51 research outputs found
Paleovegetation Researches Based on Fossil Pollen Analysis in Akgöl (Sakarya): Preliminary Results
Fosil polen analizleri göl çökelleri, turbalıklar, akarsu ve deniz sedimanları, buzullar, linyitler ve taş kömürleri gibi çeşitli ortamlardan elde edilen polenlerin_x000D_
araştırılmasını kapsamaktadır. Kuvaterner dönemine ait palinolojik çalışmaların önemli veri kaynaklarından biri de göllerdir. Araştırma alanı olarak seçilen_x000D_
Akgöl, Sakarya ilinde, Ferizli ilçesinin Gölkent mahallesinde bulunmaktadır. Gölün yüzölçümü 3,5 km2_x000D_
ve maksimum derinliği 8 m’dir. Bu çalışmanın amacı:_x000D_
gölün dip sedimanlarında fosil polen analizleri yaparak gölün çevresinde son 1000 yılda meydana gelen vejetasyon değişimlerini ortaya çıkarmaktır._x000D_
Akgöl’den karot alımında İTÜ EMCOL Araştırma Uygulama Merkezi’nin 4x4 m. platformlu piston karotiyeri kullanılmıştır. İstanbul Üniversitesi-Cerrahpaşa,_x000D_
Orman Fakültesi Orman Botaniği Anabilim Dalında bulunan Palinoloji Laboratuvarı’na getirilen karot üzerinde her 5 cm’de bir 2 cm3_x000D_
lük sediman örnekleri_x000D_
alınmıştır. Bu örneklerde “klasik yönteme” göre fosil polen analizi yapılmıştır. Hazırlanan polen preparatlarında her bir bitki taksonu için polen yüzdesi_x000D_
değerleri hesaplanmış, odunsu ve otsu taksonlara ait yüzde grafikleri TILIA adlı programda çizilmiştir. Polen diyagramından elde edilen ilk bulgulara göre;_x000D_
Akgöl ve çevresinde son 1000 yılda yaprak döken orman vejetasyonu hâkimdir. Bu doğal orman varlığının içine son yıllarda Gymnospermae taksonlarından_x000D_
sahil çamları da dikim yoluyla getirilmiştir.Fossil pollen analyzes include research of pollen grains from various environments such as lake sediments, peatland, river and marine sediments, glaciers,_x000D_
lignite and coal. Lakes are one of the important data sources for Quaternary palynological studies. Akgöl, which is selected as a research area, is located in Gölkent district of the Ferizli township in the provincial city of Sakarya. Its surface area is 3.5 km2_x000D_
and its maximum depth is 8 meters. The aim of this study_x000D_
was to investigate vegetation changes around Akgöl in the last 1000 years using fossil pollen analysis in the bottom sediments of the lake. The Piston corer_x000D_
of ITU EMCOL Research Centre was used for recovering sediment cores from Akgöl. Sediment samples of 2 cm3_x000D_
were collected every 5 centimeters on one_x000D_
of the cores at the Palynology Laboratory of IUC. Fossil pollen analysis was performed according to the “classical method”. The pollen percentage values_x000D_
were calculated for each plant taxa and relative abundance graphs were plotted in the TILIA program. According to preliminary results of the pollen_x000D_
diagram; deciduous forest vegetation has been predominant in the last 1000 years around Akgöl. Maritime pine was introduced into this natural forest by_x000D_
plantation in the recent year
A Holocene paleomagnetic record from Kucukcekmece Lagoon, NW Turkey
Lake sediments are very useful for providing high-resolution records of geomagnetic field variations, especially for the Holocene period. We present high-resolution paleomagnetic records from three cores (KCL12P1, P2, and P3) recovered from Kucukcekmece Lagoon, located at the northern shoreline of the Sea of Marmara, Turkey. The cores were subjected to a comprehensive paleomagnetic and rock magnetic investigation using oriented samples. According to the age-depth model, based on radiocarbon dating and X-ray fluorescence-derived Ca/Ti element ratios, tuned to available oxygen isotope records based on an absolute calendar-year time-scale, we obtained a new paleomagnetic record for the last 3800 years. Low paleointensities were found during 1500-2000 BP. Stacked paleomagnetic directions from Kucukcekmece Lagoon were correlated to regional geomagnetic field models. This correlation proved that the paleomagnetic records (paleointensity, inclination) obtained from the Kucukcekmece Lagoon sediments considerably agree with the data from the surrounding region over the past 3800 years
Sedimentary characteristics and magnetic susceptibility of Late Miocene paleosols of western Anatolia, Turkey
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