Abstract: Cora Maar, Kapadokya Volkanik Bölgesi, taban yayılım ürünleri, sedimanteryapılar, yığışım lapillisi, tane boyu analizi Cora Maar`(CM) is a monogenetic volcano located to the 20 km northwest ofMountErciyes, withinthe Cappadocian VolcanicProvince (CVP). Cora Maaris a typical example ofa maar-diatreme volcano witha nearly circular craterwith a mean diameterofc. 1.2 km. The CMcraterissurroundedby a well-beddedbasesurge tephra rim sequence up to 40 m in thickness. This sequence issubdivided in variousfacies dependingon the characteristics of the constituents. Having a D/d ratio of 12, Cora is a relatively mature maarcompared to recentmaar craters in the world.Cora crater is excavated within the andesitic lavaflows ofQuaternary age. The tephra sequence isnot indurated, andconsists ofjuvenile scoria clasts up to 70 cm, lithic clasts up to 130 cm, accretionary lapilliup to 1.2 cm in diameter, and ash-lapilli sized volcanic material. Accretionary lapilli are observed in almostevery level ofthe sequence, and classified as rim and core-type. Base surge layers display well-developedantidune structures indicating the direction ofthe transport. Bothprogressive and regressive dune structuresarepresentwithin the tephra sequence. Otherdepositionalstructures are impactsags andchannelstructures.Observed vertical and lateralfacies change in bedding style ofbase surge deposits can be explained by thedecrease ofthesurgeflowpower anddue to a decrease in suspended-loadtransportrate and/or an increase inbedload transportrate, respectively.Detailed sections were made bed by bedfrom 5 different locationsfrom CM tephra. These sectionswere measured and sampledfor granulometric analyses along a 400 m tephra profile 500, 750, 1000 mdistance from the crater. A total of 168 samples were sieved with mesh size ranging from = -5 - +4(32mm-1/16 mm). According to granulometric analyses, samples plot within the base surgefield on CJ vs.Md® diagram. CMsamples display a bimodal distribution with a wide range ofMdvalues, characteristicforthe surge deposits. Very poorly sorted, bimodal ash deposits generally vary from coarse tail to fine tailgrading, depending on the grain size distribution while very poorly sorted lapilli and block-rich depositsdisplay apositive skewness due tofine tailgrading.