This report, which is one of a series of reports summarizing the World’s endowment of nonfuel mineral resources, describes the location and general geologic setting of deposits of major mineral commodities in the United States. The discussion in this report focuses on those commodities produced in the United States that constituted at least 5 percent of global production or global reserve base in 2003 or had at least $100 million production value in 2001. The discussion for each commodity begins with a brief description of the chemical and physical properties of the material and how it is used. The importance of the commodity in the United States relative to the world is also presented. However, most of the discussion emphasizes the geology of mineral commodities – the important mineral deposit types, their geologic setting, and the processes that led to their formation. A compilation of almost 400 major mineral deposits in the United States is included as an appendix. <...>
Previous to the publication in 1869 of Vol. II, Palaeontology of California, the deposits on the Pacific Coast now recognized as Cretaceous were not divided into groups or formations. In that volume Professors Whitney and Gabb gave the name Shasta group to the complex series of Lower Cretaceous beds which they recognized to be of different ages, probably from the Keocomian to the Gault, inclusive. They also proposed the names Chico group, Martinez group, and Tejon group for the beds overlying the Shasta in the order named. Of these the Tejon is now generally believed to be of Eocene age, and the Cretaceous portion of the ill-defined and heterogeneous Martinez group is inseparable from the Chico.
The bright midday sun glinted off the calm waters of the Inland Sea and silhouetted the long, sinuous form of a huge mosasaur lying motionless amid the floating tangle of yellow-green seaweed. At 20 years old, more than 30 feet in length, and weighing over a ton, the adult mosasaur was almost full grown and was much larger than any of the fishes or sharks that lived in the shallow seaway.
The fossils of the Miocene beds of New Jersey, like those of the Cretaceous and Eocene beds, have never until now been systematically studied or recorded. Many of them which are as yet peculiar to the deposits of the State have, however, been described haphazard, as it were, by different writers, with scarcely any other object in view than that of describing the species which happened to fall into their hands. In this way a few of the most prominent forms have become known, but very few species are mentioned in any of.the lists of Miocene fossils as pertaining to the New Jersey fauna.
The Neoproterozoic Uinta Mountain Group is undergoing a new phase of stratigraphic and paleontologic research toward understanding the paleoenvironments, paleoecology, correlation across the range and the region, paleogeography, basin type, and tectonic setting. Mapping, measured sections, sedimentology, paleontology, U-Pb geochronology, and C-isotope geochemistry have resulted in the further characterization and genetic understanding of the western and eastern Uinta Mountain Group.
Приводится характеристика наиболее существенных сторон геологии, минералогии, геохимии и методов оценки важнейших типов урановых месторождений, составленная ведущими учеными США, Италии и Франции. Описываются поведение урана в различных зонах земной коры, образование урановых месторождений в связи с эволюцией земной коры во времени и пространстве, формы миграции к концентрации урана при образовании промышленных месторождений, а также вторичное изменение урановых руд вблизи поверхности земли. Для геологов, минералогов и геохимиков, изучающих месторождения урана.
Among Texas fossil collectors, there is a no more dedicated nor enthusiastic group than the one specializing in the collection of fossilized shark and ray i teeth. Annually, thousands of amateur paleontologists of all ages indulge in this activity for many reasons andat all levels of interest. Forthe persistent collector, teeth are found in abundance at numerous sites where Cretaceous rocks have been exposed through weathering and erosion. Popular collecting localities occurinroadcuts, quarries, creekand river - beds and at temporary exposures associated with construction for housing, highways and industry.
Building a tooth collection can be a great hobby or the beginning of a rewarding scientific endeavor, stimulating your natural curiosity about these fascinating fishes. However, CAUTION is advised. Collecting fossil shark teeth may become an obsession with you like it has for some of us! <...>
Рассмотрены принципы организации работ по подсчету запасов нефти и газа, основные вопросы, связанные с классификацией запасов, скважин и месторождений, рекомендуемая в СМА увязка методов подсчета запасов нефти и газа со стадийностью работ на месторождении, методы определения расчетных параметров и запасов нефти и газа. Существенное внимание уделено современному подходу специалистов США к вопросам нефте-, газо- и конденсатоотдачи, влияния экономических показателей на подсчет запасов и коэффициенты извлечения, использованию ЭВМ в практике решения проблем, связанных с подсчетом запасов. Приведены основные сведения по отношению к запасам нефти и газа в нетрадиционных источниках углеводородного сырья. Для инженерно-технических работников нефтяной и газовой отраслей промышленности.
Формация Фосфория в США является одной из крупнейших формаций мира. В ней заключены промышленные месторождения пластовых фосфоритов, урана, ванадия, редких земель и нефти. Благодаря ее хорошей обнаженности и детальной изученности она представляет исключительный интерес для научных обобщений и для выяснения условий образования указанных полезных ископаемых. В предлагаемой книге сведены данные по геологии, минералогии, геохимии, тектонике и условиям накопления формации Фосфория. Многие данные американских авторов обобщены и представлены в новом освещении. По-новому освещаются закономерности размещения и генезис месторождений фосфоритов и сопутствующих им элементов.
