Results 41 to 50 of about 247,595 (300)

Anomalous negative excursion of carbon isotope in organic carbon after the last Paleoproterozoic glaciation in North America [PDF]

open access: yes, 2010
Early Paleoproterozoic time (2.5–2.0 Ga) spanned a critical phase in Earth's history, characterized by repeated glaciations and an increase in atmospheric oxygen (the Great Oxidation Event (GOE)).
Bekker   +41 more
core   +1 more source

Study on the failure mechanism of the shield excavation face in the sandy cobble stratum under different buried depths

open access: yesDeep Underground Science and Engineering, EarlyView.
Abstract One of the significant challenges faced in shield tunnel construction is the risk of collapse resulting from abrupt changes in soil conditions in advance of the working face, particularly within the sandy cobble stratum. This study aims to effectively manage these sudden variations and to further investigate the failure mechanisms associated ...
Hua Jiang   +4 more
wiley   +1 more source

Characteristics of stable carbon isotopic composition of shale gas

open access: yesJournal of Natural Gas Geoscience, 2016
A type Ⅱ kerogen with low thermal maturity was adopted to perform hydrocarbon generation pyrolysis experiments in a vacuum (Micro-Scale Sealed Vessel) system at the heating rates of 2 °C/h and 20 °C/h.
Zhenya Qu   +5 more
doaj   +1 more source

Disturbance in the North Island of New Zealand: A case study using floodplain cores from the Coromandel to determine anthropogenic disturbance : A thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Geography Massey University, New Zealand [PDF]

open access: yes, 2016
It is well documented that following human occupation of a region, the surrounding environment may undergo drastic changes through vegetation pattern alterations, displacement of fauna, alteration of sedimentation and fluvial regimes, and changes to the ...
Fox, Elizabeth Grace
core  

Crustal structure and rift flank uplift of the Adare Trough, Antarctica [PDF]

open access: yes, 2005
The Adare Trough, located 100 km northeast of Cape Adare, Antarctica, represents the extinct third arm of a Tertiary spreading ridge between East and West Antarctica. It is characterized by pronounced asymmetric rift flanks elevated up to over 2 km above
Ashalatha   +36 more
core   +1 more source

Effect of confining pressure on fracture characteristics and mineralogical behavior of tight sandstone specimens after hydraulic fracturing

open access: yesDeep Underground Science and Engineering, EarlyView.
Hydraulic fracturing in tight sandstone and fracture propagation characteristics using backscattered electron‐scanning electron microscope (BSE‐SEM) images. Abstract This study focuses on hydraulic fracturing experiments conducted under triaxial conditions on tight sandstone specimens from Shivpuri district, Madhya Pradesh, India.
Pankaj Rawat, Narendra Kumar Samadhiya
wiley   +1 more source

Petrology of some oceanic island basalts: PRIMELT2.XLS software for primary magma calculation [PDF]

open access: yes, 2008
PRIMELT2.XLS software is introduced for calculating primary magma composition and mantle potential temperature (TP) from an observed lava composition. It is an upgrade over a previous version in that it includes garnet peridotite melting and it detects ...
Asimow, Paul D., Herzberg, C.
core   +2 more sources

Optimization of cut‐hole layout under high in situ stress based on numerical simulation and field tests

open access: yesDeep Underground Science and Engineering, EarlyView.
This study investigates the blast‐induced rock damage patterns under different cut‐hole layouts and ground stress conditions through numerical simulations and field tests. The findings in this study provide valuable insights for similar underground engineering applications.
Junjie Zhao   +5 more
wiley   +1 more source

Sulfur partitioning between aqueous fluids and felsic melts at high pressures: Implications for sulfur migration in subduction zones

open access: yesScientific Reports
Sulfur (S), an essential volatile in subduction zone magmatism, exhibits higher solubility in aqueous fluids compared to silicate melts. Despite its importance, the partitioning of S between aqueous fluids and silicate melts under the conditions of ...
Lanqin Li   +5 more
doaj   +1 more source

Organic Matter Accumulation Mechanism in the Lower Cambrian Strata from Well Luntan 1 in the Tarim Basin, NW China

open access: yesGeofluids, 2021
A large amount of light crude oils have been found within 4000 to 7000 m deep strata of Cambrian, Ordovician, and Silurian reservoirs in the Tarim Basin, NW China.
Qian Deng   +8 more
doaj   +1 more source

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