Steptoean positive carbon isotope excursion

Last updated

The Steptoean positive carbon isotope excursion (SPICE) is a global chemostratigraphic event which occurred during the upper Cambrian period betwee 497 and 494 million years ago. [1] This event corresponds with the ICS Guzhangian- Paibian Stage boundary and the Marjuman- Steptoean stage boundary in North America. [2] The general signature of the SPICE event is a positive δ13C excursion, characterized by a 4 to 6 ‰ (per mille) shift in δ13C values [1] [2] within carbonate successions around the world. [3] SPICE was first described in 1993, [4] and then named later in 1998. [3] In both these studies, the SPICE excursion was identified and trends were observed within Cambrian formations of the Great Basin of the western United States. [3]

Contents

Age

The age of the SPICE is dated to between 497 to 494 MA, where it has primarily been identified through the use of relative dating and biostratigraphy. The onset of SPICE is generally accepted to correspond with the second wave of the End-Marjuman Biomere Extinction, and its termination corresponds to the End-Steptoean Biomere Extinction. [1] Using trilobite and brachiopod index fossils linked to these extinctions, the upper and lower boundaries of the event can be defined. The beginning of the SPICE is identified by the extinction of shallow water polymerid trilobites, later replaced by deep water olenimorph trilobites following the observed peak δ13C value of the SPICE event. [5] The age of SPICE can also be determined based on its correlation with the well-known Sauk II- Sauk III Sequence boundary in North America. Furthermore, in addition to biostratigraphic markers the 3 million year time frame of the SPICE event has also been determined using calculated deposition rates and the length of some of the more extensively studied SPICE sequences. [2]

Localities, geology and δ13C characteristics

Localities

A map of SPICE localities during the upper Cambrian (500 Ma). Points on the map denote the locations of formations and the color indicates the paleo-water depth. Modified image is originally sourced from Pulsipher et al., 2021. Upper Cambrian SPICE Map.png
A map of SPICE localities during the upper Cambrian (500 Ma). Points on the map denote the locations of formations and the color indicates the paleo-water depth. Modified image is originally sourced from Pulsipher et al., 2021.

The SPICE event is expressed globally with known formations in 11 countries: United States, China, Australia, South Korea, Argentina, Canada, France, Kazakhstan, Scotland and Sweden (ordered by greatest to least number of localities). These locations span 4 modern continents (North America, Asia, Australia, Europe and South America), and represent 5 upper Cambrian paleocontinents: Laurentia, Gondwana, Kazakhstania, Siberia, [2] and Baultica. [6] All formations containing SPICE intervals formed between the paleolatitudes of 30°N and 60°S. [2] For a full list of SPICE localities and formation see the following maps and table.

Steptoean positive carbon isotope excursion
Modern localities of formations containing the SPICE excursion. See accompanying table for more detail.
Localities where the SPICE has been observed
(average shifts in δ13C values are derived from the Pulsipher et al. SPICEraq dataset [2] )
Modern countryPaleocontinentAverage shift
in δ13C
values (‰)		Formation
United States
(14 localities)		Laurentia+3.18 ‰Nevada:

Utah:

  • House Range [7] [3] [8]
  • Lawson Cove Range [9] [10]
  • Upper Nouman and lower St. Charles formations [11]

Southern Appalachians:

  • Copper Ridge Dolomites, Knox Group [12] [13] [14]
  • Maynardville Formation, Conasauga Group [12] [5]
  • Nolichucky Formation, Conasauga Group [5] [15] [16]

Other Areas:

  • Eau Claire Formation, Kentucky [17]
  • Franconia Formation, Illinois [18]
  • Rhinehart A-1 corehole (Hollandale "Embayment"), central Iowa [11]
  • Schodack Formation, New York [19]
  • Upper Bonneterre & Davis Formation, Southern Missouri [20] [21]
  • Wind River Range, Wyoming [7]
China
(8 localities)		Gondwana+3.15 ‰North China:
  • Changshan Formation, Tangwangzhai section, Gushan, Shangdong Province [22]
  • Chaomidian Formation, Shandong Province [23] [24]
  • Gushan Formation [23] [24]
  • Huangyangshan (HYS) section, Shandong Province [25] [26]

South China:

  • Huaqiao Formation, Wangcun & Paibi section, Hunan Province [22] [27]
  • Huayansi Formation, Duibian A and B sections, western Zhejiang [25] [26]
  • Upper Chefu & lower Bitiao Formation, Wa'ergang section, Northern Hunan Province [27] [26]

Other Areas:

  • Yaerdang Mountain profile, North-West China [28]
Australia
(4 localities)
[ Looks like 5 ]		Gondwana+4.16 ‰ Queensland:

Northern Australia:

  • Arrinthrunga Formation, southern Georgina Basin [29]

Central Australia:

  • Upper Shannon Formation, NE Amadeus Basin [30]
  • Goyder Formation, Amadeus Basin [31]
South Korea
(2 localities)		Gondwana+2.89 ‰
  • Machari Formation, Gangweon Province [32]
  • Sesong Formation [33]
Argentina
(2 localities)		Gondwana+4.15 ‰
  • La Flecha Formation [34]
  • Zonda Formation [34]
Canada
(2 localities)		Laurentia+3.02 ‰
  • March Point formation, Port au Port group, Newfoundland [11] [35] [36]
  • Petit Jadin formation, Port au Port group, Newfoundland [36]
France
(2 localities)		Gondwana+5.11 ‰
  • Val d'Homs formation, Montagne Noire [37]
  • La Gardie formation, Montagne Noire [37]
Kazakhstan
(1 locality)		Kazakhstania+5.34 ‰
  • Furongian Kyrshabakty section, southern Kazakhstan [38]
Scotland
(1 locality)		Laurentia+3.42 ‰
  • Eilean Dubh Formation, Northern Scotland [39]
Russia
(1 locality)		Siberia+4.32 ‰
  • Kulyumbe Formation, Siberian Platform, Siberia [40]
Sweden
(1 locality)		Baltica+1.5 ‰ [41]
  • Alum Shale Formation [6]

Geology

Formations containing SPICE excursions are highly variable with geologic characteristics varying greatly amongst localities. Stratigraphic thickness in particular has very large ranges between locations, with the smallest being the Wangliangyu section of China which is less than 3m. This thickness is in contrast to the Kulyumbe section of Siberia which is greater than 800m. This variability of stratigraphic thickness suggests that the regional deposition rates during the 497 Ma to 494 Ma SPICE period were not globally uniform and more regionally dependent. [2]

Furthermore, formations containing the SPICE excursion represent a wide variety of lithologies, facies and water depths. In terms of lithology, all SPICE intervals are contained within carbonate units within carbonate and silicate sequences. The most common lithology for SPICE intervals are micritic limestones, or carbonate shales, generally interbedded with thin layers of calcareous mudstone. [21] [1] SPICE intervals have also been observed in dolostone units, however these are not as common as the carbonate rocks. [2] SPICE intervals are also highly variable when it comes to facies, with examples for shallow, intermediate and deep water settings (see map in the localities section). [2] Considering the two most prominent areas of study, Laurentian formations (USA) tend to have stronger representation from shallow and intermediate facies (shallow/ near shore, shelf, intrashelf basin), [5] [21] while Gondwanan sections (China & Australia) have better representation of deep water facies (slope and basin), along with shallow and intermediate facies. [2]

Stages of SPICE

The six stages of the SPICE. The red line indicates the d13C value. Plot modified from Pulsipher et al., 2021 and Zhang et al., 2023. SPICE Plot.png
The six stages of the SPICE. The red line indicates the δ13C value. Plot modified from Pulsipher et al., 2021 and Zhang et al., 2023.

Defining standard δ13C values of the SPICE interval, it can be noted the magnitude is highly variable from location to location, with maximum excursion values ranging from 0.64 ‰ to 8.03 ‰. Regardless of values though, the SPICE interval can be identified based on a similar pattern observed in each sequence. This pattern is identified based on 6 distinct stages: pre-SPICE, early SPICE, rising SPICE, [1] plateau, [2] falling SPICE, and post SPICE [1] (see figure for visual representation of each stage).

Stage 1: Pre-SPICE

All areas of the section prior to the onset of the SPICE interval. δ13C values remain near 0 ‰, similar to modern marine dissolved inorganic carbon. [1] [2]

Stage 2: Early SPICE

Onset of SPICE, characterized by a slow increase in δ13C from 0 to approximately 1 ‰, suggesting a gradual increase in organic carbon burial and decrease in oceanic 12C. [1] [2]

Stage 3: Rising SPICE

Rapid increase in δ13C from the early SPICE value to the max value. This shift in value is generally between 3 ‰ and 6 ‰, suggesting a rapid increase in organic carbon burial. [1] [2] The onset of the rising SPICE also generally corresponds to fossil indicators for the 2nd stage of the end-Marjuman biomere extinction.

Stage 4: Plateau

δ13C values fluctuate but remain near the maximum value for a period of time. This stage is not observed in all SPICE intervals. After reaching the maximum value, most intervals proceed immediately into stage 5, the falling SPICE. [2]

Stage 5: Falling SPICE

Rapid decrease from the maximum δ13C value to near the standard ocean water value (0 ‰). The rate of decrease in the falling SPICE is generally more rapid then the rate of increase in the Rising SPICE. Generally interpreted as ocean water returning to standard δ13C levels. [1] [2]

Stage 6: Post SPICE

All areas of the section immediately following the termination of SPICE. [1] [2]

Factors affecting the magnitude of the δ13C anomaly

Despite being a global event, the magnitude of δ13C values observed within a SPICE interval appear to be highly affected by a variety of local conditions. A few common trends that have been determined are as follows:

  1. Higher paleolatitude formations (greater than 30°S) tend to have lower δ13C values throughout the sequence.
  2. Shallower facies have lower values than deeper facies.
  3. Limestone tends to have marginally higher δ13C than dolostone. [2]

Proposed mechanism

Regional sea level changes, [22] [11] cooling of upper sea water from the deep ocean, [1] ocean anoxia/euoxia, [9] [1] and trilobite and brachiopod extinctions [5] [30] are all associated with the SPICE event. This combination of factors creates the conditions for the primary mechanism of formation for the SPICE, an increase in the burial of organic carbon, caused by increased primary productivity (e.g. photosynthesis).

The spread of deep ocean anoxia or euxinia, indicated by a positive correlated δ34SCAS excursion and increased pyrite burial, [9] created conditions encouraging the preservation of deposited organic material and stressful conditions for the marine organisms. [1] Initially, these conditions would have spread slowly, limited to deep environments and having small impacts on the global carbon system. This slow initial change is represented by the gradual and small δ13C changes of the early SPICE. As time passed though, causes of anoxic/euxinia conditions increased and moving up the shelf into shallower facies. This combined with other factors such as ocean level regression (such as the Sauk II-Sauk III in North America), [11] and global cooling of the atmosphere and oceans, increased pressure was imposed on ocean ecosystems. This increase in pressure likely triggered the second wave of the End-Marjuman Biomere Extinction, [1] resulting in the disappearance of many shallow-water trilobite and brachiopod species from the fossil record at this time. [5]

With the extinction of these trilobites and brachiopods, photosynthetic primary producers likely flourished as a result of decreased predation. This combined with an increase in burial from expanding anoxic conditions and less bioturbation from now extinct ocean floor dwelling organisms would likely cause δ13C values to sharply rise. [1] This sharp rise is captured in the SPICE through the rising SPICE stage, in which δ13C values reflect this rapid change in primary productivity and burial following the extinction. [2] Finally, moving out of the End-Marjuman Biomere Extinction and into the falling SPICE, oceans likely experience significant recovery in biodiversity. Following the extinction of shallow water taxa, the better adapted deep water olenimorph trilobite fauna begin to diversify. Filling the shallow water environments left vacant by the End-Marjuman Biomere extinction. [5] This return of secondary producers, along with reductions in anoxic conditions caused by changes in climate and stabilizing ocean levels causing reductions in primary productivity and organic carbon burial. [1] Rapidly reducing δ13C values, and stabilizing to more standard ocean δ13C values observed in the post SPICE stage. [2]

Controversies

One question still being researched in relation to the SPICE is the potential of an undescribed negative δ13C excursion directly before the early SPICE stage. This undetermined negative excursion does not appear at all localities. It is theorized this excursion may have remained undetected as a result of sampling discrepancies or because it only represents a local event. [2] Another key controversy of the SPICE is its exact timing in relation to the end-Marjuman biomere extinction, and the end-Steptoean biomere extinction. Currently research can only link the onset of the SPICE to the second wave of the end-Marjuman extinction. More research is required to determine if and how the first wave of the extinction relates to SPICE. [5] Furthermore, there is still a great deal of questions about SPICE and its implication for large biodiversity events occurring in the post SPICE such as the end-Steptoean biomere extinction and Great Ordovician Biodiversification Event (GOBE). Some research suggests that the turnover in trilobite and brachiopod species that occurred during the SPICE may have a direct correlation with these subsequent events. [2]

Comparison to other anomalies

Hirnantian Isotopic Carbon Excursion (HICE)

Similar to the SPICE, the HICE event is linked to changes in the climate and falls in global sea level, resulting in anoxic conditions and an increase in organic carbon burial. δ13C values for the HICE have a similar positive magnitude, ranging from ~+2‰ to ~+7‰. Furthermore, similar to SPICE, the HICE event likely occurred over a small time period. Occurring in the upper Ordovician and lasting less than 1.3 Ma. One difference between the HICE and SPICE though, is the HICE is generally restricted to shallow water carbonate facies. [42]

Silurian Ireviken event

This early Silurian (431 Ma) δ13C excursion also shows similarities to the SPICE event, with positive max δ13C values around 4.5‰. Similar to the SPICE, research suggests this event is linked to falling ocean levels and a faunal turnover. Similar to SPICE, the Ireviken event also has a positive δ34SCAS excursion correlated with the δ13C excursion. Suggesting the influence of anoxic conditions and increased organic carbon burial. Furthermore, the Ireviken event also has global occurrences, but their expression is highly influenced by local facies characteristics, similar to SPICE. [43]

Related Research Articles

<span class="mw-page-title-main">Ediacaran</span> Third and last period of the Neoproterozoic Era

The Ediacaran is a geological period of the Neoproterozoic era that spans 96 million years from the end of the Cryogenian period at 635 Mya to the beginning of the Cambrian period at 538.8 Mya. It is the last period of the Proterozoic eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian period marks the start of the Phanerozoic eon, where recognizable fossil evidence of life becomes common.

<span class="mw-page-title-main">Paleocene–Eocene Thermal Maximum</span> Global warming about 55 million years ago

The Paleocene–Eocene thermal maximum (PETM), alternatively "Eocene thermal maximum 1" (ETM1), and formerly known as the "Initial Eocene" or "Late Paleocene thermal maximum", was a geologically brief time interval characterized by a 5–8 °C global average temperature rise and massive input of carbon into the ocean and atmosphere. The event began, now formally, at the time boundary between the Paleocene and Eocene geological epochs. The exact age and duration of the PETM remain uncertain, but it occurred around 55.8 million years ago (Ma) and lasted about 200 thousand years (Ka). The entire warm period lasted for about 200,000 years. Global temperatures increased by 5–8 °C.

<span class="mw-page-title-main">Late Ordovician mass extinction</span> Extinction event around 444 million years ago

The Late Ordovician mass extinction (LOME), sometimes known as the end-Ordovician mass extinction or the Ordovician-Silurian extinction, is the first of the "big five" major mass extinction events in Earth's history, occurring roughly 445 million years ago (Ma). It is often considered to be the second-largest known extinction event, in terms of the percentage of genera that became extinct. Extinction was global during this interval, eliminating 49–60% of marine genera and nearly 85% of marine species. Under most tabulations, only the Permian-Triassic mass extinction exceeds the Late Ordovician mass extinction in biodiversity loss. The extinction event abruptly affected all major taxonomic groups and caused the disappearance of one third of all brachiopod and bryozoan families, as well as numerous groups of conodonts, trilobites, echinoderms, corals, bivalves, and graptolites. Despite its taxonomic severity, the Late Ordovician mass extinction did not produce major changes to ecosystem structures compared to other mass extinctions, nor did it lead to any particular morphological innovations. Diversity gradually recovered to pre-extinction levels over the first 5 million years of the Silurian period.

The Furongian is the fourth and final epoch and series of the Cambrian. It lasted from 497 to 485.4 million years ago. It succeeds the Miaolingian series of the Cambrian and precedes the Lower Ordovician Tremadocian Stage. It is subdivided into three stages: the Paibian, Jiangshanian and the unnamed 10th stage of the Cambrian.

In the geologic timescale, the Capitanian is an age or stage of the Permian. It is also the uppermost or latest of three subdivisions of the Guadalupian Epoch or Series. The Capitanian lasted between 264.28 and 259.51 million years ago. It was preceded by the Wordian and followed by the Wuchiapingian.

The Paibian is the lowest stage of Furongian series of the Cambrian. It follows the Guzhangian and is succeeded by the Jiangshanian Stage. The base is defined as the first appearance of the trilobite Glyptagnostus reticulatus around 497 million years ago. The top, or the base of the Jiangshanian is defined as the first appearance of the trilobite Agnostotes orientalis around 494 million years ago.

Cap carbonates are layers of distinctively textured carbonate rocks that occur at the uppermost layer of sedimentary sequences reflecting major glaciations in the geological record.

The Lau event was the last of three relatively minor mass extinctions during the Silurian period. It had a major effect on the conodont fauna, but barely scathed the graptolites, though they suffered an extinction very shortly thereafter termed the Kozlowskii event that some authors have suggested was coeval with the Lau event and only appears asynchronous due to taphonomic reasons. It coincided with a global low point in sea level caused by glacioeustasy and is closely followed by an excursion in geochemical isotopes in the ensuing late Ludfordian faunal stage and a change in depositional regime.

<i>δ</i><sup>13</sup>C Measure of relative carbon-13 concentration in a sample

In geochemistry, paleoclimatology, and paleoceanography δ13C is an isotopic signature, a measure of the ratio of the two stable isotopes of carbon—13C and 12C—reported in parts per thousand. The measure is also widely used in archaeology for the reconstruction of past diets, particularly to see if marine foods or certain types of plants were consumed.

The end-Ediacaran extinction is a mass extinction believed to have occurred near the end of the Ediacaran period, the final period of the Proterozoic eon. Evidence suggesting that such a mass extinction occurred includes a massive reduction in diversity of acritarchs, the sudden disappearance of the Ediacara biota and calcifying organisms, and the time gap before Cambrian organisms "replaced" them. Some lines of evidence suggests that there may have been two distinct pulses of the extinction event, one occurring 550 million years ago and the other 539 million years ago.

The Mulde event was an anoxic event, and marked the second of three1 relatively minor mass extinctions during the Silurian period. It coincided with a global drop in sea level, and is closely followed by an excursion in geochemical isotopes. Its onset is synchronous with the deposition of the Fröjel Formation in Gotland. Perceived extinction in the conodont fauna, however, likely represent a change in the depositional environment of sedimentary sequences rather than a genuine biological extinction.

<span class="mw-page-title-main">End-Botomian mass extinction</span> Two extinction intervals that occurred during Stages 4 and 5 of the Cambrian Period

The end-Botomian mass extinction event, also known as the late early Cambrian extinctions, refer to two extinction intervals that occurred during Stages 4 and 5 of the Cambrian Period, approximately 513 to 509 million years ago. Estimates for the decline in global diversity over these events range from 50% of marine genera up to 80%. Among the organisms affected by this event were the small shelly fossils, archaeocyathids, trilobites, brachiopods, hyoliths, and mollusks.

The Cenomanian-Turonian boundary event, also known as the Cenomanian-Turonian extinction, Cenomanian-Turonian Oceanic Anoxic Event, and referred to also as the Bonarelli Event or Level, was an anoxic extinction event in the Cretaceous period. The Cenomanian-Turonian oceanic anoxic event is considered to be the most recent truly global oceanic anoxic event in Earth's geologic history. There was a large carbon cycle disturbance during this time period, signified by a large positive carbon isotope excursion. However, apart from the carbon cycle disturbance, there were also large disturbances in the ocean's nitrogen, oxygen, phosphorus, sulphur, and iron cycles.

The Drumian is a stage of the Miaolingian Series of the Cambrian. It succeeds the Wuliuan and precedes the Guzhangian. The base is defined as the first appearance of the trilobite Ptychagnostus atavus around 504.5 million years ago. The top is defined as the first appearance of another trilobite Lejopyge laevigata around 500.5 million years ago.

The Carnian pluvial episode (CPE), often called the Carnian pluvial event, was an interval of major change in global climate that was synchronous with significant changes in Earth's biota both in the sea and on land. It occurred during the latter part of the Carnian Stage, a subdivision of the late Triassic period, and lasted for perhaps 1–2 million years.

Euxinia or euxinic conditions occur when water is both anoxic and sulfidic. This means that there is no oxygen (O2) and a raised level of free hydrogen sulfide (H2S). Euxinic bodies of water are frequently strongly stratified; have an oxic, highly productive, thin surface layer; and have anoxic, sulfidic bottom water. The word "euxinia" is derived from the Greek name for the Black Sea (Εὔξεινος Πόντος (Euxeinos Pontos)) which translates to "hospitable sea". Euxinic deep water is a key component of the Canfield ocean, a model of oceans during part of the Proterozoic eon (a part specifically known as the Boring Billion) proposed by Donald Canfield, an American geologist, in 1998. There is still debate within the scientific community on both the duration and frequency of euxinic conditions in the ancient oceans. Euxinia is relatively rare in modern bodies of water, but does still happen in places like the Black Sea and certain fjords.

The Toarcian extinction event, also called the Pliensbachian-Toarcian extinction event, the Early Toarcian mass extinction, the Early Toarcian palaeoenvironmental crisis, or the Jenkyns Event, was an extinction event that occurred during the early part of the Toarcian age, approximately 183 million years ago, during the Early Jurassic. The extinction event had two main pulses, the first being the Pliensbachian-Toarcian boundary event (PTo-E). The second, larger pulse, the Toarcian Oceanic Anoxic Event (TOAE), was a global oceanic anoxic event, representing possibly the most extreme case of widespread ocean deoxygenation in the entire Phanerozoic eon. In addition to the PTo-E and TOAE, there were multiple other, smaller extinction pulses within this span of time.

The Selli Event, also known as OAE1a, was an oceanic anoxic event (OAE) of global scale that occurred during the Aptian stage of the Early Cretaceous, about 120.5 million years ago (Ma). The OAE is associated with large igneous province volcanism and an extinction event of marine organisms driven by global warming, ocean acidification, and anoxia.

The Paquier Event (OAE1b) was an oceanic anoxic event (OAE) that occurred around 111 million years ago (Ma), in the Albian geologic stage, during a climatic interval of Earth's history known as the Middle Cretaceous Hothouse (MKH).

The Mid-Cenomanian Event (MCE) was an oceanic anoxic event that took place during the middle Cenomanian, as its name suggests, around 96.5 Ma.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Zhang, Lei; Algeo, Thomas J.; Zhao, Laishi; Dahl, Tais W.; Chen, Zhong-Qiang; Zhang, Zihu; Poulton, Simon W.; Hughes, Nigel C.; Gou, Xueqing; Li, Chao (2023-05-12). "Environmental and trilobite diversity changes during the middle-late Cambrian SPICE event". Geological Society of America Bulletin. doi:10.1130/b36421.1. ISSN   0016-7606.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Pulsipher, Mikaela A.; Schiffbauer, James D.; Jeffrey, Matthew J.; Huntley, John Warren; Fike, David A.; Shelton, Kevin L. (2021-01-01). "A meta-analysis of the Steptoean Positive Carbon Isotope Excursion: The SPICEraq database". Earth-Science Reviews. 212: 103442. Bibcode:2021ESRv..21203442P. doi:10.1016/j.earscirev.2020.103442. ISSN   0012-8252.
  3. 1 2 3 4 5 Saltzman, Matthew; Runnegar, Bruce; Lohmann, Kyger (1998-03-01). <0285:CISOUC>2.3.CO;2 "Carbon isotope stratigraphy of Upper Cambrian (Steptoean Stage) sequences of the eastern Great Basin: Record of a global oceanographic event". Geological Society of America Bulletin - GEOL SOC AMER BULL. 110 (3): 285–297. Bibcode:1998GSAB..110..285S. doi:10.1130/0016-7606(1998)110<0285:CISOUC>2.3.CO;2.
  4. ↑ Brasier, M. D. (1993-01-01). "Towards a carbon isotope stratigraphy of the Cambrian System: potential of the Great Basin succession". Geological Society, London, Special Publications. 70 (1): 341–350. Bibcode:1993GSLSP..70..341B. doi:10.1144/GSL.SP.1993.070.01.22. ISSN   0305-8719.
  5. 1 2 3 4 5 6 7 8 Gerhardt, Angela M.; Gill, Benjamin C. (2016-11-01). "Elucidating the relationship between the later Cambrian end-Marjuman extinctions and SPICE Event". Palaeogeography, Palaeoclimatology, Palaeoecology. 461: 362–373. Bibcode:2016PPP...461..362G. doi:10.1016/j.palaeo.2016.08.031.
  6. 1 2 Rooney, Alan D.; Millikin, Alexie E.G.; Ahlberg, Per (2022-03-24). "Re-Os geochronology for the Cambrian SPICE event: Insights into euxinia and enhanced continental weathering from radiogenic isotopes". Geology. 50 (6): 716–720. Bibcode:2022Geo....50..716R. doi:10.1130/g49833.1. ISSN   0091-7613.
  7. 1 2 3 Saltzman, Matthew R.; Davidson, Jon P.; Holden, Peter; Runnegar, Bruce; Lohmann, Kyger C. (1995-10-01). "Sea-level-driven changes in ocean chemistry at an Upper Cambrian extinction horizon". Geology (Boulder). 23 (10): 893–896. Bibcode:1995Geo....23..893S. doi:10.1130/0091-7613(1995)023<0893:SLDCIO>2.3.CO;2.
  8. 1 2 Baker, Jonathan Lloyd (2010). "Carbon isotopic fractionation across a late Cambrian carbonate platform: A regional response to the spice event as recorded in the Great Basin, United States". ProQuest Dissertations Publishing.
  9. 1 2 3 4 5 Gill, Benjamin C.; Lyons, Timothy W.; Young, Seth A.; Kump, Lee R.; Knoll, Andrew H.; Saltzman, Matthew R. (2011-01-06). "Geochemical evidence for widespread euxinia in the Later Cambrian ocean". Nature. 469 (7328): 80–83. Bibcode:2011Natur.469...80G. doi:10.1038/nature09700. ISSN   1476-4687. PMID   21209662.
  10. ↑ Olsen, Amelia E. (2022-10-10). "Skeletal Abundance During the Cambrian Spice Event, Western Utah". Geological Society of America. Geological Society of America Abstracts with Programs. 54 (4). GSA. doi:10.1130/abs/2022am-378780.
  11. 1 2 3 4 5 Saltzman, Matthew R.; Cowan, Clinton A.; Runkel, Anthony C.; Runnegar, Bruce; Stewart, Michael C.; Palmer, Allison R. (2004-05-01). "The Late Cambrian Spice (δ13C) Event and the Sauk II-SAUK III Regression: New Evidence from Laurentian Basins in Utah, Iowa, and Newfoundland". Journal of Sedimentary Research. 74 (3): 366–377. Bibcode:2004JSedR..74..366S. doi:10.1306/120203740366.
  12. 1 2 Glumac, Bosiljka; Walker, Kenneth R (1998-11-01). "A Late Cambrian positive carbon-isotope excursion in the Southern Appalachians; relation to biostratigraphy, sequence stratigraphy, environments of deposition, and diagenesis". Journal of Sedimentary Research. 68 (6): 1211–1222. Bibcode:1998JSedR..68.1212G. doi:10.2110/jsr.68.1212.
  13. ↑ Glumac, Bosiljka (2011-10-01). "High-resolution stratigraphy and correlation of Cambrian strata using carbon isotopes: an example from the southern Appalachians, USA". Carbonates and Evaporites. 26 (3): 287–297. Bibcode:2011CarEv..26..287G. doi:10.1007/s13146-011-0065-2. ISSN   1878-5212.
  14. ↑ Mackey, Justin E.; Stewart, Brian W. (2019-08-15). "Evidence of SPICE-related anoxia on the Laurentian passive margin: Paired δ13C and trace element chemostratigraphy of the upper Conasauga Group, Central Appalachian Basin". Palaeogeography, Palaeoclimatology, Palaeoecology. 528: 160–174. Bibcode:2019PPP...528..160M. doi:10.1016/j.palaeo.2019.04.018.
  15. ↑ Gerhardt, Angela M.; Gill, Benjamin C. (2016-11-01). "Elucidating the relationship between the later Cambrian end-Marjuman extinctions and SPICE Event". Palaeogeography, Palaeoclimatology, Palaeoecology. 461: 362–373. Bibcode:2016PPP...461..362G. doi:10.1016/j.palaeo.2016.08.031. ISSN   0031-0182.
  16. ↑ LeRoy, Matthew A.; Gill, Benjamin C. (2019-07-01). "Evidence for the development of local anoxia during the Cambrian SPICE event in eastern North America". Geobiology. 17 (4): 381–400. Bibcode:2019Gbio...17..381L. doi:10.1111/gbi.12334. ISSN   1472-4677. PMID   30729650.
  17. ↑ LeRoy, Matthew A.; Gill, Benjamin C. (2019-07-01). "Evidence for the development of local anoxia during the Cambrian SPICE event in eastern North America". Geobiology. 17 (4): 381–400. Bibcode:2019Gbio...17..381L. doi:10.1111/gbi.12334. ISSN   1472-4677. PMID   30729650.
  18. ↑ Labotka, Dana M.; Freiburg, Jared T. (2020). "Geochemical Preservation of the Steptoean Positive Carbon Isotope Excursion (SPICE) Event in Dolomites of the Furongian Franconia Formation in the Illinois Basin". Illinois State Geological Survey, Prairie Research Institute. 600.
  19. ↑ Glumac, Bosiljka; Mutti, Laurel E. (2007-05-01). "Late Cambrian (Steptoean) sedimentation and responses to sea-level change along the northeastern Laurentian margin: Insights from carbon isotope stratigraphy". Geological Society of America Bulletin. 119 (5–6): 623–636. Bibcode:2007GSAB..119..623G. doi:10.1130/B25897.1.
  20. ↑ He, Zhenhao (1995). "Sedimentary Facies and Variation of Stable Isotope Composition of Upper Cambrian to Lower Ordovician Strata in Southern Missouri: Implications for the Origin of MVT Deposits, and the Geochemical and Hydrological Features of Regional Ore-Forming Fluids". University of Missouri-Rolla. 9611858.
  21. 1 2 3 Schiffbauer, James D; Huntley, John Warren; Fike, David A; Jeffrey, Matthew Jarrell; Gregg, Jay M; Shelton, Kevin L (2017-03-03). "Decoupling biogeochemical records, extinction, and environmental change during the Cambrian SPICE event". Science Advances. 3 (3): e1602158. Bibcode:2017SciA....3E2158S. doi:10.1126/sciadv.1602158. PMC   5336349 . PMID   28275734 – via 10.1126/ sciadv.1602158.
  22. 1 2 3 4 Saltzman, Matthew R.; Ripperdan, Robert L.; Brasier, M.D.; Lohmann, Kyger C.; Robison, Richard A.; Chang, W.T.; Peng, Shanchi; Ergaliev, E.K.; Runnegar, Bruce (2000-10-01). "A global carbon isotope excursion (SPICE) during the Late Cambrian: relation to trilobite extinctions, organic-matter burial and sea level". Palaeogeography, Palaeoclimatology, Palaeoecology. 162 (3–4): 211–223. Bibcode:2000PPP...162..211S. doi:10.1016/S0031-0182(00)00128-0.
  23. 1 2 Chen, Jitao; Chough, S.K.; Han, Zuozhen; Lee, Jeong-Hyun (2011-01-01). "An extensive erosion surface of a strongly deformed limestone bed in the Gushan and Chaomidian formations (late Middle Cambrian to Furongian), Shandong Province, China: Sequence–stratigraphic implications". Sedimentary Geology. 233 (1–4): 129–149. Bibcode:2011SedG..233..129C. doi:10.1016/j.sedgeo.2010.11.002.
  24. 1 2 Wang, Zhaopeng; Chen, Jitao; Liang, Taitao; Yuan, Jinliang; Han, Chao; Liu, Jiaye; Zhu, Chenlin; Zhu, Decheng; Han, Zuozhen (2020-05-15). "Spatial variation in carbonate carbon isotopes during the Cambrian SPICE event across the eastern North China Platform". Palaeogeography, Palaeoclimatology, Palaeoecology. 546: 109669. Bibcode:2020PPP...54609669W. doi:10.1016/j.palaeo.2020.109669.
  25. 1 2 Zuo, Jingxun; Peng, Shanchi; Qi, Yuping; Zhu, Xuejian; Bagnoli, Gabriella; Fang, Huaibin (2018-06-01). "Carbon-Isotope Excursions Recorded in the Cambrian System, South China: Implications for Mass Extinctions and Sea-Level Fluctuations". Journal of Earth Science. 29 (3): 479–491. Bibcode:2018JEaSc..29..479Z. doi:10.1007/s12583-017-0963-x. ISSN   1674-487X.
  26. 1 2 3 Li, Dandan; Zhang, Xiaolin; Hu, Dongping; Chen, Xiaoyan; Huang, Wei; Zhang, Xu; Li, Menghan; Qin, Liping; Peng, Shanchi; Shen, Yanan (2018-07-01). "Evidence of a large δ13Ccarb and δ13Corg depth gradient for deep-water anoxia during the late Cambrian SPICE event". Geology. 46 (7): 631–634. Bibcode:2018Geo....46..631L. doi:10.1130/G40231.1. ISSN   0091-7613.
  27. 1 2 Zhu, Mao-Yan; Zhang, Jun-Ming; Li, Guo-Xiang; Yang, Ai-Hua (2004-03-01). "Evolution of C isotopes in the Cambrian of China: implications for Cambrian subdivision and trilobite mass extinctions". Geobios. 37 (2): 287–301. Bibcode:2004Geobi..37..287Z. doi:10.1016/j.geobios.2003.06.001.
  28. ↑ Liu, Hu; Liao, Zewen; Zhang, Haizu; Tian, Yankuan; Cheng, Bin; Yang, Shan (2017-01-01). "Stable isotope (δ13Cker, δ13Ccarb, δ18Ocarb) distribution along a Cambrian outcrop section in the eastern Tarim Basin, NW China and its geochemical significance". Geoscience Frontiers. 8 (1): 163–170. doi: 10.1016/j.gsf.2016.02.004 .
  29. ↑ Lindsay, John F.; Kruse, Peter D.; Green, Owen R.; Hawkins, Elizabeth; Brasier, Martin D.; Cartlidge, Julie; Corfield, Richard M. (2005-12-01). "The Neoproterozoic–Cambrian record in Australia: A stable isotope study". Precambrian Research. 143 (1–4): 113–133. Bibcode:2005PreR..143..113L. doi:10.1016/j.precamres.2005.10.002.
  30. 1 2 Smith, Patrick M.; Brock, Glenn A.; Paterson, John R. (2020-01-02). "Shelly fauna from the Cambrian (Miaolingian, Guzhangian) Shannon Formation and the SPICE event in the Amadeus Basin, Northern Territory". Alcheringa: An Australasian Journal of Palaeontology. 44 (1): 1–24. Bibcode:2020Alch...44....1S. doi:10.1080/03115518.2019.1660405. ISSN   0311-5518.
  31. ↑ Schmid, Susanne (2017-02-20). "Chemostratigraphy and palaeo-environmental characterisation of the Cambrian stratigraphy in the Amadeus Basin, Australia". Chemical Geology. 451: 169–182. Bibcode:2017ChGeo.451..169S. doi:10.1016/j.chemgeo.2017.01.019.
  32. ↑ Chung, Gong-Soo; Lee, Jeong-Gu; Lee, Kwang-Sik (2011-09-30). "Stable Carbon Isotope Stratigraphy of the Cambrian Machari Formation in the Yeongweol Area, Gangweon Province, Korea". Journal of the Korean Earth Science Society. 32 (5): 437–452. doi:10.5467/JKESS.2011.32.5.437. ISSN   1225-6692.
  33. ↑ Lim, Jong Nam; Chung, Gong Soo; Park, Tae-Yoon S. (2015-12-31). "Lithofacies and Stable Carbon Isotope Stratigraphy of the Cambrian Sesong Formation in the Taebaeksan Basin, Korea". Journal of the Korean Earth Science Society. 36 (7): 617–631. doi:10.5467/JKESS.2015.36.7.617. ISSN   1225-6692.
  34. 1 2 Sial, A.N.; Peralta, S.; Ferreira, V.P.; Toselli, A.J.; Aceñolaza, F.G.; Parada, M.A.; Gaucher, C.; Alonso, R.N.; Pimentel, M.M. (2008-07-01). "Upper Cambrian carbonate sequences of the Argentine Precordillera and the Steptoean C-Isotope positive excursion (SPICE)". Gondwana Research. 13 (4): 437–452. Bibcode:2008GondR..13..437S. doi:10.1016/j.gr.2007.05.001. hdl: 11336/70755 .
  35. ↑ Hurtgen, Matthew T.; Pruss, Sara B.; Knoll, Andrew H. (2009-05-15). "Evaluating the relationship between the carbon and sulfur cycles in the later Cambrian ocean: An example from the Port au Port Group, western Newfoundland, Canada". Earth and Planetary Science Letters. 281 (3–4): 288–297. Bibcode:2009E&PSL.281..288H. doi:10.1016/j.epsl.2009.02.033.
  36. 1 2 Barili, Rosalia; Neilson, Joyce Elaine; Brasier, Alexander Thomas; Goldberg, Karin; Pastro Bardola, Tatiana; De Ros, Luiz Fernando; Leng, Melanie (2018-11-01). "Carbon isotopes, stratigraphy, and environmental change: the Middle–Upper Cambrian Positive Excursion (SPICE) in Port au Port Group, western Newfoundland, Canada". Canadian Journal of Earth Sciences. 55 (11): 1209–1222. Bibcode:2018CaJES..55.1209B. doi:10.1139/cjes-2018-0025. hdl: 1807/90557 . ISSN   0008-4077.
  37. 1 2 Alvaro, J. J.; Bauluz, B.; Subias, I.; Pierre, C.; Vizcaino, D. (2008-07-01). "Carbon chemostratigraphy of the Cambrian-Ordovician transition in a midlatitude mixed platform, Montagne Noire, France". Geological Society of America Bulletin. 120 (7–8): 962–975. Bibcode:2008GSAB..120..962A. doi:10.1130/B26243.1. ISSN   0016-7606.
  38. ↑ Wotte, Thomas; Strauss, Harald (2015-11-01). "Questioning a widespread euxinia for the Furongian (Late Cambrian) SPICE event: indications from δ 13 C, δ 18 O, δ 34 S and biostratigraphic constraints". Geological Magazine. 152 (6): 1085–1103. Bibcode:2015GeoM..152.1085W. doi:10.1017/S0016756815000187. ISSN   0016-7568.
  39. ↑ Pruss, Sara B.; Jones, David S.; Fike, David A.; Tosca, Nicholas J.; Wignall, Paul B. (2019-05-01). "Marine anoxia and sedimentary mercury enrichments during the Late Cambrian SPICE event in northern Scotland". Geology. 47 (5): 475–478. Bibcode:2019Geo....47..475P. doi:10.1130/G45871.1. ISSN   0091-7613.
  40. ↑ Kouchinsky, Artem; Bengtson, Stefan; Gallet, Yves; Korovnikov, Igor; Pavlov, Vladimir; Runnegar, Bruce; Shields, Graham; Veizer, Jan; Young, Edward; Ziegler, Karen (2008-05-23). "The SPICE carbon isotope excursion in Siberia: a combined study of the upper Middle Cambrian–lowermost Ordovician Kulyumbe River section, northwestern Siberian Platform". Geological Magazine. 145 (5): 609–622. Bibcode:2008GeoM..145..609K. doi:10.1017/S0016756808004913. ISSN   0016-7568.
  41. ↑ Ahlberg, Per; Axheimer, Niklas; Babcock, Loren E.; Eriksson, Mats E.; Schmitz, Birger; Terfelt, Fredrik (2009-03-01). "Cambrian high-resolution biostratigraphy and carbon isotope chemostratigraphy in Scania, Sweden: first record of the SPICE and DICE excursions in Scandinavia". Lethaia. 42 (1): 2–16. Bibcode:2009Letha..42....2A. doi:10.1111/j.1502-3931.2008.00127.x. ISSN   0024-1164.
  42. ↑ Jones, David S.; Brothers, R. William; Crüger Ahm, Anne-Sofie; Slater, Nicholas; Higgins, John A.; Fike, David A. (2020-02-01). "Sea level, carbonate mineralogy, and early diagenesis controlled δ13C records in Upper Ordovician carbonates". Geology. 48 (2): 194–199. Bibcode:2020Geo....48..194J. doi: 10.1130/G46861.1 . ISSN   0091-7613.
  43. ↑ Rose, Catherine V.; Fischer, Woodward W.; Finnegan, Seth; Fike, David A. (2019-02-01). "Records of carbon and sulfur cycling during the Silurian Ireviken Event in Gotland, Sweden". Geochimica et Cosmochimica Acta. 246: 299–316. Bibcode:2019GeCoA.246..299R. doi:10.1016/j.gca.2018.11.030. hdl: 10023/19002 .
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.