Geo log i cal Quar terly, 2018, 62 (1): 81–89 DOI: http://dx.doi.org/10.7306/gq.1391
De tri tal do lo mite: char ac teri za tion and char ac ter is tics
Omar RADWAN1, Ali BU KHAMSIN1 and Khalid AL-RAMADAN1, *
1 King Fahd Uni ver sity of Pe tro leum and Min er als, Col lege of Pe tro leum En gi neer ing and Geosciences, Geosciences De part ment, Dhahran 31261, Saudi Ara bia
Radwan, O., Bu Khamsin, A., Al-Ramadan, K., 2018. De tri tal do lo mite: char ac ter iza tion and char ac ter is tics. Geo log i cal Quar terly, 62 (1): 81–89, doi: 10.7306/gq.1391
In ves ti gat ing do lo mite frag ments de rived from pre-ex ist ing do lo mite-con tain ing sed i ments or rocks, that is de tri tal dolomites, con sti tutes a chal lenge in car bon ate sedimentology. De tri tal dolomites are gen er ally dif fi cult to rec og nize and their pres ence can have pro found con se quences, even in small quan ti ties, on the in ter pre ta tion of the tectonosedimentary evo lu tion and palaeoenvironmental con di tions of the en clos ing ba sin. In ad di tion, iden ti fi ca tion and quan ti fi ca tion of de tri tal dolomites may pro vide in sight into prov e nance and sed i ment trans por ta tion, qual ity of hy dro car bon res er voirs, and some as pects of the do - lo mite prob lem. Typ i cally, de tri tal dolomites are rec og nized by their clastic be hav iour, such as 1) their wide range of grain sizes and shapes, 2) ev i dence for trans por ta tion and weath er ing, and 3) their as so ci a tion with other de tri tal grains. De tri tal do lo mite can be de rived from do lo mite-con tain ing sed i ments (by re work ing) or do lo mite-con tain ing rocks (by dis in te gra tion) and can be trans ported by var i ous means in clud ing wind, wa ter, gla ciers and sed i ment grav ity flows. De tri tal do lo mite can be found in a va ri ety of lithofacies con firm ing that they are con trolled by avail abil ity of do lo mite de tri tus and not by depositional en vi ron ment. The role of de tri tal do lo mite in pro mot ing diagenetic dolomitisation is ex am ined whereby they have pro vided nu cle ation sites, for syntaxial over growth, or a source of Mg, through dis so lu tion.
Key words: do lo mite diagenesis, do lo mite prob lem, dolomitisation mod els, syntaxial over growth, extraclasts.
INTRODUCTION
Sed i men tary dolomites are com monly as signed to one of two cat e go ries: syngenetic do lo mite (pri mary), formed pene - contemporaneously in its en vi ron ment of de po si tion, or dia - genetic do lo mite (sec ond ary), formed by later dolomitisation (re place ment of cal cite by do lo mite) and do lo mite ce men ta tion (pre cip i ta tion of do lo mite from aque ous so lu tion in pore spaces) (Sabins, 1962). Oth ers use the term “pri mary” to re fer to pre cip i - ta tion of do lo mite from aque ous so lu tion in pore spaces be - cause it oc cu pies space in the rock not pre vi ously oc cu pied by cal cite (Sander, 1951). Oth ers fur ther sub di vide the “sec ond ary do lo mite” cat e gory into diagenetic and epigenetic to dif fer en ti - ate be tween do lo mite re plac ing lime stone at or af ter the time of lithification and do lo mite re plac ing lime stone as so ci ated with post-depositional struc tural el e ments, re spec tively (Fried man and Sanders, 1967).
Do lo mite de rived from pre-ex ist ing do lo mite rep re sents a third, less com mon, cat e gory (the topic of this pa per). This third type of do lo mite has dif fer ent ter mi nol o gies in the lit er a ture (Ta - ble 1). In this re view, the term “de tri tal do lo mite” is used for two rea sons. First, it is the old est and the most widely used term in the lit er a ture (Amsbury, 1962; Sabins, 1962; Lindholm, 1969;
Mitchum et al., 1969; Lyday, 1985; Bone et al., 1992; Martire et
al., 2014). Sec ond, most of the other terms in di cate that all de - tri tal dolomites have been sub jected to trans por ta tion, which is not a pre req ui site (see chap ter on trans por ta tion).
The con cept that some do lo mite crys tals/grains could be de tri tal in or i gin is com monly ig nored even though it can have a pro found im pact on the in ter pre ta tion of the do lo mite. Fail ure to rec og nize this kind of do lo mite can re sult in: mis judg ing the de - gree of dolomitisation, mis in ter pret ing con di tions of dolomi - tisation (Tal bot, 1990), and los ing in for ma tion on the tectono - sedimentary evo lu tion of the en clos ing ba sin (Martire et al., 2014).
The study of de tri tal do lo mite has ap pli ca tion to both in dus - try and ac a de mia. Some de tri tal dolomites host sig nif i cant vol - umes of hy dro car bons (Lyday, 1985). De tri tal dolomites can act as a tracer for sed i ment trans port (Ravaioli et al., 2003; Li et al., 2007) or as en vi ron men tal proxy (Cul len et al., 2000; Koz³owski, 2015). In ad di tion, study ing de tri tal do lo mite has pro vided some clues to one of the long-last ing de bate in the field of car bon ate pe trol ogy, namely the “do lo mite prob lem” (Lindholm, 1969).
Study ing de tri tal do lo mite is usu ally chal leng ing and re - quires uti liz ing so phis ti cated meth ods. This is be cause de tri tal dolomites have a wide range of char ac ter is tics and oc cur rences de pend ing on:
1) the na ture of the orig i nal source ma te rial, 2) trans por ta tion mech a nisms and dis tance, 3) type of as so ci ated min er als,
4) de gree of diagenesis to which it had been sub jected.
For in stance, in sandy do lo mite, a very slight de gree of recrystallisation is prob a bly ad e quate to hide the clastic ap pear - ance of do lo mite. On the other hand, in the finer-tex tured do lo -
* Corresponding author, e-mail: ramadank@kfupm.edu.sa Received: September 14, 2017; accepted: November 8, 2017; first published online: December 11, 2017
mite, the changes in volved in or di nary lithification would ef fec - tively re move all mi cro scopic ev i dence of their or i gin (Hatch and Rastall, 1965).
This re view will fo cus on:
–the meth ods uti lized for iden ti fy ing and quan ti fy ing the de tri - tal do lo mite,
–the char ac ter is tics of de tri tal do lo mite in clud ing pe trog ra phy, prov e nance, trans por ta tion, oc cur rences and diagene sis.
In ad di tion to crit i cal anal y sis of lit er a ture data, we will pro - vide new data on the de tri tal do lo mite of the Up per Cre ta ceous Chim ney Rock Sand stones in Utah.
CHARACTERIZATION
IDENTIFICATION
De tri tal dolomites are usu ally rec og nized if the do lo mite un der in ves ti ga tion shows a sign or signs of clastic be hav iour (Fig. 1A). There are many signs that can in di cate that do lo mite was de rived from pre-ex ist ing do lo mite-con tain ing sed i ments or rocks.
De tri tal dolomites’ grain-sizes and shapes vary widely (Poros et al., 2013). De tri tal do lo mite grain-size ranges from boul ders (Arnaud and Eyles, 2002) to very finely crys tal line ex - am ples. De tri tal do lo mite grains may oc cur as iso lated crys tals, crys tal clus ters, or both (Bone et al., 1992).
De tri tal do lo mite grains usu ally, but not nec es sar ily, show ev i dence of trans por ta tion and weath er ing (Bone et al., 1992;
Martire et al., 2014). Their edges might be sharp (Fig. 2B), abraded (Fig. 2C), ir reg u lar (Fig. 2D) or well-rounded (Fig. 1B).
Slight weath er ing can darken the grains, mak ing them ap pear cloudy in thin-sec tion. Im por tantly, some de tri tal do lo mite grains may be sub jected to break age along cleav age planes dur ing trans port. Un der such con di tion, the de tri tal dolomites can ex hibit clear, sharp-edged rhombs (Fig. 2A). Us ing stan - dard pe trog ra phy (po lar iz ing mi cro scope), ev i dence of do lo mite trans por ta tion, as shown by the well-rounded and clearly abraded na ture of the grains, can be ob served. A de tri tal na ture can also be sug gested by fab ric re la tion ships in di cat ing that con tacts be tween de tri tal do lo mite and ad ja cent grains are depositional. Pit ting, striations and frac tures along the planes of de tri tal crys tals sug gest ing they have ex pe ri enced trans por ta -
tion can be ob served us ing scan ning elec tron mi cro scope (SEM) and cathodoluminescence (CL) mi cro scope.
De tri tal dolomites show some dis tin guish ing fea tures if sub - jected to diagenesis. De tri tal do lo mite par ti cles may act as nu - clei for dif fer ent types of coated grains (e.g., ooids and oncoids) and they may be over grown by syntaxial ce ment. Over growth min er al ogy will typ i cally be do lo mite (Fig. 1B) or cal cite (Hansley and Whit ney, 1990). Over growth shape does not nec - es sar ily fol low the in ner shape, as would be ex pected in zonation. While the in ner cores may show ex tremely ir reg u lar out lines, outer rims are pro gres sively ap proach ing a rhombic out line. Outer rim zones would have the same CL sig na ture re - gard less of the CL col our of the core. Ac cord ing to Martire et al.
(2014), outer rims can grow fur ther around monocrystalline cores than around fine-grained, polycrystalline lithoclasts.
In case where the orig i nal do lo mite grains are over grown by syntaxial ce ment, the overgrowths may be dis tin guished from de tri tal cores by dif fer ences in clar ity be tween the core and the rim (cloudy core and clear rim; Bone et al., 1992; Martire et al., 2014). If there is a dif fer ence in iron con tent be tween the core and rim, overgrowths may be dis tin guished by dif fer ences in stain ing be hav iour in the pres ence of a po tas sium ferri cyanide stain (iron-rich car bon ates ap pear dark blue and iron-poor car - bon ates ap pear light blue; Evamy, 1963). One of the most ef fi - cient tech niques used to iden tify dif fer ences in var i ous part of do lo mite (e.g., core ver sus rim) is cathodoluminescence mi - cros copy. Dif fer ences in cathodoluminescence be tween the core and the rim can re veal the de tri tal na ture of the core.
SEM-based CL im ag ing can clearly show the de tri tal nu clei of some dolomites that ap pear en tirely au then tic when seen us ing CL at tached to po lar iz ing mi cro scope. CL can also dem on - strate, in some cases, the multicycle na ture of many of do lo mite grains (Fig. 2J). Grains ex hib it ing zones of con trast ing lu mi nes - cence that abruptly ter mi nate at grain mar gins sug gest abra - sion of larger zoned crys tals (Young and Doig, 1986).
De tri tal do lo mite grains are usu ally ac com pa nied by other de tri tal grains (e.g., de tri tal quartz). Good cor re la tion be tween the do lo mite grains and as so ci ated clastic grains (in terms of grain-size dis tri bu tion and rel a tive abun dances) may sug gest that they all were de pos ited by the same me dium (Lindholm, 1969). Grain-size cor re la tions can be in ves ti gated by care ful point-count ing, and amount cor re la tions can be con firmed by x-ray dif frac tion or quan ti ta tive min eral anal y sis (e.g., Qem scan).
Some geo chem i cal in di ca tors can sug gest a de tri tal or i gin of do lo mite. El e men tal data in di cat ing an as so ci a tion of T a b l e 1 De tri tal do lo mite ter mi nol ogy in the lit er a ture
Syn onyms Et y mol ogy Geo log i cal mean ing Ref er ences
“De tri tal” do lo mite from Latin de tri tus
(the act of rub bing away) made from frag ments of pre-ex ist ing rocks
Amsbury (1962); Sabins (1962); Lindholm (1969); Mitchum et al. (1969); Lyday (1985);
Bone et al. (1992); Martire et al. (2014)
“Clastic” do lo mite from Greek klastÙz
(bro ken in pieces) Bogacz et al. (1973)
“Terrigenous” do lo mite from Latin terra (earth) and gignere (to be born)
de rived from the ero sion
of land-based rocks Free man et al. (1983); Lojen et al. (1999)
“Allochthonous” do lo mite from Greek «lloz (other)
and cqvn (earth, ground) orig i nat ing in a place other than where it is found
Wiggins and Har ris (1985); Sarg (2001)
“Allogenic” do lo mite from Greek «lloz (other)
and gene« (gen er a tion) Mitch ell and Hor ton (1995)
CaCO3/MgCO3 with Al2O3, SiO2 and K2O points to the pres ence of feld spar and clays (Martire et al., 2014). An ex tra-basinal prov e nance of de tri tal do lo mite grains can be ver i fied also by dis so ci at ing the ox y gen-iso tope val ues of the do lo mite and the bulk-rock (Clay ton and Jones, 1968).
QUANTIFICATION
Quan ti fi ca tion of de tri tal do lo mite is cru cial for es ti mat ing the ac tual de gree of dolomitisation in de pos its con tain ing co-oc cur ring poly gen etic do lo mite types (e.g., de tri tal do lo mite and authigenic do lo mite). Alkuwairan (2012) uti lized quan ti ta - tive eval u a tion of min er als by scan ning elec tron mi cros copy (Qemscan®) in iden ti fy ing and quan ti fy ing dif fer ent do lo mite types in Ku wait Bay sed i ments. Qemscan® anal y sis can ac - quire modal abun dance, min er al og i cal dis tri bu tion and min eral as so ci a tion that could as sist in char ac ter iz ing dif fer ent types of do lo mite.
The quan tity of de tri tal do lo mite con tained within a host rock can have a sig nif i cant ef fect on its iso to pic sig na ture. Dif fer ent ap proaches have been ap plied to iso late de tri tal do lo mite from other car bon ate frac tions in or der to re duce the in flu ence of iso -
to pic “con tam i na tion” among dis pa rate com po nents. Mangili et al. (2010) re viewed these ap proaches and their lim i ta tions, and pro posed a new meth od olog i cal ap proach com bin ing sedi - mento lo gical and min er al og i cal ex am i na tion to eval u ate ef fi - ciently the im pact of dif fer ent quan ti ties of de tri tal grains in car - bon ate sam ples.
APPROACH 1: PHYSICAL APPROACH
This ap proach de pends on the phys i cal sep a ra tion of the de tri tal dolomites through grain-size sep a ra tion (Kelts and Hsü, 1978; Teranes et al., 1999). This ap proach as sumes that the host-rock (endogenic) grains are typ i cally smaller or larger than those of de tri tal do lo mite. The chal lenge to de ter mine a pre cise grain-size bound ary be tween de tri tal and endogenic com po - nents lim its this ap proach.
APPROACH 2: CHEMICAL APPROACH
This ap proach de pends on the chem i cal sep a ra tion of de tri - tal dolomites from other car bon ate com po nents based on dif - fer ences in dis so lu tion rate of do lo mite and endogenic grains, with more sol u ble grains re act ing/dis solv ing be fore do lo mite grains (Degens and Ep stein, 1964; Ep stein et al., 1964). The method col lects CO2 at dif fer ent times, with the as sump tion that grains of dif fer ent or i gin are be ing sep a rated. How ever, it is clear that CO2 pro duced from do lo mite can be con tam i nated by CO2 pro duced from cal cite, and vice versa, and it is im pos si ble to en sure pure frac tions of ei ther.
APPROACH 3: STATISTICAL APPROACH
This ap proach de pends on ex clud ing out li ers in iso tope data, sup pos ing that these data must have been in flu enced by de tri tal car bon ate (Mangili et al., 2010). This per haps helps to screen out sam ples with a sig nif i cant con tam i na tion, but it is im - prob a ble that all af fected sam ples will be spot ted.
APPROACH 4: COMBINED APPROACH
This ap proach is based on com bin ing microfacies, XRD and m-XRF anal y ses (Mangili et al., 2010). Af ter ana lys ing all sam ples us ing the pre vi ous tech niques, three cat e go ries of sam ple are pre pared for iso tope anal y ses:
–pure endogenic grains, –pure de tri tal grains,
–“mixed” sam ples in clud ing endogenic grains and de tri tal grains.
Af ter iden ti fy ing and quan ti fy ing the de tri tal dolomites in the mixed sam ples, the thresh old value of de tri tal do lo mite above which d18O val ues are con sid er ably shifted to wards higher or lower val ues has to be de ter mined. Fi nally, the quan - ti ta tive as sess ment of the bias in d18O and d13C val ues, de - pend ing on the quan tity of de tri tal do lo mite in cluded in a sam - ple, can be cal cu lated.
Not only does con tam i na tion with de tri tal grains af fect iso to - pic com po si tion, but it also af fects the covariance cal cu la tions be tween d13C and d18O, which has been used to de duce palaeo hydrological con di tions (Tal bot, 1990). A good il lus tra tion co mes from stud ies of lac us trine car bon ates from Pi´nico palaeolake in It aly. Ini tially, the sam ples were found to have a strong covariance be tween sta ble car bon- and ox y gen-iso tope val ues, in ter preted as re flect ing a hydrologically closed lake ba - sin (Tal bot, 1990; Leng and Mar shall, 2004). How ever, when De tri tal do lo mite: char ac teri za tion and char ac ter is tics 83
Fig. 1. De tri tal do lo mite (DD) grains in Up per Cre ta ceous Chim ney Rock Sand stones, Wy o ming and Utah, USA A – pho to mi cro graph of sand stone con tain ing very fine sand-sized, iso lated, abraded de tri tal do lo mite (crossed polars); B – back scat - tered elec trons im age show ing do lo mite overgrowths on de tri tal do - lo mite
the sam ples with a de tri tal car bon ate com po nent were ex - cluded a neg a tive cor re la tion co ef fi cient was ac quired, sug - gest ing a hydrologically open lake, which is con sis tent with the sedi mentological data (Moscariello et al., 2000).
CHARACTERISTICS
PROVENANCE
There are two pos si bil i ties for the par ent ma te rial of de tri tal do lo mite: pri mary (penecontempora neous) do lo mite or sec ond - ary (later diagenetic) do lo mite.
Re work ing of pri mary do lo mite. In a trop i cal shal low-wa ter car bon ate set ting, supratidal pene con tempo raneous dolomites
can be re worked by ae olian trans port from tidal flats into intertidal and subtidal car bon ate sed i ments (Shinn, 1983; Wells, 1983).
In tem per ate car bon ate set tings, penecon tempo raneous dolomites pre cip i tated in mildly re duc ing ma rine sed i ments just be low the sed i ment -wa ter in ter face can be re worked by high- en ergy waves (Bone et al., 1992). They can be re worked ei ther to be de pos ited in deeper wa ter or blown into coastal dunes.
Dis in te gra tion of sec ond ary do lo mite. In this sce nario, the par ent rock may be ei ther a dolostone or a dolomitic lime - stone. The lat ter rock type could yield de tri tal do lo mite be cause of the lower sol u bil ity of do lo mite com pared to cal cite un der con di tions of subaerial weath er ing (Lyday, 1985).
Around the world, there are many lo cal i ties of do lo mite which has been frag mented to a do lo mite pow der. A well-known ex am ple of this phe nom e non is lo cated in the Transdanubian Range (TR), Hun gary, par tic u larly in the Buda Hills (Poros et al., 2013, among oth ers). Ta ble 2 shows the lo ca tion of some of these oc cur rences around the world and their pro posed mech a - nism of dis in te gra tion.
TRANSPORTATION
De pend ing on the means of trans por ta tion, the size, amount and dis tri bu tion of the de tri tus will vary.
Grain-sizes of de tri tal do lo mite trans ported by wind are very sim i lar to re cent dust de pos its (gen er ally uni form silt size) orig i - nat ing from arid re gions such as the Great Salt Lake (Jones, 1953) or sabkhas and deserts around the Ara bian Gulf (Al-Bakri et al., 1984). Streams drain ing dolomitic ter rains that have sub-hu mid to arid cli mates can be ex pected to trans port do lo - mite gravel, sand and silt (Amsbury, 1962). Metre-sized do lo - mite clasts were re ported to be trans ported by grav ity-flow pro - cesses (e.g., the Great Brec cia, Port Askaig For ma tion, Scot - land; Arnaud and Eyles, 2002).
The amount of the de tri tus can vary from very min ute amounts (e.g., »1% in sand dunes of West ern Desert of Iraq;
Awadh, 2012) to sev eral hun dred metres thick (e.g., Atokan Deep Anadarko Ba sin, Oklahoma; Lyday, 1985)
Early stud ies have in ter preted the prov e nance of de tri tal do - lo mite based on the prox im ity of po ten tial source rocks (Lind - holm, 1969), but in fact the dis tri bu tion of the de tri tus var ies and does not have to be abun dant near the source ter rain. Wind trans port, for in stance, al lows the de tri tus to by-pass the shal - low-wa ter en vi ron ment (Davies, 1997; Davies et al., 1997).
De tri tal do lo mite can be sub jected to one or many cy cles of trans por ta tion (Young and Doig, 1986; Arnaud and Eyles, 2002). Some cav i ties filled with de tri tal do lo mite in di cate that they were de rived from sources in the im me di ate en vi ron ment of their pres ent ac cu mu la tion (e.g., bro ken down from cave walls), i.e. no trans por ta tion (Bogacz et al., 1973; Fu et al., 2006). On the other hand, de tri tal do lo mite can be washed into some caves by vadose wa ters that ran through and over do lo - mite bed rock (Jones, 1991).
OCCURRENCES
De tri tal dolomites have been de scribed in di verse set tings (Ta ble 3) in di cat ing that their dis tri bu tion is not func tion of a cer - tain depositional en vi ron ment but rather of whether loose do lo - mite grains are avail able in the source area or not.
Car bon ates. De tri tal do lo mite has been rec og nized, in small amounts, in re cent sed i ments from Florida Bay (Deffeyes and Mar tin, 1962) and the east ern Med i ter ra nean (Milliman and Fig. 2. Sche matic draw ing of a syntaxially over grown de tri tal
do lo mite’s petrographic char ac ter is tics un der CL (core is de - tri tal do lo mite and rim is diagenetic do lo mite) A – per fect rhomb core; B – sharp-edged core (not rhomb); C – abraded rhomb core; D – ir reg u lar – rounded core (A–D – rims tend to in creas ingly ap proach a rhombic habit, so that they are thicker where the core edge was far ther from the rhomb faces); E – iso lated rhomb/crys tal core; F – rhombs/crys tals clus ter core; G, H – the core may have dif fer ent CL sig na tures (sug gest ing dif fer ent par ent ma te rial) but the rim (over growth) is al ways the same; I – grain ex - hib it ing zones of con trast ing lu mi nes cence; J – grain ex hib it ing zones of con trast ing lu mi nes cence that abruptly ter mi nate at grain mar gins sug gest abra sion of larger zoned crys tals
Müller, 1973). On the other hand, de tri tal do lo mite de pos its, also known as dololithites, may form a very thick sed i men tary se quences (e.g., Penn syl va nian Atoka Do lo mite; Lyday, 1985).
How ever, this kind of dololithite is very rare, due to the soft and sol u ble na ture of car bon ate min er als.
Siliciclastics. Sand stones, in ma rine to non-ma rine set - tings, can have de tri tal-do lo mite grains (Al-Ramadan et al., 2013) but gen er ally only mi nor amounts. The dif fer ence in abun dance of de tri tal do lo mite within sand stone units has been at trib uted to sev eral fac tors (Amsbury, 1962; Pettijohn et al., 1972; Folk, 1980):
1 – the ex is tence of an arid or sub-hu mid cli mate in which weath er ing by car bon di ox ide – charged wa ter is kept to a min i mum;
2 – rapid ero sion due to high-re lief source ter rain (Folk, 1980 cited ex am ples of car bon ate-rich de pos its ac cu mu - lat ing in ar eas of vig or ous up lift, even un der hu mid cli ma - tic con di tions);
3 – lack of sig nif i cant trans por ta tion of the de tri tal grains (i.e., prox im ity to source area) or
4 – rapid burial with lit tle re work ing.
There fore, the pau city of de tri tal do lo mite is prob a bly re - lated to tex tural and min er al og i cal ma tu rity of the sand stones.
The pro longed re work ing re quired for pro duc tion of such ma - ture de pos its would un doubt edly have de stroyed any de tri tal do lo mite be fore the sed i ment was bur ied. The study of Al- Ramadan et al. (2013) of the Up per Cre ta ceous Chim ney Rock
Sand stones in Utah has re vealed that the amount of de tri tal do - lo mite in creases up ward to wards the transgressive sur face.
DIAGENESIS
The diagenesis of de tri tal do lo mite, through for ma tion of do - lo mite overgrowths or do lo mite dis so lu tion, can act as a fa cil i ta - tor for the dolomitisation pro cess and mod ify the ul ti mate char - ac ter of a dolomite deposit.
De tri tal do lo mite as nu clei. For do lo mite to form, it is much eas ier to grow on pre vi ously formed nu clei than to nu cle - ate di rectly be cause of the ki netic bar rier (Lindholm, 1969;
Free man et al., 1983). There fore, the pres ence of de tri tal do lo - mite grains can as sist in re duc ing the in duc tion pe riod of dolomitisation by sup ply ing the sys tem with nu cle ation points. If supratidal do lo mite crys tals, for in stance, were trans ported to intertidal and subtidal set tings, later dolomitisation could con - tinue un der eas ier con di tions than those needed to nu cle ate do - lo mite in the first place.
De tri tal do lo mite diagenesis was pro posed by Lindholm (1969) to be one of the mech a nisms that can ex plain “per va sive dolomitisation”. He in tro duced two con cep tual mod els (Fig. 3) based on stud ies of the On on daga Lime stone of New York. He sug gested that the trans por ta tion of de tri tal do lo mite and as so ci - ated de tri tus (e.g., quartz) to their fi nal depositional site will re sult in a de crease in their amount and size away from the source.
How ever, this is not al ways the case, be cause later diagenesis De tri tal do lo mite: char ac teri za tion and char ac ter is tics 85
T a b l e 2 Mech a nisms of dolostone dis in te gra tion
Lo ca tion Pro posed mech a nism of dis in te gra tion Ref er ence
Picentini Moun tains of It aly;
Si cil ian fold-and-thrust belt me chan i cal dis in te gra tion re lated
to tec tonic move ments Pappone and Ferranti (1995); Dewever (2008) South China chem i cal weath er ing dur ing re gional
karstification Ji et al. (2004)
De vo nian Winnipegosis For ma tion (Sas katch e wan, Can ada) – gi ant
un con ven tional oil res er voir by-prod uct of re gional karstification Machel et al. (2012)
Buda Hills, Hun gary
re cent weath er ing-in duced powderization (Schafarzik, 1902 and Timkó, 1909) – cited in Poros et al. (2013)
pre-Cenozoic un con formity-re lated
powderization (Földvári, 1933) – cited in Poros et al. (2013) hy dro ther mal powderization (Brugger, 1940; Jakucs, 1950 and Nagy,1979) –
cited in Poros et al. (2013) cryo genic powderization; re peated freeze
–thaw cy cles dur ing and/or af ter the
Pleis to cene glaciations Poros et al. (2013)
T a b l e 3 De tri tal do lo mite oc cur rences in dif fer ent depositional en vi ron ments
Lo ca tions Depositional
en vi ron ment
Llano up lift of cen tral Texas (Amsbury, 1962) flu vial sys tem
Atokan Deep Anadarko Ba sin, Oklahoma (Lyday, 1985) deltaic sys tem
Taklimakan Desert, Kumtag Desert, Qaidam Desert, Sanjiangyuan, Hexi Cor ri dor, Badain Jaran Desert of China (Li et al., 2007); West ern Desert of Iraq (Awadh, 2012); White Sands Na tional Mon u ment in New
Mex ico, USA (Fenton et al., 2017) ae olian sys tem
Polarisbreen Group, north east ern Spitsbergen, Svalbard (Fairchild and Hambrey, 1984; Fairchild et al., 1989); ice rafted de tri tus in the sub po lar North At lan tic dur ing gla cial pe ri ods, Hein rich lay ers (Bond et
al.,1992; An drews, 1998); Great Brec cia, Port Askaig For ma tion, Scot land (Arnaud and Eyles, 2002) gla cial sys tem Deep Springs Lake, Cal i for nia (Clay ton and Jones, 1968); Paleocene-Eocene Lake Flag staff, cen tral
Utah (Wells, 1983); varved sed i ments of the inter gla cial Pi´nico palaeolake, South ern Alps, It aly (Mangili et al., 2010)
lac us trine sys tem
can cause ad verse dis tri bu tion. If, af ter de po si tion, the de tri tal do lo mite was sub jected to diagenetic over growth for ma tion un til the host rock was com pletely re placed by do lo mite, the size of do lo mite would in crease away from the source. Since grain-size is con trolled by mu tual in ter fer ence of the grow ing do lo mite crys - tals as the rock reaches com plete re place ment, the wider the spac ing be tween the de tri tal do lo mite nu clei, the larger the size of the fi nal diagenetic do lo mite crys tals.
Dolomitisation can be very se lec tive and it may oc cur only around de tri tal do lo mite grains. It is worth men tion ing that in the ab sence of such de tri tal do lo mite grains, no dolomitisation would oc cur and the flow of po ten tially dolomitising flu ids would leave no ev i dence (Lindholm, 1969). This claim is sup ported by the pref er en tial growth of do lo mite crys tals around the do lo mite de tri - tal grains and their ab sence where there are no do lo mite de tri tal grains. Crys tals lack ing ob vi ous cores would ap pear to be en - tirely authigenic in or i gin. How ever, their growth might have been trig gered by de tri tal do lo mite, but the nu clei, if ex ist ing, could be too min ute to re solve. Gen er ally re worked pri mary do lo mite re - sults in a very nar row size range (Deffeyes et al., 1965; llling et
al., 1965). A wider range of grain-sizes would be ex pected in the case of dis in te grated sec ond ary do lo mite which had not been trans ported far (Lindholm, 1969).
De tri tal do lo mite as Mg-source for later dolomitisation and pre cip i ta tion of do lo mite ce ment. The dis so lu tion of de tri tal do - lo mite may en rich the diagenetic fluid with mag ne sium which later could be pre cip i tated as do lo mite ce ment. This dis so lu tion has been re ported to be brought about by the ac tion of mi grat - ing me te oric flu ids con tain ing or ganic ac ids gen er ated from coal mea sures, as sug gested by Tay lor and Gawthorpe (2003) (Fig.
4). The do lo mite ce ment re ported in the pre vi ous case sig nif i - cantly de creases po ten tial res er voir qual ity of the sand stones (Al-Ramadan et al., 2013).
Al-Ramadan et al. (2005) have dem on strated the im por - tance and im pact of de tri tal com po si tions on the diagenetic and re lated res er voir-qual ity evo lu tion path ways of siliciclastic se - quences. De tri tal dolomites can con trib ute to po ros ity and per - me abil ity de te ri o ra tion by fa vour ing the growth of car bon ate ce - ments and by be ing a source of pore-fill ing car bon ate ce ment (Morad et al., 2010).
Fig. 3. Lindholm’s model for dolomitization of car bon ate sed i ments (mod i fied af ter Lindholm, 1969) Grain size and abun dance of de tri tal quartz and do lo mite in car bon ate sed i ments:
A – af ter de po si tion, B – af ter diagenetic over growth on de tri tal nu clei
CONCLUDING REMARKS From a sur vey of lit er a ture, it is con cluded that:
De tri tal do lo mite grains have a wide range of char ac ter is - tics in clud ing: vari a tions in grain-size (boul ders to very fine grains), grain shapes (pla nar to ir reg u lar edges), tex tures (iso - lated to clus tered and cloudy to clear), means of trans por ta tion (wind, wa ter or ice), and lithofacies oc cur rences. Thus, they can be dif fi cult to iden tify and a va ri ety of meth ods may be re - quired to en sure de fin i tive iden ti fi ca tion of their pres ence.
De tri tal-do lo mite grains gen er ally ex hibit rel ict fea tures (i.e.
struc tures, crys tal size, CL sig na ture) in her ited from the orig i nal do lo mite strata or protolith.
The sup po si tion that de tri tal dolomites are nec es sar ily of ex tra-basinal or i gin has been chal lenged by the oc cur rence of in situ do lo mite pow der and caves filled with clastic do lo - mite.
Diagenetically over grown de tri tal do lo mite is pro posed as a pos si ble mech a nism of “dolomitisation” or at least as an ini ti a tor for later do lo mite growth.
De tri tal do lo mite: char ac teri za tion and char ac ter is tics 87
Fig. 4. Tay lor and Gawthrope model for do lo mite ce men ta tion of shoreface sand stones (mod i fied af ter Tay lor and Gawthorpe, 2003)
A – dur ing sea level rise, shoreface sand stone (in clud ing the de tri tal do lo mite) progrades basinward; B – dur ing sea level fall, or ganic-rich coastal plain can de velop and me te oric wa ter mi grate basinward; so lu - tion pass ing through these plain will be come en riched in or ganic-acid and ca pa ble of dis solv ing de tri tal do - lo mite within the un der ly ing sand stone, then be come en riched in mag ne sium; C – do lo mite ce men ta tion at the me te oric-ma rine in ter face
Ac knowl edge ments. The au thors wish to thank Dr.
J.D. Humphrey and Dr. D.L. Cantrell for their care ful re view of the manu script and A. Pradipta for his help in de sign ing the fig - ures. The au thors would also like to thank the re view ers
M. Tucker and A. Bodzioch and the ed i tor T. Peryt for their con struc tive com ments that con sid er ably con trib uted to im - prov ing the fi nal ver sion of the pa per.
REFERENCES
Al-Bakri, D., Khalaf, F., Al-Ghadban, A., 1984. Min er al ogy, gen e - sis, and sources of surficial sed i ments in the Ku wait ma rine en - vi ron ment, north ern Ara bian Gulf. Jour nal of Sed i men tary Re - search, 54: 1266–1279.
Alkuwairan, M.Y., 2012. Poly gen etic do lo mite in subtidal sed i ments of north ern Ku wait Bay, Ku wait. Ph.D. the sis, Col o rado School of Mines.
Al-Ramadan, K., Morad, S., Proust, J.N., Al-Aasm, I., 2005. Dis tri - bu tion of diagenetic al ter ations in siliciclastic shoreface de pos - its within a se quence strati graphic frame work: ev i dence from the Up per Ju ras sic, Boulonnais, NW France. Jour nal of Sed i - men tary Re search, 75: 943–959.
Al-Ramadan, K., Morad, S., Plink-Björklund, P., 2013. Dis tri bu - tion of diagenetic al ter ations in re la tion ship to depositional fa - cies and se quence stra tig ra phy of a wave- and tide-dom i nated siliciclastic shore line com plex: Up per Cre ta ceous Chim ney Rock Sand stones, Wy o ming and Utah, USA. IAS Spe cial Pub li - ca tion, 45: 271–296.
Amsbury, D.L., 1962. De tri tal do lo mite in cen tral Texas. Jour nal of Sed i men tary Re search, 32: 5–14.
An drews, J.T., 1998. Abrupt changes (Hein rich events) in late Qua - ter nary North At lan tic ma rine en vi ron ments: a his tory and re - view of data and con cepts. Jour nal of Qua ter nary Sci ence, 13:
3–16.
Arnaud, E., Eyles, C.H., 2002. Cat a strophic mass fail ure of a Neoproterozoic gla cially in flu enced con ti nen tal mar gin, the Great Brec cia, Port Askaig For ma tion, Scot land. Sed i men tary Ge ol ogy, 151: 313–333.
Awadh, S.M., 2012. Geo chem is try and min er al og i cal com po si tion of the air borne par ti cles of sand dunes and dust storms set tled in Iraq and their en vi ron men tal im pacts. En vi ron men tal Earth Sci ences, 66: 2247–2256.
Bogacz, K., D¿u³yñski, S., Harañczyk, C., 1973. Caves filled with clastic do lo mite and ga lena min er al iza tion in disaggre gated dolomites. Annales Societatis Geologorum Poloniae, 43: 59–72.
Bond, G., Hein rich, H., Broecker, W., Labeyrie, L., McManus, J., An drews, J., Huon, S., Jantschik, R., Clasen, S., Simet, C., Tedesco, K., Klas, M., Bonani, G., Ivy, S., 1992. Ev i dence for mas sive dis charges of ice bergs into the North At lan tic ocean dur - ing the last gla cial pe riod. Na ture, 360: 245–249.
Bone, Y., James, N.P., Kyser, T.K., 1992. Synse di men tary de tri tal do lo mite in Qua ter nary cool-wa ter car bon ate sed i ments, Lacepede shelf, South Aus tra lia. Ge ol ogy, 20: 109–112.
Clay ton, R.N., Jones, B.F., 1968. Iso tope stud ies of do lo mite for - ma tion un der sed i men tary con di tions. Geochimica et Cosmo - chimica Acta, 32: 415–432.
Cul len, H.M., de Menocal, P.B., Hem ming, S., Hem ming, G., Brown, F.H., Guilderson, T., Sirocko, F., 2000. Cli mate change and the col lapse of the Akka dian em pire: ev i dence from the deep sea. Ge ol ogy, 28: 379–382.
Davies, G.R., 1997. Ae olian sed i men ta tion and by pass, Tri as sic of West ern Can ada. Bul le tin of Ca na dian Pe tro leum Ge ol ogy, 45:
624–642.
Davies, G.R., Moslow, T.F., Sherwin, M.D., 1997. The Lower Tri as - sic Montney For ma tion, west-cen tral Al berta. Bul le tin of Ca na - dian Pe tro leum Ge ol ogy, 45: 474–505.
Deffeyes, K.S., Mar tin, E.L., 1962. Ab sence of car bon-14 ac tiv ity in do lo mite from Florida Bay. Sci ence, 136: 782–782.
Deffeyes, K.S., Lu cia, F.J., Weyl, P.K., 1965. Dolo mi tization of Re - cent and Plio-Pleis to cene sed i ments by ma rine evaporite wa -
ters on Bonaire, Neth er lands An til les. SEPM Spe cial Pub li ca - tion, 13: 71–88.
Degens, E.T., Ep stein, S., 1964. Ox y gen and car bon iso tope ra tios in co ex ist ing cal cites and dolomites from re cent and an cient sed i ments. Geochimica et Cosmochimica Acta, 28: 23–44.
Dewever, B., 2008. Diagenesis and fluid flow in the si cil ian fold-and - -thrust belt. Ph.D. the sis, Katholieke Universiteit Leuven, Bel - gium.
Ep stein, S., Graf, D.L., Degens, E.T., 1964. Ox y gen iso tope stud - ies on the or i gin of dolomites. In: Iso to pic and Cos mic Chem is try (eds. H. Craig, S.L. Miller and G.J. Wasserburg): 169–180.
North Hol land, Am ster dam.
Evamy, B.D., 1963. The ap pli ca tion of a chem i cal stain ing tech nique to a study of dedolomitisation. Sedimentology, 2: 164–170.
Fairchild, I.J., Hambrey, M.J., 1984. The Vendian suc ces sion of north east ern Spitsbergen: petro gen esis of a do lo mite-tillite as - so ci a tion. Pre cam brian Re search, 26: 111–167.
Fairchild, I.J., Hambrey, M.J., Spiro, B., Jef fer son, T.H., 1989.
Late Pro tero zoic gla cial car bon ates in North east Spitsbergen;
new in sights into the car bon ate-tillite as so ci a tion. Geo log i cal Mag a zine, 126: 469–490.
Fenton, L.K., Bishop, J.L., King, S., Lafuente, B., Horgan, B., Bustos, D., Sarrazin, P., 2017. Sed i men tary dif fer en ti a tion of ae - olian grains at the White Sands Na tional Mon u ment, New Mex ico, USA. Ae olian Re search, Spe cial Is sue for the Fourth In ter na - tional Plan e tary Dunes Work shop, 26: 117–136.
Folk, R.L., 1980. Pe trol ogy of Sed i men tary Rocks. Hem phill Pub - lish ing Com pany.
Free man, T., Rothbard, D., Obrador, A., 1983. Terri ge nous do lo mite in the Mio cene of Menorca (Spain); prov e nance and diagenesis.
Jour nal of Sed i men tary Re search, 53: 543–548.
Fried man, G.M., Sanders, J.E., 1967. Chap ter 6 Or i gin and oc cur - rence of dolostones. De vel op ments in Sedimentology, 9:
267–348.
Fu, Q., Qing, H., Berg man, K.M., 2006. Paleokarst in Mid dle De vo - nian Winnipegosis mud mounds, subsurface of south-cen tral Sas katch e wan, Can ada. Bul le tin of Ca na dian Pe tro leum Ge ol - ogy, 54: 22–36.
Hansley, P.L., Whit ney, C.G., 1990. Pe trol ogy, diage nesis, and sedimentology of oil res er voirs in Up per Cre ta ceous Shan non Sand stone Beds, Pow der River ba sin, Wy o ming. U.S. Geo log i - cal Sur vey Bul le tin: 1917–C.
Hatch, F.H., Rastall, R.H., 1965. Pe trol ogy of the Sed i men tary Rocks, 4th Edi tion. Hafner Pub lish ing Com pany.
Illing, L.V., Wells, A.J., Tay lor, J.C.M., 1965. Peneconte mporary do lo mite in the Per sian Gulf. SEPM Spe cial Pub li ca tion, 13:
89–111.
Ji, H., Wang, S., Ouyang, Z., Zhang, S., Sun, C., Liu, X., Zhou, D., 2004. Geo chem is try of red residua un der ly ing dolomites in karst ter rains of Yunnan-Guizhou Pla teau: I. The for ma tion of the Pingba pro file. Chem i cal Ge ol ogy, 203: 1–27.
Jones, B., 1991. Gen e sis of ter res trial oncoids, Cayman Is lands, Brit ish West In dies. Ca na dian Jour nal of Earth Sci ences, 28:
382–397.
Jones, D.J., 1953. Gyp sum-oolite dunes, Great Salt Lake Desert, Utah. AAPG Bul le tin, 37: 2530–2538.
Kelts, K., Hsü, K.J., 1978. Fresh wa ter car bon ate sed i men ta tion. In:
Lakes (ed. A. Lerman): 295–323. Springer, New York.
Koz³owski, W., 2015. Eolian dust in flux and mas sive whit ings dur - ing the kozlowski/Lau Event: car bon ate hyper saturation as a pos si ble driver of the mid-Ludfordian Car bon Iso tope Ex cur sion.
Bul le tin of Geosciences, 90: 807–840.
Leng, M.J., Mar shall, J.D., 2004. Palaeoclimate in ter pre ta tion of sta ble iso tope data from lake sed i ment ar chives. Qua ter nary Sci ence Re views, 23: 811–831.
Li, G., Chen, J., Chen, Y., Yang, J., Ji, J., Liu, L., 2007. Do lo mite as a tracer for the source re gions of Asian dust. Jour nal of Geo - phys i cal Re search: At mo spheres, 112, D17201.
Lindholm, R.C., 1969. De tri tal do lo mite in On on daga lime stone (mid dle De vo nian) of New York; its im pli ca tions to the “do lo mite ques tion.” AAPG Bul le tin, 53: 1035–1042.
Lojen, S., Ogrinc, N., Dolenec, T., 1999. De com po si tion of sed i men - tary or ganic mat ter and meth ane for ma tion in the re cent sed i ment of Lake Bled (Slovenia). Chem i cal Ge ol ogy, 159: 223–240.
Lyday, J.R., 1985. Atokan (Penn syl va nian) Berlin Field; gen e sis of re cy cled de tri tal do lo mite res er voir, deep Anadarko Ba sin, Oklahoma. AAPG Bul le tin, 69: 1931–1949.
Machel, H.G., Borrero, M.L., Dembicki, E., Huebscher, H., Ping, L., Zhao, Y., 2012. The Grosmont: the world’s larg est un con ven - tional oil res er voir hosted in car bon ate rocks. Geo log i cal So ci - ety Spe cial Pub li ca tions, 370: 49–81.
Mangili, C., Brauer, A., Plessen, B., Dulski, P., Moscariello, A., Naumann, R., 2010. Ef fects of de tri tal car bon ate on sta ble ox y - gen and car bon iso tope data from varved sed i ments of the inter - gla cial Pi´nico palaeolake (South ern Alps, It aly). Jour nal of Qua ter nary Sci ence, 25: 135–145.
Martire, L., Bertok, C., D’atri, A., Perotti, E., Piana, F., 2014. Se lec - tive dolomitization by syntaxial over growth around de tri tal do lo - mite nu clei: a case from the Ju ras sic of the Ligurian Briançonnais (Ligurian Alps). Jour nal of Sed i men tary Re search, 84: 40–50.
Milliman, J.D., Müller, J., 1973. Pre cip i ta tion and lithifi cation of magnesian cal cite in the deep-sea sed i ments of the east ern Med i ter ra nean Sea. Sedimentology, 20: 29–45.
Mitch ell, S.W., Hor ton, R.A., 1995. Dolomitization of mod ern sub - tidal sed i ments, New Prov i dence Is land, Ba ha mas. GSA Spe - cial Pa pers, 300: 189–199.
Mitchum, R.N., Bubb, J.N., Perry, D., 1969. Authigenic and de tri tal do lo mite in un con sol i dated deep-wa ter sed i ments of West Flo - rida Slope, Gulf of Mex ico: Ab stract. AAPG Bul le tin, 53: 206–207.
Morad, S., Al-Ramadan, K., Ketzer, J.M., Ros, L.F.D., 2010. The im pact of diagenesis on the het er o ge ne ity of sand stone res er - voirs: a re view of the role of depositional fa cies and se quence stra tig ra phy. AAPG Bul le tin, 94: 1267–1309.
Moscariello, A., Ravazzi, C., Brauer, A., Mangili, C., Chiesa, S., Rossi, S., de Beaulieu, J.-L., Reille, M., 2000. A long lac us - trine re cord from the Pi´nico-SÀllere Ba sin (Mid dle-Late Pleis to - cene, North ern It aly). Qua ter nary In ter na tional, EDLP – Med Spe cial, 73: 47–68.
Pappone, G., Ferranti, L., 1995. Thrust tec ton ics in the Picentini Moun tains, South ern Apennines, It aly. Tectono phy sics, 252:
331–348.
Pettijohn, F.J., Pot ter, P.E., Siever, R., 1972. Sand and Sand stone.
Springer.
Poros, Z., Machel, H.G., Mindszenty, A., Molnár, F., 2013. Cryo - genic powderization of Tri as sic dolostones in the Buda Hills, Hun - gary. In ter na tional Jour nal of Earth Sci ences, 102: 1513–1539.
Ravaioli, M., Alvisi, F., Vitturi, L.M., 2003. Do lo mite as a tracer for sed i ment trans port and de po si tion on the north west ern Adri atic con ti nen tal shelf (Adri atic Sea, It aly). Con ti nen tal Shelf Re - search, 23: 1359–1377.
Sabins, F.F., 1962. Grains of de tri tal, sec ond ary, and pri mary do lo - mite from Cre ta ceous strata of the West ern In te rior. GSA Bul le - tin, 73: 1183–1196.
Sander, B., 1951. Con tri bu tions to the study of depositional fab rics:
rhyth mi cally de pos ited Tri as sic lime stones and dolo mites.
AAPG, Tulsa.
Sarg, J.F., 2001. The se quence stra tig ra phy, sedimento logy, and eco nomic im por tance of evaporite-car bon ate tran si tions: a re - view. Sed i men tary Ge ol ogy, 140: 9–34.
Shinn, E.A., Scholle, P.A., Bebout, D.G., Moore, C.H., 1983. Tidal flat en vi ron ment. AAPG Mem oir, 33: 171–210.
Suttner, L.J., 1969. Strati graphic and petrographic anal y sis of up - per Ju ras sic-lower Cre ta ceous Mor ri son and Kootenai for ma - tions, south west Montana. AAPG Bul le tin, 53: 1391–1410.
Tal bot, M.R., 1990. A re view of the palaeohydrological in ter pre ta - tion of car bon and ox y gen iso to pic ra tios in pri mary lac us trine car bon ates. Chem i cal Ge ol ogy, 80: 261–279.
Tay lor, K.G., Gawthorpe, R.L., 2003. Ba sin-scale do lo mite ce men - ta tion of shoreface sand stones in re sponse to sea -level fall.
GSA Bul le tin, 115: 1218–1229.
Teranes, J.L., McKenzie, J.A., Bernasconi, S.M., Lotter, A.F., Sturm, M., 1999. A study of ox y gen iso to pic frac tion ation dur ing bio-in duced cal cite pre cip i ta tion in eutrophic Balde gge rsee, Swit - zer land. Geochimica et Cosmochimica Acta, 63: 1981–1989.
Wells, N.A., 1983. Car bon ate de po si tion, phys i cal lim nol ogy and en vi ron men tally con trolled chert for ma tion in Paleo cene - -Eocene Lake Flag staff, cen tral Utah. Sed i men tary Ge ol ogy, 35:
263–296.
Wiggins, W.D., Har ris, P.M., 1985. Burial diagenetic se quence in deep-wa ter allochthonous dolomites, Perm ian Bone Spring For - ma tion, South east New Mex ico. SEPM Core Work shop Notes, 6: 140–173.
Young, H.R., Doig, D.J., 1986. Pe trog ra phy and prov e nance of the Glauconitic Sand stone, south-cen tral Al berta, with com ments on the oc cur rence of de tri tal do lo mite. Bul le tin of Ca na dian Pe - tro leum Ge ol ogy, 34: 408–425.
De tri tal do lo mite: char ac teri za tion and char ac ter is tics 89
