03199nas a2200157   4500008004100000245010100041210006900142260003200211520265700243100002402900700002002924700001702944700001802961700001902979856004302998       2013                        eng d00aMicrobial carbonates in Miocene reefs in the Mahakam Delta in East Kalimantan, Borneo, Indonesia0 aMicrobial carbonates in Miocene reefs in the Mahakam Delta in Ea  aBerlin, Germanyc11/03/20133 a<p>Microbial carbonates are deposits that form by the activity of bentic microbial communities. Microbialites usually form domical, columnar or conical structures and can have laminated, clotted, dendritic or homogenous macrofabric. They have a broad distribution and can grow in a variety of different environments such as hot springs, freshwater lakes, hypersaline lakes, reefs and other marine environments. This research focuses on microbialites associated to coral reefs. Coral patch reefs in the Miocene Mahakam Delta in East Kalimantan (Borneo, Indonesia) grew in shallow marine turbid waters. These patch reefs developed from delta front to deeper (prodelta) settings in areas with temporary reduced siliciclastic input. Langhian reef deposits are well exposed in limestone quarries in the Samarinda area and locally include microbial carbonates. Two different types of microbial carbonates have been found around Samarinda in two localities 2 km apart. These sections were logged in detail and 208 samples were collected. Meso and macrostructure of microbialites were identified at the outcrops. Thin sections from carbonate samples were examined under optical microscope and microfacies were classified using the Dunham (1962) and Embry and Klovan (1971) terms. The carbonate content was analyzed using Total Inorganic Carbon analysis, with 12% carbon as a standard for carbon calibration. In the northern section, microbialites occur as low-relief domes, up to 2 m wide and 0.5 m high, with internal lamination, developed around large coral fragments at the transition from reef deposits to fine-grained siliciclastics.<br />
	The second type of microbialites has been found in the southern locality as decimeter-scale nodules (&quot;megaoncoids&quot;) formed around nuclei of large coral fragments. Small nodules were bound together into bigger nodules. Microbial micrite with laminated to digitated fabrics intergrew with coralline algae to form the thick covers of these &quot;megaoncoids&quot;, which laterally change into coral boundstones. In both sections microbialites are not components of the reef framework. They grew around large coral fragments on the flanks of the patch reefs. The microbialites that form low relief domes developed on a nearly flat, stable seafloor seawards of the patch reef. The &quot;megaoncoids&quot; in the southern section formed as a result of downslope movement of coral fragments coated by microbialite/coralline algal crust. The steep slope at the flank of the patch reef favoured falling and overturning of encrusted corals and continued growth of microbial crusts on other sides of nodules.</p>
1 aPretković, Vedrana1 aBraga, Juan, C.1 aNovak, Vibor1 aRösler, Anja1 aRenema, Willem  uhttps://ipaeg.myspecies.info/node/206901792nas a2200133   4500008004100000245010100041210006900142260003200211520123000243100002401473700002001497700001801517856012301535       2013                        eng d00aMicrobial carbonates in Miocene reefs in the Mahakam Delta in East Kalimantan, Borneo, Indonesia0 aMicrobial carbonates in Miocene reefs in the Mahakam Delta in Ea  aBerlin, Germanyc11/03/20133 aCoral patch reefs grew in shallow marine turbid waters in the Miocene Mahakam Delta in East Kalimantan (Borneo, Indonesia). These patch reefs developed from delta front to deeper (prodelta) settings in areas with temporary reduced siliciclastic input. These coral reef deposits are well exposed in limestone quarries in the Batu Putih area in Samarinda and locally include microbial carbonates. 
Two different types of microbial carbonates have been found in two localities around Samarinda, 2 km apart from each other. In the northern section, microbialites occur as low-relief domes, up to 2 m wide and 0.5 m high, with internal lamination, developed around large coral fragments. They appear at the transition from bioclastic sediments with coralline algae and corals to fine-grained siliciclastic deposits in a deepening succession.
The second type of microbialites can be found in the southern locality as decimetre-scale nodules formed around nuclei of large coral fragments. Microbial micrite with laminated to digitated fabrics intergrew with coralline algae to form the thick covers of these "megaoncoids". The large nodules are the main components of carbonate breccias deposited on the flanks of a patch reef. 
1 aPretković, Vedrana1 aBraga, Juan, C.1 aRösler, Anja  uhttps://ipaeg.myspecies.info/content/microbial-carbonates-miocene-reefs-mahakam-delta-east-kalimantan-borneo-indonesia02082nas a2200121   4500008004100000245006400041210005900105260002300164520164100187100001801828700002001846856009401866       2013                        eng d00aThe evolution of Indo-Pacific reef building coralline algae0 aevolution of IndoPacific reef building coralline algae  aBerlinc10/03/20133 aThe onset of the biodiversity hotspot in the Indo-West Pacific region took place during the Miocene. Crustose coralline algae (CCA) of this epoch from South East Asia, however, are poorly known, despite their importance for the generation and maintenance of reef biodiversity.

We studied CCA in Miocene reefs in the Kutai Basin (East Kalimantan, Indonesia) to fill this knowledge gap, crucial to understand the evolutionary history of reef building algae. CCA are mostly found encrusting corals and forming nodules together with foraminifers. Two main CCA assemblages can be recognized in the studied reefs: 1) A shallow-water assemblage, comprising two species of Neogoniolithon, several Hydrolithon species, Spongites, Lithoporella, and also Sporolithon. 2) A melobesioid assemblage that preferentially grew in darker waters, consisting of Lithothamnion, Mesophyllum and Sporolithon. The recorded palaeodepth distribution of CCA assemblages is consistent with the one reported from modern and fossil coral reefs.

Miocene CCA of East Kalimantan include some extant species, which appeared earlier than previously known. These new first-occurrence dates are used to produce a detailed time tree of the main reef building CCA species with the help of a new molecular phylogeny, which is based on five genetic markers (18S, 28S, COI, psbA, UPA). The sequences have been obtained from samples from Indo-Pacific localities and Genbank. This study comprises the biggest set of reef building CCA taxa ever analysed before, and aims to disentangle the polyphyly of traditional taxa such as the mastophoroid and lithophylloid subfamilies.1 aRösler, Anja1 aBraga, Juan, C.  uhttps://ipaeg.myspecies.info/content/evolution-indo-pacific-reef-building-coralline-algae