The role of solution in the formation of boudinage and transverse veins in carbonate rocks at Rheems, Pennsylvania

1991 ◽  
Vol 103 (12) ◽  
pp. 1552-1563 ◽  
Author(s):  
DECLAN G. DE PAOR ◽  
CAROL SIMPSON ◽  
CHRISTOPHER M. BAILEY ◽  
KENNETH J. W. MCCAFFREY ◽  
ERIC BEAM ◽  
...  
Keyword(s):  
Carbonate Rocks

scholarly journals The role of organic matter in formation of the properties of a shale deposit

2019 ◽  
Vol 484 (2) ◽  
pp. 220-223
Author(s):  
И. Ф. Юсупова
Keyword(s):  
Organic Matter ◽  
Carbonate Rocks ◽  
Strength Properties ◽  
Low Density ◽  
Lower Strength ◽  
Reduction Processes ◽  
Local Areas ◽  
Oil Shales ◽  
Mosaic Distribution

Baltic oil shales — kukersites were studied as an example of rocks with rock-forming organic matter (OM). The volumetric significance of their OM is shown (due to the low density) in the volume and thickness of the shale layers. A higher OM content is responsible for a lower strength of the shales relative to the carbonate rocks of the deposit. The variable OM contents and other heterogeneities of the shale layers (structure, nodules, etc.) are factors of the mosaic distribution of areas with different density–strength properties and, as a result, of uneven reduction of layers and their deformation in the case of OM loss (full or partial). It is concluded that the intercalation of kukersite and limestone layers leads to density and strength anisotropy of the shale deposit. Episodic loss of OM and carbonates by the shales is considered for the local areas of the deposit: here, kukersites contain only a terrigenous component with clasts of limestones, shales, and epigenetic sulfides. The loss of OM is explained by sulfate-reduction processes in the underground hydrosphere.

scholarly journals Role of the Environment in the Placement of Apocarbonate Gold Mineralization Chakylkalyan Megablock (Southern Uzbekistan)

2021 ◽  
Vol 7 (6) ◽  
Author(s):  
T. Yarboboev ◽  
Sh. Sultanov ◽  
I. Ochilov
Keyword(s):  
Carbonate Rocks ◽  
Gold Mineralization ◽  
Gold Deposits ◽  
Gold Deposition ◽  
Sufficient Detail ◽  
Available Information ◽  
Gold Bearing ◽  
Geochemical Specialization

Analysis of the available information and the results of many years of research on gold deposits in Uzbekistan made it possible to identify the main unconventional types of deposits. Among them, the most interesting are apocarbonate, crustal, sulfide-carbonaceous and apovolcanogenic quartzite (Upper-Kattakashkasai ore occurrence). The apocarbonate type is widespread in Uzbekistan, has been studied in sufficient detail and information is provided on it in this article. The article examines the existence, distribution and genesis of ores of Karlin type gold deposits. The generalizing characteristics of the Karlin type gold mineralization are given. The issues of geochemical specialization of the Paleozoic strata of the Chakylkalyan megablock are considered, the most favorable stratolevel for the localization of mineralized zones is determined, and the features of carbonate rocks in the process of gold deposition during reactions with silicic solutions are characterized. Based on the materials of regional geochemical profiling, the behavior of the main ore-forming elements in the rocks of both carbonate and volcanogenic-terrigenous strata is analyzed. As a result of the analysis, subclarkic contents of the main ore-forming elements (As, Co, Ni, Pb, Cu, Ag, V, Cr, Sc) were revealed, which create increased concentrations in gold-bearing pyrites of both apocarbonate gold mineralization and related formations.

Wildfires as a Weathering Agent of Carbonate Rocks

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1091
Author(s):  
Nurit Shtober-Zisu ◽  
Lea Wittenberg
Keyword(s):  
Forest Fire ◽  
Carbonate Rocks ◽  
Fire Effects ◽  
Temperature Gradients ◽  
Peak Temperature ◽  
Rock Weathering ◽  
Moderate Increase ◽  
Ground Temperatures ◽  
Slow Decrease

While most of the scientific effort regarding wildfires has predominantly focused on fire effects on vegetation and soils, the role of fire as an essential weathering agent has been largely overlooked. This study aims to evaluate rock decay processes during wildfires, in relation to ground temperatures and rock morphologies of limestone, dolomite, and chalk. In 2010, a major forest fire in Israel caused massive destruction of the exposed rocks and accelerated rock weathering over the burned slopes. While a detailed description of the bedrock exfoliation phenomenon was previously reported, here, we conducted an experimental open fire to determine the temperature and gradients responsible for boulder shattering. The results show ground temperatures of 700 °C after 5 min from ignition, while the peak temperature (880 °C) was reached after 9 min. Temperature gradients show a rapid increase during the first 5 min (136 °C/min), moderate increase during the next 4 min (43 °C/min), and slow decrease for the next 9 min (25 °C/min). After 12 min, all boulders of all formations were cracked or completely shattered. The behaviour of carbonate rocks upon heating was studied to identify the erosive effects of fire, namely the formation of new cracks and matrix deterioration.

Origin and role of fluids involved in the seismic cycle of extensional faults in carbonate rocks

2016 ◽  
Vol 450 ◽  
pp. 292-305 ◽  
Author(s):  
Luca Smeraglia ◽  
Fabrizio Berra ◽  
Andrea Billi ◽  
Chiara Boschi ◽  
Eugenio Carminati ◽  
...  
Keyword(s):  
Carbonate Rocks ◽  
Seismic Cycle

The role of organic matter of carbonate rocks in the reactivity of the produced quicklime

2003 ◽  
Vol 36 (2) ◽  
pp. 135-138 ◽  
Author(s):  
N. Kantiranis ◽  
A. Filippidis ◽  
B. Christaras ◽  
A. Tsirambides ◽  
A. Kassoli-Fournaraki
Keyword(s):  
Organic Matter ◽  
Carbonate Rocks

scholarly journals Dissolution of Carbonate Rocks in a Laboratory Setting: Rates and Textures

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 605
Author(s):  
Erik B. Larson ◽  
Ronald V. Emmons
Keyword(s):  
Carbonate Rocks ◽  
Carbon Budget ◽  
Dissolution Rates ◽  
Global Carbon Budget ◽  
Landscape Processes ◽  
The Matrix ◽  
Mechanical Weathering ◽  
Global Carbon ◽  
Scanning Electron

Determining the dissolution rates of carbonate rocks is vital to advancing our understanding of cave, karst, and landscape processes. Furthermore, the role of carbonate dissolution is important for the global carbon budget and climate change. A laboratory experiment was setup to calculate the dissolution rates of two whole rock carbonate samples with different petrographic makeup (ooids and brachiopods). The carbonate rock samples were also explored under a scanning electron microscope to evaluate the textures that developed after dissolution The oolitic limestone dissolved at a rate of 1579 cm yr−1, and the pentamerous limestone (dolostone) dissolved at a rate of 799 cm yr−1. Both rocks did not dissolve evenly across their surface as indicated by scanning electron microscopy, it appears the allochems dissolved preferentially to the matrix/cement of the rocks and that some mechanical weathering happened as well. This work reports that the petrography and mineralogy of carbonate rocks is important to consider when exploring the cave, karst, and landscape evolution and that attention should be paid to the petrography of carbonate rocks when considering the global carbon budget.

The Phanerozoic Carbon Cycle

2004 ◽  
Author(s):  
Robert A. Berner
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Carbon Cycle ◽  
Carbonate Rocks ◽  
Large Scale ◽  
Fossil Fuels ◽  
Land Plants ◽  
Current Debate ◽  
The Past

The term "carbon cycle" is normally thought to mean those processes that govern the present-day transfer of carbon between life, the atmosphere, and the oceans. This book describes another carbon cycle, one which operates over millions of years and involves the transfer of carbon between rocks and the combination of life, the atmosphere, and the oceans. The weathering of silicate and carbonate rocks and ancient sedimentary organic matter (including recent, large-scale human-induced burning of fossil fuels), the burial of organic matter and carbonate minerals in sediments, and volcanic degassing of carbon dioxide contribute to this cycle. In The Phanerozoic Carbon Cycle, Robert Berner shows how carbon cycle models can be used to calculate levels of atmospheric CO2 and O2 over Phanerozoic time, the past 550 million years, and how results compare with independent methods. His analysis has implications for such disparate subjects as the evolution of land plants, the presence of giant ancient insects, the role of tectonics in paleoclimate, and the current debate over global warming and greenhouse gases

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