Hybridization of mafic microgranular enclaves: mineral and whole-rock chemistry evidence from the Karamadazı Granitoid, Central Turkey

Abstract

On the Eastern Tauride Belt, the Cretaceous calc-alkaline Karamadazı Granitoid consists of quartz diorite containing mafic microgranular enclaves (MME) and leucocratic granite. The quartz diorite consists of plagioclase (An 8-65 ), hornblende, biotite, Kfeldspar, quartz, epidote and titanite. Subrounded MME in the quartz diorite are holocrystalline, finegrained, quartz diorite to diorite in composition, and display a similar mineral assemblage to their host. Large crystals in MME and quartz diorite show various disequilibrium microstructures indicative of hybridization. Plagioclase crystals exhibit inverse, normal, and oscillatory zoning with maximum core-to-rim An content increase up to 38% in the enclave and 40% in the quartz diorite. Both hornblende and augite exhibit normal and reverse zoning even in the same sample. The new field, textural, mineral compositional, and geochemical evidence leads to the conclusion that MME could have formed through injection of successive pulses of basic magma into upward mobile magma chambers containing cooler, partially crystalline quartz diorite magma. The quartz diorites show similarity to high-Al TTG (tonalites-trondhjemites-granodiorites), with their high Na 2 O, Sr, LREE, and low Mg#, Cr, HREE contents, and are suggested to be produced by extensive interaction between the crustal and mantlederived melts through mixing at depth. In contrast, leucogranites have geochemical characteristics distinct from the quartz diorites and MME, and are probably not involved in MME genesis.

Magma Mixing Genesis of the Mafic Enclaves in the Qingshanbao Complex of Longshou Mountain, China: Evidence from Petrology, Geochemistry, and Zircon Chronology

“…Moreover, the spider diagram ( Figure 7 [32]) shows that both the mafic enclaves and the host rock are rich in Rb, K and other lithophile elements, as well as elements such as La, Nd, and Sm. The trace element characteristics obtained from the present study are consistent with the relative depletion of Nb, Ta, P, Ti, U, and other high field strength elements observed within the predecessors of the Lushan chicken complex in Henan [33], the Qinling ring-spotted granite [34], the Karamadaz granite body in central Turkey [35], the Wulong body in South Qinling [36], and the mafic enclaves in the Yamatu body [26] in the Wolf Mountain area of North China. The Nb/La values for the mafic enclaves are 0.42-0.81, while those for the primitive mantle are 1.04 [37] and the Nb/La value in the lower crust is 0.4 [38].…”

Cogenetic origin of mafic microgranular enclaves in calc-alkaline granitoids: The Permian plutons in the northern North China Block

“…Although MMEs have been identified in granitic rocks around the world and have been the focus of study for several decades, their origin is still a matter of hot debate (e.g., Phillips, 1880;Grout, 1937;Didier, 1973Didier, , 1991Didier et al, 1982;Grasset and Albarède, 1994;Cheng et al, 2012;Flood and Shaw, 2014, and references therein). Several models have been proposed for the ori gin of MMEs in granitic rocks: (1) a hybrid or magma mixing and/or mingling model arguing that MMEs represent extraneous mafic magma blobs likely produced from the mantle that have mingled or partly mixed with felsic magmas derived from the crust or felsic magmas derived by fractional crystallization (e.g., Didier, 1973;Reid et al, 1983;Vernon, 1983Vernon, , 1984Vernon, , 1990Vernon, , 2014Cantagrel et al, 1984;Eberz and Nicholls, 1988;Vernon et al, 1988; Barbarin, 1990;Castro et al, 1990aCastro et al, , 1990bDorais et al, 1990;Fourcade and Javoy, 1991;Holden et al, 1991;Orsini et al, 1991;Poli and Tommasini, 1991;Elburg and Nicholls, 1995;Stimac et al, 1995;Elburg, 1996aElburg, , 1996bMaas et al, 1997;Collins et al, 2000;Ratajeski et al, 2001;Perugini et al, 2003;Tepper and Kuehner, 2004;Ilbeyli and Pearce, 2005;Kocak, 2006;Chen et al, 2009a;…”

Geochemical Characteristics of the Mafic Enclaves and Their Hosts From Neogene Erenlerdagi Volcanites, Around Yatagan Village and Sağlik Town (Konya), Central Turkey

“…In contrast, in A/CNK and Y vs SiO2 diagrams ( Figure 5) two distinct group appears, which is evident also in Lu vs La, vs #mg diagrams (not shown). Existence of MMEs suggests maficfelsic interaction and mingling (Barbarin and Didier, 1992;Kocak, 2006) by injection hot mafic magma injected into felsic magma. Accordingly, …”