Sedimentological properties and depositional environments of the Holocene sequence in Yenikapi, Istanbul

During the salvage excavations in the area of the former Theodosian harbor in Yenikapi-Istanbul several ship wrecks from the Byzantine period, archaeological objects from different periods and a Holocene aged sedimentary sequence have been uncovered. In this study the lithological, lithostratigraphical and facies properties of the Holocene sequence are investigated in detail and its depositional environment is determined. For this purpose along four profiles (S1, S2, S3, S4) 14 different sections of a total thickness of 17.75 m are studied and 100 samples are collected. The grain size distribution and mineralogical composition of the samples are defined by sieve and sedigraph analysis and by XRD method, respectively. Results of these analyses and facies characteristics of this poorly known Holocene sequence are used for the definition of the depositional environment. Accordingly, the marine sediments are deposited in a near-shore environment, with a natural embayment or estuary transgressively. Terrigenous and anthropogenic material carried by the Lycos River, at the mouth of this natural embayment, resulted in first a regression and then a high-energy fluvial system in the study area

Establishing a high-resolution stratigraphy in the Holocene marine sequence of the ancient Theodosian harbor of Istanbul with the help of dendrochronology

Salvage excavations in the Theodosian harbor (Yenikapi-Istanbul) have uncovered diverse archaeological objects including 36 shipwrecks and various Byzantine period wooden docks. The sequence of these docks provided a unique opportunity to obtain a high-resolution stratigraphy. The new approach is based on stratigraphic interpretation of deformation patterns created by the posts in soft sediments, combined with dendrochronological dating of the posts. Dendrochronology offers the potential to date the posts to within one calendar year of felling, a level of precision and accuracy rare in sedimentological analysis. The posts, most of them Quercus, were rammed during six different time periods. The first period is associated with posts cut in 528 AD. The second and third periods are dated by posts cut in 583 and 594 AD, respectively. The fourth-period dates within 8-10 years of 639 AD. The fifth period could be dated only roughly to between 690 and 770 AD. The last period produced a possible placement of after 778 AD. This new approach helps to establish a high-resolution stratigraphy. Furthermore, it provides information about sedimentation history and specific anthropogenic events

Establishing a high‐resolution stratigraphy in the Holocene marine sequence of the ancient Theodosian harbor of Istanbul with the help of dendrochronology

Salvage excavations in the Theodosian harbor (Yenikapi-Istanbul) have uncovered diverse archaeological objects including 36 shipwrecks and various Byzantine period wooden docks. The sequence of these docks provided a unique opportunity to obtain a high-resolution stratigraphy. The new approach is based on stratigraphic interpretation of deformation patterns created by the posts in soft sediments, combined with dendrochronological dating of the posts. Dendrochronology offers the potential to date the posts to within one calendar year of felling, a level of precision and accuracy rare in sedimentological analysis. The posts, most of them Quercus, were rammed during six different time periods. The first period is associated with posts cut in 528 AD. The second and third periods are dated by posts cut in 583 and 594 AD, respectively. The fourth-period dates within 8-10 years of 639 AD. The fifth period could be dated only roughly to between 690 and 770 AD. The last period produced a possible placement of after 778 AD. This new approach helps to establish a high-resolution stratigraphy. Furthermore, it provides information about sedimentation history and specific anthropogenic events