Page 6 - i1052-5173-32-1

SAMPLE LOCATION
The palynomorphs bearing tectonic sliv-
ers are ~50 m thick and crop out at two dif-
ferent localities; i.e., near the village of
Skuru (on Diskit-Turtuk road section;
34°66′75″N and 77°29′66″E) and ~300 m
ENE of Tirit Bridge (on Diskit-Panamik
road section; 34°31′59″N and 77°41′24″E)
(Figs. 1 and 2). These outcrops are tectoni-
cally juxtaposed by mafic volcanics and
slates and are located ~400 m below the
main structure of the Shyok suture in Skuru
and ~500 m below the Karakoram shear
zone in Tirit Bridge locality. The highly
cleaved and deformed outcrops are pale
brown to buff-colored and are made up of
pebbly mudstone with interspersed dark
gray-black fragmentary, coaly, and some-
times powdery remains of possible plant
fossil fragments (Figs. 1C–1E). The pebbly
mudstone is dominated by quartzite clasts
and is completely devoid of ophiolitic and
volcanic arc-related debris-clasts, matrix,
and cementing material, defying its ophiol-
itic and arc origin.

MATERIAL AND METHODS
The dark gray-black portion of half a
dozen samples of the pebbly mudstone and
associated shale were macerated to recover
spore and pollen grains. Samples were
cleaned with distilled water, and after dry-
ing, crushed into smaller pieces (2–3 mm)
and treated with hydrofluoric acid (40% con-
centration) to dissolve the siliceous compo-
nent. The samples were then treated with
nitric acid to digest the organic matter and
treated with 5%–10% alkali to remove the
Figure 2. Geological map showing different lithotectonic units of the Shyok Suture Zone (S.S.Z.) humus. The samples were thoroughly
exposed in the Nubra-Shyok river valleys, Northern Ladakh. Location of early Permian palyno- washed with distilled water, and the residue
morphs bearing locality within the Shyok Ophiolitic Mélange—exposed near the village of Skuru and
Tirit Bridge (modified after Upadhyay et al., 1999a). K.K. fault—Karakoram fault; MBT—main boundary was mixed with polyvinyl alcohol and
thrust; MCT—main central thrust; MMT—main mantle thrust; N.S.Z.—northern suture zone. smeared over a cover glass and kept for dry-
ing at room temperature. After complete
drying, the cover glasses were mounted in
2015, and references therein). The accreted defines a minimum age for the subduction- Canada balsam. For quantitative estimation,
arc units are well exposed along the Indus– related volcanics associated with the Shyok two hundred palynomorphs were counted
Shyok sutures. All along its length, the Suture (Upadhyay, 2014) and establishes a per sample. These slides are housed at the
Indus and Shyok sutures are characterized strong correlation with the equivalent suture repository of the Museum of the Birbal Sahni
by obducted remnants of Neo-Tethyan oce- zone in northern Pakistan (i.e., Northern Institute of Palaeosciences, Lucknow, India.
anic crust (Figs. 1 and 2). Suture) to the west of the Nanga Parbat–
In northern Ladakh, the rocks of the Haramosh syntaxis and in Lhasa-Quiangtang CISULARIAN (EARLY PERMIAN)
Shyok Suture Zone, trending northwest- (i.e., Bangong Nujiang Suture) to the east PALYNOMORPHS
southeast across the Nubra-Shyok River val- vis-à-vis their palaeo-geographic significance In a significant breakthrough, we report
leys, occur within intensely deformed tec- (Gansser, 1977). The geological structure of Early Permian (Asselian-Sakmarian and
tonic slices between the Ladakh batholith—to the Shyok Suture Zone has recently been Artinskian; 299 Ma to 276 Ma) palyno-
the southwest—and the Karakoram batho- described and discussed elsewhere (Burg et morphs from a metasedimentary sliver,
lith to the northeast (Figs. 1 and 2). The al., 1996; Bouilhol et al., 2013; Upadhyay, which is tectonically sandwiched within the
occurrence of Aptian-Albian rudists and 2002, 2014; Borneman et al., 2015, and litho-tectonic units of the Ophiolitic Mélange
orbitolinids from the Shyok Suture Zone references therein). zone of the Shyok Suture (Figs. 1–3). The

6 GSA TODAY | January 2022