Stephen E. Kaczmarek

Western Michigan University | WMU · Department of Geological & Environmental Sciences

Saddle dolomite is a Ca–Mg carbonate characterized by curved crystal faces, curved cleavage and sweeping extinction under cross‐polarized light. Saddle dolomite and, generally, Ca–Mg carbonates with curved crystal faces, are often assigned to the burial (hydrothermal) realm and serve as proxy archives for hydrogeochemical processes in sedimentary b...

The clumped isotope paleo-thermometer has become a valuable proxy for the burial history reconstruction of carbonate formations. To maximise the accuracy of these reconstructions, post-depositional alterations, such as recrystallisation and Δ47 isotope exchange reactions, must be understood. In this study, we examine the isotopic behaviour of calci...

Correlating shallow shelf carbonates and their deep basin equivalents is a perennial challenge in the geosciences, with wide-ranging implications. This hurdle is well illustrated in the Llandovery succession of the Michigan Basin, USA, a 40- to 265-m-thick carbonate interval represented by three lithostratigraphic units: the Cataract, the Burnt Blu...

Dolomite textures are widely interpreted to reflect physical, mineralogical, and geochemical conditions of crystal growth. In particular, nonplanar dolomites, which display non-faceted crystal boundaries and a low percentage of crystals with compromise boundaries with preserved crystal-face junctions, have long been cited as evidence of crystal gro...

This study uses high temperature (215°C) dolomitization experiments to explore the effects of sodium (Na) and potassium (K), two common constituents of natural fluids, on dolomite formation rate, stoichiometry and crystallographic characteristics. In these experiments, aragonite ooids were dolomitized in Mg–Ca–Cl solutions with either no additional...

The Eocene Uteland Butte Member of the Green River Formation in the Uinta Basin is characterized by lacustrine carbonate depositional cycles consisting of calcareous shales, limestones, and dolomites that have been interpreted to reflect climatically driven lake level fluctuations. Previous work suggests that dolomitization of three distinct strati...

Iodine concentrations in sedimentary carbonate minerals are used as a proxy to reconstruct the redox landscape in shallow oceans throughout Earth history. The proxy [I/(Ca+Mg)] assumes that only the oxidized form of iodine, iodate (IO3⁻), is incorporated into carbonate minerals, and thus its presence in ancient carbonate rocks suggests their format...

A new high-resolution, composite δ13Ccarb curve for the Michigan Basin, USA, was constructed using two stratigraphically overlapping subsurface cores that span the complete Llandovery interval. The Llandovery succession of the Michigan Basin measures between 140 m and 265 m thick and is represented by three lithostratigraphic groups: the Cataract (...

Selective dolomitization of HMC allochems in Neogene carbonates is a common phenomenon. It has been proposed that the higher magnesium concentrations [Mg] in these allochems promotes dolomitization. To directly investigate the effects of [Mg] (reported as mol% MgCO3) in biogenic HMC on dolomitization, high-temperature (200 °C) dolomitization experi...

Recrystallization of dolomite can alter textural, mineralogical and geochemical attributes used to infer environmental conditions of initial dolomitization. A meta-analysis of the published literature shows that extensive recrystallization is most common in old and deeply buried dolomites, but data from the Palaeocene–Eocene Umm er Radhuma Formatio...

Numerous Phanerozoic limestones are comprised of diagenetic calcite microcrystals formed during mineralogical stabilization of metastable carbonate sediments. Previous laboratory experiments show that calcite microcrystals crystallizing under conditions similar to those that characterize meteoric diagenetic settings (impurity-free, low degree of su...

Debating the timing, fluid composition, and mechanism of dolomitization has become somewhat of a cottage industry. Early seawater dolomitization, microbial mediation, evaporative reflux, mixing-zone dolomitization, hydrothermal convection, late burial dolomitization, are but a few of the models proposed in the literature. The most widely cited of t...

The fate of aragonite and Mg-calcite and implications for marine diagenesis

An oxide layer on the surface of silicon particles is inevitable and is necessary for their application as anode materials for lithium ion batteries with high capacity and durability. However, a thick surficial oxide layer could significantly reduce the capacity of a Si anode. In this study, Si nanoparticles with a thick surficial oxide layer of ∼2...

Magnesium (Mg) in natural waters plays a critical role in governing carbonate mineral formation, dissolution, and diagenesis. Previous laboratory experiments show that Mg can strongly inhibit direct calcite precipitation as well as aragonite to calcite diagenetic transformation. Data from natural settings, however, suggest that diagenetic calcite i...

Numerous Phanerozoic limestones are characterized by diagenetic calcite microcrystals formed during mineralogical stabilization of metastable carbonate sediments in various diagenetic environments. Laboratory experiments show that calcite precipitating under conditions similar to those that characterize meteoric settings (impurity-free, low supersa...

Various geochemical proxies are used to constrain the diagenetic origin and evolution of ancient dolomites. Dolomite stoichiometry (mole % MgCO3) and cation ordering, two mineralogical attributes that define dolomite, have also been shown to demonstrate utility in this regard. Observations from laboratory experiments and field studies suggest that...

Portable Energy-Dispersive X-Ray Fluorescence spectrometry (PXRF) is routinely used to identify stratigraphic variations in the elemental chemistry of fine-grained siliciclastics. The application of this approach in carbonates is limited, however. In this study, over 9,000 ED-XRF analyses from nine drill cores are used to document cm-scale variatio...

Phanerozoic limestones are composed of low-Mg calcite microcrystals (i.e., micrite) that typically measure between 1 and 9 μm in diameter. These microcrystals, which host most of the microporosity in subsurface reservoirs, are characterized by a variety of microtextures. Despite the overwhelming consensus that calcite microcrystals are diagenetic,...

Selective dissolution of metastable minerals and certain pore types, such as moldic and oomoldic pores, are widely accepted to indicate diagenesis by meteoric fluids in carbonate rocks. In this study, oomoldic‐rich re‐sedimented carbonates from the Happy Field in the Midland Basin which contain no evidence of subaerial environments, indicate that s...

The Lower Eocene Rus Formation in Qatar reflects carbonate deposition in a semi restricted to fully restricted marine setting on a shallow ramp. Petrographic, mineralogical, and geochemical evidence from three research cores show early diagenesis has extensively altered nearly every petrological attribute of these rocks despite not having been deep...

Neogene dolomites are common in island settings, and they have been used to understand the complex processes of dolomitization. The island of Bonaire was one of the first locations where the concept of reflux dolomitization was applied. Given this historical significance, here we re-evaluate the importance and nature of reflux using a previously un...

In the ancient rock record, early replacement of metastable marine calcium carbonate deposits by dolomite has long been associated with evidence of arid depositional environments. Such associations led to the development of the seepage reflux dolomitization model, whereby magnesium‐rich marine waters concentrated by evaporation descend into underly...

Integration of sedimentologic, chemostratigraphic, biostratigraphic, and geochronologic data identifies the profound influence that sudden bursts of carbonate sedimentation, sea-level oscillation, and hypersalinity, associated with Ireviken and Mulde carbon cycle perturbations, had on the evolution of the Michigan Basin during the Silurian. Conodon...

Carbonate rocks that have suffered early near‐surface dolomitization followed by extended meteoric exposure commonly undergo partial delithification, a process that results in the formation of dolomitic silts and sands, herein termed dologrus. Dologrus is interpreted to form as a result of diffuse dissolution in porous and permeable dolostones prio...

Aragonite and high-magnesium calcite are abundant constituents of modern shallow marine carbonate sediments, but are rare in ancient carbonate rocks. Because these minerals are metastable, they tend to stabilize to microcrystalline calcite which is ubiquitous in most Phanerozoic marine and lacustrine limestones. Calcite microcrystals exhibit a rang...

The upper Palaeocene–lower Eocene Umm er Radhuma Formation in the subsurface of Qatar is dominated by subtidal carbonate depositional packages overlain by bedded evaporites. In Saudi Arabia and Kuwait, peritidal carbonate depositional sequences with intercalated evaporites and carbonates in Umm er Radhuma have been previously interpreted to have be...

Portable energy-dispersive X-ray fluorescence (PXRF) analyzers are routinely used to generate large elemental datasets in sedimentary strata. These data provide the basis for assessing stratigraphic changes in geochemistry, bulk mineralogy, and paleo-redox conditions. The manufacturer provided procedure used to calculate elemental concentrations fr...

Palygorskite is a fibrous, magnesium‐bearing clay mineral commonly associated with Late Mesozoic and Early Cenozoic dolomites. The presence of palygorskite is thought to be indicative of warm, alkaline fluids rich in Si, Al and Mg. Palygorskite has been interpreted to form in peritidal diagenetic environments, either as a replacement of detrital sm...

Geochemical proxies and crystal textures are routinely used to infer dolomitizing conditions. Petrographic and geochemical data from the Paleocene-Eocene Umm er Radhuma (UER) Formation in central Qatar support the hypothesis that different dolomite textures reflect separate dolomitizing events. Porosity and permeability data also show that dolomite...

Refluxing brines are routinely invoked to explain dolomitization in peritidal settings. One such example is the Cretaceous Upper Glen Rose Formation (UGR) of central Texas, United States. The UGR is characterized by high-frequency cycles of variably dolomitized limestones interpreted to reflect periodic deepening and shallowing in a peritidal setti...

Limestone microporosity is ubiquitous and extensively developed in most Phanerozoic limestones. From an economic perspective, microporosity is important because it contributes substantially to the carbonate pore system, which can host significant volumes of water and hydrocarbons. Therefore, determining the presence and distribution of limestone mi...

Palygorskite is a magnesium-bearing, diagenetic clay mineral that can severely impact reservoir quality. In the rock record, palygorskite is frequently associated with Late Mesozoic and Early Cenozoic dolomites. Although laboratory synthesis under earth surface conditions has been unsuccessful, the presence of palygorskite has been inferred to form...

Eocene carbonates of central Qatar reflect deposition in a shallow sub-tidal to restricted marine setting. Because these rocks have not been extensively buried, they offer an ideal opportunity to examine the effect of significant near-surface diagenesis on reservoir quality. A 135 m research core drilled in 2016 penetrated (i) the Umm er Radhuma Fm...

Long-term global carbon isotope records (δ¹³Ccarb and δ¹³Corg) for the Silurian have been largely derived from unrestricted openmarine carbonates and shales. Here, we demonstrate how organic carbon harvested from halite-dominated evaporite deposits in a restricted intracratonic basin can be used to produce a carbon isotope record. Inorganic and org...

State and national standards for K-12 increasingly call for integration of content across science disciplines. Teachers need relevant professional development opportunities in which they learn to integrate content and scientific research in data-driven lessons for their students. The National Science Foundation sponsored Bridging the Gap workshop h...

Sequence stratigraphic interpretations using conventional geologic datasets from outcrop, core, and wire-line logs are routinely applied to carbonate rocks. The vast majority of published work on this subject has investigated shallow-water carbonates where facies shifts are readily observable. This standard approach is more difficult in deep-water...

Scientists have studied carbonate rocks for centuries, yet correlating these strata from the shelf to basin remains problematic. Conventional approaches are routinely used in shallow-water settings where facies changes allow for identification of depositional cycles. It is difficult, however, to identify and correlate depositional cycles in deep-wa...

Natural dolomites exhibit a wide range of compositional and structural characteristics with respect to the amount and positions of calcium and magnesium cations within the crystal lattice. The physicochemical factors that regulate these characteristics are, however, poorly understood. Hundreds of high-temperature dolomitization experiments were con...

Outcrops of the Cretaceous Upper Glen Rose Formation along Highway 360 in Austin, Texas record peritidal carbonate deposition characterized by subtidal mud-dominated milliolid packstones overlain by tidal-flat mudstone caps. The upper ~1.5 meter of each cycle is pervasively dolomitized. Previous work suggests that dolomitization occurred via seepag...

The A-1 Carbonate is the primary hydrocarbon source rock and an important reservoir component of the Silurian (Niagaran) pinnacle reef complexes in the Michigan Basin. The geology of the A-1 Carbonate, however, is not widely known because the majority of published research about this hydrocarbon system focuses on the pinnacle reefs. To gain a bette...

Massive nonpoint particulate-bound phosphorus (P) losses in runoff and erosion streams cause eutrophication and toxic algal blooms in surface water bodies that receive these streams. On the other hand, runoff particulates can be regarded as a “new” sustainable source of P that can be recovered and reused in agriculture to minimize dependence on min...

The Niagara–Lower Salina reef complex reservoirs of the Michigan Basin host significant hydrocarbon volumes and have recently been identified as promising targets for enhanced oil recovery and carbon sequestration. Although these carbonate buildups have been studied extensively since the late 1960's, there is still wide uncertainty and disagreement...

Use of the clumped isotope thermometer to decipher environments of dolomite formation has been inhibited by a lack of empirical data from dolomites formed at known temperatures. Calibrations for aragonite, calcite, siderite, and apatite indicate that a universal Δ47 – temperature relationship may exist across all carbonate-bearing mineral phases. H...

Micron-size pores are common in limestones, and they host significant hydrocarbon reserves in conventional and unconventional plays worldwide. Previous studies have shown that the vast majority of micropores in limestones occur in the interstices between micron-size calcite crystals that are present in nearly all depositional environments and buria...

The reef complexes of the Niagara-Lower Salina have been studied extensively over the past five decades as they comprise an immense hydrocarbon resource in the Michigan Basin. Recent studies suggest that the transition from normal marine conditions during Niagara carbonate deposition to evaporitic conditions during deposition of the Lower Salina A-...

Microporosity is important because it contributes to reservoir storage in giant oil and gas fields, and it is a likely factor contributing to the longevity of aggregates used in concrete. Due to the recent proliferation of scholarship and the easy access to digital full-text databases, we performed a “big data” meta-analysis of microporosity occurr...

Microporosity is recognized as a significant concern in Phanerozoic-age limestone reservoirs throughout the world because its presence can severely complicate hydrocarbon evaluation and production. Numerous studies have documented the occurrence and abundance of micropores, their physical appearance, and diagenetic origins in specific reservoirs, b...

Dolomite [CaMg(CO3)2] forms in numerous geological settings, usually as a diagenetic replacement of limestone, and is an important component of petroleum reservoir rocks, rocks hosting base metal deposits and fresh water aquifers. Dolomite is a rhombohedral carbonate with a structure consisting of an ordered arrangement of alternating layers of Ca2...