLAR VOLKANİZMASI VE FOSİL İNSAN AYAK İZLERİ

Öz

Çakallar çevresindeki ayak izleri ile ilgili olarak ilk bilimsel araştırma F. Ozansoy başkanlığında bir MTA ekibi tarafından yapılmıştır. Ozansoy, Çakallar volkanizmasının oluşumunu, evrelerini, izler in bulunduğu seviyenin konumunu, izlerin antropolojik özelliklerini incelemiş, Gediz vadisindeki akarsu sekilerine, bunların volkanik çakıl içeriğine bakarak hem Çakallar volkanizmasmı. hem de ayak izlerini tarihlendirmiştir (1969). Buna göre: "Çakallar konisinin oluşumu Orta Pleistosen sonunda başlamakta, Riss ile yaşıt olan 3. pluvial sekinin şekillenmesinden önce sona ermektedir. Bu dönem günümüzden 500.000-200.000 yıl önceye rastlamaktadır. İzler ise Pleistosen'in II. Pluvial Devresi (Mindel II) sonlarında oluşmuştur ve günümüzden 250.000 yıldan az önceye (fakat daha sonraya değil) aittir. Somatik özellikleri bakımından izlerde kesin olarak "erectus bipedalizm" vardır (dik yürüyen iki ayaklı bir yaşayış). Başparmak kendisini izleyenden ayrıktır. 2., 3., 4. parmaklar arasında da belirgin bir açıklık vardır. Lateral kenardaki dışbükey şekil ve 5. parmaktaki kütlevîlik belirgindir. Bunlar ilkel özelliklerdir. Bazı izlerde ayak tabanının ön kısmı nispeten geride gibi görünmektedir. Bu durum Homo sapiens sapiens evrim aşamasının gerisinde bir özelliktir."

Bu izlerin hangi insanlara ait olduğu ve ne zaman bırakıldığı, en çok merak edilen ve üzerinde durulan konular olmuştur. Erinç (1970. 20) izlerin bulunmasından önce bölgede yaptığı araştırmalara göre Çakallar volkanizmasını Kula çevresindeki volkanik oluşumların son evresine koymuş, günümüzden 10.000 - 2.000 yıl önceki dönemde meydana geldiğini belirtmiştir. Bu yaşlandırma Ozansoy (1969, 207)'un Gediz sekilerine dayanarak verdiği 250.000 yıldan çok farklı bulunmaktadır. Tekkaya (1976. 8), izlerin üstünü kaplayan cüruf tabakasında Sanver (1968) tarafından yapılan paleomagnetic incelemelerin sonuçlarına dayanarak izlerin yaşının 12.000 yıl olduğunu kabul etmektedir. Göksu (1977), termoluminesans yöntemi uygulayarak yaptığı çalışmalardan 26.000 ± 5.200 ile 49.000 ± 4.800 yıl arasında sonuçlar elde etmiştir. Bu konu üzerinde aşağıda tekrar durulacaktır.

Anahtar Kelimeler

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