Diverse origins and timing of formation of basinal brines in the Gulf of Mexico sedimentary basin

A review of five different field areas in the Gulf of Mexico sedimentary basin (GOM) illustrates some of the potentially diverse chemical and physical processes which have produced basinal brines. The elevated salinities of most of the formation waters in the GOM are ultimately related to the presence of the Middle Jurassic Louann Salt. Some of these brines likely inherited their salinity from evaporated Mesozoic seawater, while other saline fluids have been produced by subsequent dissolution of salt, some of which is occurring today. The timing of the generation of brines has thus not been restricted to the Middle Jurassic. The mechanisms of solute transport that have introduced brines throughout much of the sedimentary section of the GOM are not entirely understood. Free convection driven by spatial variations in formation water temperature and salinity is undoubtedly occurring around some salt structures. However, the driving mechanisms for the broad, diffusive upward solute transport in the northern Gulf rim of Arkansas and northern Louisiana are not known. In the Lower Cretaceous of Texas, fluid flow was much more highly focused, and perhaps episodic. It is clear that many areas of the Gulf basin are hydrologically connected and that large‐scale fluid flow, solute transport, and dispersion have occurred. The Na‐Mg‐Ca‐Cl compositions of brines in the areas of the Gulf Coast sedimentary basin reviewed in this article are products of diagenesis and do not reflect the composition of the evaporated marine waters present at the time of sediment deposition. Large differences in Na, Ca, and Mg trends for waters hosted by Mesozoic versus Cenozoic sediments may reflect differences in: (i) the sources of salinity (evaporated seawater for some of the Mesozoic sediments, dissolution of salt for some of the Cenozoic sediments); (ii) sediment lithology (dominantly carbonates for much of the Mesozoic sediments, and dominantly siliciclastics for the Cenozoic sediments); or (iii) residence times of brines associated with these sediments (tens of millions of years versus perhaps days).     

Africa's population and family planning dynamics

The historical and current demography of Africa in this discussion focuses on the context of population policy, contraceptive use, reproductive behavior, polygamy, and economic impacts. Sub-Saharan Africa countries have the highest rate of population growth in the world. 50% are aged under 20 years, and 20% are aged under five years. Urban areas are growing at the fastest rates in the world (5-6% annually). Population density remains low, except for areas where there is high soil fertility. Many African countries recognize the need for population policies. The most important donor to Africa, the World Bank, has pressured African governments to adopt family planning (FP) programs. A major World Bank study has shown that more FP services are desired by African women. Family expenditures for the 1980s for FP were estimated at $100 million annually, of which $53 million was provided by donors. Further expansion in the program is needed. The World Bank targeted contraceptive use at 25% of African married couples. Except for Egypt and North African countries, contraceptive use is around 3-4%. Another perspective on population reduction is to expand programs for child spacing and postnatal nutrition of mothers and infants. There has been a failure to turn health systems around to low-cost preventive health, particularly in rural areas. Infant mortality must be reduced before fertility will decline. Population growth can be slowed by changing the status of African women (high social status and recognition are associated with high fertility), age of marriage, child spacing, agricultural productivity, and nutrition. Demographic data on Africa have only become available during the past 25 years. African demographers are in short supply and require training abroad. Demographic data gaps and reliability problems are offset by the recent availability and quantity of survey data. Historical demography has produced conflicting results. Although some investigators, such as Ester Boserup, argue that population pressure results in agricultural innovations, Africa has yet to experience this phenomena. The youthful composition of the population guarantees continued population momentum. Fertility is enhanced by the cultural emphasis on perpetuating lineage and high fertility. Changes in reproductive behavior will depend on major social changes for women.     

Diet in the Iron Age cemetery population at Wetwang Slack,East Yorkshire,UK: carbon and nitrogen stable isotope evidence

This paper reports δ¹³C and δ¹⁵N values for human and animal bone collagen from the middle Iron Age site at Wetwang Slack, East Yorkshire, UK. The data indicate a human diet which was high in animal protein, with no evidence for any significant marine food input. No differences were found between high-status vehicle (or ‘chariot’) burials and the rest of the population and no other status differentiations are visible according to burial rite, age or sex groupings, although the data obtained for the older males display an unusual trend. No dietary variation is seen between two site phases and no evidence for an early immigrant group is present. The range of isotope values for the adult human group as a whole is small, indicating that the diet is likely to have been consistent over time and across the population, although two individuals stand out as unusual amongst the 62 analysed.     

Recovering social and cultural dynamics from plaster floors: chemical analyses at ancient Chunchucmil,Yucatan, Mexico

Phosphate analysis and trace metals analysis were used to determine activities that took place on plaster floors in domestic contexts at the ancient Maya site of Chunchucmil, Yucatan. Research on activities and the use of space contributes to an understanding of social relations within household groups as well as unforeseen patterns that structure refuse discard. The floors analyzed in this paper pertain to three structures in two neighboring houselots dating to the Early Classic (300–600 A.D.) period. Data from the chemical analyses were utilized in conjunction with associated architectural features and artifacts found on the floors. These three lines of information were interpreted with the help of models developed from ethnographic and ethnoarchaeological research. The results demonstrated functional differentiation of rooms within elaborate residences and suggested that front rooms were used to host visitors. The results also suggested that different types of debris were managed differently. Finally, chemical analyses suggest that non-elite Maya occasionally enacted rituals often restricted to elites.     

The population of the Amazon basin in 1492: a view from the Ecuadorian headwaters

"Recent archaeological, ethnohistorical and ecological evidence has begun to challenge the view that 'civilizations' failed to develop in the Amazon basin due to limitations of the tropical forest environment. As a result, estimates of the native population in 1492 have become an issue of debate. These estimates are evaluated in the light of the ethnohistorical research on the Ecuadorian headwaters. Estimates are considered by examining estimated habitat densities, the impact of Old World diseases and contemporary evidence for native cultures. The study is based on documents found in archives in Quito, Seville, Madrid and Rome. It is suggested that the population of the Amazon basin in 1492 probably exceeded 5 million but that expectations of substantially higher populations appear unfounded."     

Lifestyle,occupation, and whole bone morphology of the pre‐Hispanic Maya coastal population from Xcambó, Yucatan,Mexico

The present bioarchaeological study examines the external diaphyseal geometric properties of humeri, radii, femora and tibiae of the Classic period skeletal population of Xcambó, Yucatan, Mexico. The diaphysial proportions are evaluated using a biomechanical approach together with data from the material context and other osteological information. Our intent is to provide new answers to questions concerning lifestyle, domestic labour division and subsistence strategies of this coastal Maya settlement that was inhabited from the Late and Terminal Preclassic (300 BC–350 AD) to the Postclassic Period (900–1500 AD). Our results provide evidence for a marked sexual division of labour when compared with values from contemporaneous inland populations. The overall male and female loading patterns differ remarkably in terms of form and in bilateral comparison. A high directional asymmetry in the upper limbs is evident among males, a condition related to maritime transportation and trading activities. On the other hand, female upper limbs are characterized by very low side differences. Forces on the arms of women were probably dominated by food processing, in particular the grinding of grains or seeds. In the lower limbs, males show significantly higher anteroposterior bending strengths, which can be explained by greater engagement in transportation tasks and carrying heavy loads. In the course of the Classic period (350–900 AD), diachronic changes affect the male sample only, which suggests a shift of occupational pattern and physical demands. This shift, in turn, reflects Xcambó's changing role as the centre of a densifying settlement area and its place in the trading activities of northern Yucatan. Other topics of discussion relate to general regional trends and local prehispanic subsistence strategies. Our conclusions emphasize the value of geometric long bone analysis in the reconstruction of activity patterns and lifestyles in ancient coastal settlements. Copyright © 2007 John Wiley & Sons, Ltd.     

墨西哥,仙人掌的王国

<正>仙人掌原产于美洲,从美国的北部到南美洲的南部,分布很广,种类也很多。墨西哥位于北美洲南部,绝大部分属热带高原、海洋水汽难以到达闭塞的内部,北部又在副热带高气压带控制范围,年降水量少,荒漠分布很广。严峻的环境似乎给人和植物的生存都带来巨大的挑战,干旱缺水永远都是不毛之地的代名词,可是恣意生长的仙人掌却装点了这片土地。     

墨西哥,仙人掌的王国

<正>仙人掌原产于美洲,从美国的北部到南美洲的南部,分布很广,种类也很多。墨西哥位于北美洲南部,绝大部分属热带高原、海洋水汽难以到达闭塞的内部,北部又在副热带高气压带控制范围,年降水量少,荒漠分布很广。严峻的环境似乎给人和植物的生存都带来巨大的挑战,干旱缺水永远都是不毛之地的代名词,可是恣意生长的仙人掌却装点了这片土地。     

Phylogeography of einkorn landraces in the Mediterranean basin and Central Europe: population structure and cultivation history

Einkorn (Triticum monococcum L.) was one of the first cereals to be domesticated in the Old World ca. 10,000 years ago and to spread towards Europe and North Africa. Its cultivation declined before the Iron Age and it remains today only as a relic crop in remote areas. To investigate if the geographic distribution of genetic diversity in modern einkorn landrace accessions could be informative about the movement of this crop during prehistory, we genotyped 50 accessions of einkorn from Europe, North Africa and the Near East. Using nuclear and chloroplast microsatellites and clustering methods, we detected two main gene pools in einkorn. The distribution of these lineages revealed differences between accessions from Morocco and the Iberian Peninsula from the rest of Europe and the Near East and suggests different regional dynamics in the spread of this crop.     

Colonialism, Past and Present, in New Mexico

San Jose de las Huertas was established as a land grant community by the Spanish crown in 1765 and occupied for about 60 years. Many of its residents returned to the area after a brief respite, to found the village of Placitas, which exists today. Archaeological excavation at Las Huertas, documentary research and oral history from descendants of the original settlers reveal the shifting impact of different colonialisms, each accompanied by an image of modernity. Spanish demands were attenuated by distance and waning power. American impositions are more problematic, involving a new political economy, conflicts over land and water, as Placitas converts to a bedroom suburb of Albuquerque.     

Soundscapes of the Everyday in Ancient Oaxaca, Mexico

In ancient Mexico, sensory engagement in the form of oratory, music, and performance were major components of state-sponsored festivals and noble feasts. We think far less, however, about the soundscapes associated with rituals and everyday life in household contexts. Drawing on contextual, iconographic, and acoustic analyses of flutes, whistles, bells, costume ornaments, and ceramic vessels with rattle supports from the site of Río Viejo in coastal Oaxaca, Mexico, we argue that sound-production created a shared spatial landscape that linked community members to one another. Even in the absence of visibility or participation, soundscapes were prominent, celebrated elements of everyday life that purposely blurred the boundaries between the natural, cultural, and spirit worlds.     

Prehistory of Chihuahua and Sonora,Mexico

The North American Southwest includes much of Mexico as well as the southwestern United States. The area north of the international border has been studied intensively and its culture history is widely known; the portion south of the border has usually been ignored. This essay proposes a new term for the entire culture area, Northern Mexico, and provides a summary of local sequences for two states in the region, Chihuahua and Sonora. The general sequence in the U.S. Southwest (Paleo-Indian, Archaic, and Ceramic periods) also holds in northwest Mexico. Preceramic occupations are poorly known. The Ceramic period saw the rise of a number of local cultures, which varied greatly in adaptation and social complexity. The basic culture pattern of Northern Mexico is derived from that of central Mexico, but direct Mesoamerican intervention in the region was apparently limited. While the issue of Mesoamerican-Northern Mexican relationships has dominated scholarly debate for decades, the greater need is to define and explain cultural variability within and between local sequences.     

Ethnicity,politics, and history in Mexico and Central America

Wilson, Richard. Maya Resurgence in Guatemala: Q'eqchi’ Experiences. Norman: University of Oklahoma Press, 1995. xiv + 373 pp. including tables, figures, photographs, appendices, notes, glossary, bibliography, and index. $32.95 cloth.

Frye, David. Indians into Mexicans: History and Identity in a Mexican Town. Austin; University of Texas Press, 1996. viii + 250 pp. including figures, photographs, appendices, notes, bibliography, and index. $40.00 cloth, $19.95 paper.

Hale, Charles R. Resistance and Contradiction: Miskitu Indians and the Nicaraguan State, 1894–1987. Stanford, California: Stanford University Press, 1994. ix + 296 pp. including tables, figures, photographs, appendices, notes, bibliography, and index. $42.50 cloth.     

Game Resources, Social Interaction, and the Ecological Footprint in Southwest New Mexico

Humans have modified their environments for millennia, but the role of these impacts on economic and social strategies among communities can be difficult to assess. This is due in part to the difficulty of quantifying impacts, which hinders our evaluations of the effects of different resource acquisition strategies and impairs attempts to understand competing demands on resources and their effects on the evolution of social relations. In this paper we employ footprint analysis, a tool used in ecology, to assess the impact of prehistoric subsistence farming communities on the environment, specifically faunal resources. We use footprint analysis to quantify the impact of various strategies of game acquisition by Classic Mimbres period (AD 1000-1130) farmers in the North American Southwest. Assessments are then employed in identifying changes in social relations among communities that may have contributed to settlement changes in the region.     

Science,Politics and Fishery Management in the US Gulf of Mexico Region

Abstract

Fisheries are a major source of food for the burgeoning human population of Earth, and their management is an extremely complex process. Management of these limited resources invariably arouses emotional responses from those participating in their harvest, processing and consumption.

A review of pertinent marine fishery management literature reveals an increasing recognition of the necessity for molding the sociopolitical, economic, biological, chemical, and physical sciences into a cohesive system that will provide managers with a sound basis for making decisions. This review discusses fishery management planning in world, US, regional, and state markets. Emphasis is on the northern Gulf of Mexico fisheries, where the authors have performed most of their research. The Gulf of Mexico region accounted for 34% of US commercial landings in 1979. In the Gulf region, fishery management plans have been developed and implemented over the past several years. Regional plans for management of resources in territorial and internal waters were produced in a state–federal–university-user effort. The interdisciplinary task force included state and federal marine fishery managers and specialists, economists, cultural anthropologists, marine biologists, marine fishery industrial representatives and management specialists.

The conceptual model of the management system provided a basis for the decision-making process. The strategic plans developed in this planning process were adopted and implemented in the five Gulf States. Several fishery management models are depicted and discussed. All show either directly or by implication that both science and politics are integral parts of the management of the several fisheries. An expanded model illustrates the interdisciplinary nature of fishery management. Some recommended political structures for fishery management are also discussed.     

City and region in the credit market of late colonial Guadalajara,Mexico

Regional studies of colonial Mexico have focused on economic, sociological and political themes that largely neglect developing relationships between urban centers and their regions. Understanding these relationships is necessary for a clearer determination of the beginning of dependency and underdevelopment. Data for this study come from loan and mortgage documents contained in the Libros de Hipotecas for Guadalajara, Mexico from 1721 through 1820. The records show that most of the credit necessary for rural economies to function came from creditors in the capital city of Guadalajara. Credit flows through the countryside corresponded to the distributional patterns of population, economic activities, and social networks. Districts with larger populations consumed greater amounts of credit in part because of the presence of many potential borrowers. Those areas involved primarily in trade and agriculture also needed much urban credit, particularly at critical stages in their economic development. Districts in which the region's wealthiest families resided also received more credit through the system of personal and business contacts which channelled the distribution of credit. The net flow of credit from city to region, however, does not necessarily indicate unilateral dependence of rural districts on the capital city. An analysis of the relative benefits to creditor and debtor indicates that the relationship between city and region was characterized by mutual dependence rather than urban exploitation of rural districts.     

Woodland Pottery Function,Cooking, and Diet in the Upper Great Lakes of North America

A multidimensional approach to functional analysis was employed to examine pottery use, cooking, and subsistence in pre-European North American contexts. A variety of analytic techniques were applied to ceramic assemblages from two sites on the south shore of Lake Superior: the Middle Woodland Naomikong Point site and the Late Woodland Sand Point site. The analyses of both technical attributes and use-alteration traces suggest that a majority of pottery vessels from these sites were used for cooking throughout the Woodland period. Lipid residue analysis corroborates traditional subsistence information but specifies which foods were cooked in pottery vessels. Vessel size varies according to context rather than by time or by function, with larger vessels associated with ritual areas and smaller vessels originating from domestic spheres, a trend potentially related to feasting behavior. Interior carbonization patterns change in frequency between the Middle and Late Woodland periods, suggesting a shift in cooking and possibly subsistence practices.