Central Basin Area Research Articles

Comprehensive Evaluation of Ecological-Economic Value of Guangxi Based on Land Consolidation

The “Two Mountains” concept of “green water and green mountains are gold and silver mountains” plays an important value-oriented role in the ecological transformation of land consolidation. In this study, Guangxi was divided into five consolidation zones in combination with relevant policies, and the evolution characteristics and change intensity of ecological-economic values before and after the three phases of land consolidation in Guangxi and each consolidation zone in 2010, 2015 and 2020 were explored by bivariate spatial autocorrelation, standard deviation ellipse, and linear regression equation. Finally, the ecological-economic values of each consolidation area, which were obtained separately, were standardized by z-score, and the standardized results were matched by dividing quadrants for analysis. The ecological-economic value matching states of each consolidation area are ecological-economic value coordinated development type (central karst basin area of Guangxi), ecological value imbalance type (southeast plain area and coastal hilly plain area of Guangxi), economic value imbalance type (northwest mountain area of Guangxi) and ecological-economic value low imbalance type (northeast hilly mountain area of Guangxi). The study aims to provide a theoretical basis for the planning and differentiated management of land consolidation in Guangxi and promote the ecological-economic value transformation of the region.

Sedimentary, climatic, and provenance controls of mineral and chemical composition of the Ediacaran and Cambrian mudstones from the East European Craton

Mineralogical and geochemical compositions of mudstones were used for untangling provenance and climatic signals preserved in the upper Ediacaran - lower Cambrian strata from the western part of the East European Craton (ECC). Quantitative mineralogy and geochemistry data were obtained for 735 argillaceous rock samples from 71 wells and outcrops and compared with the analyses of Proterozoic palaeosols from the same area. Additionally, sedimentological analyses of well-preserved cores were performed to reconstruct predominant Ediacaran and early Cambrian environments. Seven major facies associations were distinguished and interpreted as both continental and basinal in nature. Terrestrial environments include weathering crust, alluvial fans, and associated interlobe areas, fluvial channels, floodplains, and lakes. Transitional environments are represented by tidal lithofacies, whereas central bay and upper offshore facies associations are typical of distal deposits. The central basin area is interpreted as an estuary opening toward the east, while a separate basin developed in Podillya. Provenance heavily influenced the mineralogical and geochemical characteristics of the sediments and affected derived weathering indices. The change from mafic to felsic sources in the western ECC is evident towards the Cambrian. All geochemical and newly introduced mineralogical weathering indices show advanced kaolinite-type weathering, evidence of a hot and humid climate during this interval. Based on these indices, mudstones are weathered to a greater extent than palaeosols. This observation is interpreted as resulting from the redeposition of highly weathered topsoils, combined with additional weathering on-route to the basin. Mineral authigenesis (berthierine, pyrite, goethite, fluorapatite, and carbonates) was particularly intensive in the terrestrial interlobe areas. Berthierine is common in most environments, which reflects the reaction of kaolinite with iron oxides, mediated by microorganisms, in shallow dysoxic tropical waters, with high lateritic sediment input. Marine, more oxic conditions in the Cambrian are indicated by a pervasive appearance of glauconite.

STRATIGRAPHY, TECTONICSAND MAJOR SEQUENCE BOUNDARY DEVELOPMENT IN TERTIARY SEDIMENTS OF CENTRAL SUMATRA BASIN

According to Satrio and Soejanto (1994), the CPI contract area of Central Sumatra basin has discovered more than 130 fields, and most of these fields are structural traps. The basin is a NW - SE trending elongate depression, which is bounded in the north- west by the Asahan Arc and in the southeast by the Tigapuluh High. To the West, it is bounded by the northwest – southeast trending Barisan Mountains, whereas to the northeast by the Strait of Malacca (Figure 1). The Central Sumatra Basin is based by the Pretertiary basement rocks and has been filled by Eocene up to the Plio-Pleistocene siliciclastic-dominated strata. Based on a three year consulting work for the CPI and discussion with many Earth Scientists of this company, and being supported by much information on the related data from published reports, the senior author has been able to propose scientific contribution on the stratigraphy of the basin and its relationships with tectonism and sea level changes.

Traditional Water Management Systems in the Danube Basin before the Introduction of River Regulation. An Essay on Environmental History

The Danube Basin is the most extensive part of the Central European basin area (with the Czech- and the Vienna Basins). The critical peculiarity of the geographical landscape of the basin is the significant expansion of temporarily or permanently water-covered areas. In the traditional age, the size of the water-covered regions depended to a significant degree on the climate and climate changes. The important regional peculiarity of the Danube Basin is that global changes in climate are reflected primarily not in the temperature but rather in levels of precipitation. In my short environmental history essay, I survey the history of water management in the Danube Basin from the Hungarian conquest to the beginning of modernisation in the first half of the nineteenth century. Following the conquest and settling of nomadic tribes, one of the most critical challenges was adapting the subsistence system to the environmental conditions, which was inappropriate for nomadism. From a water management viewpoint, meadow transhumance efficiently takes advantage of the ecological potential of the floodplains, and the channel network manages the problems caused by water shortage or water surplus. Water management became the responsibility of the village communities, which reduced the systemʼs efficiency in the feudal world of the late Middle Ages, but increased its historical stamina. The water-covered areas grew radically in the age of the Turkish wars. This process supported the cold and wet climate regime of the Little Ice Age and demonstrated the need for wartime defence around the forts. After centuries of the Turkish wars, a fundamental need arose to increase the cropland to support demographic growth. Therefore a crucial question of Hungarian modernisation became the regulation of waterways.

Benton Phase biface production for exchange: analysis of a lithic reduction area at site 40HO13

ABSTRACT Excavations at site 40HO13 in Houston County, Tennessee, documented three prehistoric lithic reduction areas associated with a Benton Phase occupation. The site was located in an area of abundant chert resources, notably Fort Payne chert. The paper focuses on lithic data from one of the lithic concentrations. The analysis determined that the lithic concentrations were the result of biface manufacture. Bifaces were roughed out at the source location. Knapping on site reduced these bifaces to late-stage bifaces. A large number of bifaces (1,453 estimated) were produced within the one concentration. It is argued that these bifaces were not used on site but were transported to other locations for further reduction and use and represent items manufactured for the purpose of exchange. It is suggested that these bifaces may have been exchanged with groups inhabiting the Central Basin area of Tennessee.

Leaky salt: Pipe trails record the history of cross‐evaporite fluid escape in the northern Levant Basin, Eastern Mediterranean

AbstractDespite salt being regarded as an extremely efficient, low‐permeability hydraulic seal, an increasing number of cross‐evaporite fluid escape features have been documented in salt‐bearing sedimentary basins. Because of this, it is clear that our understanding of how thick salt deposits impact fluid flow in sedimentary basins is incomplete. We here examine the causes and evolution of cross‐evaporite fluid escape in the northern Levant Basin, Eastern Mediterranean. High‐quality 3D seismic data offshore Lebanon image hundreds of supra‐salt fluid escape pipes distributed widely along the margin. The pipes consistently originate at the crest of prominent sub‐salt anticlines, where overlying salt is relatively thin. The fact the pipes crosscut the salt suggests that hydrofracturing occurred, permitting focused fluid flow. Sequential pipes from unique emission points are organized along trails that are several kilometres long, and which are progressively deformed due to basinward gravity gliding of salt and its overburden. Correlation of pipes in 12 trails suggests margin‐wide fluid escape started in the Late Pliocene/Early Pleistocene, coincident with a major phase of uplift of the Levant margin. We interpret that the consequent transfer of overpressure from the central basin area, in addition to gas exsolution from hydrocarbons already trapped in sub‐salt anticlines, triggered seal failure and cross‐evaporite fluid flow. We infer that other causes of fluid escape in the Eastern Mediterranean, such as subsurface pressure changes driven by sea‐level variations and salt deposition associated with the Messinian Salinity Crisis, played only a minor role in triggering cross‐evaporite fluid flow in the northern Levant Basin. Further phases of fluid escape are unique to each anticline and cannot be easily correlated across the margin. Therefore, despite a common initial cause, long‐term fluid escape proceeded according to structure‐specific characteristics, such as local dynamics of fluid migration and anticline geometry. Our work shows that the mechanisms triggering cross‐evaporite fluid flow in salt basins vary in time and space.

Implementation 3D Inversion of Gravity Data to Identify Potential Hydrocarbon Reservoir Zones in West Timor Basin

A gravity survey has been carried out in the area of West Timor, East Nusa Tenggara to identify the existence of basin structures. The existence of reservoirs and trap structures are two important parameters in hydrocarbon exploration. Geologically, Timor possibly an area known to have a very complex geological structure. This complexity can be the main factor that causes the demotivation of geologists in exploring hydrocarbons. There are many indications of hydrocarbons in the form of oil and gas seeps on the surface, especially in East Timor. But most of them are not confirmed in the field, and only a few are even found in West Timor. The method used in this study is analyzing and 3D inversion modeling gravity data. The analysis was carried out using spectrum analysis and the second vertical derivative of the complete Bouguer anomaly (CBA). From the gravity parameters confirmed by geological data, the results indicate that in the study area there are basin and basement structures thought to be formed from unconformably of andesite igneous rock and tight send sediment with a density value of about 2.5 gr/cm3 . The average basement depth is about 5.5 km with its forming structure is the reverse/thrust fault with Northeast to Southwest its strike orientation. While in the southern part, especially in the central basin area, there is indicated a layer of sand sediment that is quite thick with a density value of about 2.2 gr/cm3 and has the potential to become a hydrocarbon reservoir.

Cropping system optimization for drought prevention and disaster reduction with a risk assessment model in Sichuan Province

It is very important that making full use of the regional precipitation resources, evaluating the comprehensive risks overall and choosing drought-resisting and disaster-avoiding cropping system reasonably. Based on the meteorological data from 1961 to 2017 and crop growth period data from 1981 to 2017 in Sichuan Province, Sichuan Province was divided into seven agro-ecological zones and one non-agricultural zone according to their interregional differences and regional similarities in aspects of nature, social economy and current agricultural infrastructures. Besides, the representative station and cropping system in each region were selected. This paper evaluated the current cropping systems and cropping patterns in different agro-ecological zones of Sichuan Province by calculating the ensure index of precipitation, the yield variation coefficient, the ratio of sown area to cultivated area and the disaster resistance capability coefficient of agricultural planting areas in Sichuan Province under the background of droughts. Moreover, taking representative stations as an example, the evaluation index of cropping system optimization was put forward based on four factors, namely risk, vulnerability, exposure and the capacity of drought prevention and disaster reduction, from the perspective of the natural disaster formation mechanism. Then, a risk assessment model was established to evaluate the cropping system optimization in different agro-ecological zones of Sichuan Province. The results showed that winter wheat-maize-sweet potato (soybean) triple cropping pattern in upland is the best cropping system for the wide valley area of Southwest Sichuan (such as Panzhihua), the mountain area of Southwest Sichuan (such as Xichang), the basin-edged mountain area (such as Guangyuan) and the parallel ridge-valley area of eastern basin (such as Dazhou). Winter wheat (rape)-maize-soybean triple cropping pattern in upland is the best cropping system for the hilly area in southern basin (such as Yibin). Winter wheat (rape)-maize-soybean (sweet potato) triple cropping pattern in upland is the best cropping system for the summer-drought-prone hilly area of central basin (such as Suining). Paddy potato-upland rice rotation double cropping pattern is optimal for the Chengdu Plain under the moist climate.

Influences of microtidal regime and eutrophication on estuarine zooplankton

This study describes the ecology of mesozooplankton in the shallows of the large central basin area of the Swan-Canning Estuary on the microtidal lower west coast of Australia during the mid-1980s when, as in most other south-western Australian estuaries, it was mesotrophic. As the vast majority of species reproduce within the estuary and there is a lack of a net upstream flow of bottom water during each tidal cycle to facilitate selective tidal transport, the populations of those species are considered autochthonous. Species restricted to the estuary accounted for 63% of the total number of species and 83% of abundance. Contributions by tychoplankton to total number of species (68%) and individuals (59%) exceeded the corresponding values of 18 and 39% for holoplankton and 14 and 2% for meroplankton. Low meroplankton values result from a paucity of benthic macroinvertebrate species with planktotrophic development. Comparisons with data for the shallow basin areas of the nearby highly eutrophic Peel-Harvey Estuary were used to indicate how mesozooplankton in the microtidal estuaries respond to excessive nutrient enrichment. The mean number of species in the Swan-Canning was essentially the same as in the Peel-Harvey, whereas concentrations were only half, reflecting the lower productivity of the former estuary. However, concentrations of the four most abundant species in the Swan-Canning, the amphipod Grandidierella propendatata, the calanoids Gladioferens imparipes and Acartia cf. clausi and a harpacticoid species, exceeded those of these species in the Peel-Harvey by between 1.6 and 11.7 times. Greater concentrations in the Swan-Canning were attributable to this mesotrophic system not undergoing the reduction in oxygen concentrations and/or environmental degradation, to which these species are susceptible. In contrast, concentrations of the amphipods Corophium minor and Tethygenia elanora and large nematodes, which are tolerant of degraded environmental conditions, were greater in the Peel-Harvey. Holoplankton made a far greater contribution in the Swan-Canning than Peel-Harvey, due to substantial numbers of copepods that benefit from good environmental conditions. Mesozooplankton composition in both estuaries underwent cyclical changes during the year due to time-staggered differences in seasonal concentrations of various species. Cyclical changes and variations in composition were more closely related to measured environmental variables in the Swan-Canning than Peel-Harvey estuaries. The concentrations of many species were greater at night than during the day presumably reflecting a nycthemeral response and/or low nocturnal oxygen concentrations at the bottom of the water column.

Technogenic radioactivity of waters in the Central Arctic Basin and adjacent water area

The contemporary radiation situation in the Arctic Basin and Russian Arctic seas is assessed on the basis of data from 2013 to 2017. Statistically significant differences are revealed in the mean volumetric activity of 137Cs in the surface water layer. The tendency toward a west-to-east decrease in seawater pollution is noted. The maximum 137Cs concentrations are characteristic of the Barents and Kara seas. The least polluted waters are reported in the Laptev and East Siberian seas, which are the most remote from the sources of technogenic radionuclides in Europe.

Profile and Economic Impacts of Agriculture and Natural Resource Industries in the South Region of Florida

This report provides a profile of agriculture and natural resource industries and an overview of their economic impacts for a ten county region in southern Florida (Figure 1). Additional reports provide similar information for the central, northeast, northwest, and Suwannee River basin areas of the state. The report is based on data from the IMPLANPro database for Florida counties for 2002 and data from the 2002 Census of Agriculture.

Profile and Economic Impacts of Agriculture and Natural Resource Industries in the Northwest Region of Florida

This report provides a profile of agriculture and natural resource industries and an overview of their economic impacts for a 16-county region in northwest Florida (Figure 1). Additional reports provide similar information for the central, northeast, south, and Suwannee River Basin areas of the state. The report is based on data from the IMPLAN Pro database for Florida counties for 2002 and data from the 2002 Census of Agriculture.

Profile and Economic Impacts of Agriculture and Natural Resource Industries in the Northeast Region of Florida

This report provides a profile of agriculture and natural resource industries and an overview of their economic impacts for a 21-county region in northeastern Florida (Figure 1). Additional reports provide similar information for the central, northwest, south, and Suwannee River Basin areas of the state. The report is based on data from the IMPLANPro database for Florida counties for 2002 and data from the 2002 Census of Agriculture.

Technogenic Radioactivity of Waters in the Central Arctic Basin and Adjacent Water Areas

Technogenic Radioactivity of Waters in the Central Arctic Basin and Adjacent Water Areas

Seasonal variability of phytoplankton in river Słupia of the southern Baltic Sea

In the Baltic Sea, there can be observed seasonal variations in the structure of phytoplankton. These organisms are particularly sensitive to changes in different environmental parameters. The consequence of these changes is cyclical repeated every year fluctuation of the species composition, their abundance and biomass of phytoplankton. The spatial and temporal variability of individual phytoplankton groups is not the same in different regions of the Baltic Sea, and this is why the study was conducted in the area of the central Baltic coast, since in that particular region data on phytoplankton is not available. One of the main goals was to determine the temporal and spatial structure of the occurrence of phytoplankton, as well as to study biodiversity in the area of the estuary of the Slupia river in southern Baltic for the period between November 2014 and September 2016. The results of the research confirm typical changes of phytoplankton in three studied areas depending on the given season. The average values of phytoplankton abundance and biomass were typical for this kind of coastal waters and there were no significant species differences between these stations. The only research (and available studies) on phytoplankton in central sea basin areas is being conducted by Institute of Meteorology and Water Management (IMWM) as part of the HELCOM Baltic Sea Monitoring at station P16, which is the closest location to the studied area. When comparing the results obtained in this study to the data from the IMWM annual reports for the last decade, it can be noticed that the size and fluctuations of total biomass and phytoplankton abundance in the three studied areas are typical for the coastal region of the South Baltic.

Detailed crustal thickness variations beneath the Illinois Basin area: Implications for crustal evolution of the midcontinent

AbstractWe present high‐resolution imaging results of crustal and upper mantle velocity discontinuities across the Illinois Basin area using both common conversion point stacking and plane wave migration methods applied to P wave receiver functions from the EarthScope Ozark, Illinois, Indiana, and Kentucky experiment. The images reveal unusually thick crust (up to 62 km) throughout the central and southeastern Illinois Basin area. A significant Moho gradient underlies the NW trending Ste. Genevieve Fault Zone, which delineates the boundary between the Illinois Basin and Ozark Dome. Relatively thinner crust (<45 km) underlies most of the Precambrian highlands surrounding the Illinois Basin and beneath the rift‐related structures of the Reelfoot Rift and the Rough Creek Graben. We consider four hypotheses to explain the presence of thick crust under the central and southeastern Illinois Basin. Crustal thickening may have been produced (1) prior to its accretion to North America around 1.55 Ga and is an inherited characteristic of this crustal province; (2) by underthrusting or shortening during Proterozoic convergent margin tectonics around 1.55–1.35 Ga; (3) by Late Precambrian magmatic underplating at the base of older crust, associated with the creation of the Eastern Granite‐Rhyolite Province around 1.3 Ga; and (4) through crustal “relamination” during an episode of Proterozoic flat‐slab subduction beneath the Illinois Basin, possibly associated with the Grenville Orogeny.

Two-dimensional basement modeling of central loop transient electromagnetic data from the central Azraq basin area, Jordan

Thick sedimentary sequences are deposited in the central area of the Azraq basin in Jordan consisting mostly of hyper-saline clay and various evaporates. These sediment successions form the 10km×10km large Azraq mudflat and are promising archives for a palaeoclimatical reconstruction. Besides palaeoclimatical research, the Azraq area is of tremendous importance to Jordan due to groundwater and mineral resources. The heavy exploitation of groundwater has lead to a drastic decline of the water table and drying out of the former Azraq Oasis. Two 7 and 5km long transects were investigated from the periphery of the mudflat across its center using a total of 150 central loop transient electromagnetic (TEM) soundings. The scope of the survey was to detect the thickness of sedimentary deposits along both transects and to provide a basis for future drilling activities. We derive a two-dimensional model which can explain the TEM data for all soundings along each profile simultaneously. Previously uncertain depths of geological boundaries were determined along both transects. Particularly the thickness of the deposited mudflat sediments was identified and ranges from 40m towards the periphery down to approximately 130m at the deepest location. Besides that, the depth and lateral extent of a buried basalt layer was identified. In the basin center the groundwater is hyper-saline. The lateral extent of the saline water body was determined precisely along both transects. In order to investigate the detectability of the basement below the high conductive mudflat sediments an elaborate two-dimensional modeling study was performed. Both, the resistivity and depth of the basement were varied systematically. The basement resistivity cannot be determined precisely in most zones and may range roughly between 1 and 100Ωm without deteriorating the misfit. In contrast to that, the depth down to the basement is detected accurately in most zones and along both transects. Varying the depth of the basement or removing it completely results in a poor data fitting and, therefore, proves its significance. From the modeling study we derived bounds for the resistivity and depth of the base layer as a measure of their uncertainty.

Characteristics of pollen in surface sediments from the southern South China Sea and its paleoclimatic significance

We investigated pollen distributions in surface sediments of the southern South China Sea (SCS) and their relation to seabed topography and the environment of the terrigenous sources. In this study, we analyzed 62 surface sediment samples collected from the SCS through modern pollen analysis methods. The results of our study can be summarized as follows. (1) trilete spores dominate the pollen and spore spectrum, which reflects the dominance of ferns in the Nansha Island vegetation. Similar pollen characteristics were found for different periods of high sea level and global warming after 12Ma in ODP site 1143 and site 18287 in the southern South China Sea. Most pollen and spores on the Kalimantan Island coast are produced by herbaceous plants and trees, while few trilete spores produced by ferns are present. Furthermore, similar pollen characteristics were found for different periods of low sea level and global cooling in ODP site 1143 and site 18287. (2) Through an analysis of pollen samples from a transect line extending from the northwest to the southeast, the complex terrain of the Nansha Islands was observed to be unsuitable for pollen migration through ocean currents. Pollen counts in samples collected near the southern Nansha Islands decreased gradually from the east and west continental shelf areas to the central basin area. However, the same analysis confirmed that the Nansha Trough facilitates the entry, dispersal, and storage of pollen from external sources. (3) Principal component analysis (PCA) of samples collected from two different water depths in the southern SCS demonstrates that trilete spores and monolete spores in 4 samples near the Mekong River with water depths of <200m are transported primarily by river flow. Conversely, pollen and spores mainly transported by rivers near Kalimantan Island were found at water depths of >200m. However, analysis of samples from the northern SCS in a previous study obtained different results.

Effects of ridge-cultivation and plastic film mulching on root distribution and yield of spring maize in hilly area of central Sichuan basin, China.

A field experiment was conducted to study the effects of planting pattern (ridge culture, flatten culture, furrow culture) and film mulching on the distribution of spring maize root system and their influence on the yield of spring maize in the hilly area of central Sichuan basin. The results showed that ridge and film mulching had great influence on root morphology and root distribution of maize. The root length, root surface area and root volume of film mulching was 42.3%, 50.0%, 57.4% higher than those of no film mulching at jointing stage. The film mulching significantly increased the dry mass of root in vertical and horizontal distribution, and increased the root allocation ratio in deeper soil layer (20-40 cm) and the allocation ratio of wide row (0-20 cm) in horizontal direction. The effects of planting pattern on root growth and root distribution differed by film mulching. With film mulching, the ridge culture significantly increased the root dry mass in each soil layer and enlarged the distribution percentage of wide row (20-40 cm) in horizontal direction, as well as the dry mass of root in horizontal distribution and the root allocation ratio of wide row. The root mass under film mulching was in the order of ridge culture>flatten culture>furrow culture. Without film mulching, the furrow culture significantly increased root dry mass of narrow row (0-40 cm), and the root mass under no film mulching was in the order of furrow culture > ridge culture >flatten culture. As for the spike characteristics and maize yield, the filming mulching mea-sures reduced the corn bald length while increased the spike length, grain number, 1000-grain mass and yield. The yield under film mulching was in the order of ridge culture>flatten culture> furrow culture, while it was furrow culture > flatten culture > ridge culture under no film mulching. The reason for yield increase under ridge culture with film mulching was that it increased root weight especially in deep soil, and promoted the root allocation ratio in deeper soil and wide row (20-40 cm) in horizontal direction. The ridge-furrow culture without film mulching was helpful to root growth and increased the maize yield.

An integrated geophysical imaging of the upper-crustal features in the Harney Basin, southeast Oregon

The Harney Basin is a relatively flat-lying depression in the northeast corner of the enigmatic High Lava Plains volcanic province in eastern Oregon. A thick blanket of volcanics including flood basalts, rhyolites, tuffs, ash flows, and distinct eruptive centers covers the basin, making it very difficult to study the upper-crustal features. In addition to a portion of the High Lava Plains active source seismic data in the Harney Basin area, we employed geologic, gravity, magnetic, digital elevation, and other geospatial data in our integrated study. We generated an upper-crustal 3D seismic tomographic model of the Harney Basin using a sparse grid of 2D seismic lines and constructed an integrated geophysical model of the upper-crustal structure, which reveals that the basin reaches as deep as 6 km in its central area. The tomographic inversion also detected some unusually high-velocity (>6.5 km/s) bodies in the upper crust near the central basin area. The presence of several ash-flow tuffs and voluminous rhyolites in the Harney Basin region indicates that the sources of these materials are nearby. We observe two major caldera-shaped features within the basin, which we interpret to be likely candidates for the source of some of these tuffs. These potential calderas are associated with low seismic velocities, low gravity anomaly values, and topographic depressions. We interpret the extent and evolution of these potential calderas based on our integrated analysis.