Geology Today最新文献

Peridotites are a group within the category of ultramafic rocks. These are usually dark-coloured rocks rich in magnesium, poor in silica and lacking feldspars. Earth's mantle, which makes up 83 percent by volume and 67 percent by weight of the planet, consists largely of peridotite, which, although relatively sparse at the surface, therefore, is Earth's most abundant rock type. Unfortunately, the mantle, which lies on average at >7 km under the oceans and >35 km under the continents, is not directly accessible for observation and our information comes largely from seismic studies, inclusions in volcanic rocks and sections of the ocean floor which have been tectonically emplaced into the crust: the ophiolite complexes and abyssal peridotites of the oceans. Such rocks also occur when mafic minerals, such as olivine, pyroxene and spinel, accumulate in magma chambers. An unusual occurrence of ultramafic rocks is the lava called komatiite, representing ultramafic liquids, which are largely restricted to Precambrian environments.

As a result of several factors including overpopulation of the Earth and the ever-expanding search for groundwater resources, land subsidence is slowly becoming a global challenge. In fact, a 2021 study of 41 countries around the globe demonstrated the severity of the problem. However, land subsidence in Iran is accompanied by other issues which further complicate the problem.

Building stones demand our attention, from the simplest stone hut to the finest palace. Those of Manchester in northwest England have received deserved attention, but those of nearby Salford less so. This short stroll through Salford, close to the city's university, demonstrates some of the geological gems that have hitherto been largely ignored.

Civilization has always relied on geological materials and it would not exist as we know it without the use of minerals. For the foreseeable future, minerals will remain fundamentally important commodities. As technology changes, so does the demand for different mineral commodities. For example, as we enter the era of the battery revolution, expedited by vehicle electrification and a reduction in the burning of traditional fossil fuels (coal, oil and gas), demand for minerals used in battery technologies is predicted to increase significantly. In 2022 alone, the global mining industry had a value of over 2000 billion US dollars. Where such huge amounts of money are involved, it is unsurprising that criminal activity follows. Criminal activity in the mining, minerals and metals industries includes illegal mining and smuggling, theft (including adulteration and substitution), illegal trade in conflict minerals, fakes, fraud and environmental crime (e.g. pollution, contamination and degradation of the land, air and water). In this article, we provide an overview of the types of criminal activities associated with geological materials and the potential role of forensic geologists in mitigating the associated risks.

Forensic geoscientists assist with the investigation of locating and characterizing suspected illegal activities and provide evidence for criminal or civil courts of law. Geoforensic search in terrestrial environments can be challenging, depending on the item(s) of interest that are being looked for, the available search teams, the equipment deployed and the search area(s) itself. This article briefly details the current efforts that geoscientists are making to assist these terrestrial investigations, and provides some relevant case studies and discusses future developments.

Geoforensic trace evidence studies can be crucial for law enforcement and civil/criminal prosecution and defence, to test potential links between suspect(s), crime scenes or forensic object(s). In addition, trace geological evidence can be used to identify forensic sites of interest such as clandestine graves of murder victims. However, geoforensic trace evidence also has applications in a range of other investigations. This article briefly details the current geoscientific methods used to assist in such investigations and uses recent case studies to illustrate their use.

Geoscientists are being increasingly asked by law enforcement, environmental agencies and even wildlife trusts to investigate suspected illegal activities in and around water bodies for criminal or civil investigations. Searches and surveys in aquatic environments can be challenging, depending on the item(s) of interest that is being looked for, the available search teams and equipment and the search area. This article will briefly detail the current work of geoscientists in assisting these aquatic investigations, provide some relevant case studies and discuss future developments.

Jamoytius kerwoodi was a primitive, eel-like jawless fish that lived in the Early Silurian period (444–433 myr) and lived over a stagnant bottom environment, at the transition from a marine-influenced, probably brackish-water, deep-water basin to a shallower water, less saline and probably freshwater basin. Jamoytius lacked teeth and was most likely a free-living herbivore grazing on floating plants, as were possibly many of its euphanaropid relatives. The palaeoenvironment in which it lived compares well with that of living lampreys, especially as their ectoparasitic mode of life may have evolved from ancestral grazers.