Mid-Pliocene warm climate and annual primary productivity peaks recorded in sapropel deposition

2006 ◽  
Vol 31 ◽  
pp. 137-144 ◽  
Author(s):  
R Capozzi ◽  
A Negri ◽  
V Picotti ◽  
E Dinelli ◽  
S Giunta ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Warm Climate

Guadalupian cool versus warm water deposits in central Iran: a record of the Capitanian Kamura event

2017 ◽  
Vol 156 (3) ◽  
pp. 430-446 ◽  
Author(s):  
SAKINEH AREFIFARD
Keyword(s):  
Primary Productivity ◽  
Association Studies ◽  
Central Iran ◽  
Warm Water ◽  
Middle Permian ◽  
Warm Climate ◽  
Diagenetic Alteration ◽  
Lime Mud ◽  
Jamal Formation ◽  
Oceanic Upwelling

AbstractAn integration of geochemical and grain association studies were carried out on Middle Permian deposits in central Iran where both cool and warm water carbonates are found. The recrystallization of most bioclasts, lime-mud matrix and ooids along with high Sr contents suggests a probable original aragonite mineralogy for carbonates of the Middle Permian Jamal Formation at the Shotori section. Low bulk carbonate δ18O values imply pervasive diagenetic alteration in this section. Conversely, Middle Permian deposits at the correlative Bagh-e Vang section have a probable calcite precursor supported by low Sr contents and no evidence of recrystallization. This mineralogical variation in these coeval carbonates is considered to be due to the change in depth and temperature of the depositional palaeoenvironment. δ13C values started to rise over 2 ‰ PDB and reached a maximum of 4.3 ‰ PDB at the Wordian–Capitanian boundary at the Bagh-e Vang section. This δ13C rise is attributed to high primary productivity as previously reported in the Capitanian Abadeh Formation in central Iran. The positive δ13C excursion in these sections is correlated with the Capitanian ‘Kamura event’ identified from the mid-Panthalassian sections in Japan. No noticeable positive excursion occurs in the δ13C plot at the Shotori section making the interpretation of palaeo-productivity difficult. It is suggested that an active oceanic upwelling was the probable driver of the Middle Permian oceanic productivity in central Iran. Remarkable negative δ13C excursions around 3.7 and 4.2 ‰ PDB in Capitanian carbonates close to the Guadalupian–Lopingian boundary at the Bagh-e Vang and Abadeh sections, respectively are recorded, which are a proxy for low palaeo-productivity and a transition from a cool to warm climate, consistent with an early Lopingian sea level rise.

Limnological characteristics, community metabolism and management strategies of a coastal sinkhole in Cuba (Cenote Jennifer)

2020 ◽  
Vol 56 ◽  
pp. 24
Author(s):  
Roberto González-De Zayas ◽  
Liosban Lantigua Ponce de León ◽  
Liezel Guerra Rodríguez ◽  
Felipe Matos Pupo ◽  
Leslie Hernández-Fernández
Keyword(s):  
Hydrogen Sulfide ◽  
Primary Productivity ◽  
Major Ions ◽  
Saline Water ◽  
Management Strategies ◽  
Tourist Destination ◽  
Community Metabolism ◽  
Morphological Studies ◽  
Made In ◽  
Limnological Parameters

The Cenote Jennifer is an important and unique aquatic sinkhole in Cayo Coco (Jardines del Rey Tourist Destination) that has brackish to saline water. Two samplings were made in 1998 and 2009, and 4 metabolism community experiments in 2009. Some limnological parameters were measured in both samplings (temperature, salinity, pH, dissolved oxygen major ions, hydrogen sulfide, nutrients and others). Community metabolism was measured through incubated oxygen concentration in clear and dark oxygen bottles. Results showed that the sinkhole limnology depends on rainfall and light incidence year, with some stratification episodes, due to halocline or oxycline presence, rather than thermocline. The sinkhole water was oligotrophic (total nitrogen of 41.5 ± 22.2 μmol l−1 and total phosphorus of 0.3 ± 0.2 μmol l−1) and with low productivity (gross primary productivity of 63.0 mg C m−2 d−1). Anoxia and hypoxia were present at the bottom with higher levels of hydrogen sulfide, lower pH and restricted influence of the adjacent sea (2 km away). To protect the Cenote Jennifer, tourist exploitation should be avoided and more resources to ecological and morphological studies should be allocated, and eventually use this aquatic system only for specialized diving. For conservation purposes, illegal garbage disposal in the surrounding forest should end.

Satellite-based estimation of net primary productivity for southern China’s grasslands from 1982 to 2012

2017 ◽  
Vol 71 (3) ◽  
pp. 187-201 ◽  
Author(s):  
W Yang ◽  
T Lu ◽  
S Liu ◽  
J Jian ◽  
F Shi ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity

Effects of Predation and Trophic Conditions on the Reproduction of Tylototriton verrucosus (Caudata: Salamandridae) in Darjeeling

2011 ◽  
Vol 4 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Ritwik Dasgupta
Keyword(s):  
Frequency Distribution ◽  
Primary Productivity ◽  
Egg Size ◽  
Zooplankton Abundance ◽  
Trophic Conditions ◽  
Size Frequency Distribution ◽  
Size Frequency ◽  
High Predation ◽  
Hatchling Size ◽  
Predation Rates

The facts that small hatchlings emerged from small eggs laid under high predation levels prevailing at the lower altitudes of distribution of this species in Darjeeling while larger hatchlings emerged from larger eggs laid under lower levels of predation at higher altitudes, show that predation is not selected for large egg and initial hatchling size in this salamandrid species. Metamorphic size was small under high predation rates because this species relied on crypsis for evading predators. Egg and hatchling size are related inversely to levels of primary productivity and zooplankton abundance in lentic habitats. Hatchling sizes are related positively to egg size and size frequency distribution of zooplankton. Small egg and small hatchling size have been selected for at the lower altitudes of distribution of this salamandrid in Darjeeling because predation rates increased in step with improvement in trophic conditions at the lower altitudes.

Primary Productivity in Meduxnekeag River, Maine, 2005

2009 ◽  
Author(s):  
Robert M. Goldstein ◽  
Charles W. Schalk ◽  
Joshua P. Kempf
Keyword(s):  
Primary Productivity
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