sign in sign up
<<
Home , Katian, Lopingian, Pragian

GeoArabia, Vol. 12, No. 4, 2007 Gulf PetroLink, Bahrain STRATIGRAPHIC NOTE

Revised ages (Ma) and accuracy of Arabian Plate maximum flooding surfaces

Moujahed Al-Husseini

ssigning an age in million before of Sharland et al. (2001, 2004) using GTS 2004. Apresent (Ma) to maximum flooding surfaces Changes in the age estimate for an MFS mostly (MFS, or any other isochronous sequence occur because the bounding ages of stages were stratigraphic surface) can be a misleading revised due to better radiometric and other age- practice unless the level of accuracy is adequately dating techniques. The dating of an MFS may also quantified. change because either (1) the reference section pick was revised (i.e. it is placed in a different Nonetheless, many authors (e.g. Haq et al., 1988; body of rock belonging to a different biozone), Sharland et al., 2001, 2004; Haq and Al-Qahtani, or (2) the biostratigraphy of the reference section 2005; Simmons et al., 2007) have assigned precise was revised by, for example, the discovery of ages to MFS and sequence boundaries using new fossils offering a more correct biozonal different vintages of the geological time scale assignment. (GTS). This practice remains useful because it provides very approximate constraints on rates In Table 1 the 63 MFS age estimates of deposition, durations of sequences and their (Sharland et al., 2001, 2004) are compared to those orders, and hiatuses. This note compares how of Haq et al. (1988), Haq and Al-Qahtani (2005) age revisions in GTS affect the numerical age and Simmons et al. (2007). The comparison does assignment of Arabian Plate MFS. not account for changes due to revised positions or biozones () of the MFS, and mostly Sharland et al. (2001, 2004, Table 1) published reflects GTS revisions. Column (1) of Table 2 the biozones, their corresponding stages and compares the age differences between Haq et estimated age values of 65 Arabian Plate MFS al. (1988) and Haq and Al-Qahtani (2005) for the based on the GTS 1996 (Gradstein and Ogg, 38 - MFS that were identified 1996). These authors also correlated the ages of in Arabia. Of these 38 MFS, 13 have ages that their Cenozoic and Mesozoic MFS to those of Haq shifted by less than 3.0 My, 11 shifted by 3.0–6.0 et al. (1988). Haq and Al-Qahtani (2005) adopted My and 14 shifted by more than 6.0 My. the 63 Phanerozoic MFS of Sharland et al. (2001, 2004), but did not consider Pc10 Shifts in age of 3.0 My or more are significant and Pc20. They positioned the remaining 63 MFS because the duration of a third-order sequence (with minor modifications) in the stratigraphic is generally estimated to be 2.0, 2.4 or 2.8 My column of Saudi Arabia, and revised their (Matthews and Frohlich, 2002). Age shifts of ages based on GTS 2004 (Gradstein et al., 2004; more than 3.0 My are substantial and reflect the see GTS 2004 in GeoArabia, 2007, v. 12, no. 1, inherent inaccuracy of GTSs from vintage-to- p. 208-209). vintage.

GTS 2004 has been ratified by the International Column (2) of Table 2 compares the age diffe- Commission on Stratigraphy (ICS) and includes rences between Sharland et al. (2001, 2004) based stage names that are recommended for global on GTS 1996 and Simmons et al. (2007) based on correlations (Gradstein et al., 2004; Gradstein GTS 2004 for the 63 Phanerozoic Arabian MFS. and Finney, 2007). The estimated ages of the Nearly half (27) have changed ages by one-or-less stage boundaries have been compared by the million years (My), approximately one quarter ICS across various vintages of the Geological (15) MFS shifted in age by 1.0–3.0 My. One-third Time Scale, starting with the GTS 1937 of Holmes (21) of the MFS shifted in age by more than 3.0 and ending with GTS 2004. These comparisons My. In some cases, several MFS were closely were reprinted by permission of the ICS in Al- spaced in Sharland et al. (2001, 2004) and the Husseini (2005, see Cenozoic Comparison Chart large shifts imply a different order. For example, on p. 140; Mesozoic Comparison Chart on p. 142; the MFS P20, P30 and P40 (Khuff and Comparison Chart on p. 144). sequences) only spanned 3.5 My in Sharland et al. (2001), suggesting fourth-order MFS; whereas Most recently Simmons et al. (2007) revised in Simmons et al. (2007) they span 13.0 My, thus the age estimates of the 63 Phanerozoic MFS implying they are third-order MFS.

167

Downloaded from http://pubs.geoscienceworld.org/geoarabia/article-pdf/12/4/167/4570151/husseini_strat_note.pdf by guest on 28 September 2021 Revised ages of Arabian Plate MFS an ridgian Stage me immeridgi Albian Simmons et al. (2001)

(2005) Haq and Al-Qahtani 122.5 124.5 Early (1988) ?111.0 Haq et al. 75 NA 152.50 151.8 Late K .25 NA 151.5 151.4 Late 1. 12.0 15.0 11.6 18.0 15.0 23.0 18.5 24.5 14.6 24.8 29.0 15.9 NA 14.5 33.0 18.5 NA 15.9 20.0 Late 35.0 17.5 58.0 24.0 Early Langhian 20.0 29.0 Mid- 56.5 33.0 24.5 Early Burdigalian 29.0 33.0 59.0 Late Early Rupelian 59.0 49.0 49.0 68.0 78.0 69.5 85.0 48.6 79.5 86.0 50.0 68.0 95.0 78.0 Late 70.0 85.0 94.7 78.0 Early 85.0 Mid- 95.0 95.5 Mid- 88.0 89.0 88.0 88.0 Early 93.0 91.5 93.0 93.0 Early Age Age Age Age 111.0 107.0 111.0 110.0 Early 116.0 ?111.0 117.0 119.0 Mid-Aptian 123.0 114.0 126.0 125.5 Late Barremian 126.0 116.5 129.0 129.0 Early Barremian 138.0 128.75 141.0 142.0 Late 143.0 132.5 144.0 145.0 Early Berriasian 151 106.0 104.0 106.0 108.0 Mid-Albian 147.0 137.0 147.0 147.0 Mid- 101.0 97.0 101.0 120.0 100.5 Late Stage Turonian Albian Aptian Ypresian Albian Late Barremian Early Barremian Late? Early Late Berriasian 129.0 136.0 118.0 127.5 132.0 139.0 134.5 140.0 Early Hauterivian Early Valanginian Early Berriasian Late Kimmeridgian 152.25 138.50 154.0 152.2 Late Kim Late Kimmeridgian Mid-Maastrichtian Mid-Campanian Santonian Mid-Cenomanian Mid-Albian Mid-Aptian Mid-Tithonian Early Late Kimmeridgian 150.75 NA 150.75 151.0 Late Kimmeridgian Late Kimmeridgian 15 Early Coniacian Early Cenomanian Late 98.0 95.75 98.0 99.0 Early Cenomanian Early Early Table 1: Comparison of Ages Maximum Flooding Surfaces Table Sharland et al. (2001, 2004*) oic Late Mesoz K60 Mesozoic Early K50 Mesozoic Cretaceous Early K40 K30 Mesozoic K20 Mesozoic Mesozoic Cretaceous Cretaceous Early Early K10 Mesozoic Cretaceous Early J70 Mesozoic Jurassic Late MFS Ng40 Ng30 Cenozoic Era Ng20 Cenozoic Ng10 Cenozoic Pg50* Cenozoic Cenozoic Pg40* Neogene Period Cenozoic Pg30 Neogene Pg20 Neogene Cenozoic Miocene Pg10 Cenozoic Miocene Paleogene K180 Cenozoic Late Serravalian Miocene K170 Paleogene Mesozoic Late Langhian Oligocene K160 Paleogene Mesozoic Mid-Burdigalian Chattian Paleogene Oligocene Mesozoic Rupelian-Chattian Cretaceous K130 Cretaceous Early Rupelian Mesozoic Late Late Late Late K100 Cretaceous Mesozoic K80 Late Mesozoic Cretaceous Early Cretaceous Early J110 Mesozoic J90 Jurassic Late K90 Mesozoic Cretaceous Early J100 Mesozoic Jurassic Late J80 Mesozoic Jurassic Late K150 Mesozoic K120 K110 Cretaceous Mesozoic Mesozoic Late Cretaceous Cretaceous Late Early K70 Mesozoic Cretaceous Early K140 Mesozoic Cretaceous Late

168

Downloaded from http://pubs.geoscienceworld.org/geoarabia/article-pdf/12/4/167/4570151/husseini_strat_note.pdf by guest on 28 September 2021 Revised ages of Arabian Plate MFS Stage Simmons et al. (2001)

(2005) Haq and Al-Qahtani (1988) Haq et al. Age Age Age Age 502.0 510.0 NA NA 496.0 506.0 498.0 505.0 , 3, 540.0 NA 538.0 542.0 Base 550.0 NA NA NA NA 570.0 NA NA NA NA 162.0 168.0 153.5 175.0 163.5 163.0 170.0 167.0 162.5 170.0 167.5 Mid- 171.0 233.0 Early 238.0 235.0 Early 238.0 234.0 241.0 233.0 242.0 156.0 150.0 158.0 185.0 159.0 215.0 183.5 222.0 223.0 Early 226.0 180.0 225.5 211.0 229.5 181.0 220.0 208.0 245.0 226.0 Mid- 220.0 246.0 241.0 227.0 248.0 243.0 249.75 245.5 Carnian 250.0 249.7 250.5 250.0 / 250.5 Induan Induan 440.0 NA 440.0 437.0 249.0 NA 254.0 253.0 , Changsingian 453.0 465.0 NA NA 454.0 469.0 453.0 464.0 250.0 NA 255.0 256.0 Lopingian, 252.5 NA 261.0 266.0 , 272.0 NA 287.0 286.0 Late 333.0 NA 333.0 330.0 Late Visean 355.0 NA 361.0 363.0 Late 393.0 NA 401.0 400.0 402.0 NA 408.0 408.0 418.0 NA 418.0 417.5 Pridoli 494.0 NA 486.0 488.0 487.0 NA 483.0 480.0 Tremadocian Stage Tremadocian Tremadocian Tatarian Tatarian Early Dolgellian not specified not specified not specified Early Early Kimmeridgian Mid-Oxfordian 154.0 144.5 Mid-Toarcian Norian 155.0 Carnian 155.25 Carnian Late Oxfordian Mid-Scythian Scythian Scythian Mid-Aeronian Late Late Caradoc Late Late Late Kazanian Late Sakmarian Late Visean Late Famennian Late? Emsian Late Pragian Late Pridoli Sharland et al. (2001, 2004) Cm30 Paleozoic Cambrian Late Cm20 Paleozoic Cm10 Paleozoic Cambrian Cambrian Middle Early Middle Minevian Pc20 Vendian Late Pc10 Precambrian Vendian O10 Paleozoic Early J50 Mesozoic J30 J20 Mesozoic Jurassic Mesozoic Jurassic Middle Middle Early Bathonian Early Bajocian MFS J60 Mesozoic Era J40 Mesozoic Jurassic J10 Period Tr80 Jurassic Mesozoic Tr70 Late Mesozoic Tr60 Mesozoic Epoch Tr50 Middle Mesozoic Jurassic Tr40 Mesozoic Tr30 Triassic Mesozoic Tr20 Triassic Early Mesozoic Mid-Callovian Tr10 Triassic Late Mesozoic Triassic Late Mesozoic Triassic Middle Early Early Ladinian Early Anisian S10 Paleozoic Early P40 Paleozoic Permian Late O40 Paleozoic Ordovician Late P30 Paleozoic Permian Late O30 O20 Paleozoic Paleozoic Ordovician Ordovician Middle Early Late Llanvirn P20 Paleozoic Permian Late P10 Paleozoic Permian Early C10 Paleozoic Early D30 Paleozoic Late D20 Paleozoic Devonian Early D10 Paleozoic Devonian Early S20 Paleozoic Silurian Late Table 1 (Continued): Table

169

Downloaded from http://pubs.geoscienceworld.org/geoarabia/article-pdf/12/4/167/4570151/husseini_strat_note.pdf by guest on 28 September 2021 Revised ages of Arabian Plate MFS

Table 2: Differences in Age Estimates of MFS

(1) (2) (3)

Time Shift (My) Haq et al. (1988) and Sharland et al. (2001) and Haq and Al-Qahtani (2005) Haq and Al-Qahtani (2005) Simmons et al. (2007) and Simmons et al. (2007) 1.0 7 27 45 > 1.0 to 3.0 6 15 14 > 3.0 to 6.0 11 14 2 > 6.0 14 7 0 Total MFS 38 63 61

The estimated ages of MFS can also differ when References different authors interpret the same sequences Al-Husseini, M.I. 2005. A GeoArabia Forum: using the same GTS. The magnitude, in this Middle East tectono-stratigraphy. GeoArabia, case, is much less but still significant. This can be v. 10, no. 1, p. 13, 127-148. illustrated when comparing the age estimates of Gradstein, F.M. and J.C. Ogg 1996. A Phanerozoic Haq and Al-Qahtani (2005) to those of Simmons time scale. Episodes, v. 19, nos. 1 and 2, p. 3-5. et al. (2007); both are based on Arabia’s sequence Gradstein, F.M., J.G. Ogg, A.G. Smith, et al. stratigraphy and GTS 2004 (Table 2, Column 3). 2004. A 2004. Cambridge In this comparison, 45 MFS have ages that differ University Press, 589p. by one or less million years. About a quarter (14) Gradstein, F.M. and S. Finney 2007. On the differ by 1.0–3.0 My and two differ by more than Ordovician Period and Sub-era. 3.0 My. GeoArabia, v. 12, no. 1, p. 205-210. Haq, B.U., I. Hardenbol and P.R. Vail 1988. Any apparent convergence in estimated ages Mesozoic and Cenozoic chrono-stratigraphy between different authors using the same GTS and cycles of sea-level change. In, C.K. and/or sequences is not, however, an indication Wilgus, B.S. Hastings, C.G.St.C. Kendall, H. of chronostratigraphic accuracy. It reflects the Posamentier, C.A. Ross and J.C. Van Wagoner level of precision in estimating age values using (Eds.), Sea Level Changes, An Integrated the same data. Therefore it is important not Approach. Society of Economic Paleontologists to refer to an MFS by its estimated age value and Mineralogists, Special Publication no. 42, alone. This is because an MFS (or isochronous p. 71-108. surface), as defined in a particular study, has a Haq, B.U. and A.M. Al-Qahtani 2005. Phanerozoic well-defined position in the rock column and/ cycles of sea-level change on the Arabian or biozone. The absolute age value, however, Platform. GeoArabia, v. 10, no. 2, p. 127-160. should carry an error bar that reflects the age Matthews, R.K. and C. Frohlich 2002. Maximum extent of the biozone in which the MFS occurs flooding surface and sequence boundaries: and the uncertainty of absolute age values for comparisons between observation and orbital that interval of geological time. forcing in the Cretaceous and Jurassic (65-190 Ma). GeoArabia, v. 7, no. 3, p. 503-538. Applying numerical error analysis to geological Sharland, P.R., R. Archer, D.M. Casey, R.B. Davies, time may not be straightforward. Consider, for S.H. Hall, A.P. Heward, A.D. Horbury and example, the cited one standard deviation for M.D. Simmons 2001. Arabian Plate Sequence the age of the Aptian/Barremian boundary. It Stratigraphy. GeoArabia Special Publication 2, was recalibrated from 121.0 ± 1.4 Ma in GTS Gulf PetroLink, Bahrain, 371 p., with 3 charts. 1996 to 125.0 ± 1.0 Ma in GTS 2004; but a shift Sharland, P.R., D.M. Casey, R.B. Davies, M.D. of 4.0 My (121.0 to 125.0 Ma) exceeds the Simmons and O.E. Sutcliffe 2004. Arabian standard deviation cited for both estimates (1.0 Plate Sequence Stratigraphy. GeoArabia, v. 9, and 1.4 My). no. 1, p. 199-214. Simmons, M.D., P.R. Sharland, D.M. Casey, R.B. Acknowledgement Davies and O.E. Sutcliffe 2007. Arabian Plate sequence stratigraphy: Potential implications The author thanks Joerg Mattner and Michael for global stratigraphy. GeoArabia, v. 12, no. 4, Simmons for their useful comments. p. 101-130.

170

Downloaded from http://pubs.geoscienceworld.org/geoarabia/article-pdf/12/4/167/4570151/husseini_strat_note.pdf by guest on 28 September 2021