Late Quaternary co-seismic sedimentation in the Sea of Marmara's deep basins

25 pages, 15 figures, 1 tableauInternational audienceThe deep, northern, part of the Sea of Marmara (northwestern Turkey) is composed of several aligned, actively subsiding, basins, which are the direct structural and morphological expression of the North Anatolian Fault's northern branch. The last 20 kyr of their sedimentary fill (lacustrine before 12 kyr BP) have been investigated through giant piston coring onboard R/V MARION-DUFRESNE (MARMACORE Cruise, 2001) and chirp subbottom profiler onboard R/V ATALANTE during MARMARASCARPS Cruise (2002). Especially during the lacustrine stage, the infilling of the deep basins (Tekirda?, Central, Kumburgaz, and Çinarcic Basins; up to 1250 m depth) was dominated by turbidites (with coarse mixed siliciclastic and bioclastic basal part), intercalated in “hemipelagic-type” finegrained calcareous and slightly siliceous clays. Often – especially in the thickest ones – the turbidites show strong segregation and a sharp boundary between coarse part and suspendedload part. In the Central Basin, 8 m of a unique sedimentary event include a 5 to 8m-thick “homogenite” well imaged on seismic profiles. The latter is interpreted as related to a major – possibly triggered - tsunami effect, as described in the Eastern Mediterranean by Kastens and Cita (1981). In the marine (Holocene) upper part of the sedimentary fill, repeated to-and-from structures, affecting silt or fine sand, are evidencing seiche-like effects and, thus, earthquake triggering. Detailed correlations between two deep coring sites (1250 and 1200 m) indicate more than 100 % overthickening in the deepest one; this implies specific processes of distribution of terrigenous input by dense hyperpycnal currents (high kinetic energy, seiche effect, complex reflections on steep slopes). The peculiar sedimentary infilling of the Sea of Marmara's Central Basin (and, by extrapolation, of the whole set) is tentatively interpreted as a direct consequence of the strong seismic activity; the imprint of the latter is more obvious prior to the base of the Holocene, as environmental conditions favoured marginal accumulation (especially on the southern shelf) of large amounts of erosion products available for mass wasting

Estimasi Biaya Awal Pembangunan Hotel Dengan Metode “Cost Significance Model”

Pada permulaan perancangan sebuah proyek biasanya seperti kelengkapan dokumen gambar, spesifikasi teknis dan lain lainnya belum tersusun lengkap, sehingga perhitungan biaya secara akurat tidak mungkin bisa dilakukan. Di satu sisi Pemilik Proyek (Owner) sedini mungkin sangat memerlukan perhitungan biaya.  maka diperlukan suatu teknik pembuatan model estimasi biaya yang sederhana, cepat, mudah dan akurat. Secara umum tujuan dari penelitian ini adalah untuk bisa  memberikan masukan dan gambaran mengenai anggaran awal proyek sedini mungkin dalam waktu yang singkat dengan hasil perhitungan yang cukup akurat dengan maksud menganalisis dan mengestimasi biaya awal pembangunan hotel di Kota Bandung menggunakan Metode Cost Significant Model. . Hasil penelitian menunjukan pekerjaan struktur, arsitektur dan elektrikal berpengaruh secara signifikan  terhadap total biaya pembangunan hotel di Kota Bandung, dimana 81,60% biaya total pekerjaan dipengaruhi oleh Pekerjaan Arsitektur, Struktur dan Elektrikal. Perinciannya adalah Pekerjaan Arsitektur 38,54%, Pekerjaan Struktur 28,52% dan Pekerjaan Elektrikal 14,54%, sedangkan sisanya dipengaruhi oleh pekerjaan lain. Akurasi model estimasi pembangunan hotel dengan metode “Cost Significant Model” Di Kota bandung adalah berkisar antara -4,06% sampai dengan 14,03% dengan rata-rata 6,98%, sedangkan akurasi estimasi berdasarkan estimasi metoda parameter berkisar antara -0,33% sampai dengan 33,28% dengan rata-rata 14,17%. Sehingga jelas dengan menggunakan metode “Cost Significant Model” menghasilkan estimasi yang lebih teliti dibandingkan dengan metode parameter luas bangunan sebagai estimasi awal pembangunan hotel di Kota Bandung

Influences of Climate and Tectonic on the Middle to Late Holocene Deltaic Sedimentation in Lake Hazar, Eastern Turkey

Analyses of two piston cores from Lake Hazar together with high-resolution seismic data provide unique evidence of complex interaction of tectonics and lake level changes during the mid-to-late Holocene. This period is associated with stacked shelf-edge deltaic units at the mouth of the Kurk double dagger ayA +/- River at the western extreme of the lake. Despite the general dry climate during the middle Holocene (between 8.2 and 5.1 cal ka BP), transgressive and landward retreating deltaic successions developed due to the deepening of the lake that induced by transtentional activity of the East Anatolian Fault Zone. The arid climate during 5.1-2.6 cal ka BP is supported by the multi-proxy analyses of the cores. This period coincides with the late Bronze age deforestation, which probably provided the sediment supply by soil erosion for the deltaic deposition at the mouth of the paleo-Kurk double dagger ayA +/- River. On the other hand, the flooding of the youngest deltaic unit in the lake took place under a general wet climate after 1.4 cal ka BP. The seismic architecture and the core sedimentology indicate that the existing hydrological regime with the latest deltaic deposition started 2.6 cal ka BP was accompanied by a hyperpycnal mixing

Late glacial to Holocene water level and climate changes in the Gulf of Gemlik, Sea of Marmara: evidence from multi-proxy data

Multi-proxy analyses of new piston core M13-08 together with seismic data from the Gulf of Gemlik provide a detailed record of paleoceanographic and paleoclimatic changes with special emphasis on the timing of the connections between the Sea of Marmara (SoM) and the Gulf of Gemlik during the late Pleistocene to Holocene. The deposition of a subaqueous delta sourced from the Armutlu River to the north is attributed to the lowstand lake level at −60 m in the gulf prior to 13.5 cal ka BP. On the basis of the seismic data, it is argued that the higher lake level (−60 m) in the gulf compared to the SoM level (−85 m) attests to its disconnection from the SoM during the late glacial period. Ponto-Caspian assemblages in the lacustrine sedimentary unit covering the time period between 13.5 and 12 cal ka BP represent a relict that was introduced into the gulf by a Black Sea outflow during the marine isotope stage 3 interstadial. Contrary to the findings of previous studies, the data suggest that such an outflow into the Gulf of Gemlik during the late glacial period could have occurred only if the SoM lake level (−85 m) was shallower than the sill depth (−55 m) of the gulf in the west. A robust age model of the core indicates the connection of the gulf with the marine SoM at 12 cal ka BP, consistent with the sill depth (−55 m) of the gulf on the global sea level curve. Strong evidence of a marine incursion into the gulf is well documented by the μ-XRF Sr/Ca data. The available profiles of elemental ratios in core M13-08, together with the age-depth model, imply that a warm and wet climate prevailed in the gulf during the early Holocene (12–10.1 cal ka BP), whereas the longest drought occurred during the middle Holocene (8.2–5.4 cal ka BP). The base of the main Holocene sapropel in the gulf is dated at 10.1 cal ka BP, i.e., 500 years younger than its equivalent in the SoM. The late Holocene is earmarked by warm and wet climate periods (5.0–4.2 and 4.2–2.7 cal ka BP) with some brief cold/dry periods (4.2 and 2.7–0.9 cal ka BP)

Mut Basin, Turkey: Miocene carbonate depositional styles and mixed systems in an icehouse setting

WOS: 000396839300013The Mut Basin in southcentral Turkey contains a rich variety of Cenozoic carbonate deposits that developed on a complex preMiocene topography and can be studied in seismic-scale, threedimensional outcrops. These include open and rimmed carbonate shelves with steep slopes, small isolated platforms, and mixed carbonate-siliciclastic systems showing reciprocal sedimentation. The exceptional preservations of the stratal geometries make it possible to easily link large-scale depositional geometry to depositional facies in a variety of platform types and depositional environments. The Mut Basin provides a better understanding of (1) the control of antecedent topography on carbonate platform development, (2) the influence of icehouse conditions (e.g., highamplitude, high-frequency sea level fluctuations) on the carbonate system, (3) the link between faunal evolution and the style of carbonate platforms and stratigraphic architecture, (4) lateral and reciprocal carbonate and siliciclastic sedimentation, (5) platform asymmetry and local controls on stratal geometries, and (6) the architecture of steep carbonate margin and associated gravitational collapse deposits. These concepts are directly applicable to time-equivalent Cenozoic carbonate reservoir systems in Southeast Asia, the southern Caribbean, and the eastern Mediterranean

Geochemical proxies of sediment core Hz11-PO3 from Lake Hazar in Eastern Anatolia

The elemental composition of lake sediment cores is often the result of several independent processes. In this study we attempt to extract statistically independent climate related signals from µ-XRF multi element data of a core drilled from Lake Hazar in Eastern Anatolia, using the independent component analysis (ICA) method. In addition, we analysed ostracod shells for oxygen and carbon isotopes. The ICA method has advantages over traditional dimension reduction methods, such as principal component analysis or factor analysis, because it is based on maximal statistical independence rather than uncorrelatedness, where independence is a stronger property. The Hz11-P03 core, which represents the last 17.3 ka, was recovered from Lake Hazar which, at times, formed the headwaters of the Tigris. Applying the ICA method, we selected two out of six independent components by measuring distance correlation similarity. We propose that one of the selected components can be read as a proxy for temperature and the other for precipitation in this region. Our results indicate that the region was relatively cold and wet during the late glacial, between 17.3 and 14.8 ka BP, and wet and warm during Bølling-Allerød. The lake level dropped below today's level during the Younger Dryas stadial (12.49 and 11.76 ka BP), forming a marked hiatus in the core's stratigraphic record. During the beginning of the Holocene, while precipitation values were high, the temperature gradually increased until 8 ka BP. Between 8 and 5 ka BP, the region was warm but extremely dry. After 5 ka BP, around 3.5 ka BP temperatures suddenly fell, and three abrupt dry phases are observed around 3.5 ka and 2.8 ka and 1.8 ka BP