On The Supposed Onshore Extension Of The Penyu Basin, Peninsular Malaysia

The Penyu Basin is a Tertiary sedimentary basin located offshore Peninsular Malaysia. The basin is assumed to continue westwards beneath the Pahang River delta where as much as 115 m of Quaternary sediments overlie a bedrock of pre-Tertiary granites and metamorphic rocks. No Pliocene or older sediments beneath the delta have been reported. If the Quaternary sediments are considered as part of the Cenozoic Penyu Basin, the basin’s western limit may be delineated at the foothills of the coastal plain where those sediments onlap onto pre-Tertiary rocks. Therefore, any sedimentary rock of Tertiary age that may occur to the west of that limit most probably represents a separate basin.

Construction a map of geochemical anomalies for the predicted value of gold in the Lidin ore field of Urup Island

The purpose of this article is to study the methods of constructing maps of geochemical anomalies using geostatistical methods. The example presented in the article shows the possibility of probabilistic determination of gold in strongly overlapped areas (Urup Island, Kuril Islands). On the site of the Kolenchaty Lidinskoye ore field, the gold ore occurrence of the Kolenchaty is known. It is timed to the incision of the river and disappears outside of it. This is due to the strong overlap of the area by Quaternary sediments. Together with the uneven distribution of gold, these circumstances complicate the construction of maps of geochemical anomalies and the identification of promising areas. To solve this problem, the Statistica program was used. With its help, a matrix of correlations was built, elements of the satellites of gold were selected, and a multiple regression equation for gold was drawn up. This equation was used to probabilistically calculate gold values at each sampling point. In ArcGis, Geostatistical Analyst, geochemical anomalies were mapped from the predicted gold value by kriging, and promising areas were highlighted.

Petrography of bottom rock material

The Quaternary sediments of the Barents Sea contain a large amount of coarse clastic bottom rock material (BRM), with varying degrees of grain roundedness. Its study is important in determining the type and composition of the earth's crust, with paleogeographic constructions and revealing data on the dynamics of the ice cover. Studies of the Barents Sea BRM began in the 20s of the last century. During this period, were formed basically two hypotheses about the relationship between the distribution of BRM with elements of the sea topography and bedrock exposure. One of them considers BRM a marker suitable for identifying petrographic provinces at the bottom of the Barents Sea [Klenova, 1960]. In this chapter, on the basis of new up-to-date data obtained in 67 and 68 cruises of the RV Akademik Mstislav Keldysh in 2016–2017, the grain size, petrochemical and mineral compositions of BRM are estimated, their distribution patterns are given, transportation methods are analyzed and its feasibility is evaluated use in geological mapping. 4,193 samples were processed in Quaternary sediments, among which 86 reference types were identified. It was shown that the diversity of the composition of the Barents Sea BRM depends on glacial and ice-ice spacing. Therefore, the use of BRM for geological mapping of the bottom of the Barents Sea is unsuitable. The petrographic composition of the BRM in different regions of the Barents Sea is subject to significant fluctuations, but in general it is complementary to the set of rocks in the areas of demolition of adjacent land and depends on the extent of exaration and the removal of exaration material by the glacier to sedimentation areas.

Cenozoic Marine Basin Evolution in the Western North Aegean Trough Margin: Seismic Stratigraphic Evidence

This study investigates the interplay of evolving tectonic and submarine sedimentation processes in the northwest Aegean Sea using marine multichannel seismic profiles. We identify an extensive basin developing in the Thermaikos Gulf inner shelf, outer shelf, and slope leading to the 1500 m deep West North Aegean Trough (NAT). We establish the unconformable extent of Eocene and Oligocene sequences on the upper shelf and trace their continuation in the deeper shelf and slope of Thermaikos Gulf. The start of the Miocene and Middle Miocene developed below the well-established Messinian bounding reflectors that are mostly erosional. Important lateral variations are observed within the Messinian sequence, which is up to 0.8 s thick. Messinian prograding clinoforms are identified on the Thermaikos Gulf shelf and southeast of Chalkidiki, and a zone of irregular reflectors is attributed to the Messinian salt layer. The transpressional deformation of the Messinian in the southwestern margin constrains the timing of westward progradation of the North Anatolian Fault during Messinian. The Pliocene-Quaternary sediments are 0.6–1.8 s thick, showing the overwhelming effect of tectonics on sedimentation plus the northwards Quaternary activation at the Thermaikos apron.

Tectonic Influence on Speleogenesis of Sea Caves on Biševo Island (UNESCO Global Geopark Vis Archipelago, Adriatic Sea, Croatia)

A geological and speleological investigation was conducted in the famous Blue Cave (Modra špilja) and the Monk Seal Cave (Medvidina špilja) on Biševo Island (Croatia) to promote the island’s geoheritage through the new Visitor Centre. The island is mainly composed of Cretaceous to Paleogene neritic carbonates, which form the bedrock, whereas parts of the island are covered with thin Quaternary sediments. The caves are of small dimensions and a simple layout, composed of the main channel and few shorter side channels, all positioned in the tidal zone. Thus, the caves are semi-submerged sea caves located along the coastline. The Blue Cave and the Monk Seal Cave developed within the bedrock limestones and dolostones, respectively, within a zone of left-lateral NNE–SSW striking strike-slip faults that belong to the Biševo fault system. Conjugated discontinuities within the carbonate bedrock indicate a specific strike-slip tectonic regime. Additionally, the host rocks were probably also deformed and fractured during the rise of salt diapirs that characterise this part of the Adriatic foreland. Tectonic and bedding discontinuities form the fragments of the host rock, that combined with the impacts of the strong southern waves, significantly influenced the genesis of the caves.