Showing papers on "Assemblage (archaeology) published in 1990"

Global Patterns of Parasitoid Assemblage Size

Abstract: (1) The parasitoids recorded from 1288 species of phytophagous insects from fifty-nine countries were used to examine patterns of variation in the numbers of parasitoid species a host species supports. (2) Analysis of global data indicated that parasitoid assemblages on exposed hosts are subject to geographically and climatically driven variation in mean size, whereas assemblages on endophytic and soil-inhabiting hosts have characteristic mean sizes which are similar in all parts of the world and under most environmental conditions. (3) A second analysis examining variation within North America gave identical results, supporting the global patterns. (4) Synthesis of currently known patterns and mechanisms suggests that it may be possible to broadly characterize parasitoid communities as either interactive (and structured by interspecific competition) or non-interactive (not structured by competition) based on relationships between generalists, specialists and feeding biologies of hosts.

Length-mass relationships among an assemblage of tropical snakes in Costa Rica

Abstract: Length-mass relationships within an assemblage of tropical snakes are used to describe morphological groups. We report patterns of body size based on length and mass measurements of 603 individual snakes of 27 species captured at La Selva, Costa Rica from March 1982 through August 1984. This assemblage of snakes is composed of at least four morphological groups each of which consists of species with similar habitat preferences. These groups are heavy-bodied terrestrial forms, light-bodied arboreal forms, long-tailed leaf-litter forms, and forms of unextreme relative mass and tail length. This tropical snake assemblage is more diverse in species richness and morphological diversity than a temperate assemblage.

Paleogene paleoenvironmental trends as reflected by palynological assemblage types, Salta Basin, NW Argentina

Abstract: Abstract: Lower Tertiary microfloras from North-West Argentina were studied and their paleoenvironmental trends and paleotemperatures inferred. Palynological data were derived from outcrop samples from the Lower Tertiary Tunal, Maiz Gordo and Lumbrera formations (Salta Group) in the Alemania Sub-Basin, Salta Basin. The comparison of fossil genera with living ones allowed five paleocommunities to be recognized, namely marsh, lake, subtropical forest, moist forest, lower montane forest and montane forest in the Tunal Formation. A dominant higher altitude paleocommunity (montane) and aridity can be recognized in the Maiz Gordo Formation, and a humid montane paleoenvironment indicated for the Lumbrera Formation. The composition of the microfloral assemblages reflects warm temperatures for the Paleocene and a decline in the Early Eocene. An objective stratigraphic and paleoenvironmental evaluation of data was obtained by computerized numerical methods.

The listwanite - lode gold association in british columbia

Abstract: ing in the Ural goldfields of Russia (Goncharenko, 1970; Listwanite is a term long used by Soviet geologists workKuleshevich, 1984) that is now used in Europe and North America. It describes amineralogical assemblage that results from the carbonatization of serpentinized ultramafic rocks and represents a distinctive alteration suite that is commonly associated with quartz-carbonate lode gold deposits. Im Brit-

Curatorial Considerations for Systematic Research Collections: AMS Dating a Curated Ceramic Assemblage

Abstract: The needs of new analytic techniques that may be depleting or destructive, or which have requirements that may be at odds with other approaches, place new and different demands on curated archaeological research collections. Curatorial approaches and attitudes need to accomodate such changes in research environment and be aware of both the potentials of curated collections as well possible conflicts. A pilot study employing AMS dating of adhering residues on a curated ceramic collection is used to illustrate curatorial concerns and decisions associated with the use of modern techniques. It is argued that continued use of such collections is important, and that management decisions must keep pace with technological innovations.

Ceramic Production in the Mariana Islands: Explaining Change and Diversity in Prehistoric Interaction and Exchange

Abstract: THE TRADITIONAL APPROACH employed to describe the history and prehistory of the Mariana Islands has emphasized the cultural and linguistic homogeneity of the indigenous population, the Chamorros. Consequently, archaeologists have devoted little attention to spatial variabililty across the archipelago or to research domains that may articulate with such variability-for example, the exchange of commodities or social transactions and the extent of inter-community and inter-island interaction. Interestingly, this approach has produced an inconsistency between archaeological method and the study of culture history in Mariana Islands prehistory. For with few exceptions, artifacts recovered from archaeological sites have been treated as if they were produced and used within the confines of a single community. Yet at the same time, the material culture assemblage for each time period, spanning an array of communities, is thought to have been relatively homogeneous. Such a view can only be maintained by postulating high rates of prehistoric interaction coupled with low rates of exchange. This hypothesis has not been explicitly evaluated by Micronesian archaeologists, in terms of its methodological, theoretical, or substantive adequacy. The completion of a number of archaeological projects over the past 15 years in the Mariana Islands now makes it possible to ask, how homogeneous and similar are material culture assemblages across the archipelago at different points in time? Pottery lends itself well to this kind of questioning, because it occurs in large numbers at virtually all sites in the Mariana Islands, and its variability across a number of dimen-

A remarkable foraminiferal assemblage from the Quaternary of northeast Greenland

Abstract: Near Nordostrundingen in northeasternmost Greenland, at a locality called Kilen, at 81°10' north latitude (Fig. 1), C. Hjort of Lund University, Sweden, investigated sedimentary outcrops, and established the Ymer Formation. This is a 6-10 m thick sequence, with a rich fossil content of foraminifera, molluscs and cirripeds, reflecting interglacial climatic conditions. Absolute age determination by radiocarbon gave a minimum of 40,300 years before present, Uranium/Thorium gave 103,000 years B.P., thermoluminescence method gave 190,000-220,000 B.P., and amino-acid-derived estimates were 220,000-270,000 B.P. The Ymer Formation is, therefore, probably of Holsteinian (Yarmouthian) age (Hjort, 1981; Hjort and Feyling-Hanssen, 1987). Two sediment samples from the Ymer Formation, collected by Hjort, were investigated for their content of fossil foraminifera. The faunas were briefly dealt with in a paper by Hjort and Feyling-Hanssen (1987), but the remarkably abundant occurrence of the species Islandiella inflata (Gudina) justifies a closer account of the matter. Islandiella inflata in abundance may well turn out to be an Upper Mid-Pleistocene marker in the Arctic. One of the samples, CHT 8, was taken 7 m above present-day sea level from stratified sand with many dropstones, the other, CHT 13, at 8 m a.s.l. from horizontally stratified, well sorted medium sand. Both samples contained fossil benthonic foraminifera, 1,900 specimens/100 g sediment in sample CHT 8, 2,400/100 g in sample CHT 13. Preservation was mainly poor, a number of specimens had later chambers broken off and most had corroded test surfaces, particularly those from sample CHT 13. Acidic ground-water percolating through the sandy sediments may have affected the calcium carbonate tests of the foraminifera. In this respect it is interesting to note that many coal and lignite particles occurred in the samples, particularly CHT 13. However, identification of the specimens was not impeeded by this corrosion (cf. Plates 1-3). The assemblages are both of Quaternary age, but differ in composition. This was most probably caused by difference in water depth during deposition, rather than by any considerable difference in age.

Fremont and Anasazi Resource Selection: An Examination of Faunal Assemblage Variation in the Northern Southwest

Abstract: The Fremont Culture occupied central and northern Utah from about A.D. 450 to A.D. 1300. Relatively large faunal assemblages recovered from some Fremont sites have suggested a contrast between Fremont and Anasazi reliance on animal resources, and (by implication) dependence on domesticated crops, but comparison of numbers of specimens and numbers of species identified in 73 archaeological faunas from the northern Southwest fails to support this contrast. Both assemblage size and assemblage richness show significant geographic variation, but this variation does not coincide with cultural boundaries and cannot be directly linked to resource selection. The relationship between assemblage size and richness is statistically identical across space and time, suggesting an underlying similarity in faunal resource exploitation.

A Note on Biases in Early Excavations at Mugharet El-Wad and Nahal Oren

Abstract: Chipped stone artifacts usually comprise the bulk of recovered materials from the archaeological sites of the ear Her span of prehistory. As such, they are used to describe and characterize particular time spans, as well as geographical regions within those time spans. It is imperative, therefore, that these descriptions and characterizations be as accurate as possible. It is widely recognized, however, that early excavators in most parts of the world used excavation techniques that usually did not recover the data in such meticulous detail. The lack of sieving at most early excavations and the focus on the retention of "characteristic" tool types are two such biases. Two techniques hold potential for studying these biases and contributing important information that is otherwise lacking. One is the excavation of relevant remaining portions of a site (if these still exist), and the other is to examine the chipped stone artifacts that were not collected and that can be found in the old backdirt deposits. Recently, two small backdirt collections have been analyzed in this regard.! These represent the Natufian context from Garrod's excavations at Mugharet el-Wad, which encompass both Layers BI and B2 (Garrod 1932a, 1932b; Garrod and Bate 1937), and the Natufian context from Stekelis and Yizraely excavations at Nahal Oren (Stekelis and Yizraely 1963). Both samples were collected in the late 1960s. Tables I and 2 present the numerical and percentage data relating to these two assemblages. The tool typology used is that of Hours (Hours 1974). While not useful for distinguishing the chronological periods at Mugharet el-Wad and Nahal Oren, these data indicate the types of collection biases operating during early excavations in the Levant. The backdirt collections from Mugharet el-Wad and Nahal Oren contain high frequencies of non-geometric microliths, as well as "retouched pieces" (Hours type H), at el-Wad, and perforators. This suggests that these small types of tools, as well as opportunistic tools ("retouched pieces"), were often not recovered in the early excavations, and that subsequent publication of lithic assemblage descriptions from these sites overrepresents the other tool classes.

Some gastropods from the Upper Campanian of the Middle Vistula Valley, Central –Poland

Abstract: Fifty-three gastropod species are recognized in the Upper Campanian strata of the Middle Vistula Valley, Central Poland. The gastropod assemblage comprises 26 genera, belonging to 19 families. The mesogastropods are the major constituent of the assemblage, and are associated with the archaeogastropods, neogastropods, and opisthobranchs. The whole gastropod assemblage reflects influences of the North Temperate Realm. From ecological point of view, herbivores and predators are the most common trophic elements within this assemblage, together with a subordinate occurrence of deposit- and suspension-feeders. Of the taxonomic recognitions, notable is the first finding of the genus Palaeocypraea in the Upper Cretaceous deposits of Poland.

Locating patches and distant resources

Abstract: When searching for a resource patch an animal attempts to localise an assemblage of resources, whereas when searching within a patch it avoids leaving the assemblage until it becomes unprofitable to remain. Interestingly, the problem of finding an isolated resource is similar to that of finding a distant patch because, even though the patch might be larger, initially in both situations the target represents a relatively small proportion of the total environment. The following section considers a few of the strategies used to locate distant resource units; subsequent sections deal with searching for and utilizing resources within these units.

Blood Residue Analysis of the Lithic Assemblage From the Mitchell Locality, Blackwater Draw New Mexico

Abstract: (1990). Blood Residue Analysis of the Lithic Assemblage From the Mitchell Locality, Blackwater Draw New Mexico. Plains Anthropologist: Vol. 35, No. 130, pp. 105-115.