Basin classification and tectonic framework of the Nam Pat Group, Uttaradit Province, Thailand: Implications for the Nan Suture Zone
نویسندگان
چکیده
The Nam Pat Group of the Nam Pat Basin, Uttaradit Province, Thailand is situated in the Nan Suture Zone. Two contrasting tectonic framework models of the Nan Suture have previously been proposed: as a main Paleo-Tethyan suture and as a remnant of a closed back-arc basin. The goal of this study is to analyze the tectonic framework of the Nan Suture and reevaluate the existing tectonic models. This research infers the tectonic setting of the basin based on basin-filled lithofacies distributions, provenance, and paleocurrents. Three facies groups are identified. Facies A, B, and C are polymictic conglomerate, interbedded sandstone and mudstone, and mudstone with thin-bedded sandstone, respectively. Generally, the strata strike NE-SW, steeply dip NW, and fine toward the SE. Petrographic results of sandstone samples show that the majority of lithic fragments are volcanic rocks with lesser amount of metamorphic rocks and sedimentary rocks. The modal compositions of sandstones are analyzed on QFL, QmFLt, QmPK, LmLvLs, and QpLvmLsm ternary diagrams. The plots indicate that the sandstones of the Nam Pat Group have high proportions of volcanic-arc detritus. Paleocurrents, determined from the orientation of clast imbrications and cross-stratification, are toward the SE. The results suggest that large quantities of sediment traveled southeastward from a nearby volcanic arc into the basin. The Nam Pat Group stratigraphically overlies the Pak Pat Volcanics. The chemical features of the Pak Pat Volcanics, located to the west of the basin, show that they are andesitic volcanic rocks formed as a magmatic arc. Thus, the nearby Pak Pat Volcanics are the main sediment source of the Nam Pat Group, and the basin is best interpreted as back-arc basin rather than as a forearc basin.
منابع مشابه
Indus-Yarlung-Tsangpo Suture Zone Concept- A Second Opinion
It is believed that Greater India migrated from the southern hemisphere, collided with Gondwanaland, Angaraland and Cathaysia, thereby closing an intervening oceanic Tethys along the Indus-Yarlung-Tsangpo Suture Zone (IYTSZ).The suture zone is placed along the Chaman Fault in the Baluchistan-Afghanistan area in the west, and the Indus-Yarlung-Tsangpo in the north, whereas along the east from Th...
متن کاملAssessment of Active Tectonic Status Using Analysis of Geomorphic and Morphometric Parameters (Case Study: West Basins of Kermanshah Province)
introduction Active tectonic studies are one of the most important topics in earth science and their results are widely used for assessing natural hazards and land use development and management plans in populated areas (Pedra et al., 2009, 220).Among these, geomorphic indices have been effective in assessing active teconic in large areas due to their high speed and accuracy (Clare & Pinter, ...
متن کاملEstimation of the relative active tectonics in Shahriary basin (Central Iran) using geomorphic and seismicity indices
Iran is well known for having countless historical and instrumental records of tectonic events. Shahriary catchment, as a study area, is part of the Zagros collision seismic province. This research aimed to introduce a new method which is useful in identifying the relative active tectonic events of an area. The research method was designed in order to calculate the relative active tectonic inde...
متن کاملUse of morphometric indices in drainage network changes (Indicators in the Kordkanlo Basin)
The Kordkanlo Basin, one of the Atrak sub-basins, located in the northeastern of the Ghoochan city, the Khorasan Razavi Province; is situated in Kopet Dagh geologic zone. The overall objective of this study is to evaluate the morphotectonic effects on the drainage network of the basin, using morphometric indicators. In this research, morphometric quantitative indicators of hypsometric integral ...
متن کاملDiscussion on structural evolution of Mesozoic Peninsular Malaysia
W. Altermann writes: In their discussion of palaeotectonics and palaeogeography of Malay Peninsula, Harbury et al. propose an alternative interpretation to Sengor’s (1984) model of Triassic or early Jurassic collision of the Cimmerian (Sibumasu) block with the Indochina block in the east. Their interpretation depicts Malay Peninsula as part of Triassic and lower Jurassic Australian Gondwana. ...
متن کامل