The upper plot , bold line shows the evolution of the bulk earth or CHUR. The lower plot shows evolution of bulk earth crust and mantle, 143Nd/144Nd is transformed to εNd. Normally, the most rocks have εNd values in the range of -20 to +10.

The younger detrital zircon ages reported in the samples were low in percentage (≈8%). However, these younger ages suggested the Asian provenance contribution. The Th/U ratio of the younger grains are mostly higher than 0.3, which supports the igneous origin. However, few younger grains with Th/U ratio lower than 0.3 reflect Himalayan metamorphism’s imprints. The sample 2015KM03 represents the middle part of the formation. All the 100 detrital zircons yielded concordant ages.

The end of tectonic activity in the Thomson and the adjacent Delamerian and Lachlan orogens culminated with the development of several overlying intracratonic sedimentary basins. We examine the two largest cover basins, the Adavale and Darling, using stratigraphic logging, sandstone petrography, detrital zircon and rutile U-Pb geochronology to fingerprint sediment sources to test whether the basins were once connected and part of a much larger cover basin system. Sediment provenance of the Darling Basin is dominated by reworking of sedimentary basement, evident from large proportions of rounded zircons exhibiting a ‘Pacific-Gondwana’ age signature and detrital rutile with Peterman Orogeny ages. A much less significant age population of syn-depositional volcanic detrital zircons suggests input from contemporary volcanic sources which were more distal and extra-basinal. Arc-continent collision is a major mechanism of continent growth in accretionary orogens.

2 Volcanic pebbles in the Glarus area

According to previous provenance studies based on U-Pb detrital zircon dating, the recommended number of selected zircon grains is 80–100 grains per sample to precisely determine the source components of the sediments . In this research, we adopted U-Pb age dating of the detrital zircons, extracted from sandstones of the Kamlial Formation exposed along Kohala–Bagh road section, sub-Himalaya, Azad Kashmir, Pakistan, for constraining the provenance. The results of the analyzed samples are described below in detail. Detrital zircon U–Pb ages indicate the crystallization age.

167–172 In Stür, WW (Ed.), Proceedings of the Third Regional Meeting of the Forages for Smallholders Project, Samarinda, East Kalimantan, Indonesia, 23–26 March 1998, CIAT Working Document No. 188. Also Jeremy Baldock, Gina Palefsky, Jamie Speer; Marion Ravenscroft and Lao and Australian archaeology students. This paper is dedicated to our friend and colleague James Grieve who translated Colani’s Mégalithes du Haut-Laos into English and sadly passed away in 2020. The megalithic sites of Laos have seen sporadic efforts in archaeological research since the 1930s, with more recent excavations at three of the main sites, namely Sites 1, 2 and 52. This research has created a deeper understanding of the prehistoric and historic cultures of Xieng Khouang Province. Dating for the placement of the jars and that of skeletal material found buried around the megaliths indicates multiple use of the sites and enduring ritual significance.

Age determination

Principal component analysis of bulk-mounted and handpicked populations. Principal components 1 and 2 have variance values of 62.37% and 32.88%, respectively. Colour histogram of bulk-mounted and handpicked populations.

The detrital record can be collected from all these places and can be used in provenance studies. Tracking dispersal paths through the analysis of detrital-zircon populations is a promising new application for zircon geochronology. Detrital zircons offer an excellent way to track the dispersal system from source to sink. Such a test could begin with critical areas first; for example, a lack of Alleghanian-age zircons in Pennsylvanian-age sandstones in the proximal sediments in the Appalachian foreland basin characterizes the headwaters of an inferred dispersal path from the Appalachians to the Grand Canyon.

Herein we present a comparison between previously published 40Ar/39Ar data, including many interpreted to reflect ArE, and new in situ Rb-Sr analyses for the same specimens. This work demonstrates that Rb-Sr mica dates from across the exhumed Himalayan metamorphic core typically overlap 40Ar/39Ar dates from the same rocks that are unaffected by ArE. Where 40Ar/39Ar dates have been interpreted to reflect ArE, the Rb-Sr method invariably yields dates that are younger than the ArE date and consistent with other mineral chronometer systems. Finally, while further refinement is required, we propose a technique to extract spot ages for high Rb/low Sr biotite analyses, by correcting for common 87Sr based on the present known ratio of 87Sr/88Sr, removing the need to assume an initial 87Sr/86Sr. To pick suitable lab data acquisition to sediment provenance, grain size should be taken into consideration. For conglomerates and boulders, as original mineral paragenesis is preserved, almost all analytical methods can be used to study the provenance.

Detrital zircon geochronology

In this study we compared the ages of zircons present in sandstone from a jar at Site 1 with two samples of sandstone from the likely quarry source . Today, the BVS is restricted to a narrow belt about 20 km along the Canavese line in the Sesia–Lanzo zone (Fig.1). The composition of the volcanic rocks ranges from basalt to andesite in the high-K calc-alkaline suite and from trachyandesite to trachydacite in the shoshonitic suite (Callegari et al. 2004). The BVS represents a complex volcanic sequence of porphyries, coarse-grained conglomerates, volcanic breccias and thin tuffitic layers. Based on palaeobotanical data and K–Ar total rock ages of andesitic rocks, Scheuring et al. assessed an age of volcaniclastic rocks between 29 and 33 Ma. More recently, Kapferer et al. measured U–Pb zircon ages at 32.89–32.44 Ma for the eruption of the cal-alkaline lavas.

430Ma from T3–J1 strata in comparison with higher εHf values for that from post-J1 strata also support aforementioned viewpoint. Such sharp changes between the pre-J1 and post-J1 strata coincide with the remarkable change in regional palaeogeography from a broad shallow marine basin in the Late Triassic–Early Jurassic time to a basin-and-range-style province in the Middle Jurassic. Because of possible affinity of the Atasbogd/Zoolen and Tsagaan Uul terranes with such in south eastern Mongolia like Hutag Uul or Nuhetdavaa-Enshoo, some preliminary detrital zircon age dating on two Late Devonian sandstones are provided . Both, by revealing major Devonian peaks most likely cannot be correlated with the Hutag Uul and other terranes in the South Mongolian belt south of the MML. A common genesis with sandstones of the same age in Gurvansayhan terrane is impossible according to our sandstone framework data . In plate-tectonic terms, the Hutag Uul continental terrane first experienced extension during Silurian-Middle Devonian.

The major age peaks were recorded at ≈550 Ma, ≈650 Ma, ≈765 Ma, ≈800 Ma, and ≈965 Ma . The youngest ages reported in this sample were 86 Ma, 94 Ma, and 112 Ma . Sample 2015KM01 was collected above the lower contact of the Kamlial Formation with Murree Milfs City Formation from a coarse sandstone horizon . One hundred detrital zircons were analyzed for U-Pb age dating. The highest concentration of detrital zircons occurred between ≈400 and ≈1000 Ma, with peak ages of ≈432 Ma, ≈484 Ma, and ≈875Ma .