BIOSTRATIGRAPHIC CHARACTERIZATION OF THE CRETACEOUS DEPOSITS OF THE SAN-PEDRO MARGIN OF DRILL HOLES K1 AND K2 OF BLOCK KL: PALEOENVIRONMENT IMPLICATION

The KL block studies was carried out the eastern part of the San Pedro margin, it has an area of 2034 km2 with a water depth varying from 500 to 2750 m with two probings (K1 and K2).The objective of this work is to carry out a biostratigraphic and paleoenvironmental study based on the associations of planktonic and palynomorphicmicrofauna in the formations of the KL block boreholes. From a lithological point of view, the base of the boreholes generally comprises alternating limestone and argillite, very fine to fine grained quartz sandstone. Its upper part is overlain by claystoneinterbedded with limestone, silstone and siliceous cemented sandstone and alternating claystone, medium to coarse grained sand and siliceous cemented quartz sandstone. The Albian is determined by the presence of the species Ticinellamadecassiana. The Cenomanian is identified by the micropalaeontological assemblages composed of Globigerinelloides spp., Guembelitria spp., Hedbergella spp., Hedbergelladelrioensis, Globigerinelloides bentonensisandLoeblichella cf. hessi. The Turonian is based mainly on the species Hedbergellaplanispira, Heterohelixmoremani and Whiteinella archaeocretacea. The Early Senonian is characterized by associations of species (Hedbergellasp, Hedbergella cf. delrioensis, Buliminacrassa and Whiteinella baltica) and palynomorphs (Proteaciditestienabaensis, Odontochitinacostata, Odontochitinaporiferaand Tricolpites sp). The roof of the Campanian is known by the association of the palynomorph (Trichodinium castanae) and the microfossil (Gaudryina cretacea) The Maastrichtian is highlighted by the associations composed of species Rzehakina epigona fissistomata, Rzehakina minima, Plectina lenis, Reophax duplex, Reophax pilulifera, Reophax globosus, Gaudryina pyramidata and Afrobolivina afra) and palynomorphic species (Andalusiella gabonensis, Cerodinium granulostriatum and Palaeocystodinium australinium). All the micropalaeontological data coupled with those of the microfaunas make it possible to envisage a depositional environment of the internal platform type with continental influence on an external platform.

Sediment analysis and modelling reveal short inundation distances and low onshore flow speed of the 2018 Palu-Donggala tsunami in Indonesia

<p>On 28 September 2018, a magnitude 7.5 earthquake struck north of Palu, Central Sulawesi, Indonesia. The earthquake generated a tsunami with inundation depths of up to 7.5 m and run-up of up to 10 m above sea level. Inundation distances were only partly topography dependent and reached less than 400 m inland even where terrain did not rise steeply beyond that point. A subsequent tsunami was generated by a combination of minor fault displacement and multiple submarine landslides. In places, co-seismic coastal subsidence of >1 m exacerbated the tsunami inundation. During a post-event field survey in November 2018, we sampled three transects for sediment analysis; two in Palu City and one on the eastern coast of Palu Bay. The tsunami deposits in Palu City are predominantly massive, fine- to medium-grained sand in thin layers (<5 cm) with patchy distribution of sediments. In contrast, sediments present near Pantoloan on the east coast of Palu Bay were coarser (medium- to coarse-grained sand), thicker (up to 12 cm) and more continuous. These tsunami deposits exhibited fining and thinning landwards, and are characterized by a continuous sand sheet that extends up to 250 m inland with few post depositional changes. The grain size ranges from coarse-grained sand to silty-fine-grained sand at the landward extent. The Pantoloan site also contained wave-transported blocks of sea wall weighing up to 4.7 t in addition to sandy deposits. The blocks together with grain size data suggest that water velocities reached 3 m.s<sup>-1</sup> at more than 130 m from the coast. The tsunami deposits of Palu Bay generally exhibit sedimentological and stratigraphic characteristics shared by storm and tsunami deposits, which maybe be ascribed to the short wave length, relatively low power and short-term inundation of the tsunami and the limited availability of sediments in the nearshore environment.</p>

HYDROGEOPHYSICAL DELINEATION OF PROLIFIC GROUNDWATER AQUIFER AROUND STUDENTS’ HOSTELS IN FUPRE CAMPUS, NIGERIA

Electrical resistivity survey was conducted around Students’ Hostels in FUPRE to delineate prolific aquifer for potable water to serve the teeming population of staff and students. Five vertical electrical soundings (VES) using Schlumberger electrode configuration with a maximum current electrode spread of 300m were employed for data acquisition. WINRESIST software was employed to execute the iteration and inversion processes of computing resistivities, depths and thicknesses of the various layers and the curve types. Results indicate that the area is characterized by 4 distinct geoelectric layers inferred differently at the VES locations. Two potential groundwater aquifer zones are delineated. The unconfined shallow aquifer zones found at VES 1, 3, 4 and 5 locations have shallow overburden depth ranging between 3.7-19.3m and coarse-grained sand columns with thicknesses ranging between 2.8-17.7m while the confined deep aquifer zone found at VES 2 location coincides with deep overburden layer at a depth of 42.6m and coarse-grained sand column with appreciable thickness of 19.1m. These results suggest that boreholes for sustainable groundwater supply around the Students’ Hostels should be sited at VES 2 location and screened at a depth ≥40.0m. However, aquifers at VES 1, 3, 4 and 5 have potentials for groundwater but are vulnerable to contamination. It is recommenced that electrical resistivity and hydrogeological surveys should be conducted at different locations in FUPRE, before any borehole(s) are drilled, to delineate the appropriate aquifer for potable groundwater supply and to avoid possible contamination.

Adaptative morphology for living in shallow water environments in spatangoid echinoids*

Six spatangoid species living in an area about 1 km2 at depths of 5–18 m were investigated in the Oki-Islands in the Japan Sea. The spatangoids capable of burrowing deeply principally adapt to unstable environment where the sediment surface is disturbed by storms. They are confined to the respective habitats depending on their functional morphology; apical tuft spines and fascioles for respiration, inflated plastron and stern-like postero-ventral shape for deep-burrowing. An excep­tional spatangoid, Lovenia elongata, has specific morphologies for quick burrowing and rapid righting against disturbance of superficial sediment, which make it possible for it to live in fine- to coarse-grained sand at various water depths in spite of its burrowing just below the sediment surface.

The deposits lithological features and relict dune age in environs of Manevychi

Based on research studies was fixed time of relict form formation in environs of Manevychi – Late Pleistocene (from 17,0 + 2,6 to >12,0 thousand years ago). The deposits lithological features of form and its base was analyzed, particularly gives detail characterization of granulometric deposit composition. Predominant deposits in relict form forming are medium-grained (Mz = 1,04–1,38Ф) mediumgrade (σ1 = 0,67–0,83) sands. In sections on different depth be found lenses and layers of coarse-grained sand with small capacity 1,0–1,5 cm. in medium-grade sand deposits predominating fractions 0,50–0,30 mm. They total content is about 43,22 to 57,40%, in coarse-grained lenses and layers predominated are fractions within 0,8–0,5 mm and forming 39,38–50,64 %. Key words: relict form, dune age, granulometric composition, heavy and light minerals.

The transport and distribution of the river load from the Kacza River into the Gulf of Gdańsk (Southern Baltic Sea, Poland)

The results of measurements of suspended sediment and bed load carried by the Kacza River into the Gulf of Gdańsk are discussed. The investigations were conducted in the years 2009–2010 at the Orłowo transect and at the mouth of the Kacza River in the Gulf of Gdańsk. The research has shown that the Kacza River discharged about 673 tons of sediment annually to the Gulf of Gdańsk, with 77% being transported as bed load. The granulometric composition of the river load is dominated by coarse-grained sand fractions.

PETROLOGY AND PROVENANCE STUDY OF THE QUATERNARY CLASTIC SEDIMENTS FROM HERSO KILKIS (MACEDONIA, GREECE)

The sediments analysed are generally coarse grained, sand gravels to gravel sands. The silt and clay content of the samples is low and their textural study revealed a fluvial deposition environment. The amounts of quartz, feldspars and lithic fragments range from 33% to 56%, 8% to 18% and 28% to 52%, respectively. The samples studied may be classified as garnet-mica bearing litharenites. Quartz, plagioclases and micas are the predominant constituents. Detritai calcite and pyroxenes are present in small amounts. The samples are texturally and mineralogically immature. Detailed polarized microscopy revealed the presence of garnet, staurolite, kyanite, zoisite, routile, epidote, zircon, apatite and tourmaline, as well as of opaque minerals. These accessory minerals are considered indexes of metamorphic provenance. Geochemically the samples are classified as sublitharenites and subarkoses, all being rich in Si02- The overall percentages of quartz, feldspars and rock fragments designate intense physical weathering and rapid transport and deposition in the Herso Basin which is part of a passive continental margin (recycled orogen).