Apercu sur le Quaternaire de Salvador (Amerique centrale)

1961 ◽  
Vol S7-III (1) ◽  
pp. 59-68
Author(s):  
Jean Tricart
Keyword(s):  
El Salvador ◽  
Volcanic Ash ◽  
Coastal Areas ◽  
Explosive Activity ◽  
Climatic Fluctuations ◽  
Long Period ◽  
Volcanic Region ◽  
Relative Dating ◽  
Late Tertiary

Abstract El Salvador is essentially a volcanic region in which an older, presumably late Tertiary, complex of andesite and basalt flows and breccias and younger, more acid Quaternary rocks are represented. Following a long period of inactivity during which the Tertiary volcanic masses were considerably eroded, episodic explosive activity occurred in the Quaternary, accompanied by the formation of extensive calderas and ejection of considerable ash. Paleosols were developed in the intervals between explosions, which permit relative dating of the successive episodes. The last stages of activity were characterized by extrusion of mud flows, torrential gullying, and deposition of thick piedmont detrital beds accompanied by reworking of volcanic ash which was redeposited in dammed lakes and other depressions. The development of calcareous crusts in places constitutes evidence of significant climatic fluctuations. There is also evidence of differential subsidence in coastal areas.

The Analysis and Distribution of Volcanic Ash-Tempered Pottery in the Lowland Maya Area

1979 ◽  
Vol 44 (1) ◽  
pp. 79-91 ◽  
Author(s):  
Michael P. Simmons ◽  
Gerald F. Brem
Keyword(s):  
El Salvador ◽  
Volcanic Ash ◽  
Petrographic Analysis ◽  
Time And Space ◽  
Maya Area ◽  
Lowland Maya

Petrographic analysis of potsherds from Dzibilchaltun and other Maya sites conclusively establishes the presence of volcanic ash temper in ceramics from northern Yucatan. The distribution of ash-tempered ceramics in time and space suggests import of ash in bulk from sources in highland Guatemala or El Salvador in exchange for salt. The homogeneous nature of the ash in northwestern Yucatan supports the idea that certain trading organizations enjoyed exclusive access to that region, while competing for markets in other lowland areas.

Some pathways and factors of monogenean microevolution

1995 ◽  
Vol 52 (S1) ◽  
pp. 52-56 ◽  
Author(s):  
A.V. Gusev
Keyword(s):  
Special Reference ◽  
Sibling Species ◽  
Host Species ◽  
Continental Drift ◽  
Fish Host ◽  
Geographic Isolation ◽  
Climatic Fluctuations ◽  
Origin And Evolution ◽  
Late Tertiary ◽  
Strict Specificity

This paper discusses probable causes for the origin and evolution of groups of monogenean congeneric sibling species infecting one fish host species, with special reference to freshwater fishes. These causes comprise strict specificity, topological differentiation of parasite micropopulations in microniches (microhabitats), ecological and geographic isolation of various parasite and host populations, paleogeographic or geomorphologic (but not paleogeologic) changes during the late Tertiary and Quaternary periods, with alternating marine transgressions and regressions acting upon continents which, after the Miocene, have been less affected by continental drift, orogenesis, and climatic fluctuations. Co-evolving with their hosts, Monogenea usually diverge faster than their hosts.

Petrography of the late Tertiary volcanic ash falls in the central Great Plains [Kansas-Nebraska]

1955 ◽  
Vol 25 (4) ◽  
pp. 243-261 ◽  
Author(s):  
A. Swineford ◽  
J. C. Frye ◽  
A. B. Leonard
Keyword(s):  
Great Plains ◽  
Volcanic Ash ◽  
Late Tertiary

Breeding of Beef Cattle

1944 ◽  
Vol 1944 (01) ◽  
pp. 28-38 ◽  
Author(s):  
W. A. Stewart
Keyword(s):  
Beef Cattle ◽  
General Purpose ◽  
Coastal Areas ◽  
Beef Production ◽  
Dual Purpose ◽  
Full Size ◽  
Long Period ◽  
The Past ◽  
Colour Patterns

To-day we are considering the possibilities of improvement for beef production, and it may be useful at the outset to examine briefly the methods which were successfully employed by some of the great improvers of the past. In Bakewell's time, 1726–1795, the cattle of the English Midlands were descended from every sort which had come to Britain, except that there had apparently been little mixing with the Scandinavian hornless cattle. Hornless cattle were still confined mainly to coastal areas. The colours and colour patterns varied greatly, and some cattle were the full size of the Dutch, while others were much smaller. Some had short horns ; others had the long wavy horns which had come in with the Roman cattle, so they were generally called Longhorns. It is perhaps worth recalling that the cattle of those days were a sort of non-specialized general purpose, or actually triple purpose. The bigger beasts had been valued for draft, the cows for milk, and the carcasses of both draft-bullocks and cows were ultimately of value for beef. Incidentally, there is little doubt that the Dutch cows were the best milkers. The breeds which became the Shorthorn were dual purpose, but were bred for a long period for beef (from the 1790's to the 1870's).

Age and extent of the Ilopango TBJ Tephra inferred from a Holocene chronostratigraphic reference section, Lago De Yojoa, Honduras

2005 ◽  
Vol 63 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Peter J. Mehringer ◽  
Andrei M. Sarna-Wojcicki ◽  
Lance K. Wollwage ◽  
Payson Sheets
Keyword(s):  
El Salvador ◽  
Volcanic Ash ◽  
Major Element ◽  
Archaeological Site ◽  
Volcanic Field ◽  
Element Abundances ◽  
First Millennium ◽  
Tephra Layers ◽  
Silicic Volcanic ◽  
Reference Section

Eruption of central El Salvador's Ilopango Volcano early in the first millennium A.D. caused death, cultural devastation, and exodus of southern Mesoamericans. It also left a time-stratigraphic marker in western El Salvador and adjacent Guatemala—the Ilopango Tierra Blanca Joven, or TBJ tephra. Mineral suites and major element abundances identify a silicic volcanic ash in cores from Lago de Yojoa, Honduras, as Ilopango TBJ. This extends its reported range more than 150 km to the northeast. Analyses of glass from the TBJ tephra from the Chalchuapa archaeological site, El Salvador, and from Lago de Yojoa, Honduras, establish the first major element reference fingerprint for the TBJ tephra. The Lago de Yojoa cores also hold two previously undated trachyandesitic tephra layers originating from the nearby Lake Yojoa Volcanic Field. One fell shortly before 11,000 14C yr B.P. and the other about 8600 14C yr B.P.

The weathering of a late Tertiary volcanic ash: Importance of organic solutes

1983 ◽  
Vol 47 (3) ◽  
pp. 623-629 ◽  
Author(s):  
Ronald C. Antweiler ◽  
James I. Drever
Keyword(s):  
Volcanic Ash ◽  
Organic Solutes ◽  
Late Tertiary

Metamorphic Rocks of the Eastern Andes near Cuenca, Ecuador

1933 ◽  
Vol 70 (7) ◽  
pp. 321-330 ◽  
Author(s):  
George Sheppard ◽  
G. H. S. Bushnell
Keyword(s):  
Volcanic Ash ◽  
The United States ◽  
Metamorphic Rocks ◽  
National Museum ◽  
New Genera ◽  
Disturbed Condition ◽  
Late Tertiary ◽  
Group A ◽  
Andean Uplift ◽  
Extensive Collection

The object of the present paper is to describe certain metamorphic rocks which occur in the eastern cordillera of the Ecuadorian Andes, immediately to the east of the interandine basin of Cuenca (Fig. 1). The latter region contains a series of late Tertiary volcanic breccias, followed by hard white shales which are overlain in their turn, and possibly in part replaced laterally by the massive, white, saccharoidal and tuffaceous sandstones of Azogues, in the composition of which rearranged volcanic ash and detritus play a large part (Fig. 2). These beds, originally described collectively as the Azogues Sandstone by Wolf (1),1 were considered to be of Wealden age upon the evidence of a meagre lacustrine fauna discovered by the same author, and subsequently described by Dr. Geinitz, of Dresden, which were found in the more shaly sandstones of the group. A more extensive collection of fossils made by the present writers from the same beds and localities was submitted to Dr. W. B. Marshall, of the United States National Museum, who reports that it consists largely of new genera and species, and that the age cannot be later than the Pliocene, and it may be earlier (2). These beds are thrown generally into a series of relatively gentle folds, having a north-south trend, but occasionally they are found in a more highly disturbed condition as, for example, on the Biblian-Azogues road, where they are sometimes seen to be vertical. The strike of the folding shows that it is a product of pressure from the same direction as that which accompanied the main Andean uplift.

Household Archaeology at Cerén, El Salvador

1990 ◽  
Vol 1 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Payson D. Sheets ◽  
Harriet F. Beaubien ◽  
Marilyn Beaudry ◽  
Andrea Gerstle ◽  
Brian McKee ◽  
...  
Keyword(s):  
El Salvador ◽  
Volcanic Ash ◽  
Household Archaeology ◽  
Theoretical Framework ◽  
Access To Resources ◽  
Residential Group ◽  
Material Goods ◽  
Favorable Conditions ◽  
Storage Distribution

AbstractIn the summer of 1989, major discoveries were made at the site of Joya de Cerén, El Salvador, where sudden depositions of volcanic ash in a.d. 600 resulted in unusually favorable conditions of preservation. The theoretical framework for the research is household archaeology, the study of prehistoric household groups. Household archaeology, as applied to Cerén can take advantage of the extraordinary preservation to study households in terms of their key activities of (a) production, including food, implements, vessels, and structures; (b) “pooling,” including storage, distribution, maintenance, and curation activities; (c) transmission of knowledge and material goods including access to resources; (d) reproduction in both the biological and sociocultural senses; and (e) co-residence/membership in the functioning residential group. One of the major finds was a possible codex or Precolumbian manuscript.

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