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This textbook deals with the most important items in Marine Geology, including some pioneer work. The list of topics has grown greatly in the last few decades beyond the items identified by Eugen Seibold as central and now includes prominently such things as methane and climate change; that is, the carbon cycle and the Earth system as a whole. Relevant geophysical, geochemical, sedimentological and paleontological methods are shortly described. They should allow the reader to comment on new results about plate tectonics, marine sedimentation from the coasts to the deep sea, climatological aspects, paleoceanology and the use of the sea floor. The text tries to transmit to the reader excitement of marine geological research both aboard and in modern laboratories. Basic mineralogical, geochemical, biological and other relevant data and a detailed list of books and symposia are given in an Appendix. This Introduction builds on the third edition of \"The Sea Floor\" by E. Seibold and W.H. Berger. While much of the original text was written by Seibold, a considerable portion of the material presented in this edition is new, taking into account the recent great shift in marine geological research, some of it with great relevance to human concerns arising in a rapidly changing world.

Most studies on solute transport in coastal aquifers affected by tides focus on the transport of instantaneous released solute, and there are few studies on continuously released solute affected by tides. In this study, the image monitoring method is used to establish the quantitative relationship between the concentration of the colored tracer and the hue value of the image, and the digital image is used to determine the tracer concentration distribution. Using image monitoring method laboratory experiments, quantitative analysis of the characteristics of continuously released solute transport in coastal unconfined aquifers under the tidal influence. Experiments show that the high tide inhibits the increase in the concentration of each point in the aquifer. Under the influence of tides, the solute plume retreats towards the land. During the low tide period, the solute plume migrates toward the sea again. And the solute plume will maintain a relatively stable shape after entering the aquifer for a long enough time. Ignoring the tidal effect seems to have little effect on the estimation of the position of the solute plume, but ignoring the tidal effect has a certain influence on the estimation of the dispersion range of the solute plume. No matter whether considering the tidal action, the final dispersion range of the solute plume is almost the same. But before the solute plume reaches a stable state, ignoring the tidal effect will lead to a smaller dispersion range of the solute plume.

AbstractChameis Bay is located about 115 km north of the Orange River mouth and falls within the Sperrgebiet, an area which hosts the world’s largest gem diamond deposit. Although significant quantities of diamonds have been recovered both on land and from offshore deposits in the Chameis Bay area, the marine geology of this important tract of coastline has not previously been described in the scientific literature. Here, we report the nearshore geomorphology and seismic stratigraphy offshore of Chameis Bay through analyses of bathymetrical and seismic datasets. These data have been complemented with lithogical data obtained from 70 reverse-circulation boreholes which helped to confirm and constrain the sedimentary stratigraphy of the study area. These datasets identified four major lithological units; viz. a Precambrian basement which predominates as the footwall in the nearshore regions of the study area, a Cretaceous clay unit that represents the offshore footwall lithology and two unconsolidated Cenozoic sedimentary units. The distribution of these unconsolidated sediments is strongly controlled by the ambient accommodation space which can be quantified by considering the architecture of the respective footwall units. Architectural features within the study site include two prominent wave-cut platforms, two coast-parallel sea cliffs, and a shelf-break formed at the contact between the Precambrian basement and the Cretaceous clay footwall. Accommodation space exists on the seaward of the two wave-cut platforms, which is cut into the Precambrian basement footwall and which lies below the fair-weather wave base, and at the break in slope at the contact between the two footwall units. The former accommodation space is most notable for gravel entrapment and preservation since gulley-controlled jointing and erosional depressions at lithological contacts represent ‘fixed’ trapsites from which coarse material is less likely to be remobilised. In contrast, the trapsites formed on the soft Cretaceous clay footwall are regarded as ‘mobile’ trapsites since they can be easily reconfigured by continuing erosional processes. As a result, the gravel bodies found above the Cretaceous clay are generally thin and poorly developed. The implications of these two different trapsites are briefly discussed in terms of diamond preservation potential, where anticipated diamond sources to the Chameis Bay near-shelf include the Orange River mouth as well as material that has been reworked from proximal sources. These results represent the first detailed description of the marine geology of the Chameis Subterrane thrust sheet and complement existing understanding of the Sperrgebiet’s marine geology which largely derives from study sites on the Oranjemund Subterrane where linear beaches predominate.Graphical abstract

New high-resolution 3D seismic data image a submarine channel complex in the northern slope of the South China Sea. The channel complex stretches hundreds of kilometers across the slope and flows into the deepsea from the siliciclastic shelf margin, linking neritic environment to the pelagic plain. The evolution of the channel complex developed two sedimentary stages, stage I (19.1–18.5 Ma) and stage II (18.5–17.5 Ma), separated by erosional surfaces. In the first stage, the complex was filled with pure siliciclastic sediments, forming thick-massive sandstone intercalated by thin layers of mudstone. During the stage II, the channel complex was deposited five carbonate-siliciclastic cycles. The unexpected channel-fill carbonate deposits present allochthonous characteristics, suggesting the siliciclastic channel was surprisingly used to transport carbonate sediment from the adjacent neritic carbonate platform. By analyzing the periodical carbonate sedimentary process in the siliciclastic channel complex, we infer that it was related to the in situ carbonate production of the neritic carbonate platform and was most likely to be controlled by the relative sea-level changes. Unlike line-source carbonate slope aprons or small-sized carbonate channels, the large-sized siliciclastic channel complex links directly neritic carbonate platform to deepwater basin and can transport large volumes of neritic carbonates to the pelagic environment in a short period. The new findings help to estimate the contributions of neritic siliciclastic shelf and carbonate platform to deepwater slope more accurately. This study suggests that channel systems are more complex than expected and have significant implications on the conceptual models describing the deepwater sedimentary theory.

Transverse relaxation time cutoff value (T2cutoff ) is one of the most important parameters for nuclear magnetic resonance (NMR) logging. However, traditional experimental methods to determine the T2cutoff value are time-consuming, troublesome and expensive. In this paper, the proposed method derived from fractal theory and Coates model helps to easily get the estimation value of T2cutoff only on the condition of brine-saturated NMR T2 spectrum. To verify the accuracy, experiments of NMR, X-ray and centrifugation have been finished on the basin marine facies carbonate cores from Syria. We find that the method not only distinguishes clay and capillary bound fluid information on the T2 spectra but also effectively estimate the T2cutoff values whose errors less than 8%. Calcite, clay, dolomite and quartz show complex influence on movable porosity derived from T2cutoff estimation. Clay and movable porosity is the reason to porosity varying little but permeability varying a lot.

The International Bathymetric Chart of the Arctic Ocean (IBCAO) released its first gridded bathymetric compilation in 1999. The IBCAO bathymetric portrayals have since supported a wide range of Arctic science activities, for example, by providing constraint for ocean circulation models and the means to define and formulate hypotheses about the geologic origin of Arctic undersea features. IBCAO Version 3.0 represents the largest improvement since 1999 taking advantage of new data sets collected by the circum‐Arctic nations, opportunistic data collected from fishing vessels, data acquired from US Navy submarines and from research ships of various nations. Built using an improved gridding algorithm, this new grid is on a 500 meter spacing, revealing much greater details of the Arctic seafloor than IBCAO Version 1.0 (2.5 km) and Version 2.0 (2.0 km). The area covered by multibeam surveys has increased from ∼6% in Version 2.0 to ∼11% in Version 3.0. Key Points New gridded bathymetric portrayal of the Arctic Ocean Bathymetric crowd source data shows a new potential for the mapping community

A geologically rapid Neoproterozoic oxygenation event is commonly linked to the appearance of marine animal groups in the fossil record. However, there is still debate about what evidence from the sedimentary geochemical record—if any—provides strong support for a persistent shift in surface oxygen immediately preceding the rise of animals. We present statistical learning analyses of a large dataset of geochemical data and associated geological context from the Neoproterozoic and Palaeozoic sedimentary record and then use Earth system modelling to link trends in redox-sensitive trace metal and organic carbon concentrations to the oxygenation of Earth’s oceans and atmosphere. We do not find evidence for the wholesale oxygenation of Earth’s oceans in the late Neoproterozoic era. We do, however, reconstruct a moderate long-term increase in atmospheric oxygen and marine productivity. These changes to the Earth system would have increased dissolved oxygen and food supply in shallow-water habitats during the broad interval of geologic time in which the major animal groups first radiated. This approach provides some of the most direct evidence for potential physiological drivers of the Cambrian radiation, while highlighting the importance of later Palaeozoic oxygenation in the evolution of the modern Earth system. Oxygen in shallow shelf waters rose linearly with atmospheric oxygen in the Neoproterozoic era, potentially driving the first radiation of marine animals, but widespread ocean oxygenation came later, according to reconstructions of oxygen levels and marine productivity.

Ocean acidification may have severe consequences for marine ecosystems; however, assessing its future impact is difficult because laboratory experiments and field observations are limited by their reduced ecologie complexity and sample period, respectively. In contrast, the geological record contains long-term evidence for a variety of global environmental perturbations, including ocean acidification plus their associated biotic responses. We review events exhibiting evidence for elevated atmospheric CO₂, global warming, and ocean acidification over the past ~300 million years of Earth's history, some with contemporaneous extinction or evolutionary turnover among marine calcifiers. Although similarities exist, no past event perfectly parallels future projections in terms of disrupting the balance of ocean carbonate chemistry—a consequence of the unprecedented rapidity of CO₂ release currently taking place.