The Occurrence of Gypsum in the Tertiary Clays and Sandstones of Ecuador

1927 ◽  
Vol 64 (7) ◽  
pp. 298-308
Author(s):  
George Sheppard
Keyword(s):  
Vein Deposit ◽  
Clay Shales ◽  
Southern Ecuador ◽  
Talus Slope

Gypsum or selenite is one of the commonest “decomposition” minerals found in connexion with the exposed surfaces of the Tertiary rocks in southern Ecuador. With the possible exception of the coarser grits and conglomerates, the normal sandstones are usually veined extensively by sheets of this mineral; it also occurs in a fibrous form (plates), in agglomerations of minute scalenohedrons, flake-like folia parallel to the bedding, and also in beautiful rosette-like or “stellate” groupings. In the typical clay shales or “gredas” the distribution of gypsum is not so general, though crystals or irregular groups of imperfectly shaped crystals occur on the weathered slopes or screes. In many localities, where a steep talus slope of shale forms the foot of a superimposing sandstone cliff, the scree itself is invariably covered with broken plates of gypsum in such profusion that from a distance it has the appearance of irregular masses of ice or glass. The platy form (which usually consists of parallel laminae with vertical fibres) is probably the most common and, in reality, each plate has been formed after the manner of a typical vein deposit.

Regionalization of wind-speed data to analyse tree-line wind conditions in the eastern Andes of southern Ecuador

Erdkunde ◽  
2015 ◽  
Vol 69 (1) ◽  
pp. 3-19 ◽  
Author(s):  
Julia Wagemann ◽  
Boris Thies ◽  
Rütger Rollenbeck ◽  
Thorsten Peters ◽  
Jörg Bendix
Keyword(s):  
Wind Speed ◽  
Tree Line ◽  
Wind Speed Data ◽  
Southern Ecuador

scholarly journals Conservation Debates: People’s Perceptions and Values towards a Privately Protected Area in Southern Ecuador

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 233
Author(s):  
Verónica Iñiguez-Gallardo ◽  
Fabián Reyes-Bueno ◽  
Olga Peñaranda
Keyword(s):  
Protected Areas ◽  
Land Tenure ◽  
Protected Area ◽  
Planning Process ◽  
Social Needs ◽  
Structured Interviews ◽  
Key Stakeholders ◽  
Southern Ecuador ◽  
Negative Perceptions ◽  
Land Tenure System

The perceptions and values that local communities have towards protected areas are of great value for the improvement of these territories’ management. Such perceptions and values are often absent in the conservation planning process, particularly in those privately protected areas that are established in areas where the land tenure system is based not only on ownership but also on customary uses. Drawing on qualitative and quantitative data obtained through semi-structured interviews with key stakeholders and members of communities surrounding a privately protected area in southern Ecuador, we identify that the level of collaboration with the managers, the distance to the protected area, the percentage of untitled land, and the dependence on the resources (customary uses) are among the variables affecting these perceptions and values. Positive perceptions towards protected areas and naturalistic values are developed among those who collaborate with the protected area managers, whereas negative perceptions, and a mix of naturalistic and biospheric values are developed among those who have a sense of a lack of attention to social needs although supporting nature conservation at the same time. The evidence presented shows the importance of matching local peoples’ expectations with conservation goals during the establishment of a protected area.

scholarly journals Effects of Land-Use Change on the Community Structure of the Dung Beetle (Scarabaeinae) in an Altered Ecosystem in Southern Ecuador

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 306
Author(s):  
Vinicio Carrión-Paladines ◽  
Andreas Fries ◽  
Andrés Muñoz ◽  
Eddy Castillo ◽  
Roberto García-Ruiz ◽  
...  
Keyword(s):  
Land Use ◽  
Community Structure ◽  
Land Use Change ◽  
Dung Beetle ◽  
Dry Forest ◽  
Farm Animals ◽  
P Value ◽  
Southern Ecuador ◽  
Abundance And Diversity ◽  
Effects Of Land Use

This study evaluated the effects of land-use change (L-UCH) on dung beetle community structure (Scarabaeinae) in a disturbed dry ecosystem in southern Ecuador. Five different L-UCH classes were analyzed by capturing the dung beetle species at each site using 120 pitfall traps in total. To determine dung beetle abundance and diversity at each L-UCH, a general linear model (GLM) and a redundancy analysis (RDA) were applied, which correlated environmental and edaphic conditions to the community structure. Furthermore, changes in dung-producing vertebrate fauna were examined, which varied significantly between the different L-UCH classes due to the specific anthropogenic use or level of ecosystem disturbance. The results indicated that soil organic matter, pH, potassium, and phosphorus (RDA: component 1), as well as temperature and altitude (RDA: component 2) significantly affect the abundance of beetles (GLM: p value < 0.001), besides the food availability (dung). The highest abundance and diversity (Simpson’s index > 0.4, Shannon-Wiener index > 1.10) was found in highly disturbed sites, where soils were generally more compacted, but with a greater food supply due to the introduced farm animals. At highly disturbed sites, the species Canthon balteatus, Dichotomius problematicus, and Onthphagus confuses were found specifically, which makes them useful as bio-indicators for disturbed dry forest ecosystems in southern Ecuador.

scholarly journals Ore Genesis of the Takatori Tungsten–Quartz Vein Deposit, Japan: Chemical and Isotopic Evidence

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 765
Author(s):  
Yuichi Morishita ◽  
Yoshiro Nishio
Keyword(s):  
Oxygen Isotope ◽  
Early Stage ◽  
Isotope Ratios ◽  
Equilibrium Temperature ◽  
Granitic Rocks ◽  
Granitic Magma ◽  
Lithium Isotope ◽  
Vein Deposit ◽  
Pressure Independent ◽  
Isotope Equilibrium

The Takatori hypothermal tin–tungsten vein deposit is composed of wolframite-bearing quartz veins with minor cassiterite, chalcopyrite, pyrite, and lithium-bearing muscovite and sericite. Several wolframite rims show replacement textures, which are assumed to form by iron replacement with manganese postdating the wolframite precipitation. Lithium isotope ratios (δ7Li) of Li-bearing muscovite from the Takatori veins range from −3.1‰ to −2.1‰, and such Li-bearing muscovites are proven to occur at the early stage of mineralization. Fine-grained sericite with lower Li content shows relatively higher δ7Li values, and might have precipitated after the main ore forming event. The maximum oxygen isotope equilibrium temperature of quartz–muscovite pairs is 460 °C, and it is inferred that the fluids might be in equilibrium with ilmenite series granitic rocks. Oxygen isotope ratios (δ18O) of the Takatori ore-forming fluid range from +10‰ to +8‰. The δ18O values of the fluid decreased with decreasing temperature probably because the fluid was mixed with surrounding pore water and meteoric water. The formation pressure for the Takatori deposit is calculated to be 160 MPa on the basis of the difference between the pressure-independent oxygen isotope equilibrium temperature and pressure-dependent homogenization fluid inclusions temperature. The ore-formation depth is calculated to be around 6 km. These lines of evidence suggest that a granitic magma beneath the deposit played a crucial role in the Takatori deposit formation.

scholarly journals An Unprecedented High Content of the Bioactive Flavone Tricin in Huperzia Medicinal Species Used by the Saraguro in Ecuador

2016 ◽  
Vol 11 (3) ◽  
pp. 1934578X1601100
Author(s):  
Chabaco Armijos ◽  
Jorge Ponce ◽  
Jorge Ramírez ◽  
Davide Gozzini ◽  
Paola Vita Finzi ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Traditional Medicine ◽  
Cell Lines ◽  
Cancer Cell ◽  
Potent Inhibitor ◽  
Community Living ◽  
Medicinal Species ◽  
Chemopreventive Agent ◽  
Southern Ecuador

The flavone tricin (5,7,4′-trihydroxy-3′,5′-dimethoxyflavone) is considered to be a selective potent inhibitor of different cancer cell lines and a potential colorectal cancer chemopreventive agent. In this paper we describe a reliable UHPLC-UV-ESIMS method for the determination of tricin in Huperzia plants used in the traditional medicine of the Saraguro community living in Southern Ecuador. An unusually high amount of tricin was found in H. brevifolia and H. compacta, which exceeded the content of this flavone determined so far in other plants.

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