The time between 1640, when Álvaro Alonso Barba published his Arte de los metales ( Art of Metals ), and 1761, when Francisco Xavier de Gamboa published his Comentarios a las ordenanzas de minas ( Commentaries on Mining Ordinances ), was a transitional period in which scientific mining and metallurgical knowledge in Spanish America became operative and practical and replaced the long-standing Spanish (and European) medieval tradition of the theory of minerals and metals. Barba was the last representative of this tradition, inheriting the complex world of the classical writers, the medieval alchemists, the first news from the new American lodes, and the first steps of the Scientific Revolution. On the contrary, Gamboa did not worry about classical and medieval theories, nor did he worry about the problem of metal generation. He was concerned only about the most effective system with which to profit from mining using all the paraphernalia that the science and experience of two worlds could furnish. Both handbooks, very successful in their respective times, show clearly two different approaches to the principal question: how to best manage, from two such different perspectives, the American treasures.

ABSTRACT The museums of Philadelphia are noted for both their variety and their longevity. Some of these institutions have been present since before the American Revolution and reflect the continuity within a population for which education was always a predominant goal. Others have arisen over subsequent centuries in response to various needs. Some, such as the American Philosophical Society and the Fairmont Water Works, are eighteenth-century institutions that relatively lately acquired a more formal museum format. Colonial interest in natural history, mineralogy, and natural resources with collateral maps and papers makes them a prime resource for historians of geology. All of these institutions reflect the nature of the museum movement itself from often private or privileged collections to those both welcoming the public and serving as sturdy arms of education. Historians of geology will find maps, instruments, collections, books, and personal and government papers that are of much interest.

ABSTRACT The Rutgers Geology Museum is America’s first geology museum. Rocks, fossils, and minerals had been collected into “cabinets of curiosities” since first contact between Europeans and Native Americans, and beginning in the late eighteenth century, many of these small personal cabinets were expanded, organized, and made available to the public at natural history and philosophical societies in Philadelphia and Boston. In the first decades of the nineteenth century, geology was widely recognized as an important new science that influenced the organization of collections on display at the growing number of colleges, academies, societies, lyceums, and museums that began popping up all over the United States, but it was not until 1872 that the first museum dedicated specifically to geology was built at Rutgers College. Rutgers University, known as Rutgers College until 1924, is itself one of the oldest colleges in America. Originally chartered as Queens College in the British colony of New Jersey in 1766, Rutgers, along with Harvard (1636), William and Mary (1693), Yale (1701), University of Pennsylvania (1740), Columbia (1754), Princeton (1755), Brown (1764), and Dartmouth College (1769), was among the nine colonial colleges founded before the American Revolution. Since its inception, the Rutgers Geology Museum’s primary mission has been to educate the public on natural history–related topics. How this was accomplished has varied greatly through the years and originated with the “cabinet” of minerals that was displayed to students, alumni, and professors in the days of Dr. Lewis Beck, the first geology professor at Rutgers College. Through the efforts of Dr. George Cook, professor and vice president of Rutgers College, Geology Hall was erected in 1872 as the permanent home for the collections, and the museum and its collections became the focal point of the natural history courses taught at the time. The many professors and curators who tended to the museum and its collections over the next half century helped shape and dictate the future of science and geology education at the university, and with the creation of the Department of Geology in 1931, the museum became a center of leading geologic research and the outlet to present the results to the community. Today, the museum strives to connect with the local K–12 and university communities to inspire the next generation of geoscientists to continue building upon the legacy that the many Rutgers University geologists worked so hard to build.

Google Earth provides a dynamic mechanism with which the impact of geographic features on historical events is illustrated effectively. Using Benedict Arnold's ill-fated surprise attack on British forces in Quebec (Canada) during the American Revolution (1775) as an example, various features of Google Earth are used to support this relationship. Traveling up the Kennebec and Dead Rivers in Maine (USA), the expedition encountered topographic and/or geologic obstacles that ultimately led to failure. Illustrated placemarks were created in Google Earth to document significant sites along the route. Placemarks were linked via the Tour feature producing a flyover, where the placemarks opened to provide a narrative along the route. At the Chopps near the mouth of the Kennebec River, a geologic map overlay was applied to document the geology and structural influences on this constriction of the river that causes navigational hazard. Along the portage route of the Great Carrying Place the trail was marked and an elevational profile created to illustrate the severity of the terrain. Anthropogenic changes along the route were documented by overlays of topographic maps produced both before and after the Dead River was dammed in 1950. Finally, an historical map from 1761 showing known landforms and their relative positions was overlain to document Arnold's understanding of the route in 1775. This approach in teaching and interactive learning has proven very effective locally at all levels. Illustrations, overlays, and tours created provide improved understanding of the interaction between geography and historic events. Creation of Google Earth files such as these can be readily used and shared by schools, historical societies, and individuals to greatly enhance learning.

ABSTRACT Carl Akeley (1864–1926) started a revolution in museum exhibit design when he created his muskrat diorama for the Milwaukee Public Museum in 1890. It was the first museum exhibit to show an animal in its natural habitat and the first to have a realistic background painted to create the illusion of depth and continuity of the animal’s environment. After the Scientific Revolution began and especially during the “Age of the Marvelous” in the sixteenth and seventeenth centuries, collections of natural and human-made objects were displayed in “wünderkammern,” rooms of wonder or curiosity cabinets, often arranged in a way that we might now consider strange, without a modern understanding of systematics, environmental, or cultural context. From the Enlightenment of the eighteenth century until Akeley’s muskrat diorama, taxonomic groupings dominated museum displays. Akeley’s genius as a taxidermist gave the dioramas an unsurpassed realism. Instead of stuffing animal skins with straw and cotton as taxidermists had done for centuries, Akeley mounted the skins over armatures that he steadily improved as he moved from Milwaukee to the Field Museum in Chicago, and finally to the American Museum of Natural History in New York. He modeled ancillary items such as plants in the diorama with obsessive detail. The results were unprecedented evocations of living animals actively engaged in their ecological niches (herein defined as their place in nature, including their activities). Akeley’s focus was the same as that of the great minds of the Scientific Revolution, and it’s the same as scientists’ today: the geometry of nature, its structural detail, and spatial relationships. Akeley showed not only the form and structure of animals in his dioramas, but he also defined the environmental space that encompassed them as well. Akeley’s focus was more mundane than Descartes’s res extensa or Stephen Hawking’s dark matter between cosmic bodies, but Akeley for the first time showed the general public that they could see the form and structure of animals and the space between in an altogether new way. Today that vision has a name, ecology. And we call its conception in deep time, paleoecology.

Abstract In the early 1950s, two American geologists, Bruce Charles Heezen (1924–1977) and Marie Tharp, began mapping the sea floor to improve understanding of ocean-basin geology and to connect the oceans to the continents theoretically. Both were researchers at the Lamont Geological Observatory of Columbia University, now Lamont-Doherty Earth Observatory. Heezen and Tharp used the ‘physiographic mapping’ technique, which makes it possible to relate topographic features to underlying geology. The diagrams mostly utilized light and texture, rather than colour, and were sketched using a hachuring technique. Heezen collected data for research purposes and Tharp used his information to compile their physiographic diagrams. During this process, she confirmed previous predictions when she made an important discovery: a rift on the Mid-Atlantic Ridge. Tharp's visual interpretations of the sea-floor data contributed to the reintroduction of continental drift theory and the 1960s geological revolution. At a time when most women were excluded from scientific careers, Tharp, initially a research assistant, succeeded in this competitive arena. Working with Heezen as a geologist and cartographer, she had an unusual opportunity to participate in the era's exciting discoveries; and her contributions were acknowledged. While their data-gathering activities and analyses stimulated change and contributed to the revolution in the Earth sciences, Heezen and Tharp were not directly involved in the plate-tectonics revolution, but favoured expanding-Earth theory.

ABSTRACT With willingness to invest and good geology, the Unconventional Revolution will not remain a North American story. The first areas to reach economically successful developments of unconventional resources will probably be the petroleum-rich provinces with important legacy data, substantial existing infrastructure, and public acceptance. The Neuquén Basin (Argentina) is the first place where the Unconventional Revolution has been exported with success, and the Vaca Muerta play represents the first economical unconventional play outside North America. The history of the discovery and development of the Vaca Muerta play dances for more than a decade with an intense series of events, such as the international search of new unconventional resources, the nationalization of the main operator, dramatic shifts in fiscal regime, a quick evolution of the play concepts (from vertical to horizontal wells) and of technology (from 500 to 3000 m laterals), and the Covid-19 pandemic. Nevertheless, the situation allowed conditions for economic success. The geological knowledge of the Vaca Muerta play derives from (1) data gathered during the last decade, related to the search and discovery of the Giant Field Vaca Muerta, and (2) the legacy of 100 years of activity of the O&G industry in the Neuquén Super Basin. The integration of the geological disciplines, at different scales, presents a unique unconventional play, exceptionally thick (100–400 m), vast (30,000 km 2 ), and porous (10%–20%), with a prograding clinoform hosting up to eight landing zones, and all types of fluid segments (from black oil to dry gas). The current play concept consists in landing the horizontal wells in the proximal bottomsets and lower foresets of the clinoform, sectors with higher hydrocarbon potential and easier fracture growth. The rocks in these sectors show the best reservoir characteristics (averages: TOC 5%; porosity 12%; clay 10%–20%; water saturation 20%), the most adequate geomechanical properties (homogeneous rock with Young’s Modulus <4 Mpsi, low Poisson Ratio ~0.25, and interfaces with weak geomechanical contrasts), and a thick vertical stack (30–40 m) of lithofacies with the aforementioned characteristics. With this concept in mind, at least two landing zones have been fully de-risked, and other six have been confirmed. The Vaca Muerta play has continued to progress lowering the breakeven to US$40/bbl for oil and US$2.0 MMBtu for wet gas. As activity ramps up, these values will continue to fall. The operators in the development phase believe that the combination of costs, well performance, and product prices are earning a return in their investments. In other words, the combination of below ground factors (geology) and above ground factors (contract terms, regulations, supply chain, security, market access, etc.) are allowing the development to be profitable.

Abstract The Franciscan of the California Coast Ranges was considered a lithostratigraphic unit (a formation or group of formations) for more than a century. Normal stratigraphical methodology was practised, and few questioned the applicability of the laws of superposition, lateral continuity, and paleontological dating. Despite evidence to the contrary, researchers portrayed deformation of coherent strata. Metamorphic conditions were deduced on the basis of presumed field relations, and the geosynclinal theory of mountain building was the paradigm. A subjective choice of data allowed researchers to fit the Franciscan into a straight-jacket, and for many years it was described as a Late Jurassic Tithonian formation, deposited in a eugeosyncline on the western margin of the North American continent after the Nevadan Orogeny. The classical model failed to take into account a number of key observations that challenged accepted beliefs. Micropaleontological evidence for the Cretaceous age of some Franciscan rocks was known but not taken seriously. Finally, however, the discovery of an ammonite of undoubted Cretaceous age in a Franciscan sandstone at the type locality led to a crisis. It became impossible to ignore mounting evidence that the Franciscan contains rocks coeval to the Great Valley Sequence, which ranges in age from Tithonian to Late Cretaceous, despite the fact that rocks of typical Franciscan lithology (e.g., ophiolites) underlie the Knoxville and should therefore be older than the Great Valley Sequence. The application of the mélange concept and the assumption of underthrusting resolved the Franciscan-Knoxville Paradox, and resulted in a revolutionary change in our thinking on Franciscan geology. At about the same time, a new paradigm in geology, the new plate-tectonic theory, was introduced. With plate tectonics, crises could be overcome, contradictions eliminated, and a period of “normal science” could prevail. Franciscan research went through five stages: 1) random observations; 2) synthesis; 3) crisis; 4) revolution, or overthrow of the old paradigm and establishment of the new; and 5) mopping up. A history of the process illustrates the theory of scientific revolution advocated by Thomas Kuhn.

Abstract Lead has been a much-sought-after commodity in North America since early Colonial times. Although more sophisticated uses, such as in pipes and vessels in water systems, coins, pottery glaze, and roofing, were common in Babylonian, Egyptian, and Roman cultures, the principal need for lead on the American frontier was to make bullets. Military success in the frontier wars and in the Civil War was affected by the ready availability, or lack, of ammunition. Hence, as the population moved westward from the Atlantic seaboard and spread along the Ohio and Mississippi River systems from New Orleans, localities where lead mineralization cropped out soon attracted attention and became population centers. The Wisconsin-Illinois District (discovered in 1682), southeast Missouri (1720), Austinville, Virginia (1750), and Rosiclaire, Illinois (1830), are notable examples. There were also numerous showings that never developed into large producers. Early discovery of lead deposits was facilitated by the fact that galena, the most common lead mineral, is resistant to weathering and persists in the clayey residuum. In southeast Missouri, the greatest North American lead-producing region, all of the production for the first 150 years was from such residuum rather than from solid rock. Plate 1C shows the locations of the deposits that have produced over 95 percent of all the lead mined to date in the United States. The productive longevity of some of the early-found eastern deposits is truly remarkable. Ammunition is still a significant use for lead, but since the beginning of the Industrial Revolution in the 19th century,

Abstract Most of the Expansion of the new oil industry during the decade immediately following the Drake discovery occurred in the United States, marked by all the growing painsof raw youth ill-equipped for strange adventures. It was a period of both petty and grandiose enterprises, of quick riches and sudden failures. It was a time of Civil War and cultural revolution, when old prejudices faced their ultimate challenge and new assumptions cameup for trial. Connections with the Old World loosened and European traditions dimmed during the war-time isolation. Many geologists became directly concerned with petroleum for the first time, as realization of its importance grew. The American geologists had the most at stake, the most to learn, and thegreatest opportunities for learning. Most of the major elements of a workable doctrine of petroleum geology were shaped and fitted into place during this hectic decade. It was a peculiarly American doctrine, inspite of the inclusion of important ingredients of earlier European knowledge. During a brief period of excessive speculation the petroleum geologists had the first great opportunity for economic application of their science. Their eflorts failed dismally, partly because of their own deficiencies and partly by the caprice of fortune. Thereafter, their potential usefulness was ignored or ridiculed for many years, but their concepts, with only minor modifications, stood the test of time and constituted a discipline which a later generaion applied with spectacular success.

Abstract To understand the Mesozoic-Cenozoic development of the North American continental margin, it is of prime importance to gain a knowledge of the tectonic framework of the continent. A review of this framework provides the foundation for discussion of the evolution of the continental margin. The northern part of the North American continent is dominated by the Canadian shield (Fig. 321), a tectonic province consisting mainly of metamorphic and plutonic infracrustal rocks. These rocks are divided into several fold belts that are the products of the Grenville orogeny (880–1,000 m.y.; Grenville fold belt), the Hudsonian orogeny (1,640–1,820 m.y.; Churchill, Southern, Bear, and Nain fold belts), and the Kenoran orogeny (2,390–2,600 m.y.; Superior, Slave, and Nain fold belts; P. B. King, 1969b). On top of these fold belts are less disturbed postorogenic sedimentary and volcanic (Fig. 321) Precambrian platform deposits. This Precambrian terrane was depressed toward the south to form the foundation for Paleozoic and younger platform deposits. East of the platform tectonic province is the Appalachian system that was deformed during the Paleozoic, with major deformations occurring during the Taconic (Ordovician) and Acadian (Devonian) revolutions and the Allegheny (Permian) disturbance. The deformed belt consists of a narrow miogeosyncline in the northwest composed of folded and thrust-faulted sedimentary rocks. Southeast of the miogeosyncline is a broad eugeosyncline of de-formed and metamorphosed sequences of sedi-mentary and volcanic rocks intruded by plutonic masses. Between these two geosynclines are long strips of Precambrian rocks that are uplifted parts of the basement

Abstract The mid-American channel connecting the primeval Atlantic and Pacific oceans was subjected to forces in Upper Jurassic time that folded the sea bed into a series of parallel ridges striking SE to NW. The westward and most tenuous of the ridges was ruptured by extrusive material that grew from the channel floor and emerged to form a chain of volcanic islands—the western archipelago. Erosion of the islands and deposition to the northeast provided the sediments of the Nicoya complex now exposed along the west coast of Costa Rica and Panamá. Volcanic eruption and continuing erosion throughout the Cretaceous supplied sediment to the shallowing channel area. Deposition during this period was mainly from the archipelago, although some material was derived from the northern Nuclear Central American mass. By the end of Cretaceous most of the denuded islands had foundered and the western archipelago had disappeared. Diastrophism accompanying the Laramide revolution rejuvenated and further upfolded one of the interior ridges—the “Guanarivas island.” Eastern Panama, belonging to the Choco borderland, which had been emergent throughout the Cretaceous, began to founder in lower Eocene and was submerged by the beginning of the middle Eocene. Guanarivas island and the volcanic islands had disappeared by lower Oligocene time, which was an epoch of comparative quiescence. Renewed activity in the middle Oligocene resulted in the growth of the Talamanca ridge and the appearance of islands in southern Costa Rica and northeastern Panama. Continued growth through early Miocene culminated in development of the West Talamanca fault and total emergence of the ridge by the end of the middle Miocene. The faulted upthrust block was tilted eastward, creating compressive forces that fractured the eastern front of the high area and initiated folding on the Atlantic foreland of southern Costa Rica and northeastern Panama. The Miocene diastrophism was accompanied by the growth of volcanoes on the ridge in Panamá. Total emergence of a narrow strip of land bordered by the Pacific Ocean and the Nicaraguan depression opening to the Caribbean, resulted in the first uninterrupted connection of South America with Nuclear Central America in Pliocene time. By Quaternary time the Talamanca ridge had become stabilized and adjusted, the Nicaraguan depression was filled, leaving only Lakes Nicaragua and Managua and the San Juan River to mark its former course, and the orogen had assumed the shape we know today.