Multiple Glaciation of the Upper Franklin Valley,Western Tasmania Wilderness World Heritage Area

Part of an extensive ice cap that developed in the Tasmanian Central Highlands during the late Cainozoic discharged southwards into the valley of the Franklin River and its upper tributaries where it merged with smaller glaciers that accumulated behind local snowfences. Glacial landforms and sediments in the now heavily forested valleys indicate that at least three and possibly as many as six glaciations took place. The earliest and most extensive glaciation occurred during the Pliocene or earliest Pleistocene. At this time ice extended at least 27km down the Franklin Valley and covered at least 326km² of the study area. This ice was confluent with glaciers in the West Coast Range to the west and in the Derwent Valley to the east Such confluence offers the possibility of better correlation of glacial events between western Tasmania and the Central Highlands. The smallest and most recent glaciation occurred during the late Last Glacial Stage when the Franklin Glacier did not exceed 12km in length. The glaciers were characterised by high rates of mass throughput and were of temperate maritime type.     

Glacial Stratigraphy of the Upper Mersey Valley,Tasmania

The upper Mersey Valley was glaciated on three occasions during the Pleistocene. The youngest, Rowallan Claciation, probably commenced after 28000 years B.P. The maximum ice limit was attained before 13500 years B.P., and retreat occurred before 10000years B.P. Deposits associated with Rowallan Glaciation are weakly weathered chemically. They overlie moderately weathered deposits that were formed during the Arm Glaciation, which is inferred from relative dating data to have occurred before the Last Interglacial Stage. North of the deposits and ice limits of the Arm Glaciation extremely weathered tills and rhythmites occur. They were formed by ice of the Croesus Glaciation which is inferred to be of Early Pleistocene age or older.     

Reconstruction of the Bulgobac Glacial System,Pieman River Basin,Western Tasmania

During the Early Pleistocene Bulgobac Glaciation, a piedmont glacial system extended into the valleys west of the West Coast Range of Tasmania. The ice that fed this extensive system originated mainly to the south and east on the western Central Highlands and northern Tyndall Mountains. The palaeo-equilibrium line lay to the east of the West Coast Range. Reconstruction of the palaeoglacial system indicates that ice-surface gradients reached only ~10–15 m km^-1 over much of the system to the west of the equilibrium line, although the ice fronts were steep and rapidly ablating. The nature of the piedmont glacier is consistent with the build up of ice behind the topographic barrier of the West Coast Range. This would have resulted in ice thickening, maintained and perhaps accentuated by high precipitation as well as by the location of the equilibrium line well to the west of the western Central Highlands.     

Recent Hydrological Changes in the Avoca River Catchment,Victoria

Since the early 1970s the Avoca River catchment has experienced a marked increase in all discharges, particularly high magnitude ones. This results from a change in the rainfall/runoff relationship, which is probably due to rising groundwater tables. Since 1973 the frequency of flooding in the lower Avoca, Loddon and Avon-Richardson catchments has increased markedly, placing pressure on downstream flood mitigation and irrigation works, as well as contributing to the degradation of environmentally sensitive wetlands. It also has the potential to exacerbate rising groundwater/salinity problems of the lower catchments. Human interference and changes in the rainfall regime are assessed to explain the nature of the apparent change in streamflows of the Avoca River catchment.     

Upper Ordovician Phacopida (Trilobita) from Tasmania

Eastonian trilobite faunas of the Gordon Group in Tasmania include the new species Ceraurinella oepiki, Erratencrinurus trippi, and Pliomerina trisulcata, as well as a reedocalymeninid probably allied to Sarrabesia Hammann & Leone, 1997. Ceraurinella and Erratencrinurus have not previously been reported from Australia, the former being predominantly Laurentian but also known from NE China, the Himalaya, and Vietnam, and the latter mostly Baltic/Laurentian. Peri-Gondwanan species of Ceraurinella appear to form a clade, within which Tasmanian and Indian (central Himalayan) taxa are closest relatives.     

Tin Mining and Sediment Supply to the Ringarooma River,Tasmania, 1875–1979

Tin mining, based largely on alluvial tin deposited along the line of the ancestral Ringarooma, began in 1875 and reached a peak in the period 1905-9. Output declined thereafter and, following a brief recovery during the Second World War, had virtually ceased by 1981. Neither the methods, location nor level of production remained constant during the mining era. The widespread use of hydraulic sluicing and the proximity of many mines to the main river were major factors contributing to the high rate of sediment supply, with the Briseis mine at Derby being the dominant source. Based on data from published and unpublished papers, and mine records, the variable nature of that supply was estimated using a procedure which takes account of the effects of storage and changing practices. Many input points supplied material but the overall pattern is one in which downstream reaches made later starts and reached later peaks, suggesting that they will continue to experience the effects of an increased sediment load for some time.     

Estimates of Historical Tree Densities in the North Lachlan River Catchment,New South Wales,Australia

Vegetation structure and composition during the pre‐ and early‐European period in Australia is often proposed as a benchmark against which to measure the effects of modern landscape management practices. However, little quantifiable information exists for that historical period. One potential source of information is the land survey record, used in this study to provide estimates of tree densities that existed during the period 1870 to 1900 in part of central New South Wales. Estimates were obtained for 23 parishes in the north Lachlan River valley, between the towns of Condobolin and Tottenham. Densities were calculated from portion corner to nearest tree data obtained from historical survey plans, using the plotless, closest individual method. Densities ranged from 6.0 to 31.4 trees per hectare for parishes with enough data points for reliable calculation. These figures would account for trees of a diameter large enough to be blazed with a survey mark. Any smaller trees would be additional and, although no quantitative data existed for this, qualitative evidence suggested that the figures obtained were more likely to be underestimates due to the presence of such small trees. The study area was predominantly covered by woodlands which varied in density across the landscape, in comparison to the modern landscape where much of the native vegetation has been cleared for agriculture. Although the tree density figures should be considered to be indicative rather than precise, they provide quantifiable historical figures for past conditions in an area where the historical record is otherwise sparse. Such information is valuable for interpreting ecological changes brought about by modern land management.     

长江三峡大宁河流域的环境考古学研究

本文利用出土的考古材料及目前所见的大宁河流域环境考古研究成果,在具体分析大宁河流域人类活动与自然环境之间相互关系的基础上得出结论：大宁河流域独特的自然地理环境及其变迁使得当地各个时期的人类主要是在沿河两岸优越的自然条件中生存和发展,人类在利用环境的过程中创造并发展了各个阶段灿烂的文化,同时也在不断地影响和改造着周围的环境,周围环境的改变不可避免地又反过来影响着人类活动及其创造的文化。     

渠江流域古遗址调查简报

四川省文物考古研究院联合地市各县文管部门对渠江流域的地下文物遗存进行了调查。在渠江支流通江流域发现先秦时期遗址6处,采集到石器、陶器等遗存;在州河流域发现先秦时期遗址和石器采集点12处;在渠县境内发现3处先秦时代遗址。上述遗址与通江擂鼓寨、月亮岩及重庆江津王爷庙、峡江地区的新石器时代遗址均有一定联系,反映出了当地古代居民具有一定流动性或频繁迁徙,可能与其经济生活类型有关。     

黑龙江省穆棱河上游考古调查简报

20世纪80年代之后,穆棱河上游地区(主要是现穆棱市域)已发现120余处各时代遗址、遗迹,本文介绍的16处遗址,2处年代为新石器时代晚期,14处属青铜时代文化遗存.从发现的遗物看,应该是山地原始农业文化遗存.     

A River Runs Through It: Morphological and Landowner Sensitivities Along the Upper Missouri River, Montana, USA

Landowners along the Missouri River in Montana believe that the operation of Fort Peck Dam has initiated bank erosion, thus threatening agricultural development within the region. Their concerns have been heightened by proposals to increase discharge in order to enhance fisheries and wildlife interests. Geomorphological evaluation indicates that bed degradation and bank erosion have declined since construction of the dam, and the channel is now approaching dynamic equilibrium; public sensitivity to the proposed change is greater than the morphological sensitivity of the river. Sustainable management of the Missouri is now based on strategies that place more emphasis on partnership with local citizens.     

Integrating Geomorphological Assessments and Oral Histories in Catchment Management: Implications for the Mulgrave River,Northeastern Australia

The dramatic decline in the integrity of Australian river systems in recent decades has seen the development of landcare and catchment management groups across the continent as the main facilitators of river rehabilitation works. There is growing concern for the need to develop adaptive management frameworks that assist informed decision making through the integration of social and geomorphological knowledge into catchment planning. In the Mulgrave River Catchment of northeastern Queensland, difficult management decisions have to be made with limited access to knowledge of natural processes and baseline geomorphological data. To date management decisions have been based almost exclusively on oral histories that state that point bars are accreting and the river is becoming shallower due to bank erosion. As a result bank stabilisation and removal of sand from within the channel have been recommended in the absence of any geomorphological assessments. This study compares oral histories of river bank erosion in the Mulgrave River with geomorphic evidence to highlight the need for integrated landscape scenario planning. The results of grain size analysis of bank and bed material from 27 locations, involving 47 samples, suggest that bank erosion cannot be delivering sediments to point bars. Furthermore, qualitative analysis of historic parish maps and aerial photographs shows that there has only been moderate bank erosion at three locations along the Mulgrave River since European settlement. The study demonstrates the important role that geomorphological investigations have for catchment management and the need for management frameworks that integrate geomorphological processes and landholder priorities for sustainable river management.     

Tertiary Nothofagus macrofossils from Cethana,Tasmania

Two new Tertiary species of Nothofagus from the Early Eocene-Oligocene deposit at Cethana represent the first reports of fossil species which are not closely related to the extant Australian species N. moorei and N. cunninghamii. N. cethanica sp. nov. is most closely related to the extant New Zealand species N. fusca and N. truncata and gives further evidence of the relatively slow evolution within this genus. The other specimen is indistinguishable from extant adult N. gunnii leaves, and has been assigned to that species. This fossil shows that the deciduous habit was probably already present in N. gunnii by the Oligocene, and this may have helped N. gunnii to survive the Late Tertiary/Quaternary glaciations. Juvenile N. gunnii foliage gives some insight into the possible origins of this species, which may have been from the same ancestral stock as N. fusca, N. truncata, and N. cethanica.     

Underground drainage at Mole Creek,Tasmania

Complex patterns of groundwater flow exist in the Mole Creek karst area, Tasmania. Many surface drainage divides are breached underground The evolution of the drainage has been dominated by (I) the deflection of streams along the strike of the limestone beds; (2) progressive changes to hydraulic gradients; and (3) a history of climate change during the Quaternary that has seen drainage diverted underground by glaciers and/or by proglacial and periglacial sedimentation     

The Geography of the Anthropocene in New Zealand: Differential River Catchment Response to Human Impact

New Zealand provides a useful environment to test the notion that the Anthropocene is a new geological epoch. There are two well‐dated anthropogenic impact ‘events’: Polynesian settlement c. AD 1280, and European colonisation c. AD 1800. Little attention, however, has been given to regional catchment response to these, although it has been assumed that both Polynesian and European farming and land use management practices significantly increased erosion rates across most of New Zealand. This paper addresses the nature and timing of human impacts on river systems using meta‐analysis of a recently compiled nationwide database of radiocarbon‐dated fluvial deposits. This shows highly variable human impacts on erosion and sedimentation in river systems, which are often difficult to separate from naturally driven river activity. Catchment‐scale data with high resolution dating control record clearer evidence of human disturbance. In Northland, anthropogenic alluviation is recorded from c. AD 1300 linked to early Polynesian settlement, enhanced further in the late 19th and 20th centuries by European land clearance, when sedimentation rates exceeded 25 mm year^?1. This study demonstrates significant geographical variability in the timing of human impact on river dynamics in New Zealand, despite two synchronous phases of human settlement, and highlights the difficulty of formally designating a simple and single ‘Anthropocene Epoch/Age’.     

岷江上游新石器时代遗存及相关问题探讨

本文在近年来考古发掘材料的基础上对岷江上游新石器时代文化特征、文化性质与周边文化的关系以及马家窑文化与四川盆地早期文化的交流与互动等作尝试性的探索。     

Development of Trigger Levels to Assess Catchment Disturbance on Stream Suspended Sediment Loads in the Magela Creek Catchment,Northern Territory,Australia

Trigger levels for fine suspended sediment (FSS) load in streams are required to identify rainfall-runoff events that have significantly elevated FSS loads, compared with expected background loads, as a result of catchment disturbance. Stream FSS load data collected in the mine-impacted Magela Creek catchment in the wet-dry tropics were used to derive water quality management trigger levels for two approaches – a Before-After-Control-Impact Paired difference design (BACIP) and a regression relationship between observed FSS load and corresponding event discharge characteristics. The results indicate that both the BACIP and regression relationship approaches behave similarly, with similar FSS load events elevated above trigger levels. Notwithstanding this, it is recommended that in order to reliably assess the location and magnitude of a catchment disturbance on FSS load, a combination of BACIP and regression relationship approaches must be adopted. In this study, an event with a FSS load above trigger levels associated with both BACIP and the regression relationship fitted for the downstream site is considered to be significantly elevated as a result of a disturbance within the mine-impacted region. While this technique cannot conclusively determine whether the cause of the disturbance is mine-related or natural (such as fire or bank erosion), it is an efficient statistical method of identifying events that warrant further investigation and management action, if required.