Fluid systems and mineralization in the north German and Polish basin

The North European Basin hosts mineral deposits like the Kupferschiefer and the Mississippi Valley Type deposits in the Silesian sub‐basin in Poland. The basement to this basin, exposed in the Harz Mts and in the Flechtingen and Calvörde Blocks, contains Mesozoic Pb–Zn vein mineralization and barite–fluorite deposits as well as massive hematite veins in the Rotliegend volcanics. A comparison of the mineralizing models of these deposits with results from a basin‐wide petrographic, fluid inclusion and stable isotope study shows that the genesis of the mineral deposits can be explained by fluid systems that were active during different stages of basin evolution. These comprise syn‐ to post‐magmatic fluids derived from or mobilized in the course of the Rotliegend magmatism, fluids convecting in the Rotliegend units during the extensional basin subsidence in the Permo‐Triassic and originating from progressive devolatilization of the basin sequence and fluids derived from the overlying Zechstein evaporites. Deep‐reaching fault systems developing during the Cretaceous tectonic reactivation enhanced fluid percolation from the surface to the deep sections of the basin sequence. Identification and correlation of these fluids across the basin and in the mineralizations provide the base for a basin‐wide metallogenetic model.     

Narcissus's Mirror: Manufacture and Modernism in the American Great Basin—The Case of Pottery

The commodification of pottery cannot be reduced to strict econo-technological terms. Commodification is a cultural process, enmeshed in local, regional, and international systems of meaning. As Victorian Modernism eroded, anti-modern movements commodified traditional culture. These philosophies, themselves commodities, had repercussions on the pottery industry throughout the world. In both America and Australia, these processes produced art and studio potteries. In the American Great Basin, these changes were experienced very differently by potters from different cultures. The commodification and industrialization of modern pottery factories predicated the reification of a pre-industrial artisanal past.     

Groundwater age,brine migration,and large‐scale solute transport in the Alberta Basin,Canada

There is a great contrast in geochemical and hydrogeologic estimates of the residence times of pore fluids in sedimentary basins. This contrast is particularly evident in the Alberta Basin, Canada, which has served as the study area for important studies of long‐term fluid flow and transport. To address these differences, we developed two‐dimensional simulations of groundwater age, constrained by both hydrogeologic and geochemical observations, to estimate the residence time of fluids and the amount and timing of flushing by meteoric waters in the Alberta Basin. Results suggest that old, residual brines have been retained in the deepest parts of the basin since their formation ca. 400 Ma, but significant dilution by younger waters has reduced the age of these pore waters to no more than approximately 200 My. Shallower formations have been flushed extensively by fresh, young waters. Loss of brines and dilution of older pore waters occurred primarily after the uplift of the Rockies with the introduction of the gravity‐driven flow regime. Despite these large changes in flow regime, solute exchange between deep saline aquifers and the overlying vigorous freshwater flow system was found to be consistent with long‐term dispersive mixing across subhorizontal concentration gradients rather than by direct flushing. Sensitivity studies using an analytic solution supported the use of 100 m for transverse dispersivity in large‐scale numerical models. These simulations confirm that the age and origin of brines are in many cases poor indicators of long‐term solute transport rates in sedimentary basins, but the geochemical indicators that are used to determine the origin of brines can provide useful constraints for calculating groundwater age and are far more commonly available than isotopic groundwater age tracers.     

尼罗河流域文明与地理环境变迁研究

本文根据对尼罗河流域文明区地理环境变迁研究的结果,认为正是由于距今9000-4000年前亚非季风势力增强、季风雨量增加给尼罗河流域带来的湿润气候,为文明的形成和初步发展创造了优越的地理环境。因而尼罗河流域文明不仅仅是"尼罗河的赠礼",而应当更准确地说它是"季风雨的赠礼"。也正是由于季风雨的多寡在很大程度上制约着文明的盛衰,因此,由于从距今4000年前后开始的季风势力衰退和季风雨量锐减而导致的干旱化、沙漠化,则逐步吞噬了这一古老的文明。     

关于柴达木盆地自然生态变迁的人文考察

柴达木盆地自然生态环境十分脆弱,这种状况不但由其禀赋所决定,更与近50多年来人类在盆地开展的大规模生产活动不无关系。该时段的大部分时间,盆地内人与自然的关系基本上是对立的,从而在很大程度上导致了其自然生态环境更加脆弱并向恶化的方向持续变迁,已经严重威胁到该区域人类正常的生产生活。因此,在统筹柴达木盆地各种关系、构建和谐社会时,要更加重视其人与自然关系的和谐,以确保我国生态安全和资源安全。     

Occurrence of the ammonite Goodhallites goodhalli (J. Sowerby) in the Eromanga Basin,Queensland: an index species for the late Albian (Cretaceous)

Mortoniceratid ammonites of the Eromanga Basin of Queensland, although uncommon, are reviewed and reassessed utilising all known collections. Representatives of this group are restricted to the Allaru Formation and almost all specimens are Goodhallites goodhalli, a well-known species from the English Gault. The Allaru Formation overlies the Toolebuc Formation, widely considered to be an essentially isochronous unit because of its unusual sedimentary and geochemical character. Using G. goodhalli, the middle and upper Allaru Formation can be directly correlated with the early late Albian orbignyi and auritus Subzones of the Mortoniceras inflatum Zone as recognized in the reference ammonite zonation embedded in the standard Cretaceous time scale. Overlapping ranges of G. goodhalli and Labeceras and Myloceras allow these common Austral heteromorph genera to be also confidently assigned a late Albian age in Australia, matching their biostratigraphic occurrence in South Africa.     

Stable isotopes,diet, and taphonomy: a look at using isotope-based dietary reconstructions to infer differential survivorship in zooarchaeological assemblages

Archaeology has always faced the problem of making informed inferences based on an incomplete record. Zooarchaeological studies of prehistoric hunting and diet offer a clear case in point, where a range of behavioral and taphonomic factors can produce a substantial disconnect between what people actually captured and ate and what archaeologists recover and interpret. We explore this disconnect by presenting stable C and N data for wild faunas, archaeological maize, and three human burials from Fremont-period sites in southeastern Utah, the United States. We use these data to estimate faunal contributions to prehistoric diets and compare the results with previous zooarchaeological analyses of faunas from the same sites. Results for the two approaches differ sharply, with isotopic estimates showing much higher contributions of small and lowland game. We discuss these results in terms of both local prehistory and wider issues of taphonomy and dietary analysis.     

Emwadea microcarpa gen. et sp. nov.—anatomically preserved araucarian seed cones from the Winton Formation (late Albian), western Queensland,Australia

Dettmann, M.E., Clifford, H.T., Peters, M., June 2012. Emwadea microcarpa gen. et sp. nov.—anatomically preserved araucarian seed cones from the Winton Formation (late Albian), western Queensland, Australia. Alcheringa, 217–237. ISSN 0311-5518.

A new genus and species, Emwadea microcarpa Dettmann, Clifford & Peters, is established for ovulate/seed cones with helically arranged cone scales bearing a centrally positioned, inverted ovule from the basal Winton Formation (late Albian), Eromanga Basin, Queensland. The cones are small, prolate ellipsoidal (9.5–14 mm vertical axis, 6.3–8.7 mm transverse axis) with wedge-shaped cone scales bearing winged seeds attached adaxially to the scale only by tissues surrounding the vasculature entering the ovule. Ovuliferous tissue that is free from the cone scale extends distally from the chalaza; the seeds' lateral wings are derived from the integument. Foliage attached to the cones is spirally arranged, imbricate and with spreading and incurved bifacial blades with acute tips; stomata are arranged in longitudinal files and are confined to the adaxial surface. The cone organization testifies to placement within the Araucariaceae, and is morphologically more similar to Wollemia and Agathis than to Araucaria.

Mary Dettmann [mary.dettmann@qm.qld.gov.au] and Trevor Clifford, Queensland Museum, PO Box 3300, South Brisbane, Q 4101, Australia; Mark Peters, PO Box 366 Gumeracha, SA 5233, Australia. Received 31.3.2011; revised 23.8.2011; accepted 5.9.2011.

     

Asphaltum hafting and projectile point durability: an experimental comparison of three hafting methods

The design of a projectile delivery system often plays a critical role in the durability and breakage patterns associated with spent projectile points. This paper presents the results of an experimental project designed to examine projectile point durability and breakage patterns between three different hafting methods. Specifically, we compare two asphaltum hafting techniques drawn from archaeological and ethnohistoric accounts from the Central Valley of California with a more stereotypical cross-hatched sinew hafting system. Our results suggest a small yet statistically significant increase in durability among asphaltum hafted points, opening the door to future research on these ethnohistorically documented hafting techniques.     

A new damsel-dragonfly (Odonata: Anisozygoptera: Campterophlebiidae) from the earliest Jurassic of the Junggar Basin,northwestern China

Zheng, D., Wang, H., Nel, A., Dou, L., Dai, Z., Wang, B. & Zhang, H. 27 June 2019. A new damsel-dragonfly (Odonata: Anisozygoptera: Campterophlebiidae) from the earliest Jurassic of the Junggar Basin, northwestern China. Alcheringa XX, X–X. ISSN 0311-5518.

A new genus and species of campterophlebiid damsel-dragonfly, Jurassophlebia xinjiangensis gen. et sp. nov., is described from the Lower Jurassic Badaowan Formation in the Junggar Basin, northwestern China. Jurassophlebia differs from all other campterophlebiid genera in having PsA in the same orientation as the distal branch of AA, and in its uniquely open subdiscoidal cell with very acute apical angle in the hind wing. The new discovery adds to the Asian diversity of damsel-dragonflies in the earliest Jurassic.

Daran Zheng* [dranzheng@gmail.com], He Wang [hwang@nigpas.ac.cn], Bo Wang [bowang@nigpas.ac.cn], and Haichun Zhang [hczhang@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, PR China; André Nel [anel@mnhn.fr], Institut de Systématique, Évolution, Biodiversité, ISYEB-UMR 7205-CNRS, MNHN, UPMC, EPHE, Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, CP 50, Entomologie, F-75005, Paris, France; Longhui Dou [345317122@qq.com], Comprehensive Geology Exploration Team, Xinjiang Coalfield Geology Bureau, West Mountain Road, Ürümqi 830000, PR China; Zhenlong Dai [286321388@qq.com], No.9 Geological Team, Xinjiang Bureau of Geology and Mineral Resources, Ürümqi 830011, PR China; Daran Zheng also affiliated with Department of Earth Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, PR China.