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231.
A constitutive model for mechanical and chemo‐mechanical compaction in sedimentary basins and finite element analysis
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Compaction and associated fluid flow are fundamental processes in sedimentary basin deformation. Purely mechanical compaction originates mainly from pore fluid expulsion and rearrangement of solid particles during burial, while chemo‐mechanical compaction results from Intergranular Pressure‐Solution (IPS) and represents a major mechanism of deformation in sedimentary basins during diagenesis. The aim of the present contribution is to provide a comprehensive 3D framework for constitutive and numerical modeling of purely mechanical and chemo‐mechanical compaction in sedimentary basins. Extending the concepts that have been previously proposed for the modeling of purely mechanical compaction in finite poroplasticity, deformation by IPS is addressed herein by means of additional viscoplastic terms in the state equations of the porous material. The finite element model integrates the poroplastic and poroviscoplastic components of deformation at large strains. The corresponding implementation allows for numerical simulation of sediments accretion/erosion periods by progressive activation/deactivation of the gravity forces within a fictitious closed material system. Validation of the numerical approach is assessed by means of comparison with closed‐form solutions derived in the context of a simplified compaction model. The last part of the paper presents the results of numerical basin simulation performed in one dimensional setting, demonstrating the ability of the modeling to capture the main features in elastoplastic and viscoplastic compaction. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
232.
M. K. Fuller Y. Bone V. A. Gostin C. C. Von Der Borch 《Australian Journal of Earth Sciences》2013,60(4):353-363
Holocene sediments from southern Spencer Gulf are cool‐water carbonate‐rich gravels and sands, dominated by molluscs and Bryozoa. Five sedimentary fades are recognized: (i) molluscan gravel; (ii) branching coralline‐algal gravel, associated with shallow partially protected environments; (iii) molluscan‐biyozoan sand; (iv) mixed bioclastic sand, representative of the deeper central region of the lower gulf; and (v) bryozoan gravel, an isolated fades developed in a semi‐protected micro‐environment. The southern gulf is characterized by complex oceanographic conditions together with variations in water depth and substrate. The sediments share the characteristics of both the southern shelf and upper Spencer Gulf. Grain‐size distribution and sedimentary facies are controlled by a combination of all the above processes. Past sea level fluctuations are recognized from sea floor strand‐line deposits. The relic component of the palimpsest sediments has eroded from the Pleistocene aeolianite dunes. The sediments, therefore, reflect both the modern marine and past environments. 相似文献
233.
应用粒度分析辨别某些第四纪混杂堆积成因初探 总被引:5,自引:0,他引:5
本文从粒度特征分析了青海昆仑山垭口地区的第四纪混杂堆积和甘肃武都泥石流堆积以及贡嘎山海洋性冰川的现代冰碛之间的差异性,明显看出,由于各种第四纪混杂堆积的搬运介质、搬运过程及沉积过程不同,第四纪混杂堆积的粒度特征存在明显的不同。沉积物的粒度特征反映了沉积环境。因此,用粒度特征来辨别各种第四纪混杂堆积也是一种行之有效的方法。 相似文献
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云南白显锰矿产于中三叠统法郎组地层中,其主要矿石矿物是钡镁锰矿。矿物属沉积成因,结晶细微,局部呈沿c轴延长的细小柱状和纤维状。矿物点群2/m,常见单形:斜方柱{110}、平行双面{100}和{001}。晶胞参数:a_0=0.9758nm,b_0=0.2848nm,c_0=0.9640nm,β=88.98°,V=0.26786nm~3,Z=1。矿物反射率为18.60~25.65,相对密度3.67,文中还列出了红外光谱和差热分析新资料。 相似文献
236.
The C and H isotopic compositions of the methane in more than 160 gas samples from 10 basins in China are presented in this paper.The natural gases are classified as four types: biogenic gas ,bio-thermocatalytic transitional gas, gas associated with condensate oil ,and coal-type gas. The isotopic compositions of these gases closely related to the depositional basins, the types of organic matter,the stages of thermal evolution and the genetic characteristics of different gas reservoirs.Studies of the C and H isotopic compositions of terrigenous natural gases will provide valua-ble information on the prospecting and development of natural gases of different genetic types. 相似文献
237.
本文详细研究了福建省早二叠世童子岩期含煤岩系中风暴沉积的分布层位及沉积相序特征,在此基础上,对童子岩组风暴沉积的古地理环境进行了初步探讨。 相似文献
238.
华南变质基底的组成、边界与构造演化(研究综述) 总被引:5,自引:0,他引:5
本文据作者调查并综合有关资料,就华南变质基底的组成结构、边界性质、构造型式及演化过程作了较全面阐述;就板溪群是否为构造混杂岩,及其所代表的地质体性质作了深入分析和讨论,作者认为:华南可能存在晚太古-早元古统一变质基底,中元古末至印支期为板块活动期,印支期后,由于受太平洋板块作用影响而进入新的构造活动期。 相似文献
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