Micromorphology of Solonetzic Horizons as Related to Environmental Events in the Caspian Lowland

来源 :Journal of Mountain Science | 被引量 : 0次 | 上传用户:huwei00
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Micromorphology of solonetz species with special attention to natric horizon was studied in microcatenas at the Dzhanybek Research Station (northwestern Caspian Lowland). The solonetzic (natric) horizon is easily identified, and it occurs at varying depths, which are the criteria for subdividing solonetzes into 4 species, namely, crusty, shallow, medium and deep. In this sequence, the depth of humus-accumulative horizons increases, and the upper boundary of salinity manifestations goes down. The following micromorphological features are assumed as typical for natric horizons: angular blocky microstructures with partially accommodated aggregates having sharp boundaries and narrow plane-like packing voids; b-fabric speckled in the aggregates’ centers and monostriated at their peripheries merging into stress coatings; very few interpedal voids; organo-clay coatings; humusenriched infillings; no calcite and gypsum pedofeatures. A complete set of “natric” features was found only in the crusty solonetz; the shallow solonetz lacks only illuviation coatings, while the medium and deep species have several modifications of fabric elements: blocky aggregates have a rounded shape and are penetrated by biogenic channels favoring their further biogenic reworking; plant residues became more abundant and diverse, and blackened tissues occur; illuviation clay coatings evolved into papules; stress coatings gave birth to striated b- fabrics, thus maintaining a high plasma orientation. The thin sections of natric horizons made 50 and 20 years ago were examined to study the influence of environmental changes (increase in precipitation and rise of ground water table) on micropedofeatures. The following processes took place: (i) in the topsoil: humus accumulation and biogenic structurization; (ii) in the natric horizon-re-arrangement of clay coatings into micromass b-fabrics; and (iii) in the lower part of the natric horizon-development of pseudosand fabric, calcite and gypsum formation. The trends revealed are in good agreement with the environmental events. Micromorphology of solonetz species with special attention to natric horizon was studied in microcatenas at the Dzhanybek Research Station (northwestern Caspian Lowland). The solonetzic (natric) horizon is easily identified, and it occurs at varying depths, which are the criteria for subdividing solonetzes into 4 species, namely, crusty, shallow, medium and deep. In this sequence, the depth of humus-accumulative horizons increases, and the upper boundary of salinity manifestations goes down. The following micromorphological features are assumed as typical for natric horizons: angular blocky microstructures with partially accommodating aggregates having sharp boundaries and narrow plane-like packing voids; b-fabric speckled in the aggregates’ centers and monostriated at their peripheries merging into stress coatings; very few interpedal voids; organo-clay coatings; humusenriched infillings; no calcite and gypsum pedofeatures. A complete set of “natric ” features was found only in the cr the shallow solonetz lacks only illuviation coatings, while the medium and deep species have several modifications of fabric elements: blocky aggregates have a rounded shape and are penetrated by biogenic channels favoring their further biogenic reworking; plant residues became more abundant and diverse, and thin films of natrual horizons made 50 and 20 years ago were examined to study the influence of environmental changes (increase in precipitation and rise of ground water table) on micropedofeatures. The following processes took place: (i) in the topsoil: humus accumulation and biogenic structurization; (ii) in the natric horizon-re-arrangement of clay coatings into micromass b -fabrics; and (iii) in the lower part of the natric horizon-development of pseudosand fabric, calcite and gypsum formationThe trends revealed are in good agreement with the environmental events.
其他文献
目的对于舒适护理在门诊静脉采血过程的应用效果进行分析探讨。方法选择2014年9月至2015年9月于我院进行静脉采血的100例患者作为研究对象。将患者随机分成对照组和实验组,实
目前,广州市商业企业推行承包经营责任制已经取得喜人的进展。截至1987年年底为止,广州市商业企业除小型企业实行租赁承包经营和个别大中型企业未具备承包条件(如华侨公司借
多路巨头都把目光对准了RFID,一场争夺控制权的大战正在上演中国的RFID市场正在稳步升温。从8月初举行的2006年微软RFID大中华区RFID合作伙伴峰会上,你可以看出一些端倪。微
蒙城一中始建于1933年,1978年学校被命名为阜阳地区重点中学,1999年被省教委批准为安徽省首批示范高中。学校现有168个教学班,在校学生11000多人,在职教职工近600人,其中“正
一条小盲蛇被人当作毒蛇打死了,扔在了木材堆里。  一只小蚂蚁先发现了小盲蛇的尸体,就在路上排泄出分泌物。其他的蚂蚁嗅到之后就会来寻找。  当大群的蚂蚁沿着气味遇到小蚂蚁的时候,领头的蚂蚁与小蚂蚁用头上的触角相互碰了碰,领头的蚂蚁就接收到了信息,知道前方有美食了。于是,迅速带领大群的蚂蚁向小盲蛇的尸体奔来。  木材堆附近的小盲蛇被打死的消息传到了白蚁那里,白蚁窝发出一阵阵欢呼声。白蚁头领说:“咱们的
案情:这日,越国国王勾践与西楚霸王项羽在天国相遇。他们看到了一艘满身伤痕的破船,勾践认为这艘船饱经磨难却能坚持到最后,是世人学习的楷模;而项羽认为这艘船已经破损不堪,
2014年5月1日,新《商标法》正式实施。为确保新旧商标法有序衔接,最高人民法院制定发布了《最高人民法院关于商标法修改决定施行后商标案件管辖和法律适用问题的解释》,规定
我家门前有一棵核桃树,是我和爸爸一起种下的。现在,核桃树已经有8岁了,长得又壮又高。我很喜欢核桃树,经常在树下做游戏。  春天,核桃树长出嫩绿的小芽,树枝上开满了许多小花。风一吹,花瓣飘落在地上,像一条条毛茸茸的小虫子。我第一次看到这些“小虫子”时,被它们吓坏了。现在,一到春天,我就盼望着这些毛茸茸的“小虫子”早些出现。  炎热的夏天过去,秋天来临时,核桃成熟了。一个个绿中带黄的核桃挂在树上,像一
创意是思维的碰撞、智慧的对接、意境的传递。只要多开发你的创造性思维,你便能发掘它,利用它。 Creativity is the collision of thinking, the docking of wisdom, the tr
《英语课程标准》在评价建议中指出,评价是英语课程的重要组成部分,是实现课程目标的重要保障。通过评价,学生在英语课程学习过程中不断体验进步与成功,认识自我,建立自信,促