Two different new Tamarix smyrnensis Bunge associations on the Yeşilırmak Delta Plain (Samsun/Türkiye)

Geomorphologic, stratigraphic, faunistic, palynological and carbon isotope analyses were carried out in the area of the Tiber river mouth. The results depict a complex palaeoenvironmental evolution in the area of the Roman town of Ostia, ascertain the changes of the Tiber river delta over the last 6000 years and support a re-interpretation of some archaeologic issues. The wave-dominated Tiber delta evolved through three distinct phases. In the first step (5000–2700 yr BP) a delta cusp was built at the river mouth, which was located north of the present outlet. Subsequently (2700–1900 BP), an abrupt southward migration of the river mouth determined the abandonment of the previous cusp and the progradation of a new one. The third step, which is still in progress, is marked by the appearance of a complex cusp made up of two distributary channels. The transition from the first to the second evolution phase occurred in the seventh century bc and was contemporary to the foundation of Ostia, as suggested by historical accounts. However, the oldest archaeological evidence of the town of Ostia dates to the fourth century bc, when human activity is clearly recorded also by pollen data. We suggest that the first human settlement (seventh century bc) consisted of ephemeral military posts, with the aim of controlling the strategic river mouth and establishing the Ostia saltworks. Only after the fourth century bc the coastal environment was stable enough for the foundation and development of the town of Ostia.

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Sources of organic carbon and depositional environment in the Bengal delta plain sediments during the Holocene period

Limnology ◽

10.1007/s10201-009-0301-9 ◽

2009 ◽

Vol 11 (2) ◽

pp. 133-142 ◽

Cited By ~ 10

Author(s):

Hossain M. Anawar ◽

Takahito Yoshioka ◽

Eiichi Konohira ◽

Junji Akai ◽

M. C. Freitas ◽

...

Keyword(s):

Organic Carbon ◽

Depositional Environment ◽

The Holocene ◽

Bengal Delta ◽

Delta Plain ◽

Holocene Period

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Sea-level rise and coastal marsh sustainability: geological and ecological factors in the Mississippi delta plain

Geomorphology ◽

10.1016/s0169-555x(02)00183-6 ◽

2002 ◽

Vol 48 (1-3) ◽

pp. 233-243 ◽

Cited By ~ 123

Author(s):

Denise J Reed

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Mississippi Delta ◽

Ecological Factors ◽

Coastal Marsh ◽

Delta Plain

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Cryostratigraphy, sedimentology, and the late Quaternary evolution of the Zackenberg River delta, northeast Greenland

The Cryosphere ◽

10.5194/tc-11-1265-2017 ◽

2017 ◽

Vol 11 (3) ◽

pp. 1265-1282 ◽

Cited By ~ 14

Author(s):

Graham L. Gilbert ◽

Stefanie Cable ◽

Christine Thiel ◽

Hanne H. Christiansen ◽

Bo Elberling

Keyword(s):

Late Quaternary ◽

Sediment Cores ◽

River Delta ◽

Optically Stimulated Luminescence ◽

Delta Plain ◽

Valley Fill ◽

Subaerial Exposure ◽

Facies Associations ◽

Delta Progradation ◽

Ice Content

Abstract. The Zackenberg River delta is located in northeast Greenland (74°30′ N, 20°30′ E) at the outlet of the Zackenberg fjord valley. The fjord-valley fill consists of a series of terraced deltaic deposits (ca. 2 km2) formed during relative sea-level (RSL) fall. We investigated the deposits using sedimentological and cryostratigraphic techniques together with optically stimulated luminescence (OSL) dating. We identify four facies associations in sections (4 to 22 m in height) exposed along the modern Zackenberg River and coast. Facies associations relate to (I) overriding glaciers, (II) retreating glaciers and quiescent glaciomarine conditions, (III) delta progradation in a fjord valley, and (IV) fluvial activity and niveo-aeolian processes. Pore, layered, and suspended cryofacies are identified in two 20 m deep ice-bonded sediment cores. The cryofacies distribution, together with low overall ground-ice content, indicates that permafrost is predominately epigenetic in these deposits. Fourteen OSL ages constrain the deposition of the cored deposits to between approximately 13 and 11 ka, immediately following deglaciation. The timing of permafrost aggradation was closely related to delta progradation and began following the subaerial exposure of the delta plain (ca. 11 ka). Our results reveal information concerning the interplay between deglaciation, RSL change, sedimentation, permafrost aggradation, and the timing of these events. These findings have implications for the timing and mode of permafrost aggradation in other fjord valleys in northeast Greenland.

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Hydrogeological Classification and the Correlation of Groundwater Chemistry with Basin Flow in the South-Western Part of Bangladesh

Journal of Bangladesh Academy of Sciences ◽

10.3329/jbas.v42i1.37831 ◽

2018 ◽

Vol 42 (1) ◽

pp. 41-54 ◽

Cited By ~ 1

Author(s):

Shahpara Sheikh Dola ◽

Khairul Bahsar ◽

Mazeda Islam ◽

Md Mizanur Rahman Sarker

Keyword(s):

Groundwater Flow ◽

Water Chemistry ◽

Sea Water ◽

Shallow Groundwater ◽

Shallow Aquifer ◽

Deep Basin ◽

Deep Groundwater ◽

Deep Aquifer ◽

Delta Plain ◽

Type Water

Attempt has been made to find the relationship between the basin groundwater flow and the current water chemistry of south-western part of Bangladesh considering their lithological distribution and aquifer condition. The correlation of water chemistry and basin groundwater flow is depicted in the conceptual model. The water-types of shallow groundwater are predominantly Mg-Na-HCO3 and Ca- Mg-Na-HCO3 type. In the deep aquifer of upper delta plain is predominately Na-Cl, Ca-HCO3 and Mg- HCO3 type. In the lower delta plain Na-Cl type of water mainly occurs in the shallow aquifer and occasionally Ca-HCO3, Ca-Mg-Na-HCO3 and Mg-HCO3 type may also occur in shallow aquifer of the eastern part of lower delta plain which could have originated from the recent recharge of rain water. Na- Cl type water is also found in the deep aquifer of lower delta plain. The origin of Na-Cl type water in the deep aquifer of lower delta part might be connate water or present day sea water intrusion. Fresh water occurring in the deep aquifer in the lower delta area is mostly of Mg-Ca-HCO3 and Na-HClO3 types. This type of water originate from intermediate or deep basin flow from the northern part of Bangladesh. The probable source of deep groundwater is Holocene marine transgression (Khan et al. 2000) occurred in 3000–7000 cal years BP and the deep groundwater of Upper Delta plain and Lower Delta plain is clearly influenced by deep basin flow coming from north part of BangladeshJournal of Bangladesh Academy of Sciences, Vol. 42, No. 1, 41-54, 2018

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Feldspar Dissolution and Its Influence on Reservoirs: A Case Study of the Lower Triassic Baikouquan Formation in the Northwest Margin of the Junggar Basin, China

Geofluids ◽

10.1155/2018/6536419 ◽

2018 ◽

Vol 2018 ◽

pp. 1-19 ◽

Cited By ~ 1

Author(s):

Meng Xiao ◽

Xuanjun Yuan ◽

Dawei Cheng ◽

Songtao Wu ◽

Zhenglin Cao ◽

...

Keyword(s):

Clay Minerals ◽

Physical Property ◽

Junggar Basin ◽

Sedimentary Facies ◽

Lower Triassic ◽

Depositional Environments ◽

Source Rocks ◽

Reservoir Quality ◽

Delta Plain ◽

Feldspar Dissolution

Feldspar dissolution is a common feature in clastic rock reservoirs of petroliferous basins and has an important influence on reservoir quality. However, the effect of feldspar dissolution on reservoir quality varies under different depositional environments and diagenetic systems. The study area in this paper is located in the Baikouquan Formation in the northwestern margin of the Junggar Basin, which is significantly influenced by feldspar dissolution. Based on the analyses of core and thin section observations, QEMSEM, XRD, SEM, CL, fluorescence, and image analysis software combined with logging and physical property data, this study shows that feldspar dissolution in the subaqueous distributary channel of a fan delta plain, which has good original physical properties and low mud contents, significantly improves the properties of the reservoir. The main reasons for this are as follows: (1) the sedimentary facies with good original properties and low mud content is a relatively open system in the burial stage. The acidic fluids needed for feldspar dissolution are mostly derived from organic acids associated with the source rocks and migrate to the good-permeability area of the reservoir; (2) the by-products of feldspar dissolution, such as authigenic clay minerals and authigenic quartz, are transported by pore water in a relatively open diagenetic system and then precipitated in a relatively closed diagenetic system; and (3) the clay minerals produced by feldspar dissolution in different diagenetic environments and diagenetic stages have different effects on the reservoir. When the kaolinite content is less than 3%, the illite content is less than 4%, and the chlorite content is less than 12%, the clay minerals have a positive effect on the porosity. These clay minerals can reduce porosity and block pore throats when their contents are larger than these values.

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