Richard D. Jarrard

• Doctor of Philosophy
• Professor Emeritus at University of Utah

Clues to the dynamics of the subduction process are found in the many measurable parameters of modern subduction zones. Based on a critical appraisal of the geophysical and geological literature, 26 parameters are estimated for each of 39 modern subduction zones. To isolate causal relationships among these parameters, multivariate analysis is appli...

The alteration of upper oceanic crust entails growth of hydrous minerals and loss of macroporosity, with associated large-scale fluxes of H2O, CO2, Cl−, and K2O between seawater and crust. This age-dependent alteration can be quantified by combining a conceptual alteration model with observed age-dependent changes in crustal geophysical properties...

Cnidarians represent an early diverging animal group and thus insight into their origin and diversification is key to understanding metazoan evolution. Further, cnidarian jellyfish comprise an important component of modern marine planktonic ecosystems. Here we report on exceptionally preserved cnidarian jellyfish fossils from the Middle Cambrian (a...

The fossil record of early deuterostome history largely depends on soft-bodied material that is generally rare and often of controversial status. Banffiids and vetulicystids exemplify these problems. From the Cambrian (Series 3) of Utah, we describe specimens of Banffia episoma n. sp. (from the Spence Shale) and Thylacocercus ignota n. gen. n. sp....

Geochemical well logs were obtained at ODP Sites 767 and 770 in the Celebes Sea. The log data obtained at sea have been corrected for borehole size changes, the effects of drilling fluids, and logging-speed variations. The processed logs are then used to calculate the amounts of the three major radioactive elements (Th, U, and K) and the dry weight...

The tectonic regime within Antarctica is only poorly understood due to a general lack of seismicity and the extreme dearth of deeper drilling that has occurred on this continent. To overcome this situation in general, and to better understand the state of stress in McMurdo Sound, hydraulic mini-fracing tests were included as an important component...

An automatic technique is developed for integrating two electrical resistivity logs obtained during Leg 133, namely, the deep induction log (ILD) and the spherically focussed log (SFL). These logs are routinely run by the Ocean Drilling Program in lower resistivity sedimentary environments, where drilling through soft, poorly consolidated lithologi...

The first well logs collected below the Antarctic circle were obtained during Leg 113 at Site 693 on the Dronning Maud Land Margin (Antarctica) in the Weddell Sea. Gamma-ray, resistivity, and sonic logs were collected between 108.0 and 439.0 mbsf. The downhole logs show good agreement with the data collected from cores and provide a con­ tinuous me...

Thesis (Ph. D.)--University of California, San Diego, 1975. Includes bibliographical references. Photocopy.

We report new strain analyses of mechanically twinned calcite in veins hosted by Neogene (13.6-4.3 Ma) sedimentary and volcanic rocks recovered from the Terror Rift system in the southern Ross Sea, Antarctica, by the ANDRILL (ANtarctic geological DRILLing) McMurdo Ice Shelf (MIS) Project. Strain analyses of the ANDRILL MIS AND-1B drill core samples...

Stratigraphic drilling from the McMurdo Ice Shelf in the 2006/2007 austral summer recovered a 1284.87 m sedimentary succession from beneath the sea floor. Key age data for the core include magnetic polarity stratigraphy for the entire succession, diatom biostratigraphy for the upper 600 m and 40Ar/39Ar ages for in-situ volcanic deposits as well as...

Stratigraphic drilling from the McMurdo Ice Shelf in the 2006/2007 austral summer recovered a 1284.87 m sedimentary succession from beneath the sea floor. Key age data for the core include magnetic polarity stratigraphy for the entire succession, diatom biostratigraphy for the upper 600 m and 40Ar/39Ar ages for in-situ volcanic deposits as well as...

Some of the greatest uncertainties in our understanding of Cenozoic global tectonics and climate can be traced back to our relatively meager knowledge about Antarctica's continental lithosphere and its overlying continental glaciers. A trove of information about past tectonism and the behavior of the continental ice sheets lies buried along the sub...

The ANDRILL (Antarctic Drilling Project) McMurdo Ice Shelf (MIS) project drilled 1285 m of sediment in Hole AND-1B, representing the past 12 m.y. of glacial history. Downhole geophysical logs were acquired to a depth of 1018 mbsf (meters below seafloor), and are complementary to data acquired from the core. The natural gamma radiation (NGR) and mag...

A set of hydraulic fracturing stress measurements were carried at depths of up to 1400 m below the rig floor at the bottom of the ANDRILL South McMurdo Sound borehole. The measurements were accomplished in open hole through indurated and low permeability glacial diamicts and shales. A 2000-m long wireline hosted straddle packer system was used that...

The Wheeler Formation of West-Central Utah is a succession of mixed carbonate-siliciclastic rocks deposited during the Middle Cambrian along a passive continental margin of Laurentia (western margin, in today's coordinates). The depositional setting was a gentle ramp, bounded by a normal fault on the south. The present study focuses on the Wheeler...

Seismic studies indicate that the West Antarctic rift system records at least two distinct periods of Cenozoic rifting (Paleogene and Neogene) within the western Ross Sea. Natural fracture data from ANDRILL and Cape Roberts drill cores are revealing a picture of the geodynamic patterns associated with these rifting episodes. Kinematic indicators al...

Integration of stress data derived from volcanic alignment studies in rift-related volcanic fields and from drilling-induced fractures from ANDRILL and Cape Roberts rift basin sedimentary rock cores is beginning to define a picture of the recent to contemporary stress patterns within the West Antarctic rift system. In the western sector of the rift...

To define the present-day stress field in the upper crust and to understand the recent tectonic activity in Antarctica, a study of breakout measurements along AND-2A well was performed. The borehole breakout is an important indicator of horizontal stress orientation and occurs when the stresses around the borehole exceed that required to cause comp...

The ANDRILL McMurdo Ice Shelf (MIS) project drilled 1285 metres of sediment representing the last 14 million years of glacial history. Downhole geophysical logs were acquired to a depth of 1018 metres, and are complementary to data acquired from the core itself. We describe here the natural gamma radiation (NGR) and magnetic susceptibility logs, an...

The Middle Cambrian Wheeler Formation in Utah is renowned for its exceptionally preserved fossils. Herein, geophysical techniques (gamma ray spectrometry and magnetic susceptibility), carbonate analyses, lithofacies, and fossils are used to characterize limestones and calcareous mudrocks of the upper portion of the middle Wheeler Formation and the...

During the 2006-2007 austral summer, the Antarctic geological drilling program ANDRILL recovered cores of sedimentary rock from a 1285-m-deep borehole below the McMurdo Ice Shelf. Well logging instruments were deployed to a depth of 1017 mbsf after core recovery. This study focuses on two intervals of the AND-1B borehole: upper HQ (238-343 mbsf; Pl...

In general, knowledge of the state of stress within the Antarctic lithosphere remains largely unconstrained due in part to Antarctica's inaccessibility and because of the paucity of seismic focal mechanism solutions. As such, an important component of the ANDRILL project was to acquire new information on the stress directions and magnitudes within...

A synthesis of Eocene biogenic silica accumulation rates in the equatorial zone of the Pacific shows several relatively broad maxima spaced a few million years apart and extending from the uppermost Eocene into the lower Eocene. There is a distinct, step-like decrease in biogenic silica mass accumulation rate at 38.5 Ma (just below the top of C18n....

The Middle Cambrian Spence Shale Member (Langston Formation) and Wheeler and Marjum Formations of Utah are known to contain a diverse soft-bodied fauna, but important new paleontological material continues to be uncovered from these strata. New specimens of anomalocaridids include the largest and smallest near complete examples yet reported from Ut...

Under the framework of the ANDRILL Southern McMurdo Sound (SMS) Project successful downhole experiments were conducted in the 1138.54 metre (m)-deep AND-2A borehole. Wireline logs successfully recorded were: magnetic susceptibility, spectral gamma ray, sonic velocity, borehole televiewer, neutron porosity, density, calliper, geochemistry, temperatu...

For extrusive basalts of the upper oceanic crust, near-infrared radia-tion is reflected with a spectrum that is sensitive to the extent of crustal alteration. A published pilot study of basalts from Hole 801C showed that reflectance-based apparent alteration correlated with independent geophysical indicators of alteration (e.g., matrix density). Th...

Bulk density, porosity, and matrix density were measured on 88 basalt core plugs from Ocean Drilling Program Site 1256. Shipboard measurements using the multisensor track were reprocessed and edited to minimize the effects of core segmentation and calibration problems and are presented in this data report.

During Ocean Drilling Program Leg 199 in the equatorial Pacific, vis-ible and near-infrared spectroscopy (VNIS) was used to measure the re-flectance spectra (350–2500 nm) of 1343 sediment samples. Reflectance spectra were also measured for a suite of 60 samples of known mineral-ogy, thereby providing a local ground-truth calibration of spectral fea...

Visible and near-infrared spectroscopy (VNIS) can be used to measure reflectance spectra (wavelength 350-2500 nm) for sediment cores and samples. A local ground-truth calibration of spectral features to mineral percentages is calculated by measuring reflectance spectra for a suite of samples of known mineralogy. This approach has been tested on pow...

The hydrologic evolution of oceanic crust causes a corresponding evolution of geophysical properties. Previous studies of global datasets of DSDP and ODP core physical properties and downhole logs indicated that increasing crustal age reduces macroporosity (large-scale porosity such as cracks), matrix density, and intergranular velocity, but it inc...

  A new metazoan, Skeemella clavula gen. et sp. nov., is described from the Middle Cambrian Pierson Cove Formation of the Drum Mountains, Utah, USA. Skeemella is similar to vetulicolians, but differs from other examples of this group in the relative proportions of the anterior and posterior sections, the large number of divisions, and the elongate...

We use continuous mineralogy logs derived from multisensor track physical properties data and reflectance spectroscopy to calculate high-resolution carbonate, opal, and terrigenous mass accumulation rates (MAR) for the eight sites cored during Ocean Drilling Program Leg 199 in the equatorial Pacific. The largest change in equatorial Pacific sedimen...

Synthetic seismograms provide a crucial link between lithologic vari-ations within a drill hole and reflectors on seismic profiles crossing the site. In essence, they provide a ground-truth for the interpretation of seismic data. Using a combination of core and logging data, we created synthetic seismograms for Ocean Drilling Program Sites 1165 and...

The fluvial-deltaic sandstones of the Cretaceous Ferron Sandstone, Utah, provide an opportunity to document and compare petrophysical properties of outcrop and subsurface rocks. We find that the processes that generate outcrop exposures — uplift, erosion, and exhumation — can overprint patterns of velocity, porosity, and permeability developed in t...

High-resolution mass accumulation rates (MAR) were determined from lithologic logs based on downhole log and continuous core data for six sites at four continental margins around the Southern Ocean. Total MAR was calculated at Ocean Drilling Program (ODP) Site 1095 on the margin of the Antarctic Peninsula and ODP Site 1165 on the margin of Prydz Ba...

The hydrologic evolution of oceanic crust, from vigorous hydrothermal circulation in young, permeable volcanic crust to reduced circulation in old, cooler crust, causes a corresponding evolution of geophysical properties. Ocean Drilling Program (ODP) Hole 801C, which obtained the world's oldest section of in situ, normal oceanic crust, provides the...

Drillholes CRP-1 to 3 of the Cape Roberts Project in the Northern McMurdo Sound (Ross Sea, Antarctica) targeted the western margin of the Victoria Land Basin to investigate Neogene to Paleogene climatic and tectonic history. Drilling on fast sea ice resulted in coring a stratigraphic succession with a composite thickness of 1500 m and an age range...

Hydrocarbon production in the Bluebell field in from three reservoirs in the Tertiary-aged Colton and Green River Formations: (1) overpressured Colton/Flagstaff, (2)lower Green River, and (3) upper Green River. Kerogen-rich shale and marlstone deposited in marginal and nearshore open-lacustrine environments are the source of the waxy crude in the C...

ODP Leg 199 drilled a transect of sites in the equatorial Pacific for the purpose of studying Paleogene and Neogene paleoclimate and paleoceanography. To help achieve this goal, high-resolution mineralogy and mass accumulation rates were calculated at each site. Leg 199 was the first ODP cruise in which reflectance spectra were routinely measured f...

Assessing the regional significance of fractures in drill cores requires the collection of oriented core intervals. Direct orientation of cores during drilling is possible, but is commonly precluded because of expense and time requirements. A simple and accurate method of core reorientation is presented where high-resolution imagery of drill cores...

Antarctica is key to developing a better understanding of the net effects of plate-boundary and glaciotectonic forces on plate-interior stress regimes. From a tectonic perspective, the Antarctic intracontinental stress regime is expected to be compressive, because midocean spreading ridges segmented by transform faults surround the plate. The Cenoz...

Light absorption spectroscopy (LAS) is a mineral-identification tech-nique that measures the absorption spectrum, in visible and near-infrared bands (350–2500 nm), of a light beam reflected from any sur-face. LAS is rapid (<30 s), nondestructive, and usable on irregular, sawed, or powdered rock surfaces. Diagnostic absorption bands allow identifica...

Drillholes CRP-1 to 3 of the Cape Roberts Project in the Northern McMurdo Sound (Ross Sea, Antarctica) targeted the western margin of the Victoria Land Basin to investigate Neogene to Paleogene climatic and tectonic history. Drilling on fast sea ice resulted in coring a stratigraphic succession with a composite thickness of 1500 m and an age range...

Coring at CIROS-1 and at the three drillsites of the Cape Roberts Project (CRP) provided a record of glacial influence in McMurdo Sound, Antarctica, during the Late Eocene and Oligocene. All four sites have well established sequence stratigraphies. Prior analyses of one CRP site, CRP-2, suggested a correlation between sequence stratigraphy and prov...

The hydrologic evolution of oceanic crust, from vigorous hydrothermal circulation in young, permeable volcanic crust to reduced circulation in old, cooler crust, causes a corresponding evolution of geophysical properties. Ocean Drilling Program (ODP) Hole 801C, which obtained the world's oldest section of in situ, normal oceanic crust, provides the...

Borehole televiewer logs were recorded over 92% of the CRP-3 drillhole. Processed televiewer images detect a variety of features in the borehole wall, including bedding, lonestones, conglomerates, fractures, and breakouts. Data quality varied from poor in much of the top 350 mbsf to excellent in the lower portion of the hole. Three types of stress-...

The presence of authigenic smectite in the lower Oligocene sandstones of the Cape Roberts Project core CRP-3 from the Victoria Land Basin of Antarctica is confirmed by scanning electron, scanning-transmission electron, and light microscopy. It was emplaced as a single generation of cement within the lower portion of the Oligocene section. This sect...

A suite of petrophysical properties -velocity, resistivity, bulk density, porosity, and matrix density – was measured on 88 core plugs from the CRP-3 drillhole. Core-plug bulk densities were used to recalibrate both whole-core and downhole bulk density logs. Core-plug measurements of matrix density permit conversion of the whole-core and downhole b...

Bedding dips in the CRP-3 drillhole were determined in three ways: (1) analysis of a dipmeter log, (2) identification of bed boundaries on borehole televiewer log images, and (3) identification of bed boundaries on digital images of the outer surfaces of oriented cores. All three methods determine both dip magnitude and downdip azimuth of bedding....

Drillhole CRP-3 in northern McMurdo Sound (Ross Sea, Antarctica) targeted the western margin of the Victoria Land basin to investigate Neogene to Palaeogene climate and tectonic history by obtaining continuous core and downhole logs. Well logging of CRP-3 has provided a complete and comprehensive data set of in situ geophysical measurements down to...

CRP-3 cores were not orientated with respect to North during coring operations. However, borehole televiewer (BHTV) logging did obtain azimuthally orientated images of the borehole wall, and core processing included digital imaging of the outer surface of 85% of the cores. Images of many individual core segments can be digitally joined, or stitched...

Cape Roberts drillhole CRP-3 in the northern part of McMurdo Sound (Ross Sea, Antarctica) targeted the western margin of the Victoria Land basin to investigate Neogene to Palaeogene climatic and tectonic history by obtaining continuous core and downhole logs (Cape Roberts Science Team, 2000). The CRP-3 drillhole extended to 939.42 mbsf (meters belo...

This book was originally intended as ˜How to do science™, or ˜How to be a scientist™, providing guidance for the new scientist, as well as some reminders and tips for experienced researchers. Such a book does not need to be written by the most expert or most famous scientist, but by one who likes to see the rules of play laid out concisely. It does...

Incorporation of independent formation information into inductive log interpretation will become more important as the resolution demands on induction logging increase. Often, such information can consist of a reasoned petrophysical characterization of the target and its inductive signature. This target characterization, together with other informa...

Compressional-wave velocity in siliciclastic rocks is known to be a function mainly of porosity, and secondarily of mineralogy. We investigate the effect of cementation on velocity, using core-plug and whole-core measurements of velocity and porosity. The case study area is a drillhole at Cape Roberts, Antarctica, an environment with a rapid downho...

In the northern McMurdo Sound (Ross Sea, Antarctica), the CRP-2/2A drillhole targeted the western margin of the Victoria Land Basin to investigate Neogene to Palaeogene climatic and tectonic history by obtaining continuous core and downhole logs. Well logging of CRP-2/2A has provided a complete and comprehensive dataset of in situ geophysical measu...

Acoustic borehole televiewer (BHTV) data were recorded in both the HQ (64 to 164 m below sea floor) and the NQ (196 to 444 mbsf) sections of the CRP-2 borehole. The purpose of logging this hole with the BHTV was to provide images of the borehole wall to detect and orient natural fractures, stratigraphy, and stress-induced features (breakouts and te...

Bedding dips in the CRP-2A drillhole were determined in two ways: (1) analysis of a dipmeter log, and (2) identification of bed boundaries on digital images of the outer core surface. The two methods document the downhole increase in structural dip, to a maximum of 15° in the lowest 150 m of the hole. Dipmeter data, which are azimuthally oriented,...

Downhole changes in physical properties at CRP-2, reflecting sedimentological changes induced by glacial marine processes, are measured by a suite of well logs (density, resistivity, neutron, microresistivity, spectral gamma-ray, and magnetic susceptibility), in conjunction with a core-based lonestone abundance log. The CRP-2 section is subdivided...

A suite of petrophysical measurements - velocity versus pressure, bulk density, porosity, matrix density, and magnetic susceptibility - was undertaken on 63 core plugs from CRP-2A. These data are used to calibrate neutron, resistivity, and magnetic susceptibility well logs. Agreement between core-plug magnetic susceptibility measurements and both w...

In the northern part of McMurdo Sound (Ross Sea, Antarctica), drillhole CRP-2/2A targeted the western margin of the Victoria Land basin to investigate Neogene to Palaeogene climatic and tectonic history by obtaining continuous core and downhole logs. The background of the project and its detailed aims, methods used and results so far are summarized...

Assessing the regional significance of structural and sedimentological features in core retrieved from the Cape Roberts Drilling Project (CRP-2A) requires the collection of orientated intervals of core. Orientated borehole televiewer (BHTV) data of the borehole walls was successfully collected from 199 to 450 metres below sea floor (mbsf). Within t...

Ocean Drilling Program Leg 171A collected logging while drilling (LWD) data to investigate the porosity and velocity structure of Barbados accretionary complex. Porosity and velocity measurements were needed for interpretation of prism dynamics. However, the LWD tool string did not measure velocity, and previous velocity data from Barbados prism ar...

The electrical resistivity of siliciclastic rocks is a function both of pore-fluid resistivity and of formation factor (FF), an intrinsic rock property. For low-porosity rocks, FF depends on clay conduction and porosity. In contrast, we find that FF of high-porosity sediments (fractional porosities of 0.3–0.6) from Amazon Fan is controlled primaril...

The first hole of the Cape Roberts Project, CRP-1, was drilled in October, 1997, to a depth of 148 metres below the sea floor (mbsf) before being terminated unexpectedly by the loss of fast sea-ice seaward of the rig following a severe storm. The site lies in 150 m of water at 77.008°S and 163.755°E, 16 km off Cape Roberts. This part of the report...

The uppermost part of the core in Cape Roberts Project -1 (CRP-1), to 43.55 mbsf, is interpreted to be Quaternary in age. The interval comprises poorly consolidated clays, silts, sands, gravels, diamictons, and an association of mixed skeletal carbonate-terrigenous clastic sediments. The interval has been divided into four principal lithostratigrap...

Based on the alternation of diamicts with other clastic sedimentary facies, the predominantly lithified Miocene section of CRP-1 has been divided into lithostratigraphic Units 5 to 7, with Unit 5 further divided into 8 subunits and Unit 6 into 3. Petrological investigations of extraformational clasts indicate provenance from probable Cambro-Ordovic...

Poorly consolidated diamicton, silt, sand, gravel, and a mixed skeletal carbonate-terrigenous facies was cored from 16 m down to 43.55 mbsf and dated as 1.25 to 1.80 Ma (early Quaternary) from diatom biostratigraphy. Depositional environments range among 1) possible terrestrial exposure, 2) glacimarine sedimentation from nearby glacier ice, 3) depo...

Seeking a global empirical relationship between compressional wave velocity and porosity for siliciclastic sediments, we have brought together an extensive suite of both new and published log- and core-based data. We undertook a detailed statistical analysis of Ocean Drilling Program data from Amazon Fan to examine variables affecting compressional...

This paper reports measurements of velocity vs pressure and of bulk density, porosity, matrix density, and magnetic susceptibility in 18 core plugs from CRP-1. Comparison of our bulk densities with continuous whole-core density records shows very good agreement. Core-plug measurements of matrix density permit conversion of the whole-core density re...

Lonestone abundances in CRP-1 were investigated using three methods: core examination at Cape Roberts Camp, analysis of digital core images and follow-up core examination. For all images of split-core, we determined size and depth of every detectable lonestone larger than 3 mm. Lonestone abundance decreases exponentially with clast size. Although n...

The relationship between whole-core compressional wave velocities and gamma-ray attenuation porosities of sediments cored at CRP-1 is examined and compared with results from core-plug samples and global models. Both core-plug and whole-core velocities show a strong dependence on porosity; this relationship appears to be independent of lithology. In...

P-wave velocity, wet bulk density, and magnetic susceptibility are measured on the whole CRP-1 core to analyse their down-core patterns and relationships with lithology, and to interpret the compaction and exhumation history. Velocity and density-based porosity are inversely correlated and strongly dependent on compaction and lithology. Fractional...

At Cascadia accretionary prism, log-based porosities exhibit complex lateral changes in response to variations in cementation, horizontal compression, and fracturing. Porosities at the prism toe are lower than in reference sediments, whereas porosities landward of the toe are slightly higher than those of reference sediments. Ideally, a porosity/ve...

We have investigated the low-temperature behavior of a suite of ‘grown’ synthetic and natural magnetites that span single-domain (SD) and multidomain (MD) behavior. Synthetic samples had been grown in the laboratory either in an aqueous medium or in glass. Natural samples included SD magnetites occurring in plagioclase and truly MD magnetites in th...

Vertical seismic profile (VSP) data from two drill sites on the Cascadia margin show low-velocity zones, indicative of free gas, be. neath a bottom-simulating reflector (BSR). Offshore Oregon, at Ocean Drilling Program (ODP) Site 892, velocities drop from an average of 1750 m/s above the BSR to less than 1250 m/s below it. Sonic logs confirm that s...

Shows that although resistivity and velocity are controlled by porosity, the "connectiveness' of the solid phase (velocity) and fluid phase (resistivity) may be more important controls than porosity in these environments. Velocity logs in this environment are shown to be controlled primarily by the bulk properties of the solid fraction and fluid ph...

During Ocean Drilling Program (ODP) Leg 133, shipboard scientists obtained a remarkable quantity of both core and log measurements of the physical properties of carbonate-rich sediments. This suite of measurements provides a unique opportunity to evaluate the robustness of each measurement technique to variations in lithification, porosity, core di...

We use continuous velocity records from 12 sites and continuous density records from 9 sites from Ocean Drilling Program (ODP) Leg 133 to examine both direct and indirect controls on seismic reflectors and depth-to-time conversion for the northeastern Australian margin. In these carbonate-rich sediments, the character of both velocity and density a...

The development of an effective reefal barrier adjacent to Site 820, between 760 k.y. and 1.01 Ma, resulted in a marked reduction in sediment accumulation rates on the central Great Barrier Reef outermost shelf and upper slope. The reduction in the rate of sediment accumulation that followed development of the reefal barrier also caused a fundament...

Seismic stratigraphic analysis of the sedimentary succession intersected in Ocean Drilling Program (ODP) Sites 819, 820, and 821, on the outer shelf and upper slope seaward of the Great Barrier Reef, provides a clear indication of the importance of sediment supply and depositional base-level as two of the fundamental parameters that control the geo...