Spatial association of mud volcano and sandstone intrusions, Boyadag anticline, western Turkmenistan

Acknowledgements The Authors are indebted with Dr. Barbara Cerasetti, scientific coordinator of the Italian Archaeological Program in Turkmenistan (Dipartimento di Storia, Culture, Civiltà – Università di Bologna – Ministero per gli Affari Esteri – MAE), for the logistical help before and during the field activities in Turkmenistan. Our thanks to the administration of the National Institute of Deserts, Flora and Fauna, to the Turkmenistan Government and to Dr Aman Nigarov for the fruitful assistance in the field. We thank Prof. Marco Antonellini for the discussions on sandstone intrusions. The authors are indebted to the reviewers J. Peakall, P. Imbert, A. Hurst and an anonymous reviewer for the very helpful comments to the manuscript. Funding was provided by Prof. G. Gabbianelli for the field survey and by PRIN 2009 grants to Prof. Rossella Capozzi.Peer reviewedPostprin

Seepage rate of hydrothermally generated petroleum in East African Rift lakes : an example from Lake Tanganyika

Acknowledgements We thank Michael King and CGG | NPA Satellite Mapping for providing us with the GOSD dataset of Tanzania and the permission to publish the SAR images of Cape Kalumba oil seeps. Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Peer reviewedPostprin

Fluid sources and stable isotope signatures in authigenic carbonates from the Northern Apennines, Italy

Funding was provided by the Italian PRIN 2009 Project (MIUR research grant to R. Capozzi) and by the Royal Society of Edinburgh (grant to D. Oppo). The authors wish to thank Joachim Reitner (Department of Geobiology, Centre for Geosciences, Georg-August-University of Göttingen, Germany), Stefano Bernasconi (Department of Earth Sciences, Geologisches Institut, ETH Zurich, CH) and Mario Mussi (CNR-Institute for Geosciences and Georesources, CNR-IGG, Pisa) for contributing in the stable isotopes analyses on carbonate samples; and to two anonymous reviewers.Peer reviewedPostprin

Active faulting controls bedform development on a deep-water fan

Tectonically controlled topography influences deep-water sedimentary systems. Using 3-D seismic reflection data from the Levant Basin, eastern Mediterranean Sea, we investigate the spatial and temporal evolution of bedforms on a deep-water fan cut by an active normal fault. In the footwall, the fan comprises cyclic steps and antidunes along its axial and external portions, respectively, which we interpret to result from the spatial variation in flow velocity due to the loss of confinement at the canyon mouth. Conversely, in the hanging wall, the seafloor is nearly featureless at seismic scale. Numerical modeling of turbidity currents shows that the fault triggers a hydraulic jump that suppresses the flow velocity downstream, which thus explains the lack of visible bedforms basinward. This study shows that the topography generated by active normal faulting controls the downslope evolution of turbidity currents and the associated bedforms and that seafloor geomorphology can be used to evince syn-tectonic deposition

A 1000-yr-old tsunami in the Indian Ocean points to greater risk for East Africa

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Maselli, V., Oppo, D., Moore, A. L., Gusman, A. R., Mtelela, C., Iacopini, D., Taviani, M., Mjema, E., Mulaya, E., Che, M., Tomioka, A. L., Mshiu, E., & Ortiz, J. D. A 1000-yr-old tsunami in the Indian Ocean points to greater risk for East Africa. Geology, 48(8), (2020): 808-813, doi:10.1130/G47257.1.The December 2004 Sumatra-Andaman tsunami prompted an unprecedented research effort to find ancient precursors and quantify the recurrence time of such a deadly natural disaster. This effort, however, has focused primarily along the northern and eastern Indian Ocean coastlines, in proximal areas hardest hit by the tsunami. No studies have been made to quantify the recurrence of tsunamis along the coastlines of the western Indian Ocean, leading to an underestimation of the tsunami risk in East Africa. Here, we document a 1000-yr-old sand layer hosting archaeological remains of an ancient coastal Swahili settlement in Tanzania. The sedimentary facies, grain-size distribution, and faunal assemblages indicate a tsunami wave as the most likely cause for the deposition of this sand layer. The tsunami in Tanzania is coeval with analogous deposits discovered at eastern Indian Ocean coastal sites. Numerical simulations of tsunami wave propagation indicate a megathrust earthquake generated by a large rupture of the Sumatra-Andaman subduction zone as the likely tsunami source. Our findings provide evidence that teletsunamis represent a serious threat to coastal societies along the western Indian Ocean, with implications for future tsunami hazard and risk assessments in East Africa.This work was funded by the National Geographic Society (grant N. CP-R008–17). Maselli acknowledges support from the Canada First Research Excellence Fund through the Ocean Frontier Institute. We are extremely grateful to the editor, two anonymous reviewers, J. Bourgeois, G. Eberli, A. Prendergast, and C. Gouramanis for all the suggestions provided, which greatly improved the quality of the manuscript. We would like to thank the United Republic of Tanzania and the University of Dar es Salaam for allowing us to perform the field work activity. This is ISMAR Bologna scientific contribution number 2024

A 1000-yr-old tsunami in the Indian Ocean points to greater risk for East Africa: reply

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Maselli, V., Oppo, D., Moore, A. L., Gusman, A. R., Mtelela, C., Iacopini, D., Taviani, M., Mjema, E., Mulaya, E., Che, M., Tomioka, A. L., Mshiu, E., & Ortiz, J. D. A 1000-yr-old tsunami in the Indian Ocean points to greater risk for East Africa: reply. Geology, 49(1), (2021): E516-E516, https://doi.org/10.1130/G48585Y.1.We appreciate Somerville’s (2020) interest in our work, and the opportunity to further expand the discussion about the occurrence of a trans-oceanic tsunami in the Indian Ocean generated by a megathrust earthquake ~1000 years ago. Somerville suggests a connection between the inferred tsunami deposit presented by us (Maselli et al., 2020) and a tsunami event reported to have occurred in Nagapattinam (India) in the year 900 CE and described in Kalaki Krishnamurty’s book (Rastogi and Jaiswal, 2006)

ICDP workshop on the Lake Tanganyika Scientific Drilling Project: a late Miocene–present record of climate, rifting, and ecosystem evolution from the world's oldest tropical lake

The Neogene and Quaternary are characterized by enormous changes in global climate and environments, including global cooling and the establishment of northern high-latitude glaciers. These changes reshaped global ecosystems, including the emergence of tropical dry forests and savannahs that are found in Africa today, which in turn may have influenced the evolution of humans and their ancestors. However, despite decades of research we lack long, continuous, well-resolved records of tropical climate, ecosystem changes, and surface processes necessary to understand their interactions and influences on evolutionary processes. Lake Tanganyika, Africa, contains the most continuous, long continental climate record from the mid-Miocene (∼10 Ma) to the present anywhere in the tropics and has long been recognized as a top-priority site for scientific drilling. The lake is surrounded by the Miombo woodlands, part of the largest dry tropical biome on Earth. Lake Tanganyika also harbors incredibly diverse endemic biota and an entirely unexplored deep microbial biosphere, and it provides textbook examples of rift segmentation, fault behavior, and associated surface processes. To evaluate the interdisciplinary scientific opportunities that an ICDP drilling program at Lake Tanganyika could offer, more than 70 scientists representing 12 countries and a variety of scientific disciplines met in Dar es Salaam, Tanzania, in June 2019. The team developed key research objectives in basin evolution, source-to-sink sedimentology, organismal evolution, geomicrobiology, paleoclimatology, paleolimnology, terrestrial paleoecology, paleoanthropology, and geochronology to be addressed through scientific drilling on Lake Tanganyika. They also identified drilling targets and strategies, logistical challenges, and education and capacity building programs to be carried out through the project. Participants concluded that a drilling program at Lake Tanganyika would produce the first continuous Miocene–present record from the tropics, transforming our understanding of global environmental change, the environmental context of human origins in Africa, and providing a detailed window into the dynamics, tempo and mode of biological diversification and adaptive radiations.© Author(s) 2020. This open access article is distributed under the Creative Commons Attribution 4.0 License

Study of Mud Volcanoes to define Deep Fluid Migration

L’unione di approcci differenti durante lo studio dei sistemi petroliferi, come l’accoppiamento dello studio delle emissioni in superficie con le analisi geochimiche e strutturali, è un aspetto principale nelle strategie di sviluppo per la ricerca degli idrocarburi. La presenza di acqua connata nelle sequenze sedimentarie profonde e la sua sovrappressione che viene generata dalle spesse coperture sedimentarie, incrementata inoltre dalla generazione di idrocarburi in profondità, sono fattori di controllo primari per la migrazione e l’emissione di fluidi in superficie. I risultati ottenuti da questo studio forniscono nuovi elementi per la comprensione del ruolo dello studio dei vulcani di fango nell’esplorazione petrolifera, e nuove importanti prove per la caratterizzazione dei sistemi petroliferi nelle aree considerate.To join different approaches in the study of petroleum systems, as to couple the study of surface seeps with geochemical and structural analysis, is a leading aspect in a development strategy for hydrocarbons. The occurrence of pore water in the deep sedimentary successions and its overpressure due to the thick covering sequences, which is enhanced by the hydrocarbons generation at depth, are primary controls for the fluid migration and emission at the surface through the cold seeps. The results from this study provide new elements to understand the role of mud volcanoes study in the frame of petroleum exploration, and new important evidences for the petroleum systems in the areas considered

Cold seepages: An economic toolfor hydrocarbon appraisal

"Spontaneous cold \ufb02uid seepages are a renowned phenomenon occurring in a wide range of geologic and geodynamic settings, including deep sea fans, rapidly subsiding basins, and compressive tectonic settings (e.g., Dimitrov, 2002; Morley et al., 2011; Oppo et al., 2013, 2014). Cold seepages are marked by various struc- tures, both on land and offshore, such as mud volcanoes (MVs), methane-derived authigenic carbonates (MDACs), and chemo- symbiotic communities. Their formation mechanism requires the increase of pore-\ufb02uid pressure above the lithostatic gradient with the subsequent upward \ufb02uid migration through hydro- fracturing or along carrier beds and tectonic discontinuities." "Cold seepages have long been investigated, especially for the information that they may provide for the exploration of hydrocarbons present in different types of reservoirs associ- ated with this phenomenon (e.g., Link, 1952; Heggland, 1998; Abrams, 2005). Although the relation between cold seepages and hydrocarbon reservoirs has not been completely enlightened in numerous settings, as in fold and thrust belts, it is established that the occurrence of gas, frequently associated with oil, is a common characteristic that most of the seepage areas show. In particular, the spontaneous leakage of oil and gas represents a prime indication of hydrocarbons occurrence in the subsurface and valuable source of information on the petroleum system. The associated \ufb02uids also provide evidence of the geochemistry of deep-seated hydrocarbons. A useful example of this association is represented by the oil and gas \ufb01eld exploited near MVs along the coast and offshore in the Caspian Sea (e.g., Planke et al.," "2003; Davies and Stewart, 2005; Oppo et al., 2014; Oppo and" "Capozzi, 2016).

A new model of the petroleum system in the Northern Apennines, Italy

A geochemical study on fluids from selected spontaneous seepages and drilled wells was carried out together with geologic investigation and deep cross-sections reconstruction to examine the petroleum system in the western Northern Apennines foothills. The hydrocarbons occurring in the Miocene foredeep units that form the reservoirs are commonly interpreted as generated in a source/reservoir system. However, the low Total Organic Carbon, its elevated dilution in the sediment pile and the limited amount of successions that entered in the oil window indicate a low potential for the hydrocarbons generation. The structures deformation in the Northern Apennines foothills is mainly late Miocene to Pliocene in age and involves successions that are progressively younger towards southeast. The earlier structure forms the Salsomaggiore anticline in the western sector. The comparison of the fluids from the wells and the mud volcanoes shows high geochemical and thermal history similarities. Saline waters originate from the connate pore water entrapped in the Miocene reservoir rocks during their deposition. The gaseous hydrocarbons are a mixture of secondary biogenic methane and primary and secondary thermogenic gases. The associated oils show both early and late maturities. These evidences account for different generation and migration steps, depending on burial conditions and deformation time. The various reservoirs appear confined by the thrust detachment at different depths and by the occurrence of reactivated lateral ramps. These results suggest the occurrence of a common source rock deeper than the Tertiary reservoir units, which progressively entered in the oil window. This source rock could have wide lateral extension, at least comparable with the width of the studied area, and represent a prime exploration target to evaluate the undiscovered oil and gas resources. (c) 2013 Elsevier Ltd. All rights reserved