Summary A SkyTEM airborne survey has been flown over 1820 km2 of an area of intense agriculture in Hawkes Bay region of New Zealand. The survey is designed to map the characteristics of a coastal fluvial aquifer and support the management of groundwater resources. Processing the data from a 590 km2 subset of the survey, adjacent three urban centres, has been helped by using ground-based geophysical data. These data include ground-TEM, DC resistivity soundings, and borehole geophysical logs. Seismic reflection data across the region provide constraints on the deeper sections of the aquifer system (200 – 500 m). One of the key aims of the study is to map the variability of the surface geological strata that in places are a recharge zone and in other places a confining layer for the aquifer. The SkyTEM data have a spatial coverage (170 m line spacing and 20–30 m station spacing) that enables these units to be mapped in more detail than is possible with the current boreholes and ground geophysical data. In places the ground-based data provide valuable support for constraining the shallow SkyTEM models where data can be missing and deep parts of the SkyTEM model where the resolution is low.
Research Article| July 24, 2018 PALEOENVIRONMENTAL AND PALEOGEOGRAPHIC IMPLICATIONS OF PALEOSOLS AND ICHNOFOSSILS IN THE UPPER PENNSYLVANIAN HALGAITO FORMATION, SOUTHEASTERN UTAH JAMES A. GOLAB; JAMES A. GOLAB 1University of Kansas, Department of Geology, Lawrence, Kansas, 66045, USA Search for other works by this author on: GSW Google Scholar JON J. SMITH; JON J. SMITH 2Kansas Geological Survey, Stratigraphic Research, Lawrence, Kansas, 66046, USA Search for other works by this author on: GSW Google Scholar STEPHEN T. HASIOTIS STEPHEN T. HASIOTIS 1University of Kansas, Department of Geology, Lawrence, Kansas, 66045, USA Search for other works by this author on: GSW Google Scholar PALAIOS (2018) 33 (7): 296–311. https://doi.org/10.2110/palo.2017.074 Article history first online: 24 Jul 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation JAMES A. GOLAB, JON J. SMITH, STEPHEN T. HASIOTIS; PALEOENVIRONMENTAL AND PALEOGEOGRAPHIC IMPLICATIONS OF PALEOSOLS AND ICHNOFOSSILS IN THE UPPER PENNSYLVANIAN HALGAITO FORMATION, SOUTHEASTERN UTAH. PALAIOS 2018;; 33 (7): 296–311. doi: https://doi.org/10.2110/palo.2017.074 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyPALAIOS Search Advanced Search Abstract The Upper Pennsylvanian (Virgilian) Halgaito Formation (HF) is an ∼ 125–155-m-thick succession of carbonate and carbonate-cemented siliciclastic strata exposed along Cedar Mesa on the Colorado Plateau in southeastern Utah. Defining the stratigraphic standing of the HF has been problematic due to differing paleoenvironmental and paleogeographic interpretations. This stratigraphic confusion is likely because the HF and overlying Cedar Mesa Sandstone lie at the interface between the underlying, predominately marine carbonate Honaker Trail Formation and the overlying, alluvial-eolian Organ Rock Formation. This study uses a combined ichnological, paleopedological, and sedimentological approach to refine the paleoenvironmental and paleogeographic history of the HF. The lower, marine portion of the HF is predominately fossiliferous packstone and calcareous sandstone, containing abundant Scalichnus and Thalassinoides. Marine sandstone beds contain shallow rhizoliths and indicate a relative sea-level drop that was punctuated by at least four, small-scale transgressions. The upper, continental section contains predominately eolian siltstone with siliciclastic Entisols and mottled Inceptisols. These paleosols contain large rhizohaloes and calcareous rhizocretions that are commonly associated with abundant Naktodemasis bowni. The uppermost ∼ 40 m of strata are laminated and crossbedded siltstone that contain little to no paleopedogenic development and few ichnofossils. These eolian beds were likely sourced from the erosion of underlying marine strata of the Hermosa Group as the Elephant Canyon Seaway regressed northward during the Pennsylvanian. Thin, coarse-grained fluvial strata can be observed throughout the HF and were likely sourced from the highlands of the Uncompahgre Uplift. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Adhesive meniscate burrows (AMB) are common in alluvial paleosols of the Paleogene Willwood Formation, Bighorn Basin, Wyoming. AMB are sinuous, variably oriented burrows composed of a nested series of distinct, ellipsoidal packets containing thin, tightly spaced menisci subparallel to the bounding packet. Menisci are non-pelleted and texturally homogeneous with each other and the surrounding matrix. AMB were constructed most likely by burrower bugs (Hemiptera: Cydnidae), cicada nymphs (Hemiptera: Cicadae), and less likely by scarabaeid (Coleoptera: Scarabaeidae) or carabid beetles (Coleoptera: Carabidae), based on burrow morphology and comparison to similar structures produced by these organisms in modern soils. Extant burrowing insects excavate backfilled burrows in well-rooted A and upper B horizons of soils generally below field capacity depending on soil type. This study demonstrates that AMB are distinct morphologically from such previously described ichnofossils as Beaconites, Laminites, Scoyenia, Taenidium , and Ancorichnus. Naktodemasis bowni , a new ichnogenus and ichnospecies, represents burrows composed of nested ellipsoidal packets backfilled with thin, tightly spaced, menisci subparallel to the bounding packet. The presence of N. bowni indicate periods of subaerial exposure associated with pedogenic modification under moderately to well-drained soil conditions, or during periods of better drainage in imperfectly drained soils. N. bowni , therefore, can differentiate alluvial paleoenvironments from marine and lacustrine paleoenvironments, as well as periods of subaerial exposure of sediments deposited in aquatic settings.
This paper provides a summary review of proposed nomenclatural revisions to the Zarah Subgroup of the Kansas City Group (Pennsylvanian) in Kansas and outlines changes adopted by the Kansas Geological Survey. The Iola Limestone, which comprises in ascending order the Paola Limestone, Muncie Creek Shale, and Raytown Limestone Members, is now considered the basal formation of the Zarah Subgroup. We reinstate the overlying Liberty Memorial Shale as originally defined by Clair (1943) in the area of Kansas City, Missouri. We also restrict the Wyandotte Limestone to include only, in ascending order, the Frisbie Limestone, Quindaro Shale, and Argentine Limestone Members. Furthermore, the Lane Shale is restricted in use and encompasses all strata within the shale-dominated interval between the top of the Argentine Limestone Member of the Wyandotte Limestone and the base of the overlying Plattsburg Limestone. Within the revised Lane Shale, the KGS now formally recognizes, in ascending order, the Lower Farley Limestone, Middle Farley Shale, and Upper Farley Limestone Members. The Bonner Springs Shale is now demoted in rank and included as the uppermost member within the Lane Shale.
Abstract The Ogallala-High Plains aquifer is an important resource for irrigated agriculture in a semi-arid region of the United States. Steep declines in groundwater levels are putting increasing strain on the viability of the aquifer for irrigation, necessitating improved estimates of recharge rates and sources to the aquifer. This study uses a combined approach to obtain high resolution geochemical and isotopic composition of the vadose zone and aquifer pore fluids to better understand recharge dynamics to the aquifer. Significant differences between the shallow, intermediate and deep vadose zone and shallow and deep aquifer indicate modern precipitation is not providing a significant source of recharge to the aquifer across a large area (diffuse recharge). Rather, recharge to the aquifer is a result of either focused recharge or long-term, delayed drainage from the portion of the vadose zone which was saturated before irrigation development.
As products of past physical, chemical and biological processes at or very near the Earth’s surface, paleosols preserve data on the ecosystems, climate conditions, and atmospheric CO2 pressures coincident during soil formation. The application of paleosols as a tool for paleoenvironmental and paleoclimatic reconstruction in Brazilian intracontinental basins is a still less explored theme in the geoscientific literature. The Lower Cretaceous Itapecuru Formation, deposited within the Parnaíba Basin, Brazil, is a 600-m-thick succession of interbedded very fine-to fine-grained sandstone and mudstone containing a rich fossil record and in which paleosols are stratigraphically common. Previous paleogeographic and paleoclimate studies propose that the Itapecuru Formation was deposited under predominantly tropical equatorial conditions. However, investigating the formative conditions of such tropical paleosols and their use as paleoclimatic proxies has not been attempted previously in Brazil. In this paper, the macro and microscopic pedogenic features a hydromorphic paleosol profile in the Itapecuru Formation is described in detail and assigned as the Prata pedotype. Analyses of clay mineralogy and whole-rock geochemistry are used to define pedogenic processes, paleoclimate proxies, paleohumidity condition and paleovegetation. Estimates of paleoprecipitation and paleotemperature from the studied paleosols using climofunctions chemical index of alteration without potassium and paleosol weathering index proxy (PWI) show values ranging from 673 to 1042 mm/yr and 10.4 to 11.3 °C, respectively. Climofunction values suggest a paleoclimate of subhumid to humid during weathering processes during soil formation. The climate data also suggests that, during the Albian, the Prata pedotype was geographically within the Equatorial Humid belt with vegetation of moist tropical forests.